Technical Help

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CategoryTitlequestionanswer
AxlePinion Bearings I am experiencing what I think is pinion bearing noise in my 77B. I get a whine when I accelerate that increase in pitch from 35 to 40 MPH I get a different whine when I decelerate. If I let off the throttle I get no noise until it starts to decel. I can feel pinion bearing slop in the rear flange. How hard is it to replace the pinion bearings? Is there a good source of instructions for this?
Thanks
Keith Maxwell

KEITH!

I know this information arrives later than you had hoped.

There are only several easy repairs you can make to a differential -- after that, it's best to replace the entire diff unit. Two of these involve you: Tightening the pinion bearing, and replacing the washers behind the spider gears. The pinion can become loose -- it should have some resistance to turn -- a preload of about 12 lb-ft. It is nearly impossible to judge the resistance to turn because as soon as you begin to rotate the pinion, the crown wheel begins to turn, too. But, this is the only easy way to do
this. Place a socket on the pinion nut and some type of long bar, bolted to the diff flange. Let this long bar carry through and come to rest on the bottom of the battery box. Tighten up the nut by 1/12 or 1/6 of a turn and judge the resistance to turn. Take your time!
Instructions for replacing the washers behind the diff and pinion wheels is in my techbook and on the webpage (I believe). If tightening the pinion nut does not change the whine, then suffer it until you find another diff!
AxleRear EndDear John:
I have just found you and your web site, It is great!
I need information on resealing my pinion gear.I also have more than 1/4" of free play. My shop in Tacoma, Wa. does not want to do the job, they told me to find a good use rear end , because with out the crush sleeve its a very nastie job and hard to make it work right!? Do you
have a tech article on this or any thing in your book.. How can I get a copy of the book? If there is a charge for the information I will call with a credit card #.. The car is a 77 B thanks David Hardy

DAVID!

You have two problems: a leaky pinion oil seal and too much slop in the "spider gears" in the differential carrier housing. These can be corrected at the same time, but the first is far more serious -- you could run the diff out of oil -- a fatal error. The second is common to the Salisbury
diffs and the repair is detailed in my tech book which is on the way to you.
In the first case, it's necessary to remove the driveshaft, then remove the nut that holds the pinion / driveshaft flange. An air impact wrench is perfect for this job; I believe the nut is 1 5/16" dia. Then tap off the flange, pry the seal loose, fit a new seal, polish the surface of the flange on which the seal rides, and reassemble. The tricky part, of course, is just how tight to get the nut on the flange: too tight and the diff won't turn and/or the bearings will fail; too loose and the gears will chew up. The proper preload (resistance to turn) of the pinion is about 12 lb-in. This is difficult (not impossible) to "feel" with the half shafts and wheels on the car, for if you turn the pinion flange more than 1/4 inch, the resistance to turn includes not only the pinion bearings, but the crown wheel bearings, the wheel bearings, the tires, and the brakes! You must make a tool for holding the pinion stationary. A two foot flat steel bar is best -- drilled to accept two pinion flange bolts, yet allow
your socket to fit over the pinion nut. Rotate this tool and allow it to bottom out on the bottom of the battery box. Use your breaker bar to rotate the pinion nut. The nut will turn freely (well, sort of,) until the flange returns to its original position, then the torque rises
dramatically. Turn the nut 1/16 turn by 1/16 turn testing the preload after each rotation. Stop when the preload (again, you must judge this in 1/4" of rotational freeplay) begins to rise.
We do this job a lot without a problem -- your shop is simply not used to, or comfortable with, or unskilled in this repair. Changing the diff is a MUCH larger problem! Hope this helps
AxleAxel Hub Splines DiameterI found this once but I can't find it again.... what is Max/min allowable
for
axel hub splines outer diameter on a 75 mgb and also the matching ID
tolerance
on the wheel hub.

Do you have this info? or suggest where to look....

Kurt

Kurt! The original spline diameter on the hubs is 2.450". 2.425 is
really worn. 2.400 is dangerous!! The hub you can measure. The inside of
the wheel hub you cannot measure (well, I can't). So, I use my finger to
judge the "step" between the worn and unworn splines. If barely a step is
felt, well then, it's pretty good. If a definite step is felt, well -- it's
wheel time.

New wheels on new hubs should not have any rotational freeplay.

Hope this helps!

SAFETY FAST!
AxleBreaking AxlesHello John! Trust all is well on your end. Any ideas on what would
cause a '72 Midget to break an axle every couple years? Always driver's
side. Car not autocrossed, etc. One theory holds that if the axle
housing is even a bit out of line it will stress the axle. Appreciate
any thoughts. Bob sherman

BOB!

Some thoughts here about that frequent failure of the half shaft.
If the housing is bent, it WILL snap the shafts, no question! I do not know
how to discern a bent housing from a good one. If the hub is bent (from
installation of a bearing with a press), that might cause a problem. But
the most frequent cause I know is the failure of the washers under the
differential and pinion wheels. I would remove the "pig" and remove the
crown wheel carrier, then drive out the retaining pin and change the
washers, if not the differential wheels themselves!
AxleDiff Clunk MGB John have you any information on curing the diff clank on my 1973 MGB
All the best
--
Garry Ross

Garry!

I hope the following appears on your screen AND is helpful!
ELIMINATING REAR AXLE CLUNK

The Salisbury, Tubed-type, or "GT" rear axle
fitted to all MGB/GTs, virtually all MGBs from 1967, and
all MGCs develops a clunk after as little as 50,000 miles.
This clunk is evident when starting up, reversing, or
changing gears. It sounds the same as a faulty U-joint
without the ringing. The clunk occurs from too much free
play in the differential pinions and wheels, or spider
gears, which allow the axles to turn at different speeds
(cornering). This type of clunk is particular to the
Tubed-type axle, as the banjo differentials often travel
100,000 miles without developing excessive free play.

To test for free play, jack up the rear end of
the MGB and support it at the front of the leaf springs
with stands. Have an associate depress the brake pedal,
freezing movement of the rear drums and wheels. With the
gearbox in neutral, grasp the drive shaft and rotate it
through its free play. A movement in excess of 1/4" on
the circumference of the pinion driving flange is
justification for repair.

Repair is straightforward, requiring the removal
of only one half shaft. The rear plate is removed, two
pins driven out, and the gears literally fall out of the
carrier. The washers behind the gears are renewed. It
requires several hours for the home mechanic.

REPAIR TECHNIQUE

1) Loosen the left axle nut ( 1 5/16" ).

a) Disc Wheels -- Jack up the left rear only,
and support on a jack stand. Keep the car in gear and the
right rear wheel on the ground. Remove the left rear
wheel, remove the split pin, have an associate depress the
brakes o keep the hub from turning, and bread the nut
loose. Do not remove the nut yet.

b) Wire Wheels -- Remove the left rear spinner
or octagon nut. Drive the socket onto the nut, over the
split pin. Have an associate depress the brakes to keep
the hub from turning, and break the nut loose (by about
1/8th turn). Do not remove the nut yet. Remove the
socket to allow the shorn split pin ends to fall away.

2) Jack up the rear of the car. Place jack stands
at the front of the rear leaf springs, chock the front
wheels and drop the jack away. The rear axle will fall to
its lowest limit. Rock the MG to ensure it is steady. If
the petrol tank leaks from the top, it will be necessary
to drain the tank, or preferably, reassemble and drive the
car until the tank is low on fuel. Leaking gasolene must
be avoided. It is DANGEROUS!!

3) Drain the oil from the differential. Use a 3/8"
socket extension to remove the drain plug. 1980 MGBs have
no drain plug, and the filler plug is a 1/2" allen hex.
Drain the oil into a pan and properly discard it later.

4) Remove the left half shaft.

a) Remove the left rear wheel. Disconnect
handbrake cotter pin by removing the split pin, then
turning out with vise grips. A hammer or heat is
sometimes necessary to free a stubborn pin.

b) Remove brake drum fasteners.

1) Wire Wheels -- have an associate
depress the brakes to keep the hub from turning and remove
the four 3/4" nuts.

2) Disc Wheels -- Locate the phillips
screwdriver in the screw head, strike with a hammer, and
unscrew. Do not round out the phillips screws!! If they
will not come free, strike the screwdriver even harder!!

c) Back off the brake adjuster (1/4" square)
and remove the brake drum. The drum sometimes needs
prying or rapping to free it. Remove the hub nut (1
5/16") now and strike the cone washer with a punch so that
it drops free.

d) Load the hub by pulling on it, and strike
the edge with the hammer. It should pop free. Rarely is
a hub puller needed.

e) Remove the brake backing plate. Either

1) Remove the straps holding the brake
line to the rear axle casing so that the plate can be
pulled outwards over the end of the half shaft; or

2) remove the brake line fitting from the
wheel cylinder. Removing the line is more complicated,
necessitating bleeding, at least. Sometimes the brake
line twists and fatigues or breaks. If the backing plate
is separated from the brake line, keep the brake pedal
depressed with a stick so that the master cylinder
reservoir does not empty.

f) Remove the four 3/8 bolts holding the
backing plate to the rear axle housing (9/16" socket /
wrench), and tie the plate to the front of the leaf
spring, or lay aside.

g) Refit the hub, cone washer, and nut to the
half shaft. Then, rap the back side of the hub with a
hammer to drive the half shaft and bearing from its
housing. Turn the hub continuously while rapping!

5) Remove the spider gears

a) Remove the rear plate. Be careful not to
twist off the brake line held at the top of the unit.
Plate the handbrake cable over the top of the diff, or
wire it away so it does not interfere with the internal
work.

b) Rotate the carrier by turning the drive
shaft so that the 3/16" roll pin (tension pin) lies at an
upwards angle. Drive this pin out using a 5/32" punch and
discard the roll pin. IT MUST NOT BE REUSED!!

c) Again rotate the carrier so that the roll
pin end of the pinion pin is angled forwards. Use a large
punch (3/8") and drive the pinion pin forwards about 1/2".
Do not drive the pin too far forwards or it will be
impossible to turn the carrier!

d) Rotate the carrier to position the roll pin
end of the pinion pin to the rear. Grasp the end of the
pin with vise-grips TIGHTLY!, then twist and withdraw.
The pinion pin is hardened and the vise-grips should not
damage the surface.

e) Remove the four gears and four washers.
Often, the differential wheel washers have disappeared
altogether.

6) Prepare and Clean the Parts.

a) Hold the new roll pin (3/16" x 1 1/2" in a
vise and open the inside diameter to 7/64" with a drill.
This is necessary as the ends are slightly crimped from
cutting. If a bench vise is not available, hold the pin
vertically in vise grips and frill downwards onto a block
of wood.

b) Clean the old gasket from the differential
and rear plate. A hand held propane torch will warm the
plate sufficiently to allow the gasket to easily peel
away.

c) Replace the hub seal into its housing, if a
new seal is fitted. Use a liberal amount of grease on the
inside of the housing and the outside of the seal to
facilitate installation. Tap the new seal into place
using a wide faced hammer, or using a block of wood to
keep the seal parallel with the housing base.

7) Replace the spider gears.

a) Liberally grease the new washers and gears,
and place the differential wheels into the carrier.

b) Place the differential pinions onto the
differential wheels, directly opposed, washers on the
gears, and rotate the gears/washers so that the holes in
the pinions line up with the pinion pin holes in the
carrier.

c) Replace the pinion pin, ensuring that the
roll pin holes are aligned.

d) Drive the roll pin through the carrier and
pinion pin. Use the large punch.

e) Fit the 7/64 x 2" split pin through the
roll pin, then splay the ends. This extra thickness
dramatically increases the shear strength of the roll pin
and prevents the pinion pin from rotating and breaking
loose. THIS STEP IS IMPORTANT!!

f) Refit the back plate and gasket, using
silicone RTV sealant -- but use a thin film only.

8) Refit the half shaft and brakes.

a) Drive the half shaft and bearing into the
differential housing. Position the castle hub nut on the
half shaft so the hammer damages neither the shaft nor the
nut.

b) Plate a thin coat of RTV silicone sealant
on the backside of the hub cap, use the 3/8" bolts as
guides, and tap the cap into place.

c) Refit the brake backing plate. Reconnect
the brake lines and refit the brake line straps.

d) Refit the hub, cone washer, and nut.

e) Fit the brake drum and tighten screws (disc
wheel) or nuts (wire wheel) and adjust brakes.

f) Bleed the brakes if necessary.

g) Have an associate depress the brake pedal
and tighten the drum nuts or screws.

h) Reconnect the handbrake cable (cable
adjustment may be necessary.

8) Refill the differential. Fill only until the oil
is felt on the finger. The MGB should be level when
filling, so leave the filler plug out until the car again
sits on the lever. Refit the left wheel and drop the MGB
to the ground. Allow the excess oil to drain from the
filler hole. It is better to be a bit too low than a bit
too high when refilling the differential.

9) Jack up the left rear, leaving right rear on the
ground, and depress the brakes. Remove the disc wheel or
wire wheel spinner or nut, and tighten the hub nut TIGHT
so that the split pin holes align with the castle nut.
Fit and splay the split pin. Fit the differential filler
plug. Refit the left rear wheel and set again on the
ground.

10) Test the brakes and drive away WITHOUT the
clunk!!!


ANTI-CLUNK TOOL KIT
JACK
JACK STANDS (PAIR)
LUG WRENCH or WHEEL NUT SPANNER
3/4" SOCKET for DRUM NUTS
PHILLIPS SCREWDRIVER for DISC WHEELS
1/4" SQUARE SOCKET or WRENCH for BRAKE ADJUSTMENT
9/16" SOCKET and WRENCH for BRAKE BACKING PLATE
1 5/16" SOCKET, SIX INCH EXTENSION, and BREAKER BAR for
HUB NUTS
1/2" SOCKET and THIN 1/2" WRENCH for REAR PLATE
5/32" PUNCH for ROLL PIN
3/8" PUNCH for PINION PIN
VISE GRIPS for PINION PIN
HAMMER!
BRAKE BLEEDER WRENCH or SOCKET (1/8")
FILLER SPOUT for GEAR OIL
7/32" BIT AND DRILL for TENSION PIN
SILICONE GASKET SEALANT
GREASE


ANTI-CLUNK PARTS KIT


PART FACTORY MOSS
GASKET BTB 674 296-210
ROLL PIN (3/16" x 1 1/2") BTB 715 267-125
PINION WASHERS 1G 7445 267-130
DIFFER WASHERS ATB 7072 267-140
WHEEL SEAL GHS 179 120-700
SPLIT PIN 7/64" x 2" NPN
SPLIT PIN 5%
AxleRear wheel bearingsJohn

It is possible to change the rear wheel bearings on a 1972 GT (semi-floating axle) myself ?

A couple of garage's I have spoken to say the bearings must be pressed back in with specialist equipment. Is this true?

Any advise you can give would be greatly appreciated.

Yours Faithfully

Craig Broadhurst

CRAIG! First, it would be most unusual to have a problem with the rear wheel bearings. I cannot remember the last time we changed one!

You only need a shop arbor press -- not an exotic piece of equipment, really. Pulling the half shafts from the rear axle will be as difficult as finding the shop to press the old ones off and the new ones on.

Try this: Remove the drum, hub, and backing plate. Now refit the conical washer - BACKWARDS - along with the castellated nut. Use a slide hammer with a three finger gear puller attachment, fitting the fingers around the back side of that conical washer.

Hope this offers some direction!

FAST FORWARD!
John H Twist
AxleSpridget Axle Shaft Mess John,
Thank you for your service. This is a mess, and I hope you can help.
I'm working on a 1961 AH Sprite with a broken axle shaft. The problem
is, I cannot get the shaft out. I've tried using a slide hammer/puller
and can only get it out about 3/8". After that, all I seem to do is
scoot the car across the floor. I thought about using some sort of
dowel to shove through the other side, but the pin for the diff planet
gears is in the way. As you already know, this car has a banjo type
axle. There is no way to access the diff without removing it, and I
don't see any way of removing the diff without pulling out the axle
shaft! Can you help?

Anxiously awaiting your reply,

Chad Stretz

CHAD!

By now you've been successful, no doubt -- and I'm certain that you
found that you simply had to hold the car down and use a LARGER slide
hammer. The half shaft twisted off at the differential wheel, most likely,
and the break caused the OD of the shaft to interfere with the crown wheel
carrier. If you used a "new and improved" method to remove this, please let
me know!

FAST FORWARD!
John H Twist
AxleMGB Rear Ends Hi John -

Not sure if you're using this email for technical assistance questions
but thought I'd ask. You've been very helpful in the past and I
appreciate it.

I own an early MGB (chassis #951) with the banjo style rear end.
Unfortunately, the rear axle oil level ran low due to leaking seals at
the wheels and the outer wheel bearings got hot. I mean very hot -
smoke was flowing out of the left hand wheel well. Preceding this, that
outer bearing had begun clicking.

Out with my wife on a Sunday drive, thought the clicking was a pebble in
the tire tread at first. Didn't want to call a tow truck with my wife
along and thought I could limp it home. Mistake and expensive miles.
Should have known better.

Anyway, locally someone knowledgeable about the early style of MGB rear
end said if it got that hot, not only are the bearings ruined but the
bearing housings in the axle casting are probably distorted and I'm
better off just finding a good used entire rear axle assembly and
substituting this one for my old.

He also suggested that I'd have an easier time finding a later style
(tube type) rear end and better chances that it would be in good shape
since it would be newer and the design was much stronger. My car has
disc wheels by the way, and I want to keep it this way.

I haven't taken my old rear end apart yet but fear the worse. Having
done a rear axle swop on a GT years ago, I know that it's not too much
work. Probably easier than tearing my old rear axle assembly apart,
sourcing seals, bearings etc, and reassembling. Perhaps still to have
problems.

Anyway, my questions are these:

1) Do you agree that it's probable that my car's rear axle tube
assemblies are ruined by the overheating? If you recommend that I tear
it down to see, what do I look for in those bearing housings. Also, I
only have a three eared gear puller style puller, can I pull the wheel
hub off with this or need a more specialized tool?

2) What sort of adaption challenge would using a later model rear axle
assembly entail? I seem to recall hearing that the drive shafts are
different but I'm not certain, and that maybe there's a clearance
problem with the original style gas tank on my car. Can this
substitution work?

3) If I decide to go with a used rear axle (newer or older style), what
are some inspection tips on finding a servicable unit w/o dissassembly?
I'd assume checking for free play in the half shaft ends at the wheel
hubs, looking for obvious leaks at the wheel ends & differential case
and trying to sense excessive backlash between the ring and pinion gear
set by rotating and reversing the axle ends quickly.

That's all I can think of but I do have a known good wire wheel rear end
in my garage from a GT. Can't use it since I don't want wires and it
may not fit anyway. But it gives me a test bench to try hand or machine
tool measurements that you'd suggest before I go looking at used parts.

Thanks for your advice and help with this complex set of questions.

Chas Wasser

Charles!

I would hunt for a the proper banjo style rear end. While the
Salisbury, Tubed, or "GT" differential is heavier construction, those early
ones "never" fail (well, there ARE exceptions). Plus, the GT diffs pick up
a clunk after a while, and the banjo style diffs never seem to clunk.

If you are going to swap banjo for GT, you MUST make certain that
you keep the width the same -- the disc wheel diff is wider by 3/4" on each
side.

"They" say that the GT diff is too large for the early cars, but
I've never had a problem fitting one to an earlier car -- but then, yours is
really EARLY.

Before I went through all this, I'd pull the half shafts and then
pull the "pig" for a good inspection. If the pig is burned up, simply find
another. If the wheel (hub) bearings are burned up, buy new ones. If the
differential housing is faulty -- because one of the hub bearings spun on
it -- well then, you WILL have to find another diff.

Let me know -- I do have a complete WW banjo diff that is looking
for a new home -- but it's folly to make any plans until you've made a full
inspection of the unit you have!

Hope this little bit helps. Sorry for the delay!

John
AxleRear axle clunk John
I have a 1970 MGB with the rear end clunk. I was told you did an article
on
the problem. I can't find anything of yours on mightywords.com. Is there
another place I can look?

Thanks
Mike


ELIMINATING REAR AXLE CLUNK

The Salisbury, Tubed-type, or "GT" rear axle
fitted to all MGB/GTs, virtually all MGBs from 1967, and
all MGCs develops a clunk after as little as 50,000 miles.
This clunk is evident when starting up, reversing, or
changing gears. It sounds the same as a faulty U-joint
without the ringing. The clunk occurs from too much free
play in the differential pinions and wheels, or spider
gears, which allow the axles to turn at different speeds
(cornering). This type of clunk is particular to the
Tubed-type axle, as the banjo differentials often travel
100,000 miles without developing excessive free play.

To test for free play, jack up the rear end of
the MGB and support it at the front of the leaf springs
with stands. Have an associate depress the brake pedal,
freezing movement of the rear drums and wheels. With the
gearbox in neutral, grasp the drive shaft and rotate it
through its free play. A movement in excess of 1/4" on
the circumference of the pinion driving flange is
justification for repair.

Repair is straightforward, requiring the removal
of only one half shaft. The rear plate is removed, two
pins driven out, and the gears literally fall out of the
carrier. The washers behind the gears are renewed. It
requires several hours for the home mechanic.

REPAIR TECHNIQUE

1) Loosen the left axle nut ( 1 5/16" ).

a) Disc Wheels -- Jack up the left rear only,
and support on a jack stand. Keep the car in gear and the
right rear wheel on the ground. Remove the left rear
wheel, remove the split pin, have an associate depress the
brakes o keep the hub from turning, and bread the nut
loose. Do not remove the nut yet.

b) Wire Wheels -- Remove the left rear spinner
or octagon nut. Drive the socket onto the nut, over the
split pin. Have an associate depress the brakes to keep
the hub from turning, and break the nut loose (by about
1/8th turn). Do not remove the nut yet. Remove the
socket to allow the shorn split pin ends to fall away.

2) Jack up the rear of the car. Place jack stands
at the front of the rear leaf springs, chock the front
wheels and drop the jack away. The rear axle will fall to
its lowest limit. Rock the MG to ensure it is steady. If
the petrol tank leaks from the top, it will be necessary
to drain the tank, or preferably, reassemble and drive the
car until the tank is low on fuel. Leaking gasolene must
be avoided. It is DANGEROUS!!

3) Drain the oil from the differential. Use a 3/8"
socket extension to remove the drain plug. 1980 MGBs have
no drain plug, and the filler plug is a 1/2" allen hex.
Drain the oil into a pan and properly discard it later.

4) Remove the left half shaft.

a) Remove the left rear wheel. Disconnect
handbrake cotter pin by removing the split pin, then
turning out with vise grips. A hammer or heat is
sometimes necessary to free a stubborn pin.

b) Remove brake drum fasteners.

1) Wire Wheels -- have an associate
depress the brakes to keep the hub from turning and remove
the four 3/4" nuts.

2) Disc Wheels -- Locate the phillips
screwdriver in the screw head, strike with a hammer, and
unscrew. Do not round out the phillips screws!! If they
will not come free, strike the screwdriver even harder!!

c) Back off the brake adjuster (1/4" square)
and remove the brake drum. The drum sometimes needs
prying or rapping to free it. Remove the hub nut (1
5/16") now and strike the cone washer with a punch so that
it drops free.

d) Load the hub by pulling on it, and strike
the edge with the hammer. It should pop free. Rarely is
a hub puller needed.

e) Remove the brake backing plate. Either

1) Remove the straps holding the brake
line to the rear axle casing so that the plate can be
pulled outwards over the end of the half shaft; or

2) remove the brake line fitting from the
wheel cylinder. Removing the line is more complicated,
necessitating bleeding, at least. Sometimes the brake
line twists and fatigues or breaks. If the backing plate
is separated from the brake line, keep the brake pedal
depressed with a stick so that the master cylinder
reservoir does not empty.

f) Remove the four 3/8 bolts holding the
backing plate to the rear axle housing (9/16" socket /
wrench), and tie the plate to the front of the leaf
spring, or lay aside.

g) Refit the hub, cone washer, and nut to the
half shaft. Then, rap the back side of the hub with a
hammer to drive the half shaft and bearing from its
housing. Turn the hub continuously while rapping!

5) Remove the spider gears

a) Remove the rear plate. Be careful not to
twist off the brake line held at the top of the unit.
Plate the handbrake cable over the top of the diff, or
wire it away so it does not interfere with the internal
work.

b) Rotate the carrier by turning the drive
shaft so that the 3/16" roll pin (tension pin) lies at an
upwards angle. Drive this pin out using a 5/32" punch and
discard the roll pin. IT MUST NOT BE REUSED!!

c) Again rotate the carrier so that the roll
pin end of the pinion pin is angled forwards. Use a large
punch (3/8") and drive the pinion pin forwards about 1/2".
Do not drive the pin too far forwards or it will be
impossible to turn the carrier!

d) Rotate the carrier to position the roll pin
end of the pinion pin to the rear. Grasp the end of the
pin with vise-grips TIGHTLY!, then twist and withdraw.
The pinion pin is hardened and the vise-grips should not
damage the surface.

e) Remove the four gears and four washers.
Often, the differential wheel washers have disappeared
altogether.

6) Prepare and Clean the Parts.

a) Hold the new roll pin (3/16" x 1 1/2" in a
vise and open the inside diameter to 7/64" with a drill.
This is necessary as the ends are slightly crimped from
cutting. If a bench vise is not available, hold the pin
vertically in vise grips and frill downwards onto a block
of wood.

b) Clean the old gasket from the differential
and rear plate. A hand held propane torch will warm the
plate sufficiently to allow the gasket to easily peel
away.

c) Replace the hub seal into its housing, if a
new seal is fitted. Use a liberal amount of grease on the
inside of the housing and the outside of the seal to
facilitate installation. Tap the new seal into place
using a wide faced hammer, or using a block of wood to
keep the seal parallel with the housing base.

7) Replace the spider gears.

a) Liberally grease the new washers and gears,
and place the differential wheels into the carrier.

b) Place the differential pinions onto the
differential wheels, directly opposed, washers on the
gears, and rotate the gears/washers so that the holes in
the pinions line up with the pinion pin holes in the
carrier.

c) Replace the pinion pin, ensuring that the
roll pin holes are aligned.

d) Drive the roll pin through the carrier and
pinion pin. Use the large punch.

e) Fit the 7/64 x 2" split pin through the
roll pin, then splay the ends. This extra thickness
dramatically increases the shear strength of the roll pin
and prevents the pinion pin from rotating and breaking
loose. THIS STEP IS IMPORTANT!!

f) Refit the back plate and gasket, using
silicone RTV sealant -- but use a thin film only.

8) Refit the half shaft and brakes.

a) Drive the half shaft and bearing into the
differential housing. Position the castle hub nut on the
half shaft so the hammer damages neither the shaft nor the
nut.

b) Plate a thin coat of RTV silicone sealant
on the backside of the hub cap, use the 3/8" bolts as
guides, and tap the cap into place.

c) Refit the brake backing plate. Reconnect
the brake lines and refit the brake line straps.

d) Refit the hub, cone washer, and nut.

e) Fit the brake drum and tighten screws (disc
wheel) or nuts (wire wheel) and adjust brakes.

f) Bleed the brakes if necessary.

g) Have an associate depress the brake pedal
and tighten the drum nuts or screws.

h) Reconnect the handbrake cable (cable
adjustment may be necessary.

8) Refill the differential. Fill only until the oil
is felt on the finger. The MGB should be level when
filling, so leave the filler plug out until the car again
sits on the lever. Refit the left wheel and drop the MGB
to the ground. Allow the excess oil to drain from the
filler hole. It is better to be a bit too low than a bit
too high when refilling the differential.

9) Jack up the left rear, leaving right rear on the
ground, and depress the brakes. Remove the disc wheel or
wire wheel spinner or nut, and tighten the hub nut TIGHT
so that the split pin holes align with the castle nut.
Fit and splay the split pin. Fit the differential filler
plug. Refit the left rear wheel and set again on the
ground.

10) Test the brakes and drive away WITHOUT the
clunk!!!

ANTI-CLUNK TOOL KIT

JACK
JACK STANDS (PAIR)
LUG WRENCH or WHEEL NUT SPANNER
3/4" SOCKET for DRUM NUTS
PHILLIPS SCREWDRIVER for DISC WHEELS
1/4" SQUARE SOCKET or WRENCH for BRAKE ADJUSTMENT
9/16" SOCKET and WRENCH for BRAKE BACKING PLATE
1 5/16" SOCKET, SIX INCH EXTENSION, and BREAKER BAR for
HUB NUTS
1/2" SOCKET and THIN 1/2" WRENCH for REAR PLATE
5/32" PUNCH for ROLL PIN
3/8" PUNCH for PINION PIN
VISE GRIPS for PINION PIN
HAMMER!
BRAKE BLEEDER WRENCH or SOCKET (1/8")
FILLER SPOUT for GEAR OIL
7/32" BIT AND DRILL for TENSION PIN
SILICONE GASKET SEALANT
GREASE

ANTI-CLUNK PARTS KIT


PART FACTORY MOSS
GASKET BTB 674 296-210
ROLL PIN (3/16" x 1 1/2") BTB 715 267-125
PINION WASHERS 1G 7445 267-130
DIFFER WASHERS ATB 7072 267-140
WHEEL SEAL GHS 179 120-700
SPLIT PIN 7/64" x 2" NPN
SPLIT PIN 5/32" x 1 1/2" NPN
BRAKE FLUID LMA
90/140 GEAR OIL 2 Pints
AxleMGB 70' Rear Axle
John, I have a 1970 MGB 4 cyl. I have noticed a grinding sound coming
from the back. However,
I only hear it when the top is up. It starts in 3rd gear. If I press in
the clutch, the noise remains.
I jacked the back off the ground and ran the car in 3rd, the noise was
there, but I could not
identify exactly where it was coming from.
How hard is it to rebuild ? and can a novice do the work.

Thanks in advance
Larry Montreal Quebec Canada.

Larry!

This is a tardy response to your rear axle problem. Several things:

First: drain the old oil and try new oil.
Second: Grasp the pinion and try to shake it up and down -- there
should be NO freeplay in this shaft!!! If there is, you'll have to change
the front bearing.

Third: You can remove the back cover of the diff and make a visual
inspection of the gears -- but without the experience of having seen
hundreds, you'll only note a problem if it's REALLY bad.

Fourth: The rear wheel bearings rarely fail -- leave the car in
neutral and spin one wheel, then the other. Even then, hearing a problem
like this may be difficult.

It is possible to COMPLETELY disassemble the diff in place. The
only difficulties are withdrawing the half shafts (you need a "slide
hammer") and setting the pinion back up with the correct preload -- you need
a inch-pound torque wrench which will indicate 12 lb-in.

I've attached an article about the differentials -- this is NOT your
problem, but indicative of the degree of difficulty you'll encounter if you
disassemble the whole unit.

Get back in touch if you need more info -- I'm getting more caught
up with my emails.

Happy New Year!

John

Axle69' MGB Rear End ClunkJohn,

I have a clunk in what sounds like the driver side rear end of my 1969 MGB. It occurs when going over even very slight bumps and seems to have nothing to do with accelerating or slowing. I've checked everything for tightness and find nothing loose (shocks or springs) or visibly damaged. The shocks are the original but have no signs of leakage and are full of fluid. I'm left to assume it must be the shocks (based on browsing the web and newsgroup postings) and am prepared to either purchase new or refurbished shocks. First, do you agree with my plan of action? Should I go with new or refurbished shocks? What are the pro's and con's of a conversion to tube shocks? I'm intrigued by the handling performance enhancement reported for tube shocks but since I'm not a very aggressive driver it might be more logical to stick with the stock shocks and maybe upgrade to the heavier fluid as you recommend on your web site. I gather if I go with a rebuilt original shock it's important to have a reliable rebuild company and consequently I would appreciate your recommendation or better yet maybe learn that I can purchase them through University Motors. I think I owe you one from when I previously took your advise on purchasing an ANSI exhaust system but overlooked the fact that I could have actually purchased the system from you. Thanks in advance for your assistance (again!),

Tim


Tim!

The shock is most likely NOT the problem. You should first tighten the shock to the frame as they do come loose (rarely). Secondly, with the rear end of the car up off the ground supported on jack stands under the rear axle (not the frame or springs), grasp the shock link and violently shake it. My guess is that the shock link is faulty -- egged out at the bottom -- that's pretty common.

To change it, remove the shock from the frame, remove the plate from the bottom of the leaf spring; remove the nuts, and strike the threaded stud with a BIG hammer and "pop," the shock link will separated from the damper arm and from the rear spring plate.

Hope this helps!

John
AxleAxles and Wheels Dear John Twist,

I located your email from your web-site. I have a technical
question which I tried to locate in the Q&A section of your web
site and did a search as well but while there were many similar
questions I do not feel as if I know the answer to my question.

Here it is:

I own a 1971 MGB and want to change my wire wheels for Rostyle wheels.

I have found another MGB owner who would like to swap his (1979 MGB)
ROstyle
wheels for my (1971 MGB) wire wheels.

I have removed the wheels and hubs that hold them to the axle and then
looking at the MGB workshop manual noticed a difference in the
diagrams
showing two axles, one for disc wheels and the other for wire wheels.

Is it necessary to replace the axle shafts as well? From what I can
see on the outside of the axle shafts all dimensions and components
look
identical, is there some internal difference?

I would appreciate your assistance or direct me to a response you have
already made so as not to have to repeat yourself. Thanks again.

Eric Connell

Eric!

Your exchange would be relatively simple if your associate had a
pre
77 MGB. As it is, the exchange may be difficult.

The front hubs swap back and forth -- no problem. Just make
certain
you have enough shims to set up the end float; and DO NOT get the hubs
switched left to right.

The rear axle must be changed COMPLETELY -- the disc wheel diff
is
wider than the wire wheel diff. This would not be a problem, but in 1977
the factory added a rear anti- sway bar. To make this exchange in my
shop,
I would cut the ears for the sway bar from the 1979 rear axle and fit the
works to your car, no problem. Then, I would fit your rear axle to his
car,
mount the sway bar, load the rear axle to it is "just" beginning to lift
the
car, and weld those ears onto your old diff.

Let me know if you want more information!

John

Thank you very much John,

I appreciate your advice. Another question unrelated,
will you be attending the All British Car show in Kansas City this
fall? I think it is in September?

sincerely,

Eric



Eric!

I'll be at the Abingdon Summer Party in Abingdon IL on August
17th -- that's as far west as I'm travelling for the rest of the year.

John
AxleRear End Clunk Cont.Tim!

The shock is most likely NOT the problem. You should first tighten the shock to the frame as they do come loose (rarely). Secondly, with the rear end of the car up off the ground supported on jack stands under the rear axle (not the frame or springs), grasp the shock link and violently shake it. My guess is that the shock link is faulty -- egged out at the bottom -- that's pretty common.

To change it, remove the shock from the frame, remove the plate from the bottom of the leaf spring; remove the nuts, and strike the threaded stud with a BIG hammer and "pop," the shock link will separated from the damper arm and from the rear spring plate.

Hope this helps!

John

John,

Good call. I've replaced the links and all the clunks are gone. The one that was obviously bad was on the opposite side I thought the noise was coming from. It had worn an oblong hole in the upper connector and was quite loose. I also replaced the rebound straps while I was at it- they were the originals and were cracked in multiple places with very little elasticity. I don't drive the car that much but what a joy to drive now without all the rear end noise. I truly thank you for your assistance.

Tim
AxleMagnette Rear AxelsHi John,
Anyway, a fellow has offered me a 4.1 rear axle (pumpkin) from a 1960 MGA 1600. Would this fit the ZB Magnette? As easy as the early MGB 3.9? Do I need the half shafts? Does the spline coarseness or fineness differ between these gear sets? If it will work, is it just an exchange or is there more to it? Finally what would be the approximate roadspeed in mph per 1000 rpm?
Thanks for your time,
John
John!

There are three different sets of differential wheels you can fit into these diffs: 10 spline; 25 spline; and 26 spline. You can always take the wheels from YOUR diff and insert them into the 4.1 diff.


According to my workshop manual, the relative road speeds for these diffs is:

8/41 5.125 14.4
8/39 4.875 15.2
9/41 4.555 16.2
10/43 4.300 17.2
10/41 4.100 18.0
11/43 3.909 18.9

All based on a 15" rim (but probably with bias ply tyres)

John
Axle'69 MG Midget rear axleWhat is the recommended torque tightness on the Midget rear axle bolts..the U bolts that hold the thing to the springs????
I can't seem to get mine to stay tightened. Even tried using "airplane" bolts (the ones with the plastic locking inserts) but this is no good either.
Just bought a whole new set of nuts washers and lock washers (the split type) and presently have them down to 20-25 lbs/ft each bolt. This seems to have squashed the new rubber pads nicely but will it be enough? Don't want to bend the mounting brackets which it seems I can easily do if go too tight. Any thoughts or recommendations??? I can't find a "factory" recommended figure in any of my shop/service manuals.

Thanks

G.Wayne
Wayne!

We don't put a torque on them as much as we watch what's happening with the U bolts, the rubber mounts, and the plates. I like to tighten them until I "just" begin to see the plates begin to distort. You can always double nut them to keep them from backing off. Is your problem that the nuts loosen - really? -- or is the problem with torque steering from the back of the car?

John
AxleRing GearJohn
I am doing a complete rebuild of 1970 MGB Roadster and as part of it I
was going to install a new ring gear. I would like to know what is the ID
of the ring and what is the OD where it fits to the flywheel? In other
words what is the interference fit? The reason I ask is because I think
the old ring gear was slipping because there is a ridge that the old ring
gear had to get over in order to get it off. I can't imagine that ridge
should be there. It would seem to me the two dimensions should be in a
manual since you should check them before installing a new ring gear. None
of my 4 manuals have anything.
Don
Don!

In my 30+ years of working on MGs, I've never seen a slipping ring
gear from any engine, any year. Further, I am not certain if I have ever
had to change a ring gear on a 68- MGB since the starter motor is
pre-engaged and doesn't damage the teeth on the gear during operation. Yet,
from the description of your flywheel, it certainly seems that the gear may
have been slipping. I do believe that a less expensive route would be to
find a used flywheel (with a good ring gear), and substitute it for yours.
To answer your question, I do not have those measurements.

Hope this helps.

John
AxleRear Axel BearingsJohn,

I'm trying to put together an MGA/early MGB rear axle to hang in the rear of my MGB GT race car. This axle came to me in pieces missing all the bearings.

Two questions:

I have an old shop manual that calls out special tool "pinion setting tool #18G-191-82. What are the dimensions of this gauge?

Might you have generic numbers for the bearings in this diff?

Thanks.


Alan
Alan,

The critical measurement here is the distance from the center of the carrier bearings to the head of the pinion. If that's off by 0.005" you can get howling. However, I do not know that measurement. If you want to call at the shop, today, I can give you the Timken numbers for the two pinion bearings and the carrier bearing (times two), but I don't have those numbers here at the house.

I am not certain where you can find that pinion depth number. Barney Gaylord has a large site at www.mgaguru.com.

I've been bothered that I do not know this number. I know I can get it from experimentation, but someone out there must have it already.

John
AxlePinion Oil Seal 1968 MGBHello John,

I need to replace my pinion oil seal on my tube axle. I am concerned about having to use special tools as per workshop manual. I do have standard torque wrenches. Do you recommend this operation? If not, I am not sure who could do this here in the Milwaukee area.

Thanks for you advise.

Henri


Henri,

This is a difficult task to do at home as you need a "special tool"
and the drive flange can be very difficult to remove.
Basically, you're going to remove the front flange of the differential, pry
out the seal, fit a new seal, and refit the flange. The flange is
sometimes stuck, stuck fast -- so you need to tap it forward with your
hammer, turning it slightly between each tap so nothing is bent or stressed.
When the flange comes off, you will want to polish the contact surface with
some fine grit paper (600 or so).

The old seal comes out with a pry bar or with a long, heavy
screwdriver. The new one is inserted and tapped into place with a hammer --
carefully!

Now comes the part that needs finesse. Reinstall the flange, fit
the nut, then begin to tighten the nut, constantly feeling the restriction
to movement of the front flange. You are searching for a pre-load, or
resistance to turn, of about one foot pound. The "feel" is a very slight
tightening. The problem here is that the flange rotates independently of
the crown wheel by as little as 1/8" on its circumference -- and you must
gauge the preload in that distance! Further, you should not use an air
impact to turn the nut as there is little control. You should use a long
1/2" breaker bar. But, you have to keep the flange from turning, so you'll
have to make up a tool that you can bolt to the front flange. I've used a
3/4" piece of rod, about two feet long, with two 5/16" holes on one end.
Run two 5/16" bolts through those holes, fix them tightly with nuts, and use
that, passed through the 5/16" holes in the diff flange to keep the flange
from turning. You could bolt this tool to the front flange, but then you
wouldn't be able to feel the preload. Tighten, feel; tighten, feel;
tighten,feel. Eventually you'll begin to draw the two taper bearings close
together and achieve this very slight resistance to turn.

I'd be pleased to review this with you on the phone. Of course, it
would make a good addition to our YouTube videos.

BTW, don't forget to refill the diff with oil!

Hope this helps!

John
AxlePinion Oil Seal I need to replace my pinion oil seal on my tube axle. I am concerned
about having to use special tools as per workshop manual.
I do have standard torque wrenches. Do you recommend this operation?
If not, I am not sure who could do this here in the Milwaukee area.
This is a difficult task to do at home as you need a "special
tool" and the drive flange can be very difficult to remove.
Basically, you're going to remove the front flange of the differential,
pry out the seal, fit a new seal, and refit the flange. The flange is
sometimes stuck, stuck fast -- so you need to tap it forward with your
hammer, turning it slightly between each tap so nothing is bent or
stressed. When the flange comes off, you will want to polish the contact
surface with some fine grit paper (600 or so).

The old seal comes out with a pry bar or with a long, heavy
screwdriver. The new one is inserted and tapped into place with a
hammer -- carefully!

Now comes the part that needs finesse. Reinstall the flange, fit
the nut, then begin to tighten the nut, constantly feeling the
restriction to movement of the front flange. You are searching for a
pre-load, or resistance to turn, of about one foot pound. The "feel" is
a very slight tightening. The problem here is that the flange rotates
independently of the crown wheel by as little as 1/8" on its
circumference -- and you must gauge the preload in that distance!
Further, you should not use an air impact to turn the nut as there is
little control. You should use a long 1/2" breaker bar. But, you have
to keep the flange from turning, so you'll have to make up a tool that
you can bolt to the front flange. I've used a 3/4" piece of rod, about
two feet long, with two 5/16" holes on one end. Run two 5/16" bolts
through those holes, fix them tightly with nuts, and use that, passed
through the 5/16" holes in the diff flange to keep the flange from
turning. You could bolt this tool to the front flange, but then you
wouldn't be able to feel the preload. Tighten, feel; tighten, feel;
tighten,feel. Eventually you'll begin to draw the two taper bearings
close together and achieve this very slight resistance to turn.

I'd be pleased to review this with you on the phone. Of course,
it would make a good addition to our YouTube videos.

BTW, don't forget to refill the diff with oil!
AxlePinion Oil Seal I need to replace my pinion oil seal on my tube axle. I am concerned
about having to use special tools as per workshop manual.
I do have standard torque wrenches. Do you recommend this operation?
If not, I am not sure who could do this here in the Milwaukee area.
This is a difficult task to do at home as you need a "special tool"
and the drive flange can be very difficult to remove.
Basically, you're going to remove the front flange of the differential, pry
out the seal, fit a new seal, and refit the flange. The flange is
sometimes stuck, stuck fast -- so you need to tap it forward with your
hammer, turning it slightly between each tap so nothing is bent or stressed.
When the flange comes off, you will want to polish the contact surface with
some fine grit paper (600 or so).

The old seal comes out with a pry bar or with a long, heavy
screwdriver. The new one is inserted and tapped into place with a hammer --
carefully!

Now comes the part that needs finesse. Reinstall the flange, fit
the nut, then begin to tighten the nut, constantly feeling the restriction
to movement of the front flange. You are searching for a pre-load, or
resistance to turn, of about one foot pound. The "feel" is a very slight
tightening. The problem here is that the flange rotates independently of
the crown wheel by as little as 1/8" on its circumference -- and you must
gauge the preload in that distance! Further, you should not use an air
impact to turn the nut as there is little control. You should use a long
1/2" breaker bar. But, you have to keep the flange from turning, so you'll
have to make up a tool that you can bolt to the front flange. I've used a
3/4" piece of rod, about two feet long, with two 5/16" holes on one end.
Run two 5/16" bolts through those holes, fix them tightly with nuts, and use
that, passed through the 5/16" holes in the diff flange to keep the flange
from turning. You could bolt this tool to the front flange, but then you
wouldn't be able to feel the preload. Tighten, feel; tighten, feel;
tighten,feel. Eventually you'll begin to draw the two taper bearings close
together and achieve this very slight resistance to turn.
BodyPaintJohn; I would like to direct you to both the Original MG Forum in which I helped to establish as well as to a particular thread: http://www.mgexperience.net/phorum/read.php?71,2252359 As you are aware I am certain- the MGB community is squarely divided in the necessity to maintain their cars for road use, drivable upgrades and current safety modifications; and performance enhancements; just as many are keen on preserving and maintaining originality. However- there needs to be a compilation of points of originality for MGB production far beyond what is detailed in Clausager's book ORIGINAL MGB which yourself and one of the MG Experience members Lloyd Faust proofread. You have seen my restoration photographs and are aware of my efforts to accurately build an historic SCCA rally car on an as original platform. Within this thread we are examining two points of originality whether the bolts and seals of the front inner fender flitch were painted; but also of the rugated paint found in that area; on the underside of the monocoque; and along the bottom of the cockpit; floor pans; and transmission tunnel. This was not a rustproofing to our knowledge but Lloyd Faust has suggested it to be soundproofing which is quite plausable since it is found in sound transmittal areas within the car's interior. The paint does contain upon examination a tar like substance within the raised areas. John- What do you know about the inner fender panel- was it painted at Pressed Steel then added to the car in Abingdon? This would account for the unpainted bolts and rubber seal. As far as the sound deadening paint- examples suggest application as early as 1962 throughout the production range. Lloyd Faust provided a 1974 example. What are your observations here? Our efforts are aimed at perhaps establishing a restoration manual for the MGB encompassing the years of production and as many aspects as we can. It would be similar to efforts by Corvette and Austin Healey owners and organizations such as the NCRS to document authenticity. Would you be willing to become a reference for this effort? It would require email correspondence periodically as different aspects of the production are confirmed and documented. Thank you for your time and consideration in this matter. God Bless! Tony Brown RN mgbbrownTony, The cars were delivered to Abingdon painted with the hood fitted. My best guess here is that the splash panels were fitted after the fenders were fitted, hence the unpainted bolts (and Phillips screw at the bottom). This is only my best guess – I cannot back it up. As far as the undercoating on the bottom surface, I cannot tell you whether it’s rust preventative or sound deadening. Remember that those tar like panels were fitted into the recesses of the embossed floor – that’s sound deadening for sure. But the goop on the bottom? I would guess it to be rust preventative as the sound deadening was handled on top. But again, this is only my best guess. Tony, you know that I have an extensive library of factory publications, and most (but not all) of the confidential service memoranda sent to the dealers by the manufacturer (BMC, BL, JRT). So, yes, I would be pleased to be included in this effort. Do not forget the incredible knowledge within the British Motor Trade Association (britcar.org). I noticed you still have Caroline listed in the address. This past Saturday was the third anniversary of her death. Thanks for all your work to ensure that our cars are original! John
BodyPaint Suggestion> Question: Hi, John! > > First off, let me say that I wish I lived near to your shop instead of in Washington state so I could bring my B in for service. > > I have a 1974 B that is Citron. I purchased the car many years ago because it is virtually rust free and I have never liked the colour. I have the engine out to rebuild and am considering painting the engine bay with a new colour so that when (and if!) I repaint the car, that work will be already done. > > However, a couple of people told me that the Citron colour is rather rare, so my question is: Should I repaint my car a more subdued colour or are Citron coloured Bs rare enough that I should just swallow hard, make a fresh pot of tea and live with it? > > Thanks for your opinion and advice. > > Regards and best wishes to you in rebuilding your company. > > Peter DuPrePeter, Some guys like redheads. Some guys like blondes. Citron is one of those rare earth colors like mirage, aqua, limeflower, or tundra. In the day it was called snot yellow ('cause it's not green and it's not yellow) but with all these years passed, it is rarely seen and fascinating. I can tell you that changing the color the car is a very difficult job to do correctly. The trunk must be changed and the interior has to be removed to cut in around all the door jambs etc. Me? I'm "Mr Original." I'd keep it Citron. The factory code is BLVC 73. Paint codes include: ICI 8653; PPG 44947; Dupont 43276; Glasso Rinshed Mason 6669.. Hope this helps!
BodyPaint Code You were referred to me as someone whom could possibly help with a paint code question. I am restoring a 67 MGB and want to paint it Tartan Red. I've gotten paint code charts on the internet for DuPont (that's the paint my body shop uses). According to the chart Tartan Red is Dupont # 8204. I went to the Dupont automotive paint distributor yesterday to get a "sampling" of the paint and they said that # 8204 did not come up in the computer. Their Tartan Red for British Leyland was 8402. I am confused. I want to paint the car the right color but I am not sure of the info I have. Can you direct me?

Thanks for your help,
Gaye Hanley

GAYE!

It would appear that there is a typo in the information that you have. I would trust that the paint supplier will provide the correct color. Remember that no two "Tartan Red" MGBs are the same (any more). The vagaries of on-site mixing, even with "computer controlled mixing" will result in different colors, let alone the temperature of the spray booth, humidity, etc. Hope everything works out well for you!
BodyHood CableHi John:

The cable to open the hood of my '77 MGB broke. Any idea how to get the hood open?

Thank You
Clarke

CLARKE!

The bonnet cable pulls the release lever to the left -- so, look through the air grille with a BRIGHT LIGHT to try to see this lever. Then, with a long screwdriver or shaft, attempt to move the lever to the left (RIGHT as you view it!) Good luck!

While you are having some difficulty with this, imagine the problem of a TR6 owner whose cable has broken. His problem is truly horrid as the bonnet opens from the back and the cable and latch are totally hidden from view!
BodyBumpers, Front Grille, Chrome Pieces, Tubes, TiresJohn,

Thanks for answering my Questions about restoring my existing Wire Wheels. I have a few more questions and would greatly appreciate your response.

1. Who do you recommend purchasing after market bumpers from. Scarborough Faire, Moss or Victoria British? I have been told Scarborough Faire has the most original looking bumpers on the market. Moss told me they just re-tooled their bumpers for a better fit. Do you have a preference for fit and finish?

2. Who do you recommend purchasing the front grille from? Moss or Victoria British. Do you have a preference for fit and finish?

3. Of the three parts suppliers do you have a preference on all the chrome pieces. Vents, badges ..etc.

4. I called British Wire Wheel and they told me about tubeless sealing on certain wire wheels. Do you recommend tubeless sealing or sticking with tubes?

5. Can you give me a recommendation on tires. Which do you like better and are these the right size for the car 165xSR-15 Michelin XZX or Dunlop SP20?

Thank you

Cliff

CLIFF!

I do have over 800 messages in my in box, if you can believe that!

We do most of our purchasing from Moss and our generally satisfied with their parts, but the chrome parts from any source are problemsome.

Let me suggest this: get your old bumpers replated -- this will cost you about $400 but the job will be REALLY good and MUCH better than the new units. Buy the repro overriders if the costs of re-chroming are exorbitant.

The same goes for the grille -- especially the grille!! The new grilles are not formed properly so the body MUST be fitted to the grille, not the other way around.

The smaller parts are more easily purchased new rather than chromed, but the original parts are ALWAYS of better quality.

The windscreen frame must be rechromed, as new parts are not available.

Purchase your wire wheels from British Wire Wheel in Santa Cruz, CA -- they sell the Dayton wire wheels which are best in the trade. I prefer the Michelin XZX, but those are not easily available.

Remember that the larger suppliers are: Moss, Victoria, Scarborough Faire; and in England, Brown & Gammons in Baldock; Moss Darlington in Durham; and in Belgium (?) is Anglo parts.

Hope this helps!
BodyTrunk LockHello John,

I really enjoy your MG web pages. I have a technical question. The trunck lock on my 74 MGB roadster is broken. The botton pushes in but there is no spring back and the latch doesn't relaease. How do I get into the trunk to remove/repair it?

Thanks in advance,

Kevin Gervais

KEVIN!

You may find the first option, as disgusting as it seems, to be the easier. Just DRILL out the center of the pushbutton -- then by wrenching the guts of the pushbutton completely out, you can gain access to the lever in the latch. The second operation requires a lot of finesse.

Make a tool of 3/8" square stock in the shape of a "U". One upright is about four inches, the other upright about three feet. The base of the "U" is the distance between the left reverse light and the latch. Remove the left reverse light, and work this tool into place. Fiddle for two minutes or four hours, trying to press the latch lever rearwards. It's helpful to have another MGB around the continue to look at and practice on (another MGB whose trunk opens normally, of course).

Our most difficult opening job was Rita's MGB -- she had no less than 20 pairs of shoes in the trunk!
BodySheet-metal FabricationJohn -

I am seeking some advice regarding sheet-metal fabrication to replace some rusted panels on my 1949 YT. I have purchased new sills from NTG in England, but the resemblance between those and the originals is not totally clear to me. At best, they don't quite replace all the material that needs repair. From your Website, under "clubs and other links, for the Y type I found the name of Jerry Keller, 14 Birchwood Road, Denville, NJ 07834. I wrote (snail-mail) to Mr Keller but my letter was returned "07834, NOT DELIVERABLE AS ADDRESSED, UNABLE TO FORWARD".

While I've done a fair amount of welding on the B (having recently reconstructed a badly rusted '65 pull-handle shell) the YT is a whole new kettle of fish. I am committed to doing this work myself, even if it means learning how to fabricate compound curves. So far it appears the problems are in the sill areas and below the spare wheel opening - the wings and running boards appear to be in excellent condition - although I've only removed those on the left side. Time is not a factor and I am only interested in learning to do it correctly.

Two questions:

1.) Do you know of a newer address for Jerry Keller?

2.) Do you have some other advice or suggestions?

I can do this on my own - and if necessary, I can figure out how to do it without advice, but it seems a shame to re-invent the wheel. If somebody out there has the experience and advice, I'd be happy to pay for it. (It's a case of "Give a man a fish and he eats for a day, teach him how to fish and he eats for a lifetime.") So far I've joined the Y type registry of the MGCC and the NEMGTR and I'm joining the Octagon Car Club. In all cases, I have asked for the same advice. I have also asked for advice on the MG list (mgs@autox.team.net). It seems nobody has had this experience.

You've always been so helpful - many thanks for any advice you can give me.

Allen Bachelder

ALLEN!

Contact Ron Embling in Otego, New York, for some direction; also, contact Hank Rippert (fairwind@bellsouth.net) to find a newer address for Jerry Keller. The problem is not so much Y but (I know you think I'm going to say Y NOT, but I won't) metal over wood body work.

We just happen to have a YT in the shop right now. If you want some digital pix, I can send them.

Good luck, Allen!
BodyRadiator Grill ShellI am searching for a radiator grill shell for a 1952 MGTD. Do you have one or know of someone who may?

Thank you,

Hubert Talley

Hubert!

Try Gerry at Abingdon Spares; Skip at Shadetree Motors; Mick Conde at Keystone Classic Cars in Jeanette, PA. Also, visit www.mgcars.org.uk.

Hope this helps!
BodyPaint SuppliersJohn,

Thanks again to you and your staff for the technical seminar. What a great winter break--some MG'ing/ good comraderie. What more could you ask for in February!

I talked to Lisa about what I had found in the area of painting systems and she suggested I cover you with the specifics for you files...

It started when I was told the New Racing Green (BLVC25) was not available in base coat/clear coat by the major US manufacturers. That got me looking around since my B was previously painted New Racing Green and I wanted to repeat the color. I found ICI--can't remember if it's Imperial Chemical Industries or Imperial Coating Industries, but was told that they are a British firm and that they were the paint supplier to MG as well as most other British automotive manufactures. They had what I was looking for and told me they could provide virtually any color used by MG.

Their "North American Headquarters" is located in Westlake, Ohio, a Cleveland suburb and their customer service rep is Jim Skal at 1-800-647-6050. The closest distributor to me and probably you also is an outfit called Single Source in Troy, Michigan. Their technical man is named Brian and he can be reached at (248)616-3403.

Don't know if this is new to you but thought you'd want to know if it is.

Thanks again.
Ted Barron

TED!

Thanks VERY MUCH for this information!
BodyWelding U.M. When I replace the rocker panes on my 58 MGA, can I get away with running a beaded weld along the top of the sill/rocker assy instead of using spot welds? I am having a tough time finding a spot welder to economically rent or purchase.
Thanks
John Bries
P.S. Your website is great!

John!

Instead of running a bead all along the top of that rocker panel or sill, try this: drill a series of 1/4" holes through the rocker panel, just below the top edge. Now, weld up the inside of these holes with your MIG / TIG / gas welder. Grind off the excess. Now the weld is just as a pot weld, very strong, and the draught excluder will fit. BTW: Todd Clarke of Clarke Spares in Doylestown, PA, is having NEW, REAL, ORIGINAL style draught excluder produced. Contact him for the good stuff. No one else's really fits well.
Hope this helps!
BodyWiper MotorsJohn
I continue to restore my 1935 MG PA. There is always something more to do. Do you restore wiper motors for this vintage car?
John Schmale
Mahomet, Illinois

John! I have been successful in rebuilding the wiper motors. I have yet to wind an armature, but that will probably occur this winter, as I have several which need that degree of repair. Send yours up and I'll take a
look at it.
BodyHardtop Seals Hello, John. Thank you in advance for taking the time to respond to my inquiry. I am at the end stage of the restoration of a 1971 MGB roadster. I have located, restored, and painted an original Works fiberglass hardtop as a part of this restoration. I have searched far and
wide for a source for the following seals for the hardtop:
(i) the rubber header rail seal; (ii) the rubber seal between the hardtop and the rear deck of the car; and (iii) the seals between the hardtop and the windows of the car.
Everyone seems to have the header rail. No one seems to have the other two. Any ideas or suggestions? Perhaps you have one for sale? Any advice would be greatly appreciated.
Greg Chait Atlanta, Georgia

Greg! The only place I can imagine would be through Brown and Gammons in Baldock, Herts, England. They advertise heavily in the British Magazines, and I've found that they have many, many items not available here. Perhaps they have a website? Don't know. Find them through www.mgcars.org.uk. Hope this little bit helps.
BodyFloorboardsjohn,
could you provide me with the material specifications for mga floorboards?
thanks. Rick Gregg

RICK!

My experience with MGA and T type floorboards is that they are marine plywood with either five or seven plies. It's been a long time since I've tried to cut any -- I buy them from Moss, now, as the new ones come sized correctly, they look nice, and they're chamfered and routed where they
should be.
BodyRemoving BodyJohn
I'm preparing to remove the body of my 57 MGA Coupe to do a frame off restoration. I have no idea what wait I'm looking at lifting and supporting. Can you give me a ballpark estimate of the weight?
> Also, I have a single car garage that I'm doing the restoration. I will need the body to be supported by saw horses that will allow the chassis to move out from under the supported body and back again for storage. What height clearence do I need for the saw horses?

Your help will be appreciated. Thanks
Marty Schlining

Marty!

While we have four MGAs at the shop in various stages of disassembly, including one coup?©, none of the chassis are sans body right now. Let me "guess" at the clearance you'll need -- three feet on the underside of the
saw horses. We support MGA bodies all the time with saw horses, so there's no problem here. You'll need six healthy, virile men to left the body off the chassis -- all wearing gloves to protect their hands from the sharp
edges.

Let me make a couple of comments about your restoration: #1, order ALL the parts that you figure you're going to need RIGHT NOW; #2, REMOVE ONE PART AT A TIME -- then clean it, wash it, buff it, rework it, do whatever you're going to do to it, ensure that it's gaskets and fixing bolts etc are with it, and wrap it up in clear plastic, place it on the shelf, and ONLY THEN, remove another part; #3 work around the body until it is stripped to just the body shell; #4 weld the body while it's on YOUR frame; #5 remove the body and send it off to the body shop for slicking/painting; #6 build up the chassis;#7 build up the body when it returns -- wiring, heater box,wiper assy, dash, etc; #8 refit the body to the chassis; #9 do your final assembly.

Marty, this is the best advice I can give you on this MGA. One part at a time. I've been at this for thirty years; I've seen a lot of home restorations started (and many fewer completed). Time is the most precious commodity -- don't waste it trying to remember where things go. Rebuild
one part at a time.

Hope this helps!
BodyMGB Chassis Measurement SpecsJohn
Have 1971/2 MG BGT with bent front chassis members following an accident. Need complete chassis measurement specs for CarBench chassis straightening mahine. Car's chassis number is GHD 5260957G. Can you help?
Neville


NEVILLE!

I do have a set of measurements for the MGB, but cannot send them easily on this machine (don't know how), but would be willing to fax them to you. Please Email me your FAX # and I'll send out what I can find. However, I
have technical seminars starting next week Wednesday and those last for three weeks -- it's combat time for me and I won't have an extra minute. But, if you send the number, I'll try to get it out to you on Monday.
Hope this helps!
BodyColorCan you tell me the correct color of green for a 1973 mgb. I am going to
paint it usun enamel.thank you, Bill Metcalf

Bill! I believe your car is Mallard Green, which has some blue in it.
This was the official green for 1973. The codes I have are BLVC 22
(factory code); Ditzler 44638; Dupont 30014; Rinshed Mason BM 169D. Hope
this helps!
BodyPaint Codei wish to paint my 70 mbg blue royal, this is a correct color for my 70
mgb
however, the car is currently british racing green .
since i have nothig for my paint shop to match, i attempted to use the
ditz
and rm
numbers as listed in moss motors catalog.
the paint shop says that the colors are for a laquer paint that has been
discontinued for use in california.
the touch up paint listed in moss's catalog is no longer available, and
none
of the
paint suppliers have chips that old to match.
perhaps you know of a california legal paint formula, or where i might
source
a
paint chip??
factory code is bu38....rm#bm039....ditz#....12635....ault & wilborg#
23322/28603
and ici #5186
i browsed the info on university motor's web page and the only add'l info
is
"use 14475" next to the ditz#
i need a sample soon to select a complementing shade of leather for the
trim
shop to start working on my interior.
i appreciate any help you may be able to offer
my name is dennis lemmings and i am using my neighbors computor ( i
havent
forced myself to purchase one yet)

Dear Mr Snake

Even though your car was "totally" painted, there are sections, notably
under the dash, that were not covered with the BRG. You have limited
choices here. The first is less expensive: find a paint shop that will go
the distance for you in finding the correct code. I know that PPG, the
parent of Ditzler, has a color library in Detroit or Cleveland, and they
will give you an "eye match" from your old color to a modern mix. I expect
other manufacturers can provide the same service. The second is to have
someone outside California get the color mixed, spray it onto a panel, and
send that panel to you. Then your paint shop can match a modern mix to the
older lacquer color.
If you wish to take the second path, I'd be happy to get the panel sprayed
-- but by the time we're done, I expect that it will cost you about $75.
Let me know.

Your unsigned letter using no capitals was difficult to read.
BodyBody ShopJohn:

As much as I would like to load my '72 MGB on a flatbed and have it
driven to Grand Rapids to have the true experts perform some much needed
body work, at the present time, my wife simply will not allow it.

I am wondering if you have any knowledge of a reputable body shop in
central Illinois or the St. Louis, Missouri area which has experience (and
a good reputation) for restoration work on MGs.

Thanks in advance for any assistance you can offer.

Brett K. Gorman

Brett!

Contact John Mangles who operates a body shop in the greater St Louis
area. He's known throughout the MG clubs there.
BodySebring Lightweight Body KitJohn,
I'm looking for a Sebring Lightweight body kit. I know that I have seen
them
in magazine articles. I have a '68 B-GT that would be perfect for this.
Can
you help me locate one of these kits?

Thanks in advance for the help,
Mark L. Smith

Mark!

I am sorry to be of no help whatsoever. You might contact the
individual magazines: British Car; British Marque Car Club News; MG
Magazine; in this country -- or try MG World, MG Enthusiast, Enjoying MG, or
Safety Fast from England.

You might try Tim Handy, MG Matters, Goode, Virginia (near
Lynchburg) -- he successfully campaigns his works MGB.
BodyWipersHi John:

I have another very basic TD questions? My question concerns the number
of wiper blades that should appear on my 1951 (10/10/51) MGTD Mk II. The
British owner of my local English Classic garage says that I am suppose
to have THREE (3) wiper blades, not two as it has now. I have looked
through my meager collection of books on T Series MGs and cannot find a
photo showing three blades. But the claim seems to have some merit.

My wiper motor is in the middle of the windshield, as portrayed on the
cover of "The Compete MGTD Restoration Manual" by Horst Schach. The arm
that extends from the motor to the connecting bar, that sweeps the left
and right wiper blades, has a holder that is similar to the left and
right arms and seems might accommodate a center blade. Is there suppose
to be a center blade? I would like my car to be as original as possible.

In addition to this question, do you know of any books primarily on the
Mk II (TD/C) model?

Stu Keen

STU!
The British owner of your local classic English shop is mistaken. The
centre placed wiper motor still carried two wipers, just as the RH placed
motor. However, it is possible, and some prefer, to fit three blades on
the two speed motor (too slow, or too fast!).
BodyCaptive NutsI need three captive nuts for the safety catch on an aluminum MGB hood.
The
nuts insert into the receptacles on the hood and are twisted 90 degrees to
be retained for mounting the safety catch. Please advise if you can
supply
them or know of anyone who can.

Thank you,

R. G. Watson

Mr Watson!

I would try to find a shop who can fit "Riv-nuts". We use these to
repair the fixing points on the body which accept the fixing bolts for the
top bows on the MGA and MGB. Call around to some body shops. The ones we
use are 1/4-28, but I'm certain you can find them in 10-32, also.
BodyColorsJohn,

I am doing some minor home restoration of my "67 B-GT. I am repainting
the "trunk" space under the rear deck. As I sanded off some of the flat
black paint that I had applied in the '70s, I discovered a yellow
(fan/pulley yellow) paint over the sandy beige/white base/red primer
layers of paint. Was the factory color the yellow paint that I am
seeing? My memory of the color has faded. 🙂

Thanks for you help
Rick

RICK!

I understand that your 1969 MGB is Sandy Beige. I've seen this
colour only several times. It's very rare!

I am certain that the factory did not paint a bright yellow in the
spare tire area! The bodies were primed and painted at Pressed Steel and
delivered to Abingdon with doors, boot, bonnet, and the tops fitted. The
only place I know to find the "School Bus Yellow" yellow, is on the fan and
pulley.

Wish I could offer you more!

SAFETY FAST!
BodyFender Welting JOHN, WE ARE HOPING TO ONCE AGAIN JOIN YOU AT THE SUMMER PARTY. WE ARE RESTORING MY MGA AND CAN NOT LOCATE TAN FENDER WELTING. I KNOW YOU WILL KNOW SO IF YOU HAVE TIME COULD YOU PLEASE EMAIL ME THE INFO.
THANKS AGAIN JUDY JOHNSON

Judy! I am doing my best at catching up with a LOT!! of old Email. The original fender welting on the MGA has a "T" cross section. I like the Volkswagen black T fender welting myself -- I believe it looks better in almost all color combinations than the original gray stuff. Any other colors?
Well, try a VW supplier. Of course, you can always have fender welting made, but then it is a rolled type (folding material over a piece of small diameter hose or plastic filament).

If you've already found something, let me know what do happened upon so the next time someone asks it won't take so long to answer!

SAFETY FAST!
BodyRemoving Body1960 MGA-fenders off, doors off, etc and ready to lift body off. I plan

on hoisting off, lifting at four points, but the box beams under the
doors are seriously rusted out and I don't trust them for strength and
don't want the body to clamshell on me. I will brace across the
doorways at top solidly. Door posts are in very good shape.


Any thoughts about this?

thanks John

George Stringe

GEORGE!

Remove the front and rear cockpit surround. The exposed holes
are large enough for 5/16 threaded rod. Cut two pieces of electrical
conduit or water pipe, just long enough to fit across the cockpit, front to
rear. Run the threaded rod from the back, through the pipe, and secure it
on both ends with nuts (under the dash and under the rear "shelf"). Use
washers to achieve a good fit so you don't pull the cowl or rear! Now the
car is really stiff and you can lift it away without damaging the sills any
further.

BUT WAIT!

Achieving a good fit on the MGA body is a quest rarely
completed. DO NOT REMOVE the body from the frame until you have finished
all the welding that you can while the body lies undisturbed. Remember, the
doors do not lie! All fitting comes from the doors (and the front door
posts). Weld in the repair sections for the post, the inner sill, the outer
sill -- as much as possible BEFORE removing the body from the frame. After
the body is off, complete the welding on the inside.
BodyHeritage Body ShellsMr. Twist
Does the fact that your company has achieved British Motor Heritage Approval mean that Heritage body shells are available thru your company?
George Procyshyn
Cleveland, Ohio

University Motors Ltd of Ada, Michigan, USA are proud to announce that they have achieved British Motor Heritage Approval. They are now one of two approved workshops in the United States and one of about a half dozen who are authorised to display the MG logo in North America.

GEORGE!

There are two types of Heritage Approved Specialists -- one type (me) can use the logos; the other type (Moss, Victoria, Roadster Factory) can purchase Heritage and Rover parts at a great discount. We are a service shop and have no mail order parts -- we do sell parts from the front counter. You know that a body shell rebuild requires a fantastic amount of work!

Good Luck! SAFETY FAST!
BodyGluing TopHi:
I am going to put a new top on my 1975 MGB this coming week end and in the
instructions it says to glue the top to the front bow. Could you tell me
what type of glue to use? Thank you.

Dennis Vallier

Dennis! We use two types of glue in the shop: 08080 and 08083, both made
by 3M. The 08080 is the better glue, as if, by some reason, you make an
error, you can peel the top away from the top bow. The 08083 is dynamite
stuff that demands that you are right the FIRST time. Use the 08080. It's
about $20 for a big can.

BTW, be certain to shake out all the old rivets from the hole on the
left (right?) side of the top bow or you'll hear those things rattling
around forever!

Hope this helps!
BodyLocationHey John:
Thank you for the fast reply and for the tip about the rivets. I'll be
sure
to get the 08080 glue because I'm not that good at getting it right the
first
time. I just put in a new windshield (5 tries) but I did get finally.
Thanks again!

PS - we are from the Forrest Hills area but didn't own a MG when we lived
there, we are now all the way down south in Franklin, TN (by Nashville)

Dennis Vallier Dennis!

Well, we live on Buttrick, just three houses north of 28th Street.
Not the 28th you know and love, but the rural one with houses and barns.
Our kids go to Thornapple Elementary. The shop is on Fulton, just a mile
west of Amway. Stop by if you come back up this way!
BodyColorsTo whome it may concern~~~~

I was just wondering what are the original colors for a 79 MGB..... I am
15
years old and about to be 16 & I am helping restore an MGB which will be
my
car. I can't decide on what color the car should be , but I want it to be
an
original. I know that some of the original colors for a 79 are : Pageant
Blue
, Brookladns Green , Carmine Red , Vermillion Red , Inca Yellow , Russet
Brown , Leyland White , and Black. I was just wondering if there are any
other original colors that I can look into before I make a decision.
Please
write me back soon to let me know.

Amalie

AMALIE!

You've got the colors down, alright. That Carmine Red is a slight
derivation from Damask Red, a maroon, used from 1954! If you want a good
looking engine compartment, my personal favorite is Inca -- it makes the
underside and underbonnet areas "electric." British Racing Green is about
as specific as saying "tree" but that Brooklands Green is a good looking
green. Russet Brown is, well, an "earth" color. Leyland White is as
brilliant as a refrigerator!

I tell people who are considering a color change to go out to a car
lot -- drive around, look at the cars, and choose a modern, 1999 color.
After all, it's YOUR car -- you can paint it what you want -- purple with
pink pokadots if that's your fantasy. Some say, "You MUST keep it a factory
color." Some, myself, included, only urge you to do so. But remember this,
ANY COLOR CHANGE is a Herculean task!! If you do not completely strip and
repaint the underbonnet area, then the car will always look AWFUL when the
bonnet is up!

If you need assistance with color codes, etc, write back.
BodyColor Codescan you give me the ORIGINAL color codes for the 79 MGBs??? Thank
you~~~Amalie

Amalie!

Here goes:

I couldn't easily print the list here, so I've sent it as an
attachment in Microsoft Word. I hope you can receive and read that format!
Plan to spend nearly $500 on gaskets, motifs, grilles, etc to make the car
look NEW after the paint job. Moss Motors has an excellent supply of the
parts you'll need.
BodyColor Codes when I ask you for the original color cods for the 79 MGBs you gave me
something to download but for some reson I can't get into it , but I still
want to know the original colors so can you send them to me a different
way??? Thank you.

Amalie

BLACK BLVC 90
RUSSET BROWN BLVC 205
PAGEANT BLUE BLVC 224
BROOKLANDS GREEN BLVC 169
CARMINE RED BLVC 209
LEYLAND WHITE BLVC 243
INCA YELLOW BLVC 207
BodyQuestion Mr. Twist,

I first read of you in the MG DYI book (Lindsay Porter?) from several
years
ago. I wonder if you could provide some guidance to me on the appropriate
paint for a '72 MGB-GT. Moss calls for Green Mallard whereas Teglerizer
indicates British Racing Green (GN25) may be used. My preference is to
use
a BRG but I want to be historically accurate. This car is not intended to
be a concours car but rather a regular driver. Any recommendations?

Thanks,

Tony McKinney



Anthony A. McKinney

Tony!

A couple of notes about the colours: British Racing Green is like
the word "tree." A tree is not a bush, but there are MANY kinds of trees.
So it is with British Racing Green. There were many greens used throughout
MG production, but Mallard Green is the proper green for your 1972 MGB. My
wife's research shows a BLVC 22 code. That New Racing Green is very dark
and very nice, but it's not correct. It's your car! Paint it the colour
you want.
Mallard has a lot of blue in it -- it's a very nice colour!

John

FAST FORWARD!
John H Twist
BodyCanvas top Mr. Twist,

I would like to install a canvas top on my 1968 MBG. I notice in the Moss
catalog the they are available for 1971 - 1980 only. What would I have to
do
to install one on my car?

What do you think of the canvas tops?

I appreciate your help.

Sincerely,
Wilburt Easom

Wilburt!

My computer was down for a while, and I got sooooo far behind.
Perhaps this will help at this late date.

There are three types of soft top frames -- all of which will fit
all MGBs from 1962 -1980. There is the stow-away variety which separates
in the middle, stows in the boot, and allows for a great amount of room in
the cockpit. There is the scissors or knee action, designed by a sadist,
which was fitted from about 1964 - 1969. Then, there is the wonderful
Michelotti (incorrectly, but commonly pronounced Mich a lotty -- instead of
the correct Italian Mick a lotty) which will accept the zip out top.

I prefer the vinyl tops, but those fabric tops certainly look nice!

FAST FORWARD!
John H Twist
Body1977 MGB - converting to chrome bumper Hi, I have a 77 MGB tourer, and was wondering if you knew where to ge the suspension conversion kit to take my 77 rubber bumper and convert it to a chrome bumper MG, I can't find anywhere that has it.
Mike Smith

Mike!

You wrote last April so you've probably already received answers and have decided on a course of action. My advice, at long last, is to leave the rubber bumpers on your car. If you want a chrome bumpered car, buy one -- don't try to make one! I did change a rubber bumpered car to a chrome bumpered one -- once. I wouldn't do it again!
BodyMGA Side Curtain RubberHi John,
I hope you have had a nice holiday season and the very best to you for the New Year. Do you know of a source where I can buy the rubber to replace around my side curtains of my MGA?
Thanks,
Stan

Stan!

You have asked the "eternal" question. That is, I've had this question for twenty years and still don't have a pat answer. There are several rubber extrusion firms which make a host of differently sized and shaped cross sections. I have a catalogue at the shop, but I cannot remember the name of the firm (it's in MN or WI). If you'll call during tech time (1-2pm EST M-F) next week, I'll try to answer this for you. This week I'm on vacation in North Carolina.

Happy New Year

John


maybe Metro Moulded Products????


BodyTemplate for 1967 MGB Carpet John,
Do you have any idea where I could possibly get a "life size"
template for cutting carpet to fit a 1967 MGB. I have a
body that has no
carpet currently in it. So removing the old carpet and
using it as a
template is not an option.

I also want to carpet the car in a non-traditional color (some shade
of blue) so therefore ordering carpets from MOSS or LBC is out. The
special
order dealers I have checked to order custom made carpets
are definitely
out
of my financial league.

I can get the carpeting material locally. However, I would have to
attempt to cut via hit and miss. I have
seen .jpegs of templates online, but have no idea how large
I would have
to
blow these pictures up to get a true representation of what
size each
piece
should be.
Any ideas??????
sandy

Sandy!
This is my suggestion. Use very thick paper, or
better, cardboard,
and make templates. You don't need one big chunk of
cardboard -- just keep
taping one piece to another. Then you'll have a suitable
template from
which you can cut your carpet. The hot setup would be to
trim the carpeting
so it "fits like a glove" and then have the edges bound. Automotive
upholstery shops are often surprisingly inexpensive for such work.
We make templates from cardboard for wood floor
boards for the MGBs,
so this is a "proven" method!

John

John:
Woohoo got it!!! I am cooking with bacon grease now.... You are a
scholar and a gentleman...thanks so much. I don't plan to install the
carpet until this spring, but getting them at least cut and fitted is a
worthwhile winter project.
By the way....do you do body work??? I am hoping around April
timeframe to be able to afford to have some serious rust removal /
restoration /parts replacement done on the car. The sills on both sides
are shot, those support bars that hold the battery boxes in place ( I looked
underneath the car and saw that a few bars have completely rusted
through)
are pitiful if not altogether gone and the floor boards are like Chinese
rice paper. The instrument fascia (is bent in places and I swear looks
crooked to me) and dash gauges are alas...oh well...really just kinda
sad
looking. And my blue MG is very hard to start at this point....

I know you do restorations....but I don't want to bring the car
back to absolute mint condition (oh that I could afford the expense),
but
to
a reasonably good looking; and a definitely safe operating level.
Welding
is
not my forte (a skill I hope to earn at some point) but the car does
need
body work done to it.

No sense in me trying to pretty up the interior if the body isn't
sound. Aside from a full restoration as listed on your site; could you
do
the minor body work (well minor in my eyes) I require??? Since I am
already begging.....one more question....how about paint jobs????? Once
I
have you guys get the body "de-rusted" could you then paint the car at
your
facility????


ok, I have probably used my wooden nickel worth of question...

thanks for the quick response....away I go to find material to make
carpet
templates...

sandy


Sandy!

We do body work! Generally, welding each side of the car -- that
is
the bottom of the front fenders, the bottom of the rear fenders, the sill,
the vertical plate, the castle section, and some of the inner frame -- all
for about $1000 per side.

We can paint the car, too, but we'll need to see it to really give
you the options and the costs. There are two types of paint jobs --
complete and partial; there are two qualities of paint jobs -- "tape and
spray" and "disassembly." The prices range from about $500 to $8,000.

Are you still in the reserves? Is there a chance you'll get
called
up, or worse, called back?

John


John,
Long time no talk. Company bonus time approaches (mid April)....so
as I ponder how I can use the dough on my little MG...here's the next
question.

I just saw a 1971 MGB with a cabriolet top. It actually folded back
just like on modern car, manually but it folded right onto the car!!! It
was beautiful. The frame was totally concealed and the header rail was in
the same matching material. The lady had ordered it from England for about
$500, which I thought was great. Could one of these cabriolet tops be
placed (obviously with the correct modifications) onto a 67?

Still planning on bring the car up in April and have you guys do a
thorough check on it. I have been working a bit on getting her running a
little more reliable (cleaned up the float mechanism on one of the
carburetors last night) so I won't have tow the car up to you. Still can't
get her to idle less than 1500 rpm without her cutting off. However, she
does start up far more reliably so that's a start (the engine was totally
seized up 2 weeks ago when I started).

I have pretty much removed all the rotted carpeting, crappy seats,
torn panels, etc. The car is gutted. Hoping I can have you guys do all
the
"ugly" looking stuff I have found. I have stopped most of the engine oil
and fuel leaks, but still have a electrical problems (no interior lights
of
any sort, no heater blower, no horn, etc, etc) which I am no way versed
on
repairing.

Do you guys only do seminars in Feb? Nothing else during the year?
I love working on the car. I would love to do some more technical stuff,
but
lack the experience. If you decide on doing other seminars sign me
up!!!!.

Thanks for the concern about the whole war thing.... Nope "I'se
aint got ta go". A broken collar bone and shoulder have put on the "lame
and useless" list....woohoo!!! I have seen enough wars....Panama,
Saudi....tired of people I don't know shooting at me....I must honesty say
I
am glad I won't be the one worrying which person of a 360 man Maintenance
Company I might not bring home. I lost two soldiers in Saudi....never
again
do I want to write parents about such a thing... Let us hope the whole
world comes to it senses.

salutations to you and your crew....I always read your updates with great
interest.

sandy....the one handed typist...

Sandy!

It would probably be best for us to finish our "complete
lubrication" before you purchase a new cabriolet top. You know, our lube
will put everything into perspective for you -- we'll have a "complete" list
of all the faults and their approximate costs of repair.

We'll look forward to seeing you up here in April. Hope your bones
heal quickly!

John
BodyBadge BarsJohn,
Is there a good way to display club badges on a rubber bumper (1977-MGB)? Does anyone make a retrofit bar for the 'B"? Thanks, Al Webster

Al!

If you want a "chrome" badge bar, then you'll have to fit it horizontally through the fresh air opening in the bumper and fix it horizontally to the small shelf, just behind the fresh air grille.

Another option is to remove the front bumper, bend up a bar, and fix it (self tapping screws/bolts) to the back side of the front bumper.

I have seen some of these at meets, but if Moss doesn't carry them (www.mossmotors.com) I don't know what else you can do but create one!

John
BodyTips on Fitting on a New Top to Header PieceDo you have any tips on fitting a new top to the header piece. It seems like I have to strech it so tight that it will not close. Thanks Bill

Bill!

A couple of notes at this late date. Make sure you shake out all the rivets from the hole in the end of the header bar or you will forever listen to the metallic rush of those rivets every time you turn a corner.

Fit the top on the hottest day, at the hottest time during the day so the top has expanded a LOT.

Fit it snug at the centre of the header bar and work outwards. Use 3M 08083 glue.

Yes! You do have to fit it snugly!

If you have any further questions, drop me a note or give me a call during technical hour.

John
Body77 MGB Wiper Motor


John,

Thanks for all of your help to the British car community over the years.
I have a question regarding the windshield wipers. My 1977 MGB has
water getting in the car on the wiper cable. It drains down one side
onto my ankles, but worse yet it walks down the cable the other
direction and gets into the wiper motor. I took my motor apart
recently, and the whole inside is rusted. The brushes are shot, so I am
going to buy a new motor. I don't want to put it in, however, until I
stop the leaks. I have replaced all three of the gaskets on the wiper
transmissions, and sealed them with windshield sealer, but the leaks
persist. Any ideas?

Thanks,
Dave
Dave!

Generally, the water getting into the car does not come from any
other place than the holes in the front fenders/cowl through which the
windscreen pillars pass. I would take some clear RTV Silicone Sealant and
squirt it under the gasket at the base of the windscreen pillar foot. Use a
liberal amount and wipe off the excess. Hope this helps!

John

BodyWiper Motor Question
John,Thanks for all of your help to the British car community over the years. I have a question regarding the windshield wipers. My 1977 MGB haswater getting in the car on the wiper cable. It drains down one sideonto my ankles, but worse yet it walks down the cable the otherdirection and gets into the wiper motor. I took my motor apartrecently, and the whole inside is rusted. The brushes are shot, so I amgoing to buy a new motor. I don't want to put it in, however, until Istop the leaks. I have replaced all three of the gaskets on the wipertransmissions, and sealed them with windshield sealer, but the leakspersist. Any ideas?
Thanks,Dave

Dave! Generally, the water getting into the car does not come from anyother place than the holes in the front fenders/cowl through which thewindscreen pillars pass. I would take some clear RTV Silicone Sealant andsquirt it under the gasket at the base of the windscreen pillar foot. Use aliberal amount and wipe off the excess. Hope this helps!
BodyMGB Removal of side vent windows to install new rubber seals Mr. Twist,
I am having difficulty removing left & right side vent windows to install
new rubber seals to replace perished ones. I can't seem to remove the
swivel piece of glass to properly fit and install new seals. Your advices
are appreciated.
Thank You,
Richard Coleman

Richard!

Richard!

It is necessary to remove the nut from the bottom of the "swivel
pin" which lies frustratingly, inaccessibly within the door. This nut is a
1/4-28 so you'll need a 7/16" socket -- but a warning -- you can easily
break off the stud -- then you're really up a creek. Unless that nut comes
loose very easily, I would -- you won't like this -- I would gut the door --
rear track, then front assembly. It's a real hassle getting it out, but you
won't break anything! Then, you can work carefully with the nut on the
bench -- AND, you can have the time to clean up the assembly. If you're
determined to do it in place, spray it down with WD-40 for a couple days
before wrenching on that nut! The nut is a nylock and hold a spring
sandwiched between itself and a plate on the underside of the door skin.

John

BodyPaint Installed wood pieces for restoration in TD?I am starting the restoration of a 1950 MGTD. I have purchased all new wood and am ready to install some of the pieces. I am wondering if the wood should be painted the same color as the body or leave it natural. Do you have any information to assist me???
thanks


I've had a number of T type tubs apart and the metal is certainly painted where it's exposed; it's primed everywhere; but the only paint on the wood is overspray. You can certainly make a good case, after reconstructing the wood frame, before fitting the metal, to THOROUGHLY coat the wood with a preservative!

John
BodyDoor Hinges
Hello John,
I have a 76 MGB and the door hinges have quiet alot of lift in them. Instead of purchasing new hinges would it be possible to bore out the hinge and install bushings and a new pin?

Best Regards,
Chris
Chris!

I've never repaired an MGB door hinge, but have done so -- in the manner you suggest -- with T types. I'm certain your method will work! BUT -- before removing the hinges from the body, drill two 1/8" holes -- oops, you guys can't do that anymore -- that's a 3mm hole -- one on the top of the hinge, one, on the diagonal, on the bottom -- so you can line the hinge up quickly and easily to it's original location. The hinge determines how the front of the door lines up with the front wing skin (side to side, not fore and aft).



John
BodyRubber Bumper Conversion
John,

Do you have or know where I can find a conversion kit to convert from rubber to chrome bumpers? I have a 1980 MGB that I would like to convert.

Thanks,

Jim Ray
Jim!

Take my advice to heart. If you want a chrome bumper MGB, buy one!! Converting your rubber bumper car IS possible, but it is SUCH a lot of work -- and, in the end, what do you have? A cobbled MG.

Offhand, these are some of the things you have to do: change the front fenders; change the rear fenders; change the front crossmember; shorten the steering; lower the body onto the rear axle - or - move the axle UP with spacers (a lot of sway!).

I wouldn't do it. BUT, if you insist, I can find some name of people who have done it who can give you some pointers -- but they may give you the same unsolicited advice first!

John

BodyPaint
do you know what kind of paint the MG came from factory( enamel or acrylic....)? thank george
George!

The earlier cars (T types) came with nitrocellulose lacquer. The MGAs had several finishes. The MGBs and Midgets came in enamel, but probably not acrylic, as that's a fairly newer process. What are you doing?

John
BodyPaintDear sirs,

as i am currently involved in a restauration project, i am looking for the original paints of "british racing green" and "lotus yellow". do you have any idea how i can get a hold of these or else solve this problem with a best possible result?

Thank you for any inspiration,

yours, truly,

I am completely unfamiliar withy Lotus Yellow. British Racing Green is as specific as the word "tree." There are hundreds of variations. What year and model are you trying to paint?

John
BodyRubber seal for 72B TrunkJohn:

I replaced the rubber seal on my 72' MGB trunk lid . Since then the trunk lid does not sit flush with the rest of the body. I have tried adjusting the hinges, lock etc without success.

Any suggesstion?

** Two suggestions: Wait for the seal to collapse; contact the seller (Moss? Victoria?) and ask them what to do.
BodyGT re-shellGood Day,

I found your address through British Motor Heritage web site and you are the closest to me.

I am located in Carleton Place Ontario, just outside of Ottawa. I am trying to get information on the cost, etc of a reshell for a 1969 MGB GT. I just purchased this car and wil be starting my project this fall and want to do a cost comparison of all bodywork, time to reshell if avail in North America.

Thanks


Mike
Mike!

While we are within the Heritage Network, our licence covers our workshop -- we do not purchase parts from Heritage. This is my suggestion -- call The Roadster Factory in Armagh, PA and see if they'll bring one in for you -- or, call Brown and Gammons, Baldock, Herts, and see what it will cost of sent one to you. Offhand, I would think that one would cost around $6,000 US, delivered near to your door.

Let me know what you find out and what you decide to do!

John

bodyMGA Aluminum BumperHi John. I have a question... Thanks to Larry Gillion, a friend. I was told that your are the master on MGA's that can help. My 1959 MGA has a motor#BP15GB122565, a body #66648 and gear box #1691. My question is," Why does my car have a aluminum front bumper"? It's all aluminum, no question about it! Can you Help? David

David!

The original MGA bumpers are not much different than the ones you purchase today from Moss -- steel, plated in copper, then nickel, then chrome. The bumpers you have -- the aluminium ones -- those were aftermarket bumpers made by Tasker Metal Products probably 30 years ago. Tasker continues to make grilles, etc. They might have some interesting information if you were to ask (I never have!).

Hope this helps!

John

bodyBolt PaintingHello John,



My question is: Do the bolts in the bonnet channels get painted (were they painted from the factory)? Also, was the engine number plate painted from factory?



Thanks,



Rich
Rich!

I'm certain that the answers are YES and YES. Contact Rick Ingram as he headed the concours judging for the NAMGBR.

John
bodyPlastic to ChromeHello, I was interested in buying a 1980 MGB, which of course has the plastic bumpers. However, I have read a few articles online which give directions on how to convert from plastic to chrome. I was wondering if your company would be able to provide such a service and for how much?

Thank you
The "rule" here is: If you want chrome bumpers, buy a chrome bumpered MGB! It is very expensive to change from rubber to chrome. I would think that it might cost around $2000 for a conversion -- that's just off the top of my head.

John
bodyPipingJohn,

Is there piping on both sides of the interior trim rails on an MGA?

Mark
Mark!

Top and bottom of the dash cockpit, crash rail; outsides only of the door cockpit rails; outsides only of the curved pieces at the rear of the doors; outside only of the strip across the back -- on the front side of this piece is fitted the pocket for the side curtains.

Hope this helps.

John
bodyRubber GlazingHi John,

I have a ‘65 MGB and the rubber glazing for the bottom of the window needs to be replaced. The part is no longer available. Any suggestions on a replacement and sealant?

Thanks,
Jeff

Jeff!
I assume you mean the glazing between the metal "U" and the door glass, within the doors? I know we've used the newer Moss MGA windscreen rubber (frame to glass). Be sure to support the glass with blocks of wood in your vise -- you need to hold the glass really fast so you can fit the metal "U" -- a large, soft hammer works well to urge the pieces together. If you get scared, just take the individual pieces to a glass shop.

John
bodyRubber to Chrome BumperHi John
1. Loved reading your tech accumulated tech tips. Noticed the "sage advice" about converting a rubber bumper MGB to the
chrome
bumpers, and why go through the hassle?

I have a one owner 1976 MGB with only 31,000 actual miles on it. Got it
from
the owner when he retired and moved back to England last fall. I also
have
two MGBGT-(1969 and a 1974) that I brought for parts and the overdrive.
the
74 has lots of rust but runs well and the chrome bumpers are perfect. My
question is that if I have both cars sitting in front of me and I pull
the
rubber bumpers off the 76 and try to swap them out for the 74 bumpers,
can
it be that easy or is there a lot of welding and making of parts
(brackets,
etc.)) I notice that Moss Motors has a kit out to do this but the
bumpers
alone are about two thousand dollars, if you include the grill. They did
tell me that I can buy just the templates and brackets.

And two. I want to lower the 76 at the same time to chrome bumpers
specs.
Can I swap out the 74 gt front and rear springs to lower the 76. The
tech
book says that the gt springs are about one inch shorter than the rubber
bumper car.

If you can give me a simple answer on the two questions,
Why does the 1974 gt handle so much better than the 76 rubber bumper car?

2. Of course you are absolutely right. Its just that I had this wonderful
condition 1976 with very little mileage drop into my hands from a neighbor
who purchased it new. Then from there I bought up two GT's from someone in
Charlottesville, and then you know how it goes from there. Middle age
crazy
I guess.

Will the front and rear sway bar (and mounting hardware) from the 74 GT
work
on the 76? Or should I simply bite the bullet and order it from Moss?

The more I think about chrome bumper swap the less it sounds like I ought
to
be doing it. I am going to change over the su's this weekend though and
pick up an after market exhaust system. And then call it quits. But rubber bumper cars don't seem to bring a lot so I guess I'll be stuck with it.
Bobby!

1. You have to decide what you want. Do you want a rubber bumper
MGB?
Do you want a chrome bumper MGB? You already have the rubber bumper car;
it's already paid for. You could clean up and sell the rubber bumper MGB
and purchase a chrome bumper one. That's not a bad option.

But, trying to turn a rubber bumper MGB into a chrome bumper MGB
is
folly!

If you want your 1976 MGB to handle as well as the BGT, then
simply
fit a large diameter anti-sway bar at the front! If you want your 1976
MGB
to run fast, remove the Stromberg and fit the dual carbs from one of the
older cars (along with the matching distributor).

Trying to lower the 76 MGB is very difficult -- it requires a
completely different front crossmember assembly. Fitting lowered springs
changes the steering geometry and the MGB will not, cannot, handle
properly.

You CAN make your 1976 MGB perform and handle very well!
Hope this little bit steers you in the right direction,


2. The sway bar components from the earlier chrome models will fit the rubber model -- but there is only an anti-sway bar in the front. Use the
thick one from the GT!

Good luck.

John
bodyIt only leaks when it rainsHi John,

I got your e-mail address off of the NAMGBR tech tips website. I am also
familiar with your company's well respected reputation.

I'm seeking some advise.

I have a 1970 MGB-GT that accumulates water in the passenger compartment
when I either wash the car (a little bit of puddling) or if I get caught
in
the rain, which thankfully isn't too often, but can create allot of
puddling depending on the severity and or length of the storm. Until
recently I've turned a blind eye to it as when this does happen I can
usually remove the rubber floor mat and mop up with a paper towel etc.
However, I just finished a sound proofing / insulation project and
wouldn't
you know the car was out in the parking lot at work when one of these
massive deluges that we've been getting recently passed through. As a
result the insulation acted like a sponge and, well you can guess the rest
(Capillary action at is best!). I had to take the seat and all the
carpeting etc out to dry this time. As I write this I have a small fan in
the car drying everything out as thoroughly as possible.

Where is this water coming from? I am aware of the problem with that drain
tube from the cowl vent. I clean that 2 -3 times a year and I see no sign
of the water entering from the vents.

The water traditionally puddles along the side of the transmission tunnel
down by the radio housing and directly across from that by the map pocket.

Any thoughts?
Tim
Tim!

It's pretty odd for a BGT to leak so badly. The technique is to lie
in the car and have someone spray the garden hose on the car (can you do
that in California yet?) and find the leak -- a flashlight helps!

The most common location would be around the rubber that holds the
windscreen in place. After that, I'd suspect the seal between the door and
the door opening.

Please let me know what you find!

John

bodyCar ButcheryI wonder if you can help me with something. I just purchased a 74 1/2 MGB which is in great overall condition, good runner, no rust, sills perfect etc. However, in tracking down a speedo/transmission problem I discovered that many years ago someone had cut through the frame cross cross member that runs across the centre underside of the car, evidently in a botched attempt to remove the transmission without removing the engine. The weld is terrible with gaps etc. The MGB specialist who serviced the car for many years was unaware of this as the joint was convered with undercoating. He indicated that he didn't think this was a structural problem given that it had been done a long time ago and nothing had shifted. I guess I am looking for a second opinion and was wondering if I should have a new piece properly welded in to replace the centre cut section. Your thoughts on this would be greatly appreciated!

Kind regards,

Gord

Gord!

I've seen this butchery before. The frame is exceptionally durable, and if the rest of the car is rust free, then I doubt that the lack of good welds here will cause any dramatic loss of torsional rigidity. If someone could do a good job for a couple hundred bucks, I'd go for it. But I wouldn't suggest it was worth $500 to have fixed.

Hope this helps!

John
bodyPaint FormulaHello John, first, thanks for your web site, I have referenced it often. Next, I have just purchased some clipper blue piping for the TC I am rebuilding from Mr. Art Lewis. He told me that it matches the paint formula supplied by you. Could you share that formula with me? Thanks, Tom, Tom!

Matching paint is always difficult, and some colors are more difficult than others. Most paint suppliers have a spectrometer that can read the paint color, then they mix a paint to match.

The only codes I have for Clipper Blue are:

Ditzler DDL 12297
Rinished Mason BM 042

Ditzler has become PPG, and they have helpful people at their paint library who can cross the number above with a more modern paint. I do believe they're located in Cleveland.

I hope some of this helps!

John

bodyFender InstallationHi John,

I have a 1976 MGB, I am installing the original fender (wing) back into my car. I would like to know on rear end wings 3 long 5/16 bolt and couple of oval spacer washer if it goes between the scuttle and the wing. I tried to install one washer per bolt (5/16) but the alignment is out. Could you tell me how many oval washer required per each bolt and the location of the washer? And what is the gap between the door and the wing?
Thank you very much,
Jorge

Jorge,

The washers fitted between the body and the rear of the fender there at the scuttle are fitted "as required." If you are installing the original fender, then the fitment should prove easier than the fitting of a replacement fender! I would get all the bolts started, then work the fender, if possible, and by very little, to ensure that the gap from top to bottom is parallel. Be certain to attach the bottom of the fender to the bottom of the sill. Draw all the bolts snug, fit as many washers as required, as necessary, so that when you snug the bolts at the scuttle neither the scuttle nor the fender are bent inwards. Fill that gap with body putty to prevent leaking from the windscreen.

I hope this helps a bit!

John
bodyDoor SkinsHello, John...

I have replaced the door skins on my '65 MGB, now the door handles won't fit into the holes.

Can I cut the skins to make the original pull type handles work, or do I need to change to the push type door handles? I have the original internal door latch hardware.

Thanks,

John
John!

Cut the new doors. Measure twice, cut once!

John
bodyWiper BladesJohn,
I have a 1977 mgb with 23,000 original miles. I need to replace the wiper blades. How do you remove the inserts or blades?

Also, I have a noise coming from the water pump or pulley, the pulley has a wee bit of play...any suggestions?

thanks,
jim

Jim!

There is usually a tab which, when pressed away from the arm, allows the blade to slide off the end of the arm. Yours may have 20 years of corrosion (even if you cannot see it) making it difficult to break the blades free from the blades.

The water pump always has a very slight amount of freeplay. BUT, it should not sound as if it has gravel in it! Loosen the fan belt and run the engine without that belt in place. Does it make the same noise? If so, it's not the pump. If it doesn't then you know it's the water pump or the alternator.

Hope this helps.

John
bodyRust ProofingHi John

I just purchased a rust free 1971 MGB GT from California. I've imported the car to Canada near Toronto.

I've been thinking of getting the car rust proofed with an oil spray.

I've been looking for advice on whether I should do this or not. The car will be garaged most of the time and only driven on warm sunny days in the spring, summer and fall.

I've done a lot of research on the web and every where I turn your name comes up.

Thanks
Mike!

All cars have rust -- the questions are: 1) how much; and 2) how to keep it from spreading. I would, positively and absolutely rust proof your car with Waxoyl!

Remove those big foam pads from inside the ends of the rear fenders; remove the white interior panels to the rear of the rear windows; remove the interior panels from behind the doors; remove the splash panels under the front fenders behind the front wheel; remove the sill tread plate (if you do not have these, purchase some).

Before using the Waxoyl, use compressed air to blow out those areas you will be coating. Blow all around the inside of the rear wheel arch -- both from the back and from the front. Blow out all the crud that's collected at the bottom of the front fender. If you want, drill some one inch access holes in the top of the sill (that's why you purchased the sill tread pieces, to cover those holes) and blow out the inside of the rockers. Get that Waxoyl warmed up (in a bath of water on the grill or on the stove) and then spray it inside the rear fenders from the back and from the front (from behind the front doors); spray it into the sills; spray it into the cavity under the front fender.

Now this Waxoyl will drip and stink for a while -- so maybe it's better to do this towards the end of the season. Leave paper on the floor to catch the drippings. Expect the car to drip when you have it parked on hot, black, tarmac next summer.

The good news is that this waxy oil will inhibit the ability of the oxygen in the air to wreak havoc with the iron in the body. It will positively stop the advancement of rust and it will prohibit the formation of new rust. It's the most wonderful stuff since sliced bread! How much to use? It's sold in a container that looks like the old Imperial gallon -- you'll go through one of these at least.

Hope this helps!

John
bodyBadgesHey John!


Hey you are familiar with the radiator nose badge for the MGA, and the "reproduction" by Moss. Have you, or anyone you know, any of the originals (cast aluminum with some foundry's name embossed on the back) in good shape you might want to part with? Let me know please sir.

THanks!

Brian
Brian,

I've taken the new Moss badges, heated them up (carefully) and applied much more solder to ensure that the stud doesn't break free. Will this solve your problem. I just don't have any old ones.

John
bodyEngine Bay CleaningJohn,

I want to wash the engine in my 76 MGB but don't know what to cover up to keep protected from getting water in it. Could you assist me.

Thanks
Chris
Chris!

Ensure the engine is warm, leave it running, and put about 20 quarters into the quarter car wash machine. Spray the engine down with soapy water, then switch over to the degreaser, if it's available, then switch back to the soapy water. You can get one inch away from everything to get it really clean. Sometimes you'll flake off loose paint. The only component to avoid is the alternator. The distributor is going to get wet anyway. At some time, the engine will finally stumble and quit. Lay down the wand, turn the ignition OFF, and continue.

To restart the engine, remove the cap and wires, dry off the plugs, dry off the coil tower, and dry off the cap and wires. By the time you get home the engine will be running poorly again -- so remove the cap at home and allow it to ventilate.

I spray off engines all the time. I love a clean engine bay!

John
bodySide Curtains, TDDear Sir,
I have a 1951, MG-TD. I also have two questions relating to the MG that I hope you can answer.
First, what is the difference between side curtain frames for the two and three bow tops. My MG is a two bow top and I want to be sure I have the correct frames.
Second, I would like to fashion my own wind wings. Do you know where I might be able to locate the chrome hinges for such a project.
Any help you can give me will be appreciated.
Respectfully,
Fred
Fred,

I would like to explain the differences between the frames, but I can only tell you that if you have the wrong ones with the top that they don't fit. I know that isn't much help.

What IS important, is that you fit the side curtains BEFORE you fit the top! Position the curtains so that the front of the rear frame is parallel with the rear of the front frame. Place the fixing mounds in on the interior panels, assuring an overlap (front to rear). Then fit the top, positioning the fixing point behind the door so that the top fits down tightly against the top of the side curtains.

Look on eBay for a set of used windwings; look at JC Whitney out of Chicago for a similar item.

Hope this helps!

John
bodyFender (Wing) MirrorsHi. Can you help me?

I am having an ongoing argument with a fellow British car enthusiast about
fender mirrors. I remember hearing long long ago that the MGB GT and MGC
GT were required to have fender (wing) mirrors fitted because of a British
law that classified the GT as a small truck. According to that British
law, all GTs shipped to the USA had fender (wing) mirrors.

My friend says mirrors were a dealer option and there was no law governing
the placement of mirror locations.

I'm also doubting my memory, because I can no longer find that reference.
If you know that I am right, could you somehow quote me that law or
explain it to me? Thanks for your help.

Craig

Craig,

If there were rules in place for GTs in England, they would not have
been applied here.

I am just sure that the cars were shipped here without mirrors and
that they were dealer installed -- with instructions -- but dealer
installed. That means that some have minor variations as to the placement.

Those wing mirrors look cool but aren't worth a damn for seeing
what's behind you. I've always preferred a much larger mirror, or one
mounted on the door.

Ken Smith may be able to help with some of these originality
questions.

John
bodyOld RustproofingJohn:

I appreciate your insight on many fronts. I had a '63 "B" that I had to sell several years ago due to finances. I just bought an '80 MGB with 18,000 original miles. The car apparently was bought in Europe and used to travel on a vacation in 1980. Shipped back here. Owned by original owner until I bought it. It has a dried up wax-like material in the engine compartment-- rustproofing?? Any idea how I can remove it? The paint underneath still shines if you flake it off with a fingernail.
Ideas?


thanks,

Ken
Ken,

That may be aftermarket rustproofing -- but it sure sounds like the original Cosmoline (cosmolene) that the factory used to undercoat the cars to prepare them for their overseas shipment. The dealer used a HOT powerwasher to remove the goop when the cars arrived --- it was part of the pre-delivery preparation and inspection. At this age I doubt hot water would do the trick -- but you might try it -- gallon after gallon of really hot water. In the end, you may have to use some mineral spirits -- kerosene -- something like that. Don't get excited and scrape as you'll damage the finish underneath -- try a couple of solvents and this stuff should dissolve and become easy to remove. What it'll do to your garage floor, I don't know! What a mess! You know, you might even try the quarter car wash to remove it before or after a mineral spirit application.

Hope this helps.


John
bodyMudguard NutsWell maybe I'm there already. I have an 80 B and I can't seem to find the correct nuts for mudguard in front of the engine. I can't even find them in the Moss catalog or Victoria B.C. We use 10-32 nylock nuts.
bodyNew Vent Window SealJohn, spoke to you in the 80's when you rebuilt my carbs.
I still have the car and am rebuilding completely. Problem is the vent windows don't fit at the top when the new seal is installed. The bottom fits against the windscreen pillar, but the top is tight and pushes outwards. If the windshield were tilted slightly out it would fit but this is not the answer. There is no adjustment it seems. What am I doing wrong?
Many of the new seals are not the same size, same density, nor do some of them have the same cross section as the originals. What to do? You can bend the vent window frame towards the center of the car and away from the center. I know that sounds creepy (What will I break??) but you can, in fact, yank on them pretty hard to achieve a better fit. You'd think that the glass track would be distorted, but I've never encountered a problem.
bodyColor CodeCan you provide a color code along with the Mfg. for MGA Dove Grey . I am trying to buy touch-up paint and they said they could find any formula for Ditzler 32085. If you can shine any light on my delima I would be appreciative. Thanks again for you inspection on the MGA as it made my decision to purchase much simpler
Frank
You might try the PPG library in the greater Cleveland OH area. They can provide an "eye" match from the old code. On the other hand, since your car is probably not original, you might just drive it to your local paint shop and ask them to scan it and provide a color.
bodyPaint Code / Body NumberWhile trying to confirm the color code for my 1974 Midget (Citron color)
so I can purchase some touchup paint, I came across a plate screwed to the
front of the driver's side door frame (opposite from the black plate with
the manufacture date and VIN). This has the code GU N456861P. This is
NOT the VIN, nor is it the paint code that I have found online, which is
BLVC73. Do you know what that unknown code is, and also, did MG put a
paint code anywhere on the cars?
This is the Body Number: G for MG; U for United States; N for
roadster, a sequential number, and then P for Pressed Steel, the body
manufacturer. The closest I have on file here is GUN456334P carrying a VIN
of GAN 5UE 146 997 G.

But on to Citron. We call it "'snot yellow" because it's not green
and it's not yellow. Your best bet is to take it to the paint store and
have them scan the paint. Who knows if the paint is original -- and even
then, trying to get a good match is difficult. Better you should get paint
that matches your car. The paint code is NOT located on the car.
bodyMGB Interior Parint were the '77- '80 mgb engine, trunk, wheel well compartments and interior shell, doors, painted with the same high gloss as the exterior? The engine bay and boot (trunk) were certainly that same high gloss. The wheel wells were painted body color, along with the bottom and interior. I cannot imagine that the body manufacturer changed paints, but there certainly was no preparation of the interior. Further, I'm sure that the later cars (as yours) had an undercoating affixed to the undercarriage as well as the inner wheel arches. This undercoating was painted.

Most owners, when faced with a restoration, make their MGBs just a little nicer (well, they try to) than they were originally. I certainly would! So, I'd strip off the undercoating from the inner wheel wells, at least, so that they and the inner fenders had that same gloss as the exterior surface.
bodyDoor ReplacementI'm in the process of restoring my 1965 MGB. It is an early '65 with pull-handle doors. I've not been able to find replacement doors or door skins that will work with the original door pulls and lock sets. I currently have push-button door skins installed and the lock sets are too long to match up flush with the exterior door surface.

Any advice on where to find early ('62 - 64') door skins or replacement doors?
If it is the bottom of the door which is rusy, then a newer skin would work if you split it at the chrome strip line. Beyond that, I have to say I cannot be of much help. EBay is a potential source of used pieces. Hope this helps a little bit!
bodyLeaking Windscreen I recently browsed through your technical Q&A and recalled that when driving in the rain (a rare occasion), my left pant leg cuff gets wet and my passenger's right leg cuff gets wet.

I forgot to use welting when re-mounting the fenders two year ago, for I didn't notice any when disassembling the car.

Do I need to re-install the fenders to seal out the rain, or is there some other solution which would not require unbolting the fenders? Can I sneak in some brushable seam sealer, or is it best to do some dissasembly and use a roll putty type (black sticky stuff from a roll)?

It is possible to squeeze some filler between the fender and the body, but that probably isn't the problem. You can purchase white body caulk and force it between the body and the "T" welting on the fender. Use a softer plastic paddle for fear of damaging your paint. Also, push it in from the front -- at the front fender trough and the body.

But, I'll bet that the problem with the leaking is from the windscreen. Lift the rubber pads and fill the area under the pad with silicone sealant. Let that dry and test it.

Test the seal by spraying the garden hose against the suspect area and get your buddy to lie inside and watch (or the other way around). Now if you train a strong direct stream against any area of the car, it will leak. Just try to duplicate a heavy rain.
bodyMGB Top InstallationI want to replace to top on my MGB and have never replaced a top before. I've found one in the Victoria British catalogue. My question is, is there an instruction booklet on how to do this? Do you know where I could get one? When replacing the top, are there other parts I should buy as well? I don't know of an insruction manual for the soft top, but here are some hints.

For a really great fit, make sure the car and the top are REALLY warm. The best time of year is July and August! If you're doing this in your garage, get a space heater or salamander heater and blow into the car, heating the soft top from the inside out.

Drill out the rivets that hold the header seal and aluminium strip. Then shake those rivets out of the header bar through the hole provided in the end. If you don't the car will rattle at every corner!

Use 3M 08088 glue. Mark the center of the header bar and the windshield. Mark the center of the top material -- use chalk on the top. Attach the top at the back, glue the header rail and the contact area of the top material. Start at the middle and work outwards. Pull it REALLY tight. The top often has to go through several heat and cool cycles to rid it of wrinkles.

Use pop rivets again in the header seal strip -- or use sheet metal screws. Be sure to trim off the excess material. Always buy a new header seal and header seal strip.

Hope this helps a little bit -- I have to tell you that I have never installed an MGB top myself! One of the guys here in the shop has always fit them.
bodyIdentification PlatesA mechanic friend recently inherited a 1967 MGB-GT that he is
rehabilitating. He would appreciate information that would help him locate
all the identification tags in the engine compartment or replace the
missing
ones.
There is a tag on the engine: 18GB U H ...... between the second
and third spark plugs. There is a tag to the right of the radiator on the
right inner fender, screwed in place with the VIN eg GHD 3L ....... There
is a tag welded to the body on the left side of the rad (opposite of the VIN
tag) with the body number eg MGB......... Once you have the VIN, you can
write to British Motor Heritage at Gaydon in England and purchase a copy of
the production information.
bodyMG T Type Stripped WoodMy 53TD is coming alive for the 4th time in the 45 years I have owned it....but difficulty with the door locks....First, the screw holes in the wood are stripped out....Second..the machine screws that Moss sent (and they say they are correct) are not quite long enough to reach through the door panels, and I can't find longer screws with the correct threads.....then I'm not even sure that the locks will line up with the strikers....(which have the same worn out screw holes)...... What can I use to re-new these holes???............there's got to be a way !!!!!!!!!!

I have just installed the (New Red Leather) interior, and really don't want to have to take it off.....but I will if that is all I can do.....I could replace the captured nuts with nuts with SAE threads maybe..and use longer screws...??? I thought about "forcing" a screw with SAE threads.......but then I am afraid it will bind and that I will cause the nut to twist in it's capturing device.....
You could drill out the holes to 1/2" and fill it with wood glue and a dowel. This will give you a new hole. Make sure you put a stop on your drill so you don't hit your door. The screws are probably 10-32. If you tell us how long we could mail some to you.
bodyHints On Installing A Convertible TopMy question is , what is the method of installing the Header Rail to a new convertible top on a 1970 MGB ? I have found info on lowering and raising the top , but nothing on how to install the Header . How many and which fasteners should be secured , how much tension should the vinyl have when attaching the Header , should the Header be attached to the windshield ?

As you can see , I don’t have a clue on the installation procedures , and I worry about damaging the new top .

We have a few hints to help you. First off make sure you install it on a hot sunny day outside. That way there will be no chance of your top wrinkling. We also use a pop rivet gun instead of screws, there are about 16. make sure you shake out all of the pop rivets so they wont rattle around. Lastly you need to glue the top to the rear bar. Use 3M 08 088 glue.
bodyMidget Fenders Greetings from ENMGR in Cleveland, OH. Here is a Midget question: just how different are the fenders between the chrome bumer and rubber bumper cars? I have a '74 RWA Midget that needs a new left fender, and I have two beautiful '75 fenders for that side, I had planned to neatly section at the factory seam thru the headlamp opening. However, on my test fit I have discovered the upper frt inner corner does not align to my hood. Any insight on this?
I am not quite sure on how to help you. You can make anything work. It just may take a lot of time cutting and welding. The correct fenders would be a lot easier.


bodyChrome PlatingI have a small dent on my TD headlight.Who would you recommend taking it to for chrome plating?Graves Plating in Georgia. Find a full list of platers in Hemmings Motors News or on hemmings.com
bodyMG Bpdy PipingI am looking for a source for MG Red colored body piping. I am restoring a 1953 TD and I have been unable to find a vendor that has it in stock in any color other than black. I want to avoid having to paint the piping as it seems ill advised to paint such a material for obvious reasons.
If Moss does not have the right color in stock, you can have any automotive upholstery shop make some for you. They'll know what to do -- but you want to use as small of a rope down the center as possible (based on the gaps between your fenders), and you'll want a lip of at least four inches in places. It's easy to cut the excess away. Your upholstery shop can make up the fender piping or fender welting in any color that you want to match or accent the color on your TD.
bodyFactory Undercoat RemovalI appreciate your insight on many fronts. I had a '63 "B" that I had to sell several years ago due to finances. I just bought an '80 MGB with 18,000 original miles. The car apparently was bought in Europe and used to travel on a vacation in 1980. Shipped back here. Owned by original owner until I bought it. It has a dried up wax-like material in the engine compartment-- rustproofing?? Any idea how I can remove it? The paint underneath still shines if you flake it off with a fingernail.
That may be aftermarket rustproofing -- but it sure sounds like the original Cosmoline (cosmolene) that the factory used to undercoat the cars to prepare them for their overseas shipment. The dealer used a HOT powerwasher to remove the goop when the cars arrived --- it was part of the pre-delivery preparation and inspection. At this age I doubt hot water would do the trick -- but you might try it -- gallon after gallon of really hot water. In the end, you may have to use some mineral spirits -- kerosene -- something like that. Don't get excited and scrape as you'll damage the finish underneath -- try a couple of solvents and this stuff should dissolve and become easy to remove. What it'll do to your garage floor, I don't know! What a mess! You know, you might even try the quarter car wash to remove it before or after a mineral spirit application.
BrakesBrakesDoes your TD copper nickel brake line set fit the MG Magnette of the same vintage? I believe you have me confused with another supplier as we do not offer brake line sets. However, each model is unique as far as placement and lengths, so I would either continue to search for the correct set -- or, purchase a length of brake line, new fittings, and a brake line tool. Making the bubble flares common to the T types and Y types is not difficult at all. Remember that there is nothing wrong with the original 3/16" steel line (which is readily available). And, too, there is stainless line which never rusts! Hope this helps.
BrakesBrake Master Cylinder RebuildI would like to rebuild my brake master cylinder in 68 MGB. It is a Beck/Arnley unit with an oversize bore, .750 , Beck/Arnley no longer makes a rebuild kit for it. Have you ran across this or is there a solution short of replacing the master cylinder? It was working fine when started restoration 3 years ago, just thought I should freshen it after sitting that long. Hope to have the car on the road by summer!? I haven't seen one of these cylinders in a long time -- almost had forgotten that they existed. I want to say that a firm in California was doing these rebuilds, as well as shocks. They're gone now. They found it less expensive to bore out the the cylinder rather than sleeving it -- and make up new pistons and used slightly oversized seals. I believe your only option is to purchase a new cylinder. Keep your old cap, though, if you want it to appear original, as the cap style changed about 1970 and those early caps are no longer supplied. Hope this helps!
BrakesHandbrake AdjustmentHey Guys, I was wondering if you could give me some advice or point me in the right direction of some information about adjusting the handbrake (parking brake) on my 1975 MGB gt I am struggling to find any ifo about this.Thanks in advance.....your youtube info has already been very helpful , I was pointed in its direction by a member of the MG owners club in Edinburgh Please find attached a pic of my wonderful MGB GT Thanks Loads GordonGordon, First, back off the 5/8" nut on the handbrake cable so that the cable itself goes loose and cannot affect the adjustment of the rear brakes. Then adjust each of the rear brakes. Use a 1/4" square socket or spanner. Unscrew the adjuster all the way, grease the threads, then run the adjuster screw in until you cannot turn it -- don't break it off, of course! Then back the adjuster out, quarter turn by quarter turn until the drum runs free. The workshop manual says the distance between fully locked and fully free is 1/4 turn. In practice, it's usually two quarter turns. Once that's all done, then you can adjust the handbrake. This is more easily a two person job. Use a pair of vise grips to hold the cable from turning, then begin to screw the 5/8 brass nut on the handbrake cable farther onto the cable. After every adjustment (a turn or so) have your associate pull up on the handle. The workshop manual asked for "three clicks" above horizontal. This works well on the RHD drive cars because you can get a good purchase on the handle with your left hand. On the LHD MGBs, it's better to get an angle of about 30 degrees, as one has to read over the tunnel. Hope this helps!
BrakesBrake & Fuel Line FittingsMr. Twist

I have recently started restoring a 1979 and 1980 MGB and have tried to find fittings for brake lines and fuel lines as I intend to renew all the tubing and fittings. for both these systems.

I contacted MG World magazine (Philip Raby) and they gave me your name as a source for this information.

I would appreciate information on where to find a manufacturers name, address or location and address of where drawings for these systems as well as other systems may be obtained. I am sure MG must have had a list of drawings, etc, with bill of material for the major systems of their automobiles. Any information you could forward would be appreciated.

Thanking You

Louis P. Jaarsma
Richmond, CA 94805

Louis!

There are two places you could find this information: British Motor Heritage Industry Trust, Gaydon, Warwickshire, England. Anders Clausager is the archivist there -- they have all remaining factory records; or, you can contact Moss Motors as they are a Heritage Supplier and have access to factory information.

In the end, I doubt you'll be able to get copies of the drawings -- either because they no longer exist, or because of the red tape. Remember that on your 1980 MGB, the brake fittings on the master cylinder at 10 x 1.00 metric and the rest are 3/8-24 UNF.

I hope this helps.
BrakesDisc BrakesJohn,

Do you happen to know what brake/caliper and rotor the factory used on the rear of the MGC GTS cars? I'd like to convert the rally car's rear brakes to a disc setup; I hadn't known Abingdon had done it already (although it doesn't surprise me) until I recently was looking at some pix of the GTS cars and noticed rear disc brakes.

Safety Fast!

Phil

PHIL!

I haven't a clue! Nor do I know anyone who would know! But, you might try Ron Gammons at Brown and Gammons -- he had a lot of knowledge about the "GTS" at the summer party. Try him through www.ukmgparts.com
BrakesBrakesJohn,

I have a technical question for you concerning my 1948 MGTC's brakes. As you know these brakelinings are riveted to the shoes. I have riveted them several times and have always had problems with damaging the linings. If you don't do them tight enough, the linings are loose--if you rivet too tightly, you crack the linings. I had thought that if they can be bonded to the shoes--things would be easier. Is that possible?? Is it advisable?? I can continue to live with the riveting issue--but thought it might be easier and better to get them bonded if possible.

Tom Turner

TOM!

We always have TC shoes BONDED by the local brake company. Further, they radius the new shoes to fit the drums. As a note of caution -- for whatever reason, it is not possible (easily) to turn TC drums. Riveting is pretty old fashioned (of course, so is that TC!) and not as good as bonding.
BrakesBrakes John, I have a question on brakes for a 1977 mgb. I have a rebuilt master and rebuilt calipers and new wheel cylinders. Upon bleeding the system, I still have excessive pedal travel---could there still be air in the lines??? Should I rebleed the master and what is the story with unsrewing the pressure failure switch. The Bently manual said to unscrew it 3.5 turns while bleeding.

mike murdola

ps--I used to be the territory sales rep for Moore Business Products in the Ada/Lansing/Flint area of Michigan.

MIKE!

Your 1977 MGB should have virtually NO pedal travel, with the engine off. It should be nearly ROCK HARD!

So, go out and drive the car, drag the brakes to help "bed them in" and readjust the rear brakes. My bet is that the rear brakes simply need adjusting. And, remember the adjusting sequence: Back off the handbrake cable, unscrew each adjuster, grease it up, turn it into the backing plate until it is TIGHT, then back it off, quarter turn by quarter turn until the wheel "just" spins free. The distance between fully locked and fully free should be one quarter turn. For new shoes, it's more like 3 quarter turns. Then, readjust the handbrake.

There is always the bizarre possibility that you've fitted the calipers left to right. The hose enters at the top and the bleeder is at the TOP!

Hope this helps at this late date!
BrakesBrake Booster Do you have any information on the brake booster troubleshooting? The problem is dragging calipers. Other sources have been checked out and the brake booster seems to be the culprit at this point. (kits were put in the calipers, rotors turned, new hoses installed, m/c has not been rebuilt but appears to be working correctly). The booster is functioning and providing assist to the brakes, but something appears to be interfereing with its action when at rest and pressure continues to be applied to the m/c. We have not tried a rebuild kit for the booster. We have replace the rubber grommet on the vacuum hose entering
the booster housing. We haven't found much information in the Haynes manual, or your tech manual, or the Porter book (1st edition) on the booster.
Any information you can provide would be useful.
Bill Mills
Raleigh, NC

BILL!

I would first inspect the freeplay in the brake pedal. If the brake light switch is screwed too far into its housing, then there is no freeplay, and the brakes are always on (if just a little). As long as you have not worked with the booster or the brake master cylinder, then I would not suspect these as the problem. I wonder, too, if you've actually been out on the road, of if this dragging is something you've noticed in the shop -- which might just be the normal amount of drag. If, in fact, the
front brakes are heating up when driving then there is a real problem. Find this by trying to squeeze one of the brake caliper pistons back into the bore (remove the pad first and lever the piston with screwdrivers), and
cracking the brake line loose at the hose and at the master cylinder to figure which one is causing a line restriction. Remember that those fittings in the brake master cylinder are one of the only METRIC applications in the entire vehicle! Hope this little bit helps.
BrakesBrakes John: Thanks for rebuilding MGA carbs for me this summer and for assisting my mechanic resolving the leak. I've got another question about my MGA (1957). I had a fluid leak in in two of my brake wheel cylinders, so I sent all 6 of them to White Post for resleeving and rebuilding. I had rebuilt the master cylinder about 9 months ago, and it was working fine. The cylinders arrived back from White Post, and I put them on this past weekend, along with a new clutch slave cylinder and all new flexible hoses. I have
bled, and bled, and bled the system, and no more air is coming from the cylinders (I use an Eezi-Bleed). The clutch works fine, but I am getting no brake action. The brake pedal still goes to the floor. Before putting the
front wheel cylinders on, I pulled the piston and dust cap off of one and examined the seals etc, because I understand that different internal seals can be used, depending on manufacturer. The wheel cylinders are not Lockheed. The set up appears to be what is illustrated in the MGA parts
manual and the Moss catalog, except that I noticed that Whitepost did not put an expander (illustration 103, page 25 in new Moss catalog, Part # (180-170) behind the cup that is next to the piston. Consequently, the spring rests directly on the rear of the rubber cup. There is no seal on
the piston. Could my lack of any pressure in the system be a consequence of the missing expander in all 4 brake cylinders up front? I'm not sure what else to try. Any suggestions would be appreciated. My daughter is going
to be driving this car occasionally, and I want these brakes to be perfect.
Thanks as always. Regards, Dennis Werner

Dennis! There are several considerations here with the MGA 1500 Drum/Drum brakes. First, is that the front wheel cylinders are installed correctly. The front cylinder of the front brakes should have the piston pushing DOWN.
The rear cylinder of the front brakes whould, therefore, should push UP. I believe that the cup expanders are important -- they keep the cup in position and lengthen the usable time of the cup. There is a one way valve at the rear of the BRAKE master cylinder bore. This incorporates a rubber ring (a square sectioned O ring), and a odd, top
hat style valve with a rubber plug insert. This valve keeps some pressure in the brake system. You may have to adjust your brakes -- the pedal movement you are experiencing might just be in the initial adjustment of the shoes. You may have to adjust your brake pedal freeplay -- you MUST have about 1/2" freeplay at the pedal for the brakes to work properly. You may have an air leak at the rear of the master cylinder. This is a difficult line to tighten, at best. Use a "crow foot" that fits your 3/8
drive socket set (7/16" crowfoot). I hope some of this helps! Come on up to our technical seminars in
February!
BrakesDust Seal Retaining RingsHello,
I am about ready to rebuild the calipers on my '72 B, and have been informed of the difficulty in reinstalling the dust seal retaining rings. Is there any secret to facilitate the reinstalling of the retaining rings upon reassembly? Thanks.
Chris

CHRIS!

You've probably already got those calipers finished, but if not -- and for others, here are some hints. First of all, you MUST separate the caliper halves, despite the warnings. Then, you much CLEAN the relief around the caliper bore until it has NO MORE DIRT or RUST!!. Fit the dust seal into the retaining ring, smear both with the red brake assembly grease, and push the ring into the bore as far as possible by hand-- keeping it level the whole time. Then, use the tiniest hammer you have to slightly tap tap tap around the circumference until the ring is in place.
IF the ring begins to TILT then STOP, pull it out, and start again. If you bend the ring, you will NEVER get it back into place! Fit a new caliper O ring between the halves.
BrakesSpacerJohn,
Thanks very much for your reply and the suggestion on reforming the
spacer.
When you say " ignore this spacer" do you mean leave it out and is the
pre
load in lb-ft or lb-in? Thanks again for your help. Hope to come to one
of your workshops this summer. Gene


Gene!

I would reform it, re-install it, but watch the pre-load from your gauge
when assembled. We do this by "feel" when we replace the front seal on the
diff. But, then, we've done a lot of them!

John
BrakesVibration When BrakingJohn, I'm not sure if you respond to tech problems via email, I
understand it
may be impossible for you. Here's my problem...1974 MGB-GT (chrome
bumpers)
at highway running speeds (50-70MPH) application of brakes results in a
very
high frequency shudder/vibration thru the steering wheel. No
vibration/pulsing
occurs at lower speeds. I rebuilt the calipers and installed new
rotors...no
change. Could this be king pin/bushing or steering rack related? Thanks
for
all you do for the marque. Dick Fabrizio/Boston...email= John, I'm not sure if you respond to tech problems via email, I
understand it
may be impossible for you. Here's my problem...1974 MGB-GT (chrome
bumpers)
at highway running speeds (50-70MPH) application of brakes results in a
very
high frequency shudder/vibration thru the steering wheel. No
vibration/pulsing
occurs at lower speeds. I rebuilt the calipers and installed new
rotors...no
change. Could this be king pin/bushing or steering rack related? Thanks
for
all you do for the marque. Dick Fabrizio/Boston...email= John, I'm not sure if you respond to tech problems via email, I
understand it
may be impossible for you. Here's my problem...1974 MGB-GT (chrome
bumpers)
at highway running speeds (50-70MPH) application of brakes results in a
very
high frequency shudder/vibration thru the steering wheel. No
vibration/pulsing
occurs at lower speeds. I rebuilt the calipers and installed new
rotors...no
change. Could this be king pin/bushing or steering rack related? Thanks
for
all you do for the marque. Dick Fabrizio

DICK!

I do respond to these questions, Email, but sometimes it takes a while.
Perhaps you've already got your problem solved? In that case, please write
me back because I cannot think of any good reasons why you are experiencing
these problems. Well, I can think of loose wheel bearings -- do you have
the hub nut torqued to about 60 lb-ft? Are the front shocks good and tight
against the front cross member? Did you change the brake pads, too? I'm
certain it's not the kingpins or rack and pinion -- those are simply
transmitting the vibration. What you feel begins at the rotors.
Stay in touch as you sort through this!
BrakesCotter PinJohn Thanks for the information on grease and oil! Not quite ready to
work
yet, I am still trying to find a 7/64x2" cotter pin, my stores have a
11/2"
and a 1/8" x2" so until all the parts are ready to go and it get a little

warmer in my shop I"ll keep rereading the shop manual.

again Thanks

David Hardy

David -- that split pin (cotter pin) simply has to pass through the center
of the roll (tension) pin to give it a little extra thickness (greater
shear strength) and, folded over, helps to prevent it from walking out.
Another size might work.
BrakesBrake ProblemsJohn -

' Sorry this is rather long, but I need some advice. Back in May I
started
having problems with a soft low brake pedal on my '76 B. It's never been
firm like my non-servo Bs but it got quite a bit worse. A Roanoke Brit
Car
Resto guy noted the engine idle was affected by the brake pedal and
suggested it was probably a vacuum leak in the servo. So I sent a servo
from my '76 parts car off to Apple Hydraulics and got it rebuilt.

While at it, I put in brand new master cylinders (clutch and brake) from
Moss and on advice of the same guy in Roanoke, flushed out the whole
system
and converted to DOT 5. I did bench-bleed the MC first. Still got a soft
pedal and within three days my left front caliper was leaking (I've never
had a caliper leak in all my 15 years experience with MGBs).

' Was about to rebuild calipers (as I've done on other Bs) and discovered
Advance Auto has rebuilt calipers with OE pistons for $35.99 - with
lifetime warranty. So I flushed out the system - thoroughly - converting
back to Castrol GT/LMA DOT4 before installing rebuilt calipers. Again, I
bled the whole system thoroughly - starting with left rear, then right
rear, right front and finally left front. There's no DOT 5 left in the
system.

Still soft pedal. Pads are good. The brake hoses were replaced about two
years ago, as was the left rear wheel cylinder which I discovered leaking
at that time. Shoes looked good then. Car has gone about 15,000 miles
since then.

The right rear wheel cylinder is the only item in the system that I
haven't
replaced. It is working and although I haven't had the drum off, there is
no outside sign of leaking. I am aware that lots of DIYers put rear brake
shoes on wrong and mine are right - like in the Bentley illustrations.
The
rears are set as high as I can get 'em without overheating the hubs - in
fact I had to back my left rear off a bit. Even when it was set too high,
soft pedal.

If I pump the brakes once, on the second application, they feel good. I
know this is a classic symptom of rears in need of setting up, but that's
not the problem. At the worst, the pedal may feel awful but the brakes do
work well - although the right rear tends to lock up first on hard stops.

I even turned the brake light switch in about 1/2-turn - which minimizes
the 1/8th-inch pedal freeplay and, not surprisingly, makes no difference.
The pedal does not "leak down" nor am I losing any brake fluid. In fact,
I
swear the level in the reservoir went UP slightly after a 40-mile test
drive. Could there still be an air bubble in the system...? I suppose
although it seems unlikely. What could I be overlooking? Should I
replace
rear brake shoes?

Many thanks!

Allen Bachelder

ALLEN!

The possibilities lie in just several areas: Brake adjustment;
air in the system; faulty
servo -- so:

With the engine off, your brakes should feel firmer than your
1962-1974 as the master cylinder piston diameter is larger -- hence less
distance to move the same amount of fluid. If the brake pedal is not REALLY
firm here:

Again, adjust the rear brakes: slacken off the handbrake all
the way; back off the rear adjusters until they stop, grease them up, turn
them in until you cannot turn them anymore, then back them off, quarter turn
by quarter turn, until the drum "just" runs free. The rotation between
fully locked and fully free should be one or two quarter turns. If that
doesn't do it...

Inspect the front brakes: are the calipers right side up?
Bleeders at the top? Again bleed the system, SLOWLY. Bleeder open, pedal
to the floor, bleeder closed, pedal up. Bleed the rears first, about eight
bleeds on one side, two on the other. Fronts should be bled five times a
side. If that does not do it:

Remove the master cylinder -- I know, it's not easy -- and
measure the distance that the pushrod extends from the front of the servo
assy. THIS IS A CRITICAL MEASUREMENT!! I ground off two long nuts to 0.408
for "factory tools." These you thread over the studs, then place a drilled
piece of flat stock over the studs to find that the pushrod "just" touches
the bar. The pushrod is not easily adjusted, but it's possible.

FYI: If the engine speed increases with the servo depressed,
then there is a leak in the one way valve -- rebuilding is necessary.
However, you'll find now that repeatedly pumping the brakes will increase
idle -- each pump allows a bit of fresh air to enter the intake manifold.
I have never had to replace a brake master cylinder. Rebuilding them is a
DREAM compared to the earlier ones! We rarely replace the clutch master
cylinder, but find that rebuilding it, in place, (DO NOT HONE), works well
in nearly every case. We use SILICONE BRAKE FLUID rarely!! It is full of
its own problems.

Please work back and forth with me and tell me what the problem
was -- when you find it!
BrakesBrake Fluidjohn,



i got a print out from you a number of months ago about dot 5 brake fluid.
there was a reference to removing .050 inches from the piston on some
cylinders. i need to know if this is needed on my MG.



Thanks,


fred langford

FRED!

I would use silicone fluid ONLY if your underbonnet is PERFECT and
ABSOLUTELY BEAUTIFUL. If it is as most underbonnets, do not use the
silicone fluid. The notes I made were regarding the MGA and Midget twin
master cylinder. You need not make that correction to yours.

FAST FORWARD!
BrakesBrakesJohn -

I can't thank you enough for your detailed response - on a weekend yet!
It
looks like the '76 B brake problem is going to sit for awhile as tomorrow
morning we're taking the '73 B to visit Ontario relatives and on to Grand
Bend for the NAMGAR Hosers Eh! GT.
The '76 brakes will be first-priority when we return (the '76 is my daily
transportation!), and I will be posting my progress(or lack of it) to you.
At any rate, if I don't respond for about 10 days, that's the reason.

This is the same behavior as before I replaced the servo, master cylinder
and front calipers, so my meagre sense of logic has me looking elsewhere
for the solution. But on the other hand the idle does increase slightly -
at least when I pump the brakes. ' Can't overlook the possibility that
the
rebuilt servo is defective.

I did disconnect the vacuum hose from the manifold and found the nonreturn
valve would not let me blow back in the hose. Is that an adequate test?
By
the way, this car is converted back to dual HS4s and I have the vacuum
line
connected to the center of the intake manifold where the gulp valve used
to
be. ' Used a brass "L" fitting that threads correctly into the manifold
and has a stepped hose fitting on the other end. Is this arrangement OK?

Again, THANKS! Last time I needed advice, it was in regard to my O/D.
You
told me to replace O rings on the solonoid, I did it, and it's been great
for over two years since.

Allen

ALLEN!

The possibilities lie in just several areas: Brake
adjustment;
air in the system; faulty
servo -- so:...

Please work back and forth with me and tell me what the problem
was -- when you find it!
BrakesBrakes FixedJohn -

' Didn't expect to be writing back this soon, but I had a couple of hours
this afternoon and WOW, VOILA, EUREKA, and lots more! I started with the
adjusters, doing what you said. The RR adjuster still bothered me - I
couldn' feel the 'detents' every 90¬?, so I pulled the RR drum. Now here
comes the real fluke: what's that inside the drum? Why it's a brake
lining! The lining had completely detached from the forward shoe. It was
at the bottom of the drum when I took it off - presumably it rotated as far
as the other shoe would let it - but that meant no shoe for the adjuster to
press against. To keep things in balance, I replaced shoes on both sides.
Now I really have brakes!!! Perhaps it's a combination of several previous
problems but with new MC, new calipers, new servo, and now new shoes, they
feel much better than they ever have.

There's a moral here somewhere. When something goes wrong I tend to
replace everything. And on more than one occasion, the solution has been a
fluke - something simple that I overlooked. A lot of this was unnecessary
I'm sure, but then there is some piece of mind in knowing the entire brake
system is tip-top. The next time I need a rebuilt late-model MC, you know
where it's going! Do you do servos also? I didn't see it listed in your
bench services.

But never in a million years would I have guessed a loose brake lining.
And if I were to guess what the symptoms of a loose lining might be, I
would suspect some strange noises from that drum - NOT a soft pedal.
Strange - that was the wheel that was locking up first in hard braking. Go
figure...

Again, thanks for all the attention!

Allen

ALLEN!

We've only seen loose linings, as you've described, several times.
Very unusual, to say the least!

Glad it's all done!
BrakesMaster CylinderCan the master cylinder in a 1974 be rebuilt in place or must it be
removed?

Thanks in advance for your help.

I need to know the model of MG; I need to know brake or clutch. But,
offhand, the clutch master cylinder can be rebuilt in situ; the brake master
cylinder requires someone very familiar with the unit as it can easily be
damaged during rebuild!
BrakesTool to Release C-clips from Tandem Master Brake CylinderSir: Is there a "special" tool required to release the C-clips from the
tandem master brake cylinder? I had no trouble with the main. I am really
stumped as is a few good mechanics in the area.
1974 MGB part.
Sincerely
Dave Mendenhall

DAVE!

I used to use a set of snap ring pliers that I had ground down --
but those would not last. Now I just use a pair of layout scribes (very
inexpensive) to draw the ring loose from it's relief and bring it up the
bore. Be VERY, VERY careful, as any damage to the main piston will cause
the cylinder to leak. I always polish the piston on the lathe and then on
the buffing wheel to remove the scratch marks I've made -- as well as the
ones caused by years of dirt.
BrakesBrake Fluid, University MotorsFor some factual information on Silicone DOT5 Brake Fluid please contact :
Automec Equipment & Parts Ltd 36 Ballmoor Buckingham ENGLAND MK18 1RQ Fax 0044 1280 823140 or see our Website www.automec.co.uk

There is so much wrong information particularly on American pages - surprising since the stuff is only made in the States - that it would take weeks to deal with all of the points raised. We have been selling SBF DOT5 and using it ourselves since 1982 and wouldn't sell or use anything else. We have had two vehicles go over 200,000 miles on it! Basically - IT IS NOT A RACING FLUID but it will not boil below 260c(500f) and many club racers do get good results with it. It will not damage paint. It will not catch fire easily as 'glycol does - just check the relative flashpoints. Contrary to many reports it is very easy to switch to SBF - we have never changed a seal or hose, we certainly would never use anything other than SBF to flush through during the normal bleeding process. We bleed by the book and since all SBF is purple the job is even simpler. It is permanent because it effectively absorbs no moisture. It prevents corrosion and all of the problems associated with that. The viscosity is stable thru most temperature extremes you are likely to encounter - which is why the US Army specify it - and in a very short time it is very cost effective. ie The BMW Dealers here charge more than 100pds.stg. just to change the fluid at a service interval - good business eh! Not with us anymore - we use it exclusively in all of our vehicles, including a BMW728 and an 840 and wouldn't use anything else! You should use however DOT or SAE rated hoses, and other perishable items. Since SBF is DOT rated it should assure you that it has been proven to be compatible with all the other DOT/SAE rated items in the system - hoses, seals,fluid and switch material (this latter item DOT rated seems to be difficult to get hold of and we suspect that something in those switches can from some sources cause problems)

Ray Smith
PS Are you in anyway connected to the famous UMECO Mayfair London back in the sixties? I used to work with them!

RAY!

Thank you VERY kindly for this note. I use silicone fluid in the shop on the very nicest cars only. Those with "normal" firewalls get the Castrol LMA. I've run into several problems with the silicone: Seal swelling; premature leaking; difficulty in bleeding. The seal swelling is a problem with the MGA and T type master cylinders where a bleed hole is covered by the swelling. Knowing this, it is easily avoided by changing the position of the master cylinder, slightly. The premature leaking has not been scientifically proven, it just seems that way! The difficulty in bleeding we've experienced is aeration of the fluid by rapid pedal movement -- of course, this can be avoided too. Perhaps I should try to use more of this fluid. More and more of our vehicles are sitting, unused, for longer period of time. I wonder if the problems of frozen cylinders and damaged bores would lessen.

I worked in Hanwell, W7, in 1972-73. University was quite an operation then -- something like 40 fitters and boys on the shop floor, and that wonderful lubrication/tuning line, behind glass, that was the envy of all shops, British and European. Yet, there never seemed to be any improvements made while I was there. Returned to the USA in 1973 and figured if the name was good enough for them, I'd borrow the use of it. Now I am a Heritage Approved Workshop, recommended workshop by the MGOC, trade member of the MGCC, recommended workshop by a number of the US clubs, and the original University Motors is gone. It's a long way from Michael Bradstock to me, but I continue the name and reputation. I still have my UMECO shopping card!
Brakes72 MG Midget Master CylinderHi John-
We have just purchased a 72 Midget. The plastic cup on the master cylinder is
weathered and broken. Our first efforts to find one have been useless.
Any thoughts or words of wisdom. We an get the rebuild kits and the plastic cap.
Thanks
Morris and Rita

Morris!

You should be able to find a master cylinder CAP or a master cylinder RESERVOIR from Tom at British Miles 1-800-WE-FIX-MG.

FAST FORWARD!
John H Twist
BrakesMGB Brakes Dear John,
I got your email address from MG World Magazine. I am hoping you
may help me with the following problem :-

I have just finished rebuilding the braking system of my 1972 MGB.
I have resealed the master cylinder, renewed the pipes and replaced
the rear cylinders. The only component I have not touched is the remote
servo.
I have bled the system thoroughly using a pressurized bleeding kit,
starting
with the wheel furthest away from the master cylinder but I cannot get
rid of
the spongy brake pedal.
I have heard that the remote servo system is hard to bleed and that some
people mount the servo upside down to help. Is this really necessary or
am
I doing something wrong ?
I have never driven the car yet as it was bought needing restoration so I
don't
know if the brakes or servo were ok before they were stripped down.
Can you offer any advice ?

Regards

Glenn

GLENN!

You can probably quickly determine IF the spongy pedal is due to the
servo. Purchase a BCA 4002, a female/female coupler, disconnect the servo
and connect the lines to the coupler. After bleeding the pedal should be
ROCK HARD! That is, unless you are using silicone brake fluid which gives a
spongy feel and must be bled very, very slowly to avoid aeration.

We do not have external servos fitted in the US, so I am not
familiar with them on the MGBs -- but I do have experience with the Girling
units on the MGC and on the big Healeys. I cannot remember an episode the
cause of which I would attribute to a problem with the servo. Once, years
and years ago we tried to bleed an MGA and just couldn't get ANYWHERE -- it
turned out the calipers were fitted left to right and the bleeders were on
the bottom.

Let me know the answer to your problem when you discover it so I am
better informed about the remote servo Lockheed systems.

SAFETY FAST!
John Twist, Service Manager
BrakesChanging brake switch without bleeding brakesJust wanted to thank you again for your time during the Sterling
Inspection on my 1958 MGA. As a newcomer, I appreciate your willingness
to share the finer details so willingly, so that I may improve the car
even further. When I returned to the hotel on Saturday afternoon, the
first thing I did was make a list of all of the points you mentioned (at
least I think I got them all). From there, I'll endeavor to correct them
as soon as possible.

I was wondering about one thing in particular. You mentioned that the
brake lights probably didn't work because the brake switch doesn't last
more than about 6 months if using Silicon fluid. It appears Silicone is
by far the better choice for many reasons, so I think I should get used
to the idea of changing the switch as necessary. Here's the big
question: Can the switch be changed without bleeding the line?

By the way, my wife Elaine and daughter Kristin were also at the show,
and all of us enjoyed your banquet remarks a great deal.

If you're interested, we have our MGA pictured on our web site (listed
below). Just click on the last button in the left frame of the site.
(Kristin has named the car "Abby" in honor of where it was built.)

Thanks again,

Best Regards

Bill Pederson

Bill!

I apologise for not writing back in a more timely manner. But, I
can still save you some time. It is NOT necessary to bleed the brake system
after changing the brake light switch. The normal course of events is that
when you remove the brake switch, gravity pulls brake fluid out of the
fitting (rather than air getting introduced), so simply (although quickly)
replacing the switch is an easy matter.

Hope this helps at this late date!

John
BrakesMaster cylinder freeplayHi John:

This seems like a never-ending story! I wrote a nice, polite letter to the mechanic citing your and Mike Ash's theories. He has agreed to take another look at the car to see if he can take out some extra free play in the linkages. But that scares me a bit as I know that if you take out enough free play you can eliminate the problem.

Up to a point, what is the danger of taking out freeplay at the master cylinder operating rod? I will also suggest rebuilding the master cylinder and see what he thinks about that. Thanks again for your interest.

Frank

Frank! You can take all of the freeplay out, with the exception of the last little "tunk," which translates to about 1/2" at the pedal. Hope your guy can get it right!

John
Brakes1977 MGB Roadster questionsJohn,

I am in Albuquerque, NM, and am trying to get my daughter's 1977 MGB
Roadster, which has been in storage for over 10-years, back on the road.

I have seen your ad in Hemmings Motor News, and Technical Tips in AMGBA's
Magazine (Octagon). As such, I would like to solicit your recommendations
on a couple of items, and also inquire about the "Seminars" you offer.
Starting with the seminars, are instructions on rebuilding the brake and
clutch hydraulic systems offered by correspondence? I am having the
engine
rebuilt (locally), and would greatly appreciate your advice on the other
subsystems.

Questions:

Brakes: I discovered a couple of days after pumping the brake pedal that
I
have a leak coming from the master cylinder and/or servo unit. Is the
Servo
Assembly a vacuum boost unit, and as such, I only need to install a repair
kit in the master cylinder? Does rebuilding the front Caliper Assembly
require special tools?

Tires: What size tires do you recommend for Rostyle Wheels? The car
currently has 165 SR14 tires, and the only brand available locally in that
size is from Vredestein. The Moss catalog says 175/70-14, and 185/70-14
will fit. The 185's diameter comes close to the 165, but is almost an
inch
wider. What are your thoughts on low profile tires (70-series) vs the
original 165-80 series?

Radios: Do you carry adaptor plates for the Radio Console? I have an
inexpensive Radio Shack "shaft-style mount" unit, but installation
requires
an adaptor plate. In the book "Original MGB", by Anders Ditlev Clausager,
on
page 52, it shows a Motorola Radio installed in a 1977 North American car,
which looks great. Do you sell replacement radios?

I would greatly appreciate your "words of wisdom" on the above items.
Thank
you in advance for your help.

Regards,
PJT


When you wrote last spring, I was overwhelmed with technical queries
and with work in the shop. It's taken this long to get back with you -- and
you've probably already got your MGB on the road.

The brake master cylinder is an easy fix -- just to remember that
the fittings for the brake lines are 10x1.00 metric. AND, the heavier
spring, the BLACK spring, fits into the cylinder first. The servo rarely
needs attention, but requires CAREFUL attention to measurements if you do
disassemble it!
The front brake calipers are easy to rebuild -- you'll need seals,
pistons, AND the "square" O ring that fits between the caliper halves.
Fitting the new steel sleeves on the dust seals can be F R U S T R A T I N
G -- so don't ruin or throw away the old ones!

We always use 185/70 Kelley Metrics on the MGBs at the shop. They
seem to work very well. Some day, some manufacturer will come back out with
165/14. Those Michelin 165/14 XZX were the best tires ever made for the
MGB.

How did you come out with the engine and the rest of the work?

FAST FORWARD!
John H Twist
Brakes1964 MGB Roadster - new brake rotors Hi John,

I have a '64 B roadster that requires new brake rotors. What is the best
way to measure the run out on the new rotors? What is the best way to
pull
the dust cap from the hub?

Thanks in advance.

Regards,
Jeff Scruton

Jeff!

You must have wire wheels? You'll need to fabricate a tool using a
very deep 5/16-24 nut. Fit a bolt into one end of the nut, lock the bolt to
the deep nut with a regular nut. Then, thread the whole works onto the stud
on the dust seal. Grasp the bolt/nut tool with your vise grips and tap it
out with a hammer. You may need to chase the thread if the DPO buggered the
threads with vise grips. Do you have an MGB 1968-1980? If so, you can use
the nut at the right rear of the head -- this is EXACTLY the nut you need --
this one takes a long 3/8-24 bolt.

You won't need to check the run-out on the new rotors, as they come
within spec -- but if you do, expect nothing more than several thousandths.

Set up the front wheel bearings WITHOUT the caliper in place.
Replace the shims as they came out, then tighten the nut to about 60 ftlb
(really tight). The front hub should be loose enough to spin freely, but
not so loose that it "tunks." If it tunks, remove shims; if it's too tight,
add shims. The shims come in 0.030, 0.010, 0.005, and 0.003.

Hope this helps!

John
Brakesbrake master cylinder Re: 1969 MGB-GT brake master cylinder rebuild. I have removed the
spirolox
ring and removed the circlip. The unit will not come apart. I cannot
remove
piston. It will not come out. I assume that the plastic white bearing is
so
tight that it won't come out. Any suggestions? Should I blow it out with
air or try to? How else is this removed?

Randy!

This brake master cylinder is probably the most difficult unit in
the entire car to dis-assemble, repair, and re-assemble without ruining it!
Leaf springs might be more laborious, but there you can see what you're
doing.

Look at your factory workshop manual -- at least a cross section
view. You'll note that from the front to the rear there is: Pushrod,
Piston, spirolox ring, spring, circlip, white plastic washer, front seal,
spacer, circlip, and thick washer. You MUST NOT DAMAGE the piston or all is
lost!!! You cannot squeeze it, you cannot gall it, you shouldn't even
scratch it!

Remove the pushrod, spirolox ring, spring, and front circlip.
Remove the reservoir. Fit a 3/8-24 bolt into each outlet. Use air pressure
with a rubber tipped blow-gun on the front-most hole (under the reservoir).
The white plastic ring WILL come out. Sometimes you have to tap it
rearwards, sometimes you have to lubricate the walls with oil, but keep
working it, back and forth (air and small punch) until it pops out! The
front seal will come out behind it. Then remove the spacer ring. Now the
tricky part.

Remove the deepest circlip with a pair of scribes. Don't use snap
ring pliers -- they just will not work. Use a pair of scribes. Do your
best NOT to scratch or gall the piston.

Hone the cylinder, polish the piston. Fit new seals -- we have a
jig to separate the pistons, but at home you can make a case just to fit the
seals over the large diameter of the piston (tedious at best). Ensure that
the second cup points FORWARDS.

Use LOTS of Girling red assembly brake grease.

If you don't want to risk damaging the cylinder (or if you have
already), send it to me and I can probably fix it back up. Worse case is
that you have to purchase a new cylinder.

I charge 1.5 hours for the rebuild -- $90 plus the kit which is
about $30. Half the price of a new cylinder -- and mine look really nice
when they come back!


John
BrakesMGB BrakesAfter a rebuild of the brake master, the front brakes of my 1968 B lock up
after driving a couple of blocks. They release when I crack open any
front
connector (bleeder, between the PDWA and the MC). My MC has an
adjustment
for the distance between the primary and secondary pistons.

Are there any suggestions for correcting this problem? Local shops don't
have much use for looking at my LBC!

Thanks for any help you can render,

Steve Bondeson

Steve!

The most common error is the misplacement of the brake light switch.
Unscrew the switch until you have 1/2" of pedal freeplay. That will
probably do it!

John
BrakesMGB Brakes Cont. John,

Thanks for the suggestion. The free play was not the problem so I'll keep
searching for another solution!

Thanks again for responding.
Steve

Did you refit the front, large coil spring on the primary piston -- the one
that fits externally? You have a very unusual problem!! Are you using
silicone brake fluid?

John
Brakes
Hi John,

I have a 1972 MGB, restored about 5 years ago. At the end of last season,
I
experienced some uneven braking only at low speed. By uneven braking I
mean
the the car would sort of lurch or shake when the brakes were applied and
the
car was almost stopped (below 10 mph). This problem seemed to occur only
after the brakes were warmed up. However, the car still stopped quite well
in
spite of the lurching.

I thought that the front rotors were probably warped, so I bought new
rotors, pads, clips, etc and replaced everything a week or so ago.
Unfortunately, the problem has not gone away. Do you know where I should
look next? Should I now do a repair and replace on the rear brakes, or is
there somewhere else that I should be looking?

Thank you.

Steve Swarin

Steve!

You've already fixed the problem by now, I expect -- I apologize for
my tardy response.

Here are some thoughts, but PLEASE let me know what you found and
how you fixed it!

If the brake rotors are warped, you'll feel the pedal pulsating. If
the pedal doesn't pulsate, the rotors are not warped.

If the brake drums are out of round, or there is some sort of
problem in the rear, the car can sometimes feel like it's surging -- but
there won't be a discernable tremble or pulse in the pedal.

Adjust the rear brakes! Of course, slacken the handbrake first,
then re-adjust it when the rear brakes are properly adjusted.

Let me know what you found!

John
BrakesMGB Brake Uneveness Hi John,

I have a 1972 MGB, restored about 5 years ago. At the end of last season,
I
experienced some uneven braking only at low speed. By uneven braking I
mean
the the car would sort of lurch or shake when the brakes were applied and
the
car was almost stopped (below 10 mph). This problem seemed to occur only
after the brakes were warmed up. However, the car still stopped quite well
in
spite of the lurching.

I thought that the front rotors were probably warped, so I bought new
rotors, pads, clips, etc and replaced everything a week or so ago.
Unfortunately, the problem has not gone away. Do you know where I should
look next? Should I now do a repair and replace on the rear brakes, or is
there somewhere else that I should be looking?

Thank you.

Steve Swarin

Steve!

You've already fixed the problem by now, I expect -- I apologize for
my tardy response.

Here are some thoughts, but PLEASE let me know what you found and
how you fixed it!

If the brake rotors are warped, you'll feel the pedal pulsating. If
the pedal doesn't pulsate, the rotors are not warped.

If the brake drums are out of round, or there is some sort of
problem in the rear, the car can sometimes feel like it's surging -- but
there won't be a discernable tremble or pulse in the pedal.

Adjust the rear brakes! Of course, slacken the handbrake first,
then re-adjust it when the rear brakes are properly adjusted.

Let me know what you found!

John
BrakesSpirlox Ring and Clip ProblemJohn,

i just saw your write up on the master rebuild! I have a 74 b and have master all striped down still having piston in bore.. can't figure out hou to get spirlox ring and circlip off???

Please advise I was hoping the brake mastrer was going to be as easy as the clutch?

Thanks
Harrison

Harrison!

The spirlox ring requires two people -- one to hold the large cup towards the cylinder, another to peel the ring from the end of the piston. Then, off comes the large cup and the heavy spring. Next is a normal circlip on which you can use circlip pliers. After that is a white plastic spacer. This can be difficult, but I've found that air pressure will blow it out. Seal up the two outlets (3/8-24 bolts in the outlet reducers). Place your airgun at the forwardmost hole and PUFF -- it should blow the white plastic ring out of the cylinder. If it doesn't, carefully tap the ring back into place, and PUFF again, and again, and again, tapping the ring back down each time, maybe squirting WD40 or similar penetrant on it. Finally it WILL pop out. Under that lies a large lipped seal (which will come out with the white plastic spacer) and under that lies a black steel ring which will fall out. Now comes the difficult circlip!

Use two sheet metal layout scribes (I commonly refer to them as "dentist tools") to squeeze the ring to a smaller diameter and twirl it out. DO NOT scratch the master cylinder piston!!!!

Then, you'll probably want to separate the master cylinder piston halves so you can fit the new seals. This too, is difficult. We have a small jig that holds the spring cub out of the way to drive out the world's second tiniest tension pin (DON'T lose it!!).

Or, you can send it to me and for one hour, I'll disassemble it, hone, polish, and rebuild it. That's $60 plus parts.

Let me know!

John
Brakeswheel cylinder circlips
I have a 1969 MGB, I've removed my old wheel cylinders and am trying to install the new ones but am having no luck installing the new circlips. I've pounded flat the old ones and have them installed but I'm not sure I trust them. Is there a trick or tool I need to install this type of circlip? Thanks in advance for your assistance.
Tim!

First, you have to hold the cylinder tightly against the backing plate. There is no better tool for this than another person levering it back with a large screwdriver.

Second, fit one end and the middle of the circlip over the cylinder, then, with a smaller screwdriver (than the one above), twist or pop the last leg of the circlip into place. It should take about ten seconds!

Hope this helps!

John

Brakes67 MGBI have
just aquired a '67 that has been sitting for 15 years. One question I
have
is about the braided stainless steal brake lines: Do they have rubber on
the inside or is it all ss? Also, do you know of someone who makes a
stainless steel gas tank, please?
Thank you,
-Jeremy

Jeremy!

The stainless lines must have rubber on the inside or the fluid
would leak through any woven metal. I see those from time to time, but I'm
a believer in the original brake lines. I do not know of a manufacturer of
stainless MGB tanks, but you might check MG Owners Club (through
www.mgcars.org.uk).

John

BrakesA Master Cylinders

I believe I saw somewhere that you perform resleaving
of MGA master cylinders? If this is the case, can you
tell me what it costs to have the work done and
whether you recommend brass or stainless?

On the mgcars.org BBS there are a number of people
that claim brass is too soft and leaks, especially w/
silicone fluid. Not sure which route to take.

thanks, Jake
Jake!

It is true that silicone fluid leaks FAR FAR FAR more easily than
"real" brake fluid. It is true that the ONLY advantage to silicone fluid is
that it does not eat paint. It is true that brass sleeved cylinders seem to
leak more silicone fluid than real fluid. But why? I cannot imagine it's
because the brass is "soft," but something's going on, for sure.

You can have the cylinders resleeved in stainless. You can buy new
cylinders. What is the condition of your bulkhead? Is it perfect? If it
is, you MUST use silicone fluid. If you use a brass sleeved cylinder, you
have to have a sponge under the master cylinder (same colour sponge as the
bodywork!). I have no experience with silicone and original and/or
stainless sleeved cylinders.

Hope this helps.

John

BrakesBrake Lights Stay onOK, I am with you on this.

The car is a 74 ½ (Rubber Bumper) “B”. The problem is the brake lights themselves not the warning light. For some reason, they just intermittently just like to stay on. As I said, this is my third switch, I have adjusted it just about from end to end yet the problem continues.


I have been pulling my hair out on this one (and I am quickly running out of a precious commodity). When I back the switch off, it just won’t make contact – when I leave it in a position where it just does make that contact – it goes back to being stuck on. If I pump the pedal, it sometimes goes off – sometimes not.



Changed the switch twice – nada!!!

Glad to see you writing – love the updates – and you’ve even convinced me to get involved again. I just joined the local British Car Club (really a triumph club but they gave it a second name to draw non-triumph owners.



Anyway, don’t know if you remember, probably not, but last year I wrote about my brake switch and told you that I just kept having problems getting the brake lights off.



Well, I followed your directions and did change the switch – but still have the same problem. Lights stay on. If I pump the pedal there’s a 50/50 chance that they will go out – but either way, new switch or old switch, the lights want to stay on.



Could there be a short somewhere in the trunk which would keep the lights on??






LarryB



Larry!

Gosh! Are the wires crossing right there at the switch? Is the brake light circuit accidentally grounded (which quickly burns out switches) -- have you been to the body shop lately? Do the brake lights work WITHOUT a switch in the circuit?

Proper installation demands that you screw the switch in until you have about 1/2" pedal freeplay. The position of the switch controls the freeplay.

What can you tell me?


It is possible for us to solve this. Let's start at the top. What year and model? Are we talking brake lights or are we talking the brake warning light in the dash?



It's almost always the POSITION of the brake light switch -- how far it's screwed in (which, in turn, controls the position of the brake pedal). Make certain you have 1/2" pedal freeplay!



Good luck!



John




BrakesRebuild KitsI got my MG back yesterday and have driven it about 150 miles since then. Basically they did a compression test, major tune up, valve adjustment (with new valve stems), carb balance, mounted the tires I bought on eBay and adjusted my brakes quite nicely.


The car is much snappier then before and feels a lot safer with the brakes and new tires.



There are still a few issues that maybe you could give me some advice on.



1- They said they “couldn’t” set the fast idle properly and I noticed it was stumbling when cold this morning. It started OK but couldn’t maintain a good idle. They also say they have the rebuilt carbs fully leaned out and it’s still running rich according to their exhaust analyzer. Do these two problems suggest anything in particular?


JOHN!

There are particular problems with most of the rebuild kits -- which keep the main jet from travelling high enough to make the mixture lean enough. Did we rebuild the carbs? I cannot remember. The problem with the high idle is yet another problem -- either the throttle discs are not closing far enough or there is a leak between the carbs and the manifold. Tell me more about the rebuild.







2- They adjusted the valves and put in 5 new valve stems, but I would swear the engine is “rattling” even than before – although not all of the time. It rattles when you’re “pulling” after upshifting, then it quiets out. It hasn’t used and oil in the 150 miles and it does have good compression and good oil pressure. I have heard that all MGs “rattle.” Do you think they got the adjustment wrong or do you think the rockers are just too worn to adjust? Or is it true that rattling is normal?

Well, the engine shouldn't rattle at all, of course, but many do. Some have what appears to be a gearbox rattle, evidenced at full throttle -- a noise transmitted through the gear lever remote control housing. Then, there is the rattle from low octance. And worst, there is the rattle from faulty rod bearings. Are you keeping a solid 60# of oil pressure on the road? Let me know!



John


BrakesBrake Line John,
I have a question for you. I have a friend of mine that owns a TD.
On the front brake where the brake line runs from one cylinder to the
next, the line split. I replaced the line. On the replacement line I
double flared the steel line. The old line that came out had a bell type
flare. It is working fine now but, I am concerned this may cause a
problem in the future. Any thoughts or suggestions?

Thanks,
Larry
Larry!

You are describing the double flare and the bubble flare. Both of
these flares allow a double thickness of steel tubing between the nut and
the seat. In comparison, a single flare has only one thickness of tube
between the gland nut and the seat. Double and bubble flares are
interchangeable except that only double flares are used on the male ends of
later style brake hoses (front MGA, MGB, rear MGB). The creation of the
double flare requires a bubble flare as the first step.

Hope this helps!

John
BrakesSqueaky BrakesMr. Twist

1. What are squeaky brakes a sign of in a TD?

The brakes stop the car great. There are no signs of fluid leakage. And it doesn't happen all the time. But there's definitely a "sometimes" squeak in the right front as you come to a complete stop. It seems loudest on hot, dry days.

The brakes were off and adjusted by a shop last spring and they said they were good at that time. That was 5500 miles ago.

2. Thanks. I think you hit it on the head. I do hear it on hot days.

Oh yeh, how do you get those drums off? I tried that once and gave up. Is it different than an old American car? I know that I watched Greg do it at the seminar and he had it off in no time, but I couldn't figure it out.

Also, I need to do brakes for a friend who has a TD with wires. Is that a lot different?

John
John!

1. In disc brakes, the squeal is caused by a glazing of the pad and rotor. I suspect the same is true here. It's usually caused by light use and is worse when the temperatures are hot!

Fix this by removing the drum (not so easy on a TD!), sanding the inside drum surface with 80 or 100 grit sandpaper to remove the glaze, and then sanding the shoes to get the glaze off them, too.


2. Remove the dust cap, remove the nut (the RH side of the car has a RH thread; the LH side of the car has a LH thread -- they tighten in the direction of wheel rotation.

Back off the brakes ALL the way.

Use a "puller" on the three studs and place the screw against the stub axle.


John
BrakesRebuilding MC for Midget As I am rebuilding the brake master cylinder on my 74 Midget -a new one
costs over $200 and a rebuild kit is $20- I find I cannot remove the snap
ring holding the piston due to how far it is in the cylinder and any
normal pair of pliers do not have tips long enough to reach it. According
to the workshop manual there is a specific tool #18G1112 to reach this
clip. Do you have any idea where I might find one of these?

Thank you for your time,
Paul
Paul!

You are attempting one of the most difficult rebuilds! Make
certain that you do not scratch the bore or the piston. Cleanliness and
polish is CRITICAL.

Purchase two metalworking layout scribes (we call them 'dentist
tools" in my shop). With your associate training a light down the bore,
work the ears of that internal snap ring inwards and bring the ring up and
out . With this method, it truly easy!

You'll have more difficulty removing the pin which locks the two
pistons together. Fashion a simple holder from some wood -- and DON'T lose
the pin!

Good luck!

John

BrakesMG Brake Rebuild GuideJohn,

1. Must be the hoses. I backed the brake switch/adjustment screw all the way
off and still had problems. I even when as far as removing the brake presure
warning housing (5 port brass setup) and cleaned it. Strange that there
wasn't any issues before the MC rebuild and brake bleed. I guess too much
brakes is better than no brakes.

Thank you John. I'll get those flex lines replaced. Would rerecommend doing
all 4, front and back?

Another question, suspension. I have the rear shock conversion setup. The
car doesn't ride very stiff and so I was looking into getting new leaf
springs for the rear, but I'm not sure what to do for the front. Is it true
that I can had a heavier weight oil to the front shocks to stiffen up the
ride? Or do I need to look into new stiffer front coils? for a 74 RWA, what
leaf springs would you recommend?


2. Thank you, this definetly helps. If I can pickup some rear lever shocks for
a decent price, I'll get rid of the tubes. The tubes were on the car when I
bought it. After looking at the car I think the ride higth is good and it
looks level. I want to try the heavier oil in the front levers. For the
life of me, after looking at the setup, I cannot figure out how to
add/remove the oil? I have the shop manuals, but I cannot find anything
walking me through changing the oil on them. What is the correct method?

Richard

Richard!

1. Use factory hoses unless you opt for those stainless steel lines.
The stainless lines flex less and make the pedal harder than it was
originally. I don't know the price difference.

On your suspension. The springs control the ride height. The
shocks control the compression and rebound speed.

Look at your Midget from the side. Do the wheel arches run
concentric to the wheels? If so you have no spring problems. Or, measure
from the ground, through the center of the wheel, to the bottom of the wheel
arch. All four corners should be the same. Normally, the leaf spring on
the driver's side collapses first. This causes the car to pivot on a line
from the driver's front wheel and the passenger rear wheel. This causes the
passenger front to rise.

If the car sits horizontally, DO NOT change the springs! On top of
that, the supply of springs right now is of erratic quality - so your
original springs are the better springs.

I am no fan of replacement, add on, tube type shocks. Those lever
shocks work just fine. If you want to stiffen their action you can purchase
valves (very expensive), or you can drain them and refill them with heavier
oil. We use a 50 weight hydraulic oil with a seal sweller and an anti
foaming agent. As long as the shock is not faulty (failed seals or sloppy
axle), then this stiffer fluid trick is the nuts.

Put those tube shocks on eBay and use the money for something
worthwhile!


2. Changing oil the in the shock requires that you remove it from the
vehicle. Then, remove the main valve -- be careful, there are a couple of
springs. Then, remove the backing plate (eight screws). Do NOT tear the
gasket! Use a gasket scraper, putty knife, something, to lift the gasket
from the body or the plate -- but don't tear it!

I usually flush out the unit with some carb cleaner or mineral
spirits. Then, fill the reservoir and replace the plate. Place the unit in
your vise with the hole for the valve upright. Drool oil into the valve and
piston assy while stroking the arms SLOWLY! Moving the arms too quickly
will aereate the fluid. Overfill and screw the valve back in.

Done.

Hope this helps.

John

Brakes John,

I talked with you two days ago about my 79B master brake cylinder and the repair kits. Just as you said I did have an 'O' ring stuck in the cylinder by the pressure differential unit. When that 'o'ring came out a plastic sleeve also came out. Where on the pressure
differential unit does the plastic sleeve go in regards to that 'O' ring that I had to hook out.

Question 2: Is there a brass washer needed when refitting the pressure warning switch to the break cylinder? None came in the repair kit or with the new warning switch.

Questrion 3: After putting the unit back on the car and hooking up all the brake lines when we go to bleeding the lines brake fluid drips from the pressure warning switch.

What am I doing wrong?


Bob


Bob!

The warning light switch is not designed to hold back brake fluid pressure. If there is a problem with that shuttle valve, fluid will drip out of the switch.

There are two types of shuttle valves. Each requires a different diameter O ring. Either you fitted the wrong O rings - or - you sheared or cut one of the O rings on re-installation. You will need only to remove the master
cylinder, remove the shuttle valve, and carefully examine the O rings. Study, too, the diagram that came with the master cylinder kit.

After you have fitted the correct O rings, or, after you have purchased new O rings to replace the sheared one(s), refit the master cylinder, bleed it, and THEN fit the brake warning light switch.

Care, cleanliness, patience, and assembly lube (we use Sli-glide from NAPA) are all important when rebuilding this master cylinder.

Hope this helps!

John
BrakesBrake Master Cylinder OverhaulJohn,

I talked with you two days ago about my 79B master brake cylinder and the repair kits. Just as you said I did have an 'O' ring stuck in the cylinder by the pressure differential unit. When that "o'ring came out a plastic sleeve also came out. Where on the pressure differential unit does the plastic sleeve go in regards to that 'O' ring that I had to hook out.

Question 2: Is there a brass washer needed when refitting the pressure warning switch to the break cylinder? None came in the repair kit or with the new warning switch.

Questrion 3: After putting the unit back on the car and hooking up all the brake lines when we go to bleeding the lines brake fluid drips from the pressure warning switch.

What am I doing wrong?


Bob
Bob!

The warning light switch is not designed to hold back brake fluid pressure. If there is a problem with that shuttle valve, fluid will drip out of the switch.

There are two types of shuttle valves. Each requires a different diameter O ring. Either you fitted the wrong O rings - or - you sheared or cut one of the O rings on re-installation. You will need only to remove the master
cylinder, remove the shuttle valve, and carefully examine the O rings. Study, too, the diagram that came with the master cylinder kit.

After you have fitted the correct O rings, or, after you have purchased new O rings to replace the sheared one(s), refit the master cylinder, bleed it, and THEN fit the brake warning light switch.

Care, cleanliness, patience, and assembly lube (we use Sli-glide from NAPA)are all important when rebuilding this master cylinder.

Hope this helps!

John
BrakesLeaky Master CylinderJohn:

I have replaced the pipe and hose connecting the clutch master cylinder and the slave cylinder on my chrome bumper 1974 MGB. However, not all of the air can be bled out of the clutch hydraulics. I have found brake fluid leaking where the pipe attaches to the clutch master cylinder.

I've removed and reattached the pipe at the master cylinder several times. The threads appear to be fine. I can tighten the securing nut down to the point where there is not any play between the pipe and the fitting inside the clutch master cylinder. Applying a non-hardening thread sealer to the threads has not stemmed the flow of fluid where the pipe threads enter the clutch master cylinder body. I'm concerned about stripping the threads because of the amount of torque needed to tighten the securing nut. The pipe was purchased from one of the major MGB parts suppliers.

I believe the master cylinder's internals to be ok. I started this project upon finding a leaky clutch hose. While removing the old hose, the clutch pipe broke where it attaches with the hose. The new hose is not leaking at
either of its attachment points.

Any advice would be much appreciated.

Thank you.

Sincerely,

George
George!

The banjo fitting at the rear of the clutch master cylinder is sandwiched between two copper washers. Ensure those are there. The steel line should fit snugly into the banjo fitting. Here's what to do first.

Loosen the steel line from the banjo fitting. Working through the hole in the firewall may be an access -- working behind the master cylinder may be another. Use a 7/16" line wrench. Then, loosen the banjo bolt. Back off the bolt to make certain the two washers are there. Now, retighten the fitting -- don't strip it out (as you have cautioned yourself) but get it REALLY tight! Then, tighten the steel line. If this fails, there must be a problem with the steel line, or there's dirt or something where the steel line is fitted into the banjo fitting.

Hope this helps.

John
BrakesBrake Master Cylinder ConversionJohn

I have a 1967 MGB-GT that I am restoring. The question I have is -- should I, or would you recommend that I change from a Single Line Brake Master Cylinder to a Dual Line MC (without servo). The installed MC is a single line unit but needs replacing (tin can rusty and leaking as well as rusty internals). I will also be replacing the rear wheel cylinders as well as the front calipers. I know new/extra brake lines will be needed as well as a pressure valve assembly. I guess I'm thinking of the safety side of things - If I lose fluid from one side I would have at least one half of the braking system to stop me. I saw several early MGBs that had converted to dual lines at MG2006. I looks pretty straight forward to make this change. I guess also I would need to change the brake light switch from the 4-way union to the pedal box - is this correct?

Thanks

Kent

Kent!

The prospect of losing ones brakes is horrific indeed, but I can tell you from 35 years experience driving and servicing MGs, that this hardly ever occurs. And, nearly always, it's easy to detect a problem with the brakes before a full failure. So, from my vantage, changing to a dual circuit system is not necessary. I have driven my 1962 MGA since 1976 and have never experienced a brake failure. That's not to say that a couple of times the brakes have felt pretty bad -- but they've never "gone out."

If you were to change, you'll need to move the wiring for the brake lights up to the pedal box. Simply salvage the pieces you need from a new model MGB.

Hope this helps!
BrakesBrake Fluid and BleedingJohn:

I read in the last MGBD about the problem with the clutch hydraulic system. The one question that you didn’t answer was the bleeding problem with that system. My wife had threatened me, and derided my mechanical ability, because of the bleeding system I was using kept
her pumping the clutch pedal for long periods of time. I finally found that if you take the slave cylinder off, it was usually off anyway for repair, blow the piston to the full out position, and fill it with fluid. Then, making sure the master cylinder reservoir is drained of most of the fluid, the slave cylinder still loose from the
engine is attached to the fluid line. Now, holding the cylinder so that the port is up, force the piston fully in. There is enough fluid in the slave cylinder to fill the line, and flush any air into the master cylinder, and up and out the way air wants to go.

After fighting the leaks with silicone brake fluid, I have now changed to Valvoline full synthetic brake fluid which seems to be avery good alternative. Also, NAPA now carries a very good brake and caliper grease, “Stay Lube Synthetic Brake and Caliper Grease”. It is compatible with all paints and rubbers, and has a good tack to
stay in place and not bleed. So far, seems to work well keeping moisture out of the aluminum T brake cylinders.

Dan

Dan,

Thanks for the note and the updates about the synthetic fluid.

When I'm bleeding a clutch, I use the following technique:

Remove the bleeder and use your finger;
finger off, pedal down
finger on, pedal up
wait twenty seconds -- during this time the vacuum in the mc bore draws fluids from the reservoir
finger off, pedal down
finger on, pedal up
wait twenty seconds .....

Continue this way for four to six bleeds, then when a gurgle of fluid bursts from the bleeder hole, refit the bleeder and use that instead of your finger.

This technique is quick and has served me well for 25+ years!

John
BrakesPressure SwitchJohn,
Now my question, do you see a problem if I leave out the pressure switch on the dual pressure valve distribution block? Just put a short bolt in instead? The 'push to test' switch on the dash has failed and is useless at best. I am upgrading the braking system on a resurrected '65 B and plan to use the newer master cylinder. OH, I an grafting on the front end from a '71 and it has the mounting hole for the distribution block on the left fender, so it will be easy
to install the newer system.
Thanks, John

Geoff
Geoff!

A short bolt,. 3/8-24 x 1/2" will be just fine. The shuttle valve will not leak switch in or out, as there are O rings on the piston within. Yet, to prevent any failure, that bolt will do the trick.

John
BrakesFaulty BrakesDear John,


I am renewing my brakes on my 1969 MGB Roadster MarkII , which I have owned since new.
I sent the the brake master cylinder to White Post restorations for rebuilding and when returned , I installed the unit bled the brakes , but would not hold pressure. I sent it back, they renewed again. I installed again. Still no luck. I bought a completely new master brake cylinder from Victoria British, installed it. Same problem , brake pedal goes to floor, ( will not hold pressure?). The only thing that is left to be renewed is pressure valve assembly. this is the dual line system. the pressure valve assembly looks like a brake line union mounted to the inside front fender.

Could this be not functioning properly and therefore not holding pressure, i.e.. firm pedal feel. I bled the brake lines as the MGB shop manual describes, so I do not think it is air in the brake lines. And I have NO leaks of brake fluid.


Thanking you for your reply to my question.


Help!

Best regards Barry
Dear Barry,

I cannot believe that two master cylinders are faulty, so the
question is: What's wrong with the brakes.

Let me go through some of the common faults:

If the rear cylinders leak, they're faulty. If the rear cylinders
are faulty, they leak. If they do not leak, they're OK.

If the brake warning light block, the shuttle valve, leaks, it's
bad. If it doesn't leak, it's OK.

The front calipers must be installed with the bleeders UP so that
all the air is expelled when bleeding. This may be your problem. Again, if
the calipers leak, they're faulty; if they do not leak, they're good
(unless, of course, they're frozen, but that's yet another problem).

Bleed the rear cylinders first -- the one farthest away from the MC
first (the left one). Once you've expelled the air, then adjust up the rear
brakes. Then, bleed the fronts.

Give me a call! In any case, perhaps you do need a new brake
warning light assy, but unless it's leaking, you do not.

Hope this helps!

John
BrakesSquealing Disc BrakesGood Day John,
I spoke with you 2-3 weeks ago about squaling rear brakes and you suggested that the noise was probably coming from the front disc brakes. The noise could be eliminated by taping duct tape to the back side of the pads which I did. Unfortunately the squeal was not totally eliminated although the squal was less pronounced. I should add that the noise was gone when the brakes were hot.

Not completely satisfied with this fix, I found a Permatex product that claimed to eliminate disc brake squeal. Called "Ultra Disc Brake Lube" it is a synthetic lubricant used to lubricate pins, slides, bushings, pistons, rubber sleeves and seals. ALSO PREVENTS DISC SQUEAL. At $1.49 a package, I gave it a try and so far, it is working well.

I thought I would pass this information on. Thanks for your help and advice. It is always well received.

Best Regards
Ron
Ron,

Thanks so much for the heads up. We had a TR6 in here a couple of weeks ago that gave a headache when you drove it (or rather, when you stopped it) because it squealed so badly. One of my guys, as it turns out, had some product as you've described and placed multiple layers on the back of the pads, curing it with the propane torch between applications. But, in the end it did work.

Thanks so much for getting back with me!

John
BrakesBrake Detection SwitchJohn,

1969 MGB

Brake detection switch leak problem:
Break fluid is leaking out of the brake detection switch by the wires,
(not at the threads) of the 5-way union/pressure valve assembly. My
question is can just the switch be replaced, the union/assembly or does
the whole union/assembly and switch need to be replaced.

Thank you.

Keith
Keith,

The brake warning light valve body is the problem. There are two
little O rings in there, one or both of which are leaking. You have three
solutions:

Remove the switch and replace the switch with a very short 3/8-24
bolt and copper washer so it will no longer leak. Of course, the brake
warning light will not work.

Remove the entire block, open it up and replace the O rings.

Purchase a rebuilt unit (we sell them for $70) and fit that.

Hope this helps!

John
BrakesMGC Brake BoosterI picked up a 69 MGC roadster last fall that had been stored for 5 years. I am gradually working toward having it back on the road. Right now I am trying to minimize expenses until I can actually drive it and completely evaluate it.

It has dual Girling brake boosters, both of which are leaking fluid into the vacuum chamber. I have been told that the Girling boosters are bad and I should switch to Lockheed. I've also seen a C converted to a single booster. What is your experience with the Girling boosters? Any other advice concerning these boosters?
There is nothing inherently wrong with the Girling boosters. The repair price, however, is a stunning $700 each, or so, from Whitepost Restorations, Whitepost, VA. The advantage of the Lockheed boosters is that they're "only" $500 or so. Now is it not necessary to have the boosters rebuilt by Whitepost if the bores are OK and don't need sleeving -- but to find out you've got to disassemble them -- and find the repair kits.

You can fit a complete pedal box assy from a 1975 - 1980 MGB into the MGC as the bore diameter of the master cylinder is smaller than the original MGC cylinder, therefore reducing pedal effort. However, with this arrangement, you cannot fit the factory original air cleaners.
BrakesMGB Faulty BrakesI am renewing my brakes on my 1969 MGB Roadster MarkII , which I have
owned
since new.

I sent the the brake master cylinder to White Post restorations for
rebuilding and when returned , I installed the unit bled the brakes ,
but
would not hold pressure. I sent it back, they renewed again. I installed
again. Still no luck. I bought a completely new master brake cylinder
from
Victoria British, installed it. Same problem , brake pedal goes to
floor,
( will not hold pressure?).

The only thing that is left to be renewed is pressure valve assembly.
this
is the dual line system. the pressure valve assembly looks like a brake
line
union mounted to the inside front fender.

Could this be not functioning properly and therefore not holding
pressure,
i.e.. firm pedal feel. I bled the brake lines as the MGB shop manual
describes, so I do not think it is air in the brake lines. And I have NO
leaks of brake fluid.
I cannot believe that two master cylinders are faulty, so the
question is: What's wrong with the brakes.

Let me go through some of the common faults:

If the rear cylinders leak, they're faulty. If the rear cylinders
are faulty, they leak. If they do not leak, they're OK.

If the brake warning light block, the shuttle valve, leaks, it's
bad. If it doesn't leak, it's OK.

The front calipers must be installed with the bleeders UP so that
all the air is expelled when bleeding. This may be your problem. Again,
if
the calipers leak, they're faulty; if they do not leak, they're good
(unless, of course, they're frozen, but that's yet another problem).

Bleed the rear cylinders first -- the one farthest away from the MC
first (the left one). Once you've expelled the air, then adjust up the
rear
brakes. Then, bleed the fronts.

Give me a call! In any case, perhaps you do need a new brake
warning light assy, but unless it's leaking, you do not.
BrakesBleeding The BrakesHope you had a nice holiday. Got my car home this weekend. The brake and clutch pedals went right to the floor and didn’t come back any to quick. Topped off the fluid (the master was dry), opened the bleeder on the clutch slave and had my daughter pump the hell out of the clutch. All I got was some fluid running out of the bleeder but no fluid moving out of the master. The pumping of the clutch didn’t have any effect on how quickly the fluid moved out of the slave.



Is this an obvious master cylinder rebuild? If so, I may give it a try myself but its nice to know I have you as a backup. Approx. cost for you to rebuild?

After 15 years of storage the best best is to rebuild the master cylinder -- that's for sure. But the bleeding technique is important, too. Follow these steps.

Fill the master cylinder
Remove the bleeder from the slave
Depress the clutch pedal
Place index finger on bleeder hole
Foot off the pedal
Wait twenty seconds
Finger off
pedal down
finger on
pedal up
wait twenty seconds
and continue this repeat until you have a good burst of fluid -- usually about five strokes.
THEN
fit the bleeder and bleed several more times, cracking the bleeder loose instead of using your finger.

BrakesBrake FluidI know you have had this questions before many times! I have
a 1979 MGB, what type of brake fluid do i use, will CASTROL LMA
DOT 4 work???? and what type of rubber dose the 1979 mgb use in
the brake system
The Castrol LMA is the PERFECT brake fluid for your car. I don't
know what type of rubber, Viton, neoprene, or whatever is in those
cylinders. I do know that silicone fluids can cause those pieces to swell.
But the DOT 4 Castrol is the good fluid!
BrakesBrake Light SwitchI have just purchased a B manufactured 11.74
The brake lights are inoperative but do not need
relamping. I have read all the posts regarding switch
position and pedal free play but nothing in there (or
any other manual that I have) about replacing the
switch itself.
I am guessing the seat needs to be removed so you can
squirm in under the dash but is there anything else
that needs attention? Is there a hydraulic line
connected there that could possibly leak?
Are you in for a treat or what!! The brake light switch is located on
the cover of the brake master cylinder box, under the bonnet, right in front
of both master cylinders. You'll need a 9/16" wrench to loosen the jam nut.
Use a small amount of grease to lubricate the threads on the new switch, fit
the jam nut, and screw the switch into the hole until you achieve that 1/2"
of freeplay.

BUT -- just before you do this, disconnect the switch from the wiring
loom and connect the two loom wires together (GREEN and GREEN/BLACK). Turn
on the ignition and the brake lights should be shining brightly. If not,
you've got another problem.
BrakesRear Brake DragPlease assist with the following problem I have on my 1971 MGB.

Car has just been totally rebuilt from ground up, it has been sitting for
2 or 3
months.

Finally I go for a drive only about 8 to 10 miles and when I get back the
rear end
feel like it is on fire, the heat coming through to the wheels seems
excessive.

I have had the diff totally re-built and the rear brakes.

Seems the brakes might be sticking, please let me know if you think this
might be
the problem and how to fix, the hubs were so hot you could not touch them.
It is not uncommon, after a brake job, for the rear brakes to drag.
Here are some things you can do:

1) Exercise the handbrake cable -- find two buddies to help you
out. Slacken the handbrake adjusting nut to the end of the threads (under
the handbrake handle). Disconnect the handbrake cable from the left hand
(nearside) brake lever and grasp the fork with a pair of vise-grips. One
person is inside the car to pull the handle up; one person is at the left
rear, vise-grips in hand to pull the cable off; and the third is working the
grease gun, pumping grease into the cable as the other two move the cable in
and out about 100 times. At the end of this exercise, the cable should be
really free.

2) Adjust up the brakes, using a 1/4" square socket. First, back
the adjusters all the way out (towards the center of the car), then grease
the threads, then run the adjusters in as far as you can turn them
(obviously, don't get then so tight that you break them off!), then back
them off, quarter turn by quarter turn until the drum "just" runs free.
When the brakes are all bedded in, the distance between fully locked and
fully free should be 1/4 turn -- in practice it's usually two or three.

3) Then, adjust up the handbrake so that the handle is at a
comfortable height for you when it's fully tight. The workshop manual calls
for two or three clicks -- which is fine for you RHD guys, but waaay too low
for LHD.

4) Of course, there's always the chance that your rear brake lines
(the steel ones) are crushed and while you can get fluid into the cylinders,
the spring tension cannot get the fluid back into the master cylinder. Feel
the lines to make sure they're not crushed. Also, the flex lines go bad
after 15-20 years. Lastly, make sure that the brake light switch is
adjusted so that you have a full 1/2" of pedal freeplay (or the brakes will
be on all the time).
BrakesBrake Line CleaningI have following question, the previous owner of my 1971 MGB roadster painted the engine bay however he also painted the brake lines ( white ). How would you recommend to remove this from the brake lines? Without damaging the lines.
You have two options: 1) replace the lines; 2) clean the lines. I would choose to clean the lines as it's easier. The fittings on the ends are 7/16"AF and the lines are British/USA thread 3/8-24. Remove each line and clean them with either steel wool and/or medium grit sandpaper (I'd start with 180 grit and then go finer). To keep them from rusting, clear coat them with a clear enamel. Use a "touch" (difficult to convert this to metric!) of grease on the threads to ease re-assembly, but not so much as to contaminate the brake fluid.

You know that brake fluid removes paint more quickly than nearly any fluid, so pump the system dry before disassembling.
BrakesBrake Cylinder Sleeving and Brake Fluids A customer recently pointed out to me an entry in your Q & A Database
on which I'd like to offer a few comments. I'll paste it below for
your quick reference. I think you are aware that I have been
installing brass sleeves in brake cylinders for many years. I lay
not-so-modest claim to considerable expertise in the field.

I can think of no mechanical basis for a claim that brass sleeves leak
fluid, silicone or glycol, due to being too soft. Many Little British
cars, and others, use aluminum alloy cylinders that are softer than
the tempered brass normally used in sleeving. If softness caused
leaking, they all would leak.

Assuming correct assembly and smooth bores of proper size, any leaks
in sleeved cylinders, no matter whether with brass, stainless steel or
even aluminum, are due to incorrect installation of the sleeves. There
are many small shops which do sleeving locally, and whose operators
may or may not have any idea what they are doing. There are two such
shops close to me in northern California, and I have re-done a number
of their jobs due to leaking. I've also re-done a number of jobs done
by my chief competitor in Virginia. The failure rate of my own
sleeving work is almost zero, whether filled with silicone or glycol
fluid. Silicone is, as you say, far more prone to find an escape
route, but that route is most likely to be at line connections rather
than within the cylinder.

I agree with your comment that "the ONLY advantage to silicone fluid
is that it does not eat paint." It has a number of disadvantages, and
I never recommend it.
You'll remember that I sent quite a number of cores to your for
sleeving a year or so ago. I do appreciate you comments about the sleeving
and will include them in the technical database.

But, speaking of sleeving and your major competitor, give me some
clue about your prices. The cylinders we have done are the T type, single
bore; the MGA dual bore; the MGB tandem (two different bore sizes); and,
rarely, wheel cylinders.
BrakesTrouble Bleeding BrakesI am rebuilding the tandem cylinder on the MG but cannot get the brakes
to bleed correctly. (The clutch slave cylinder bleeds just fine.)
Looking at the flat, circle end of the plastic valve on the return
spring, I see a tiny groove above the horseshoe-shaped inner design.
Do the opening of the horseshoe and the groove have to be positioned a
certain way (up, straight down, etc) as I put the cylinder back
together?
John
says that if you are using silicone fluid the pedal feels funny. If you
are using real brake fluid it could be in your pedal freeplay
BrakesMGB Brake Pressure SwitchI found your You Tube video on the MGB Brake Pressure Switch useful in diagnosing the problem with my 73 MGB. My light works but I have brake fluid leaking from the center of the white plastic brake pressure switch you showed. I believe that my shuttle valve needs to be rebuilt.

I presume to get the shuttle valve out I remove the 5 brake line connectors and then the large nut/cover to get at the valve. Then replace the O-rings and put everything back together. Anything special about the O-rings or are they a standard part at NAPA? Any advice you can provide would be appreciated.
The brake failure switch is pretty easy to rebuild. The early ones used a lipped seal, but the later ones use O rings. They are simply fractional size O rings, but they must be compatible with brake fluid, of course. You can also simply fit a bolt into the switch hole (3/8-24) with a copper washer, and the valve will cease leaking externally. Of course, it's better to do the job right!
BrakesMGA Brake PressureI just changed all the brake cylinders and shoes in my 58 MGA. I have
bled over a quart of DOT3 (which it had before) through the system and
can find no bubbles on any of the brakes. I can pump up the brakes and
hold them, but after taking the pressure off, the brakes go right to
the floor. I am trying to get my car ready for the trip to Watkins
Glenn (Sept 8). The master cylinder is about 10 years old and was
working fine. I have been using an EZ-Bleed type system which seems
to work fine (but still work!).
Because you have a 1958, I will assume that it is a 1500, with drum
brakes in front and drum brakes in the rear.

Make certain that you have adjusted all six adjusters correctly:
Turn them until the wheel locks, then back off one click. Sometimes it is
difficult to control that "one click" in reverse. Gain mechanical advantage
by grasping the screwdriver with a wrench or vise-grips to give you more
control.

Make certain that the bleeder on the front brakes is at the front
cylinder and is pointed UP. Make sure that the cylinders on the front are
positioned so that the bottom shoe is pushed DOWN from the front cylinder.

If you are still experiencing problems, then squeeze each brake hose
in succession -- rear, left front, right front. After blocking off the
fluid from passing through (vise-grips, but not too tight!), judge the
change in the movement of the brake pedal. If all three hoses are crimped,
then the pedal should not move AT ALL!!!

If you rebuilt the master cylinder, make certain that the one way
valve is fitted to the rear of the brake cylinder bore, and not the clutch.

ClutchClutchIs there a any way to change a clutch in a 1969 Healey sprite without pulling the engineI'd like to tell you that there is an easier way, but there is not. Remove the bonnet, remove the radiator, and pull the engine. I would remove the gearbox at the same time. Change the oil seal at the back of the gearbox -- Oh, BTW, drain the gearbox before pulling or you'll end up in an oil swamp. Change all three clutch components -- pressure plate, disc, and release bearing -- plus, replace the release bearing fork bolt and bushing. You'll need a new exhaust gasket and this is a wonderful opportunity to change those lower radiator hoses. Plan to rebuild the clutch master cylinder and slave cylinders. You can rebuild the MC in place. Hope this helps.
ClutchClutch InstallationCan a clutch be replaced in an MGC-GT without removing the engine? thanks in advance for you reply It is possible to remove just the gearbox from an MGB if it's a standard box and not an overdrive. This is a very difficult job, but once learned it takes very much less time than pulling the engine. I cannot tell you if the same is true on an MGC. On the B, the cross member is removed, the remote control assy removed, and the gearbox is rotated -- moved back into the frame, then down and out. Are you a member of the MGC Register? Keith Sanders may know someone who knows far more about this than I do.
ClutchPricing, Stuck Clutch PlateHi John,

I met you when you looked at my Midget at a roving tech session at the 1999 MG Heartland in St. Joseph, MO. Could you either give me pricing advice on an MGC, or if you get this type of question too much, maybe refer me to a site that might have some information.

I'm interested in an MGC that I haven't looked at yet other than from a distance, but would like to get some guidelines before I go. He says it:

hasn't run in three years,
the clutch plate is stuck,
has some rust,
has hard top and multiple tonneau covers,
He wants to start around 3,000,
has owned it for 20 years.

Any advice would be appreciated.

Thank you. S.F., Sincerely, Jeff Storms

JEFF!

Make sure you go out and drive the car BEFORE you drive it! You know, you can free up that clutch plate by the following method: Start the engine and get the car warm. Point the MGC down the road or down the driveway, put it into second, turn the key and start it up. As you begin to drive down the road, hit the throttle and the clutch pedal at the same time. The clutch will probably break loose quickly -- but sometimes it takes a mile of driving like this. Obviously, the owner should do this! If he wants a quick verbal course, have him call during my technical hour (1-2pm EST Monday-Friday).

Just offhand, if the rust is not too great (around the doglegs...) AND the car runs and drives, then $3,000 sounds very fair.

I have cc'd Tom Boscarino and Keith Sanders. They know more about MGCs than all others combined.
ClutchMGA Conversion John, As you may recall I spoke to you on the telephone a few days ago about my MGA conversion problems. The ressure plate was rubbing on the bell housing. I have found out since there are two manufacturers for the pressure tes. The Borg&Beck is much smaller than the Quintel Hazell. wraping my pressure plate to a
Borg&Beck solved my problem. (Both also have the same part number.)
Thought you might be interested in this.
Adrian Haemmig

Adrian! Thank you very much for your information. I knew that I'd heard of this problem before, but couldn't remember what the problem was. I wonder about the Laycock unit -- not that I would use it. The University Motors shop rule is: Always use NEW BORG and BECK clutches. Thanks for letting me know!
SAFETY FAST!
ClutchClutchMr. Twist:
I currently have a 1980 MGB. When you press the clutch pedal....is it normal for it to travel all the way to the floor before it will allow shifting? The car will not shift when on a hill ( after stopping)....it seem the clutch is not disengaging (gears grind). Is this because the linkage is weak? The brake pressure is too weak .....wonder if these problems are related. Other than the hill problem....it runs fine except I don't think I should have to press the pedal all the way to the floor to shift.
John Griffen

I believe the problem you have is simply a failure to disengage. Most often, a rebuild of the clutch hydraulics will solve this problem. Rebuild the master cylinder in place (it's not necessary to remove it from the car)
and DO NOT HONE the cylinder. Rebuild the slave cylinder while either hanging from the clutch slave hose or on the bench -- you may hone this cylinder. Use Lockheed original parts. Bleed the system in the following manner: Remove the bleeder screw and use your finger for the first five
bleeds: Finger off, pedal down, finger on, pedal up, wait TWENTY SECONDS, repeat. After those first five bleeds, replace the bleeder screw and bleed without waiting the twenty seconds. It is strange that this problem is
more evident on a hill and for that I do not have a handy answer -- but try the hyrdraulics.
ClutchClutchJohn,

I thought you might like some feedback concerning a problem I
described to
you in a phone conversation last month. To recap, I was having problems
obtaining proper operation of the clutch hydraulic circuit. I had
installed a
new clutch assembly, new master cylinder, and new slave cylinder. I
initially
bled the system using an EZBLEED system, then followed with the procedure
recommended in your tech manual. I still was not able to obtain what I
considered to be an acceptably firm clutch pedal.

Upon inspection of the new Lockheed slave cylinder, I noticed that
the
bleed screw was located on the bottom half of the unit. I expected to see
the
bleed screw near the top of the slave cylinder, as it was on my previous
Lockheed slave cylinder. I un-bolted the slave cylinder so that it could
be bled
with the bleed screw in the top position. After bleeding in this manner,
my
clutch hydraulics now seem to be performing properly with about 3/8"
pushrod
travel.

A call to Moss Motors revealed that I should have removed the bleed
screw
in the new slave cylinder from its connection and relocated to the
alternate
threaded opening in the slave cylinder before installation. I had
incorrectly
assumed that it was set up properly from the factory. I'll definitely
remember
to check this next time.

John McCarthy

JOHN!

We just had the same thing happen in the shop (although it was a
TR6). One of the guys was bleeding and bleeding but the pedal never seemed
quite right. I yelled from across the shop floor, "Is the bleeder on the
top or the bottom?" He responded that the bleeder was on the bottom ("but
it came in that way, Boss"). He switched it and two bleeds later the clutch
worked like new! In some of the most bizarre cases, we've dropped the
cylinder AWAY from the gearbox, bled it, and re-installed!

So, you're not alone!
Clutch1960 MGAHello John

I have rebuilt the engine of my 1960 MGA. In the
process I replaced the clutch plate, release bearing,
and front and rear transmission seals. The flywheel
was also refaced.
I installed the engine and transmission and the engine
runs perfectly, but the transmission jams so I can't
shift. When the motor is shut off the stickshift will
go into all gears. When the motor is running the only
gear I can shift into is 2nd, and then there's a
rumbling sound from the transmission. The other gears
grind if I try to shift. I think the clutch is
engaging properly because the pushrod at the clutch
slave extends and the motor rpm's drop about 100rpm
when the clutch pedal is depressed. If the motor is
shut off and the shifter is put into 1st gear, and the
motor is restarted with the clutch depressed, a
rumbling sound is heard from the transmission but it
won't shift out of 1st gear.
Can any adjustments be made without having to pull the
engine and transmission out again? It's a big pain in
the butt reinstalling the transmission.
Is it possible to remove the plate on the side of the
transmission and make adjustments if possible.
Cold weather has come and it's difficult to pull the
car outside to remove the engine/transmission.
Any advice would be greatly appreciated.
Thank you.

Bob!
Judging from your descriptions, you've still got the car on
jackstands. Put it on the ground and go out and drive it around the block a
couple of times. Depress the clutch frequently, just to exercise the
pressure plate, disc, and hydraulics. Sometimes, at the point of
installation, there is a burr, high spot, wave, something, on the clutch
disc that does not allow the clutch to disengage. You may have to pull the
engine again -- but don't do it until you've given the MGA a field test!

The clutch slave rod should move 3/8" to achieve disengagement (I
know it looks like one inch, but it's NOT).

Hope this helps!

John
ClutchWorking on Clutch Freeplay at the Master CylinderHi John:

I believe we have our virus/worm problem worked out and you should receive this "clean." This is just a re-transmission of the last e-mail which your server rejected.

Thanks for the follow-up. I haven't done anything yet (except for replacing my 20 year old SU pump!). What's your opinion on working on the clutch freeplay at the master cylinder (my last question to you)? I will probably write a letter to the shop owner, referencing your and Mike Ash's theories, and see what he says. Since any proper fix will probably require removal of the engine/transmission, my guess is that he won't be interested in fixing the problem.

Is it likely that sleeving the master cylinder now would cure the problem? I have no loss of fluid and braking action is fine. Thanks again.

Frank Lindauer

Frank!

What did you ever find out about that clutch?

John
Hi John:

Thanks for your continued interest in my clutch problem. My mechanic checked freeplay at the slave cylinder and at the master cylinder, taking out any he considered excess. He also replaced a clevis pin with slight wear at the mcylinder push rod. The improvement is slight, but not complete. He emphasized that moving the shifter into first gear must be done slowly and deliberately (which I do anyway), but there is still often a slight "crunch."

Maybe I'm expecting too much. You have recommended all along rebuilding the master cylinder. If some fluid is getting past the seals, resulting in less pressure, I guess, wouldn't there be signs of leakage at the external dust cover? There is none.

Frank Lindauer

Frank! You can take all of the freeplay out, with the exception of the last little "tunk," which translates to about 1/2" at the pedal. Hope your guy can get it right!

John

Hi John:

This seems like a never-ending story! I wrote a nice, polite letter to the mechanic citing your and Mike Ash's theories. He has agreed to take another look at the car to see if he can take out some extra free play in the linkages. But that scares me a bit as I know that if you take out enough free play you can eliminate the problem.

Up to a point, what is the danger of taking out freeplay at the master cylinder operating rod? I will also suggest rebuilding the master cylinder and see what he thinks about that. Thanks again for your interest.

Frank
ClutchMGB Pilot (spigot) bushingDear John,

When removing the clutch from my 1972 MGB, the pilot bush just fell out
of the end of the crank.

Is this supposed to happen? Should the bush (1" long) be replaced? Can
a new one be installed via careful tapping with a drift, or need it be a
pressed-on job?

Gearbox History: Engine and gearbox were removed so I can install a
rebuilt OD gearbox in place of the non-OD box. New clutch, release
bearing, fork bolt and bushing are included in my plans. I'd driven over
the past 20 years with the old box, putting up with no 3rd-gear synchro
when following an 80-mile cruise, the old box locked up suddenly in
traffic at about 30 mph. After a couple of hours, I was able to move
clutch & gears to get the "B" on a trailer to return home. Everything
worked, just not well. With engine idling in Neutral (and clutch pedal
up) there was a scraping noise like a bad release bearing. Noise went
away by pushing clutch pedal in. The clutch would engage in gear, but I
wouldn't trust it too far.

Hope this info helps. Can't wait for your knowledgeable response.

Thanks very much, Greg Soulsby



Greg!

The spigot bush or pilot bushing should be pressed TIGHTLY into the
rear of the crankshaft. Sometimes the crank appears slightly oversize, or,
more likely, the spigot bush slightly undersize. Fit a new bushing and use
a bit of Locktite bearing locker to glue it into place. Drive the bushing
in with a socket -- but BE CAREFUL as any lip on the inside diameter will
interfere with the free movement of the first motion shaft and cause it to
SQUEAL when it's cold!

My guess is that your MGB gearbox ran low on oil and the layshaft /
laygear bearings are galled or broken up. When you have the clutch pedal
released, several parts of the gearbox are turning -- the first motion
shaft, the laygear, and the three speed gears. The reason your box is noisy
is because bearings or bushings have failed -- and they're turning in
neutral. When you press on the clutch the gearbox comes to a stop -- hence
the noise disappears.

Hope this helps.

John
ClutchCost of New Clutch
John,
Thanks for taking the time to answer my question. John what would I be
looking at cost wise to have you rebuild the master and slave cylinder?
What is the cost of having a new clutch put in? Thanks again
A new clutch, hydraulics included, is about $700. The hydraulics alone are
about $125 or so. John

ClutchClutch for 71BI have a MGB '71 with the 1800 engine. If at all possible, I need to know how to find out the number of splines on the clutch. It is very oil soaked and needs replaced. I would like to keep driving until I get all the parts so I don't want to take it apart until then. Thanks PatPat!

Most likely you have a standard MGB clutch. Purchase ONLY a FACTORY NEW, BORG & BECK clutch (sold by AP), from Moss or whomever. The clutch kit comes with three pieces: the clutch disc, the , pressure plate, and the release bearing. The clutch disc has 23 splines!

In addition, you'll want the release bearing fork bolt and bushing -- and you'll want to rebuild the clutch hydraulics (master, slave, and slave hose).

If, indeed, the disc is oil soaked, you'll want a rear seal and the associated gaskets.

Good luck!

John
ClutchMidget Clutch BleedI am in the process of rebuilding my clutch hydraulic system. Thus far I've replaced the master cylinder, pipe, hose and slave. After I bleed the system I get very movement at the slave, so little that the clutch does not disengage. Any thoughts on what the problem might be?

Rich!

The clutch pushrod should move about 3/8" which really isn't very much! Is it possible that the clutch disc has rusted against the flywheel -- how long has the car been sitting since you last drove it?

Sometimes you can get the system working simply by going out and driving it! Point the Midget down the driveway, start it in neutral to warm it up, then turn it off, shift into first or second, and start it in gear. Drive around the block, depressing the clutch and the throttle at the same time -- that will break the disc loose (if that's the problem). Just driving and exercising the clutch sometimes makes it all start working.

Let me know what you find!

John
ClutchCar SlipsJohn,
I could use some help. On my way to mg meet in new jersey I ran into a car
I was going about 20 MPR before accident, I was able to continue on, but
noticed that once in awhile something would slip. I could rev motor back
and forth between 2,000 and 2,500 rpm without changing speed of car.
The only time it seems to happen is in 3rd or 4th gear when not in overdrive.
I hit hard enough to have motor move forward about 1/4" I could sure use
some ideas, insurance person will be out soon and I don't know what to
tell the person is wrong.
Thanks
Rich
Rich!

The overdrive is damaged. Consider these expenses:

Remove and refit the engine and gearbox -- about 10 hours at $72/hour (UML shop rate), so there's $720. Any time the engine is out, you MUST change the clutch -- that's another $200.

Rebuild the overdrive only, for about 4 hours, or $288 plus whatever is the fault (I suspect the cone clutch (sliding member) which Moss sells for about $400) plus some gaskets and O rings for about $100.

That's 720 and 200 and 288 and 400 and 100 or about $1700.

Hope this helps.

John
ClutchClutch BleedHi John,
I’m a new MGB owner. It’s a 1978 with 49,000 on it. I cannot get the clutch to bleed – I replaced the bleeder valve, and yet the gears still grind (unless I pump the clutch several tiems when I first get in the vehicle. Doe that mean I need a new hydraulic system?
Thanks,

Greg



Greg!
Failure to disengage is caused by a failure of the clutch hydraulics or the clutch itself. 99% of the time it's the hydraulics.

There is the master cylinder. If it leaks, it's bad. If it's bad it may not leak externally (just internally). There is the slave cylinder. If it leaks, it's bad. If it's bad, it leaks. There is the clutch hose. If it's bad it swishes as the fluid tries to move through it's restricted inner diameter and the clutch is slow to respond.

You can rebuild the master cylinder in place. Don't hone the cylinder, just replace the parts.

You can rebuild the slave in place, but it's always best to replace the slave hose.

When you go to bleed the system do so like this:

Use your finger as the bleeder for the first 5-10 bleeds. Finger off, pedal down, finger on, pedal up WAIT TWENTY SECONDS. Finger off, pedal down, finger on, pedal up WAIT TWENTY SECONDS. I wrote that twice just to be emphatic. After you've bled the system about five times or so you'll get fluid -- not air. Replace the bleeder instead of placing you finger back on the bleeder. Now, open bleeder, pedal down, close bleeder, pedal up, wait five seconds. After another five time you will have expelled all the air from the system.

Hope all this helps!

John



ClutchScreeching ClutchHi John:

I found you on the web.

I just had a new clutch installed on a 1977 MGB. It chatters a little when I rest my foot on the pedal and makes and intermittent screeching noise. Any ideas?

Thanks,

Frank

Frank!

First, explain your problems to the person/firm who replaced the clutch and ask them to make the job right! You paid for it!

The clutch pedal trembles because the thrust plate on the pressure plate is not running true -- not running perpendicular to the first motion shaft -- it's wobbling. This evidences itself by the pulsing clutch pedal. Your mechanic should have replaced the clutch with a NEW Borg and Beck pressure plate, disc, and release bearing.

The screeching you hear needs more explanation -- but IF it occurs when the car is sitting still with the clutch depressed, especially when the car is cold, then the spigot bushing is lipped.

Let me know how this works out for you.

John
ClutchClutch FailureHi John,
I have a 67 MGBGT with overdrive. Ever since I bought the car a few years back, the shifting has been less than stellar, especially going up and down from and to 2nd gear (nothing unusual there).

Recently, I discovered the clutch master cylinder was leaking, so I replaced it. At the same time, I replaced the line running from master to slave cylinder, and, for good measure, replaced the slave cylinder. This improved clutch operation and shifting considerably. Until the other day when my son went to drive it and couldn’t engage any forward gears.

Even though the clutch pedal feels solid when depressed, the gears still grind when I try to engage them, as if the clutch itself were still engaged. I went under the car and watched as my son worked the clutch pedal, and the slave cylinder appeared to be moving the release arm fine.

I’m fairly certain the previous owner worked on the clutch himself, which makes me think this could be a source of the problem (he did some front end work, and put the hubs back on the wrong sides. Didn’t notice this, and had a wheel come off. No major damage or injuries, thank goodness).

If the hydraulics appear to be working fine, is it likely that something has gone amiss with the clutch assembly?
Thanks very much for your time.

Kendall
Kendall!

A failure to disengage the clutch can be caused by faulty hydraulics (the usual case) or by a failure of the clutch disc. If, when you examine the clutch slave cylinder, you find a movement of 3/8" or more of the pushrod, then the hydraulics are doing their job.

The clutch disc can disassemble, leaving little pieces of fabric stuck between the pressure plate and disc, or between the flywheel and disc. Usually, you can free these pieces by starting the car in gear, clutch depressed.

But, it appears as though you'll have to R&R the engine to change that clutch. And, this is a perfect time to sort out the second gear synchronizer!

Hope this helps!

John
ClutchClutch HydraulicsJohn,


I was tempted to call about this problem, but thought that it might be one worth posting as others may have a similar problem. I have checked your site's and others' tech tips and have not seen a post similar to this issue. I have a 1970 MGB that I recently purchased in very good condition. Many parts have been replaced and it is a solid car and engine. We recently took it on a 200-mile trip with no issues and excellent performance. A few weeks later, having sat in the garage unused during that time, I started it up and let it warm up for a short jaunt. Having been an MGB owner a few decade ago, I know to always check and top off all fluids before any outing and I did so in this case, in particular the clutch and brake reservoirs. We took off, running and shifting normally. One block from our house to the first stop sign, downshifting without problem. One more block to a 90-deg turn, and I note the clutch pedal feels VERY stiff. I complete the shift and have a 1 mile straight-away to the next stop sign. On trying to downshift at this point (maybe 2-3 minutes since we left the house), the clutch pedal is like a rock - immovable. Interestingly, once I put the gearbox into neutral (with engine off), I can now shift into any gear with no noise or grinding (with engine running), but it's as if all are the same as neutral (to clarify, the car doesn't move). Also note that there were absolutely no noises, grinding, or metal-on-metal sounds at all when this happened - the pedal just seemed to lock up. We towed it back home and unfortunately it sat there for 5 months due to lack of time and money. Today I started it up without problem, and found the master cylinder was dry, so I topped it up and tried to pump the pedal. Still stuck, but noticed leakage around the braided hose fitting that attaches to the slave cylinder. While it would be nice to replace both cylinders and the hose, that's a bit expensive. I disengaged the clutch pedal arm from the master cylinder by removing the connecting pin, and I'd say the master cylinder piston should have more movement than what I'm seeing, which I'd describe as "barely moving".
Also, the reservoir cap has a very slight crack in it, but enough to leak fluid when pressing the pedal, and I'm not sure that it should be air and pressure tight but that would seem to make sense. From your experience perhaps, any
idea as to what cylinder is more likely to be the problem (ie, maybe you replace 10 of one for every 1 of the other?).
Also, both rebuild kits have very few parts in them. I'm thinking that if I have a bad or jammed piston then a complete replacement would be in order. Is it worth rebuilding these cylinders, or only if they function but perhaps leak internally thus not keeping up sufficient pressure?

Thanks for your help!

- Herb
Herb,

Regarding the clutch hydraulics:

If the slave leaks, it's bad; if it's bad, it leaks. If it's not
leaking, it's OK.

If the master cylinder leaks, it's bad; BUT, it can leak internally
and you won't know it except that you cannot build up enough pressure to
move the release bearing fork.

The release bearing fork moves 3/8" to 7/16" when it's working. It
will look like much more, but put a ruler up against it and that's all it
moves.

If the slave hose gets plugged up (which they're all doing now) then
with your foot you can develop enough pressure to push the slave cylinder
out, but the pressure plate doesn't have enough force to push the slave back
in. So, the next time you use the clutch, the slave piston pushes out a
little more than it should, as it does the next and the next.... Finally,
the slave piston pops out of the slave cylinder, the fork jammed against the
back of the gearcase housing.

This is what I believe has happened to you. So, change the slave
hose.

Call for more information!

John
ClutchSlave CylinderI'm in the process of replacing clevis pin and slave cylinder pushrod in my 70 B. Im having some difficulty lining up the holes in the slave pushrod and the cluth lever. i have pushed it into the slave as far as it appears to want go and it is misaligned by approx half the diameter of the clevis hole.
Do I need to drainthe slave? I also tried to take the slave of housing and install pin but i can't align slave bolts to housing.

You should be able to push it way beyond what it actually moves.
ClutchMGA Comp Clutch@ 10 years ago you did a complete restoration on my 1960 MGA-and it still
looks great! Part of that restoration was the fitting of a diaphragm clutch
in place of the stock MGA clutch. About a year and a half ago I had a very
bad accident (not in the MG
The competition pressure plate sandwiches the clutch disc between the
pressure plate and the flywheel with much greater force than the standard
disc. The advantage at that time was that the comp MGB plate was more
fierce than the spring type cover offered for the MGA. The situation has
changed a bit. We now use the comp MGB clutch on all our MGB work as we've
had one, perhaps two, Borg&Beck covers exert too little pressure, allowing a
BRAND NEW clutch to slip! Other shops have not encountered this, but this
type of problem is SO expensive (we had to do the clutch again, for free,
for our customer), that we've moved to this comp clutch. Now, this new comp
clutch is not as stiff as the original comp clutch.

The way I see it, you have two options pretty easily available. Fit
a new MGB pressure plate; or send the master cylinder off for a rebuild and
ask for the rebuilder to use the smaller piston on the clutch side. That
would result in less pressure needed to push the slave, but you'd have to
push it farther.
ClutchRelease Bearing I wonder what would you say about the
difference of the MGB clutch release roller bearing and the carbon bearing.
There is a couple of pictures of an old stock I was able to find. Not
original spare but similar.
We use only the original Borg and Beck carbon release bearing. The
roller bearing appears to be better, but it is not. We nearly always use
factory or original style parts.
CoolingEngine OverheatingMany of my fellow B drivers here in Dallas, Tx echo my overheating problems with my ride. my ride being a 77 B it never seems to quite get to red but gets to close for my comfort maybe its due to our temp in this area. I had the radi cleaned and rotted out when I took off and replaced, also installed a new water pump elec fan works fine I have thought that maybe one could add more fins and a bigger tank thus expanding the capacity I am sure you have talked about this many times before so you might direct me to the proper location to read about your thoughts any help appreciated J CollinsJon, When the engine is tuned perfectly the best you can achieve is 1/3 of the energy at the flywheel leaving 1/3 in the radiator and 1/3 down the exhaust. When the car is not tuned perfectly, you'll get less at the flywheel and more into the radiator or down the exhaust. So, the first thing to do is to set the timing correctly. Lately I've dramatically changed the way I time our MGB engines. I now set them at 32 degrees before top dead center at maximum distributor advance -- around 4000 rpm, vacuum disconnected. You have twin cooling fans on your car. Ensure that these turn anti-clockwise as you face the front of the car or the air will be pushed forward. Even the newest MGB is now 32 years old. Radiators begin to lose their efficiency. A recore is very expensive at about $350; a new radiator is much less expensive -- but the new rads are much lighter than the old ones. They probably won't last as long. Water pumps always pump water. Sometimes they leak or growl, but they always pump (well, I've only seen three or four exceptions in 40 years), so the pump is not the problem. The size of the expansion tank is of no consequence as long as the cooling system remains full. Double check your temp gauge by using a pyrometer on the thermostat housing or on the front of the head just below the thermostat. a reading of 190 equals a vertical alignment of the temp needle. As long as the car does not boil over during operation then the engine is not "too hot." Hope this helps.
CoolingHot RunningJohn:

You may remember I am Willard Brown's brother and had my '67 MGB rebuilt last year by Peter McCarthey of Midnight Auto here in New Jersey. You were kind enough to be supportive when ever I had questions on the details of the engine rebuild.

I am a NAMGBR and have an additional question about engine temperature. From reading my MGB owners manual / shop guide I have learned that the operating temperature for an MGB engine should not be greater than 190F.

I am concerned because while operating my newly rebuilt engine at 65 - 70 mph the engine temperature has been in access of 190F. The temperature has gotten as high as 200F on short 45 mile highway run. This concerns me because the ambient temperature was only 72F. You may recall my mechanic suggested that the car would not require an oil cooler, so on reassembley no oil cooler was used. A new radiator, water pump, 160F thermostat, all the recommended insulation for the bonnet and around the radiator have been applied.

The rebuilt engine compression has been increased from 8:3:1 to 9:5:1. I have driven the car approximately 1400 miles.

Is it normal for the engine temperature to be 195F or 200F?

What can be done to correct this problem?

We have retard the fuel mixture and changed the timing, it has not help. It has been suggested to me that the engine needs 2000 miles to really break in and settle down and may run hot until then. Is that true? I do not want to burn up my rebuilt engine.

Do you have have any suggestions? Please reply as soon as possible, thank you.

Paul M. Brown

PAUL!

The newer gasoline seems to produce more heat than the old gasoline -- this may seem like an urban myth (perhaps it is), but many of the earlier MGs (with precise instrumentation) seem to run much hotter now than they did 20 years ago. I would not be concerned with 200F, but here are some things to check:

1) Test the temperature gauge itself for accuracy. Remove the bulb from the engine, put it into a pan of water, boil the water (with your propane torch), and see if the gauge is reading 212F.

2) Set the timing back correctly -- it should be 20 degrees BTDC at an idle of about 800.

3) Feel the radiator with your hand as the engine is running. The rad core should have the same temperature all the way across, yet it should be slightly cooler at the bottom than at the top. If you encounter a "stone cold" section, then you've found blocked tubes.

4) Run high octane gasoline -- you might try some octane booster for a long distance run to see if this makes a difference. I am so keen on keeping the compression ratio at 8:1 so that the mid-grade gasoline works well. I've found that higher compression ratios result in greater heat generation when used with mid-grade gasoline.

5) Do not waste time or money changing the water pump -- that is not the problem.

6) Moss sells this "water wetter" stuff (silicone, I believe) that reduces surface tension, thereby reduction the possible aeration of the coolant, and that can help dissipate the heat more quickly.

Hope some of this helps!
CoolingHot RunningHi guys, and greetings from down under in New Zealand.

Its another stinking hot summer here in Auckland, and the outside temperature gets up to around 28+ degrees. Not the kind of climate MGCGTs like for keeping the engine temperature down, and herein lies my problem.

My 68CGT is fully restored, and this includes a recored radiator far superior in cooling capacity than the original (so I'm told!). Still however I see the temperature gauge get up over 212 degrees in the traffic; the car gets so hot that the fuel evaporates in the carbie bowls despite the presence of a new heat shield and the fact that the exhaust is fully wrapped. I know the heat is doing damage to the car; I am very concerned about warping the head etc as these are only available on an exchange basis now.

The car is running a non standard eectric fan after the original one broke. This covers around 60% of the radiator surface (not enough!). I have 2 questions for you guys:

1 - how hot should these cars get - I am told normal running temperature even stuck in traffic should not exceed 190 degrees;

2 - can you suppy a very slim line electric fan to fit the car and cover a good % of the radiator surface? I don't imagine that UK owners have the same problems given its much hotter here, but the cars do run hot, so someone must have a solution for it. I had heard Kenlowe (?) did a fan?

Love to hear from you as I am getting desperate here and there may be one less CGT on the road at the rate I'm going....

Cheers

David Sellars
MG Car Club, Auckland
New Zealand.

DAVID!

Barrie Cartmell was here for our summer party in August -- and his car ran relatively cool all the way from Maryland to Grand Rapids (about 1000 miles). Just about when he wanted to return, it began to overheat. Finally, after trying EVERYTHING else, I removed the water hose from the hot water valve to the heater and placed a garden hose into the heater line and turned it on. This, somehow, blew air from a pocket in the head. The car INSTANTLY began running cooler. Is this your problem -- well, probably not.....

Double check your ignition timing -- I would think that 20 BTDC at idle would the MOST you should have.

You should be running at least a 185F thermostat; you should be running a 50/50 solution of antifreeze, although the boiling point can be raised by changing that to a 70/30 mixture (I think), and heat dissipation can be increased by the use of "Water Wetter" which is simply some silicone in the water (it gets rid of the bubbles).

The Kenlowe Fan is British, I think, and is probably available from Brown and Gammons in Baldock, Herts. It's probably available from Moss Motors in Goleta, CA, too.

Hope this little bit helps. You might consider joining the American MGC Register, both Tom and Keith's addresses are in the cc line.
CoolingHot RunningJohn,
Really enjoyed your summer party.
Recently bought a '57 MGA. It runs really hot, 185-195. It's very
noticible because the heat comes into the cockpit. Is this typical of
this model? I have removed the thermostat and put in the blanking ring.
I have replaced the radiator and flushed the engine with the Prestone
stuff. I am now questioning the water pump. Could the impeller be worn?
Also, I am wondering if the waterjackets are corroded after all these
years. Is there a way to diagnose the problem? Your thoughts would be
greatly appreciated.

Keith Lewalski

Keith! Nearly all MGA owners complain that their cars run "hot," yet few
of them really run "too hot." An operating temperature of 185 - 195 is
CORRECT!! Let's go through this: The temperature of the engine is AT LEAST
the temp of the thermostat. Fitting a 180 or 195 thermostat to the MGA is
not incorrect -- the engine wants to increase to operating temperature AS
QUICKLY AS POSSIBLE so that the mixture can be moved from rich to normal.
The UPPER end of the coolant temperature is determined by the ability of the
cooling system to dissipate the heat. This in turn, depends on the quality
of the radiator and the amount of air that flows through it.
The water pump is NEVER* (all rules have exceptions) the problem
in an MGA overheating situation. Cooling can sometimes be effected more
efficiently by adding "water wetter" to the coolant. A re-cored radiator is
a wonderful investment IF it is needed.
As long as the coolant DOES NOT boil out while the car is
running, then the engine is NOT OVERHEATING!! Certainly expect some
expansion (and resulting dripping) when the rad is overfilled and the
underbonnet temp is really high (for the fifteen minutes after shutdown).
If the engine is producing too much heat for the radiator, then
inspect the timing -- it should be 20 BTDC at idle.

Keeping heat from the cockpit is a simple matter. Make your
improvements to the interior in this order: Convection; Conduction;
Radiation. So, plug ALL the holes in the firewall / bulkhead / gearbox
cover. You should not be able to see daylight looking from under the dash
when the bonnet is open! Cover the toeboards and the gearbox tunnel in a
thick rag padding -- some has a reflective covering (for the radiation).
Over that place your carpeting.

MGAs ARE hot cars to drive when the ambient temp is high -- even
worse in the flat counties in Northern Indiana! I've rarely been so hot as
once trying to get from around Crawfordsville up to South Bend following
county roads -- and then, just when Caroline and I though we were going to
die fromt he heat, we encountered a BLACK sky, the temperature plummeted, we
ended up soaked to the bone and horribly chilled. I don't carry
sidecurtains -- but now and then wish I did (or had).

Anyway, except for the problem with the heat in the cockpit, all
sounds about OK. I'd replace that blanking sleeve with a 180 thermostat!
CoolingFan ColorHello again John:
I forgot to add another question to my previous e-mail that I'm sure you
can
answer.
Did MGA 1500 engines have black or yellow fans?
Thanks for your help.
Sincerely,
Brian

We always paint the fans yellow -- I personally like the color
combination -- but for the purists.... red's the color on the 1500.
CoolingFan ColorDear John,
I found the section in Clausager's Book on MGA fan colors, and it
indicates
that 1500 engine fans were black until 1958, then changed to red. See page
64,
Cooling System, in Original MGA.
Sincerely,
Brian Findley

Brian!

Thanks for the note. I'd swear I've never seen a black fan blade!
Anders' books are the "gospel" so I'll believe it.
CoolingMGB/GTDear John;

Could you help me with a small problem? On the way home from the Summer Picnic I lost the second cooling fan motor. You had replaced the first motor a few years back. I disconnected the bad motor and finished the trip home on one fan. I need to get another motor and I remember that you told me that there is a direct replacement that is actually a motor for a US car. What is the model car for this motor?

Thanks for the help. I am looking forward to the next time that we will be together! John

JOHN!

Sorry for this long delay in answering!

For the life of me I cannot remember the type of motor you need! Shop around for those Lucas motors -- they're as expensive as over $100 and as inexpensive as $30 depending on who has them. I believe it's a Toyota motor -- but there's a problem with the shaft diameter, or something. If you've found a US replacement, let me know so I can pass the information on!

All the best. I'm still driving the GT every day!

FAST FORWARD!
John H Twist
CoolingOEM cooling fans 1980 MGB John,
I have recently put my 1980 MGB back in operating condition after a 7 year
rest. Yesterday I noticed that one of the electric cooling fans in front
of
the radiator blows air into the radiator, the other is sucking air out of
the engine compartment in the reverse direction of the air flow when the
car
is moving. Is this right? If not, how do I correct this? Thanks, Glenn.

Glenn!

The fans should blow air INTO the engine bay -- they spin
ANTI-CLOCKWISE (the engine spins clockwise). Because the motors are
permanent magnet motors, the will spin in a reverse direction if they are
connected backwards OR if they've been serviced and the case has been
replaced backwards. So -- you have the info on how to reverse the direction
of the clockwise motor. Either reverse the wiring or
disassemble the motor (slightly) and rotate the case. The heater motor and
the starter motor are both FIELD WOUND motors and always spin the same
direction, no matter the direction of the current.

Hope this helps!

John
CoolingBlanking SleevesHi John,
I have a question about blanking sleeves. I'm taking my sons 77 B to Washington DC this summer. I have had trouble in the past with overheating in traffic. I have installed a lower thermostate(160) and an after market electric fan. What would be the effect of installing a blanking sleeve for the summer, then changing back in the winter?
Thanks, Forrest


Forrest!

How did the blanking sleeve work out for you last summer in DC? I'm going there tomorrow but it's about 30F and I'm in a Toyota Sienna, so overheating shouldn't be a problem!


John
CoolingTemperature Guage Reading John,
I talked to you Friday on the phone about my temperature gauge reading.
I've
changed the thermostat, sending unit, urp switch and changed gauges and
the
gauge still registers on the hot side of the gauge going down the road. I
had
the timing reset a couple of weeks ago when all this seemed to start, and
that is the next thing I'm going to check.
Is there anything else?
Your help would be appreciated.
Thanks
Randy Hull


Randy!

It's been a while since we corresponded about your problem.

Have you changed the voltage stabiliser, located behind the dash,
just above your left knee -- with male and female spades -- GREEN and
GREEN/LIGHT GREEN wires.

Let me know what you did to repair this problem.

John
Cooling64B Block Water Drain

The water drain for the block was completely blocked with sediment. Dug as much out of the hole in the block as possible but.. no water. Used compressed air but nothing dislodged.

Is this a sign of serious blockage? Can I clean out the water passageways by removing the head? Would like to avoid tearing the engine out of the car, if possible. Thanks,

Mike
Mike!

You may be able to clean out that passageway from the outside of the block. Sometimes it's necessary to remove the head (and I wouldn't do that just to clean out the block drain). The block drain is a 1/8" BSP thread (or is it 1/4" -- I think 1/4").
Clean out that hold as well as you can. THEN, use a 90 degree layout scribe and work at the base of the hole at about 10:00 or 11:00 -- that's where the block drains into the hole. Continue cleaning, picking, and blowing with your air gun -- I think you can, with different type of scribes, wire, something, clear that hole.

John

Coolingpull freeze plug? John,

Thank you. One last question...

I was avised to pull the freeze plug just above & to the
right of the drain tap. That way I might get at the
dirt, etc.

Does that make sense?

Mike
No!

The only way to get down into the recess in the block is angled down
from one of the water jacket holes at the rear of the block -- with the head
removed. I'll bet with some patience and some STRONG scribes or dentist
tools that you'll be able to clean the passage.

John
Coolingwhere to fill cooling system?
Hello,
I have a 1978 MGB Roadster. I drained my cooling system, and I need to know where to fill my cooling system up, I have no rad cap, and don't know where to fill up.

Thank you
Fill the cooling system from the top of the thermostat housing, at the top, front of the engine. There should be a black plastic or brass plug there (sometimes replaced with an American square headed pipe plug). Remove this cap, drool the fluid in carefully, squeezing the top rad hose from time to time to get the system FULL.

I'm certain you have a rad cap -- but it's on that overflow tank on the right front fender. Let that remain full, too.

John

p.s please email me ASAP
CoolingMGA Radiator Cap Sir, I have a '62 MGA MkII that I'm returning to the road after nearly 32
years of being my brother's garage decoration. Question: Did the original
radiator cap have a rubber seal ? Mine has a brass outer ring that presses
against the brass flange in the radiator neck (I think it's probably the
original cap). The inner air return disc doesn't look as if there'd be
anything to hold a rubber seal. Should I chuck it?

Jim
Jim!

Remember that the MGA rad cap (along with the TF and the early
Midgets) have a longer cap than all the later cars. Yes, there must be a
rubber seal to hold the pressure in the radiator. A 7# cap is plenty.
Each pound of pressure increases the boiling point by three degrees
Fahrenheit -- so that 7# cap is good to push the boiling point to 232 F.



John
CoolingUnderbonnet TemperatureGood Morning John:

I have a 1958 MGA 1500 that has started to spit and sputter in 2nd and 3rd
gear after being at a long red light. It will smooth out in time but it is
disturbing. The car only does this after it is warm. Any thoughts as to what to look for. Also John I'd like to thank you for attending th 38 GOF in Palm Coast Fl. Everyone I talked to appreciated your help.
Bernie
Bernie!

It certainly seems that the underbonnet temperature is rising so
high that the gasoline is boiling in the float bowls (hence an uneven and
often lean mixture causing the spitting).

You might try a different type of gasoline. You might try to
deflect some of the heat away from the float bowls, or wrap the float bowls
in some insulating material.

Your temperatures are so much greater than ours (especially this
season!) that I do not have much experience with these overheating problems.

Try Mike Ash!

John
CoolingInduction HeaterHI John

I would like to know the purpose of the induction heater in my MGB and if i can take it out.

Thank you very much in advance,

Raymond
Raymond!

I assume you have a 75- MGB. On these models there is an induction heater, switched by a thermostat within the unit. When it's REALLY cold (but since I've never got one of these to work, I don't know how cold....), the switch closes.

The goal of clean running is a reduction in unburned hydrocarbons -- that is, no raw gasoline getting through. So, this heater is designed to vaporize the air/fuel mixture a bit more than the vacuum at the main jet can do when the starting conditions are frigid.

You can remove this, but spacing the carb becomes a problem.

If, on the other hand, you are referring to the "flapper valve" on the air cleaner -- this does the same job as the electric heater, only better! And, yes, you can remove this valve and run the air cleaner with underbonnet air only.

More questions? Give me a call during technical hour!

John

CoolingEngine TemperatureHi John,
You have helped me in the past and I hope you can again. What temp should this engine be running? It presently seems to find it way to 190. Of course if it is hot outside or it is city stop and go it runs warmer. I have removed the thermostat and replaced it with the sleeve and have had the radiator recored all with no effect on the temp. The engine seems to run smoothly so I assume that the timing is ok. I think 190 is a bit warm but that is why I'm asking you. Is it ok or is there anything else I can do to try to lower it aside from fitting it with an ice pack ? 🙂
I enjoyed your article in the MG Driver. Thanks for taking that section over. I can't think of a more worthy author.
Thanks again,
Bob
Bob!

The temperature you are running is excellent. Modern engines need to run warm, they must run warm to vaporize the modern fuels. You do not want to run cold -- say at 165F.

Remember that the thermostat controls the bottom of the temperature range, not the top -- so I would fit a 195F thermostat in place of that blanking sleeve.

The car is running too hot only if it boils over. To prevent this, you have a water/antifreeze solution which raises the boiling point slightly. You also have at least a 7lb cap -- and for each lb of pressure, the boiling point is raise 3F -- so add 21 degrees to 212 and you're not boiling until at least 233 -- and THAT would be pretty hot. My own MGA runs at 230 sometimes -- when its really hot outside, when I'm running on the expressway at 80, but mostly it runs right at the thermostat setting -- about 190.

Hope this helps!

John
CoolingLosing CoolantGood Morning John,

I have a 1979 MGB with an engine that’s been rebuilt 2 years ago. An issue that has come up this year is that I continuously lose coolant. I typically find a small puddle of coolant under the car after most rides which comes from the expansion tank overflow tube. I’m not having any overheating issues and I do not believe I have any leaks in the system. It gets to the point when I need to add a significant amount of coolant every couple of weeks. I do understand that it is challenging to eliminate the air in the system which I believe to be the problem. Any tips or tricks on filling in order to eliminate the air pockets? Also, when I check the expansion tank after it’s cooled, it spews coolant from the cap due to the pressure, even after a week. And I find the expansion tank to be filled to the top. Is this normal?

Also, on another topic, I have quite the delay on my tachometer. When I start it up, the tach will not show anything. It kicks in when I rev up the engine. I’m not sure what this may indicate. I thought you may have some insight on it.

My first two stops for troubleshooting are always your technical manual and your web site. Thanks for all your help!

Jorge




Jorge!
I'll put my money on a leak from the combustion chamber into the cooling cooling jacket -- at the head gasket. Suppose there is a tiny, and I mean tiny, leak between the cooling jacket and one of the combustion chambers. The coolant just cannot get under enough pressure to push into the cylinder. BUT, when the engine runs, the pressure is so high that a tiny amount of that pushes into the cooling system. This pressurizes the cooling system. This pushes coolant into the expansion tank.

Two other telltale signs are white smoke from the tailpipe, and, should you remove the plugs from the engine right after a high speed, hot run, you'll find one of the cylinders slightly steaming.

I should add that a cracked cylinder head can also cause the problem and once, but only once, we had an engine with a vertical crack in one of the cylinders.

Of course, it might be something else....

The tach is just showing its age. Flick the face with your index finger and that needle will pop into position!

Hope this helps!

John



CoolingCoolant OverflowJohn

I have found your website very helpful in what will be
a long slow rolling restoration of my B. I have one
issue that mere web searches cannot seem to answer. I
hope you can help.

I have owned my 1967 MGB for less than a year.

I had noticed over time that after running there was
an overspray of coolant in the engine compartment. I
put a length of tubing with a collection bottle on the
radiator overflow spout as a diagnostic aid. This
resulted in no overspray and some coolant collecting
in the bottle. At most there has been a few ounces of
coolant at each running.

After this test I purchased a new radiator cap (7psi).
There continues to be the same nominal overflow into
the bottle.

Do I have a problem or is some regular coolant
overflow normal for a 67 B?

Thank you for your time.

Regards

-Willie
Willie!

The top of the radiator is the expansion tank. Just after the engine is shut down the latent heat causes the coolant to expand greatly. If the rad is filled to the neck of the expansion tank then some of that coolant will be displaced onto the ground (or into your bottle). However, after a couple of runs the coolant level should stabilise. If you continue to fill the rad it will continue to overflow. If, however, the coolant level continues to decrease -- until you can see the top of the core in the rad (peering through the cap), then there IS a coolant leak.

Common causes of coolant leaks are: water pump -- which sometimes leaks ONLY when running; heater control valve, but that drips directly onto the distributor cap and causes erratic running; hoses, but those usually are quite evident; leaks in the radiator, and those, too, are usually evident; along the RH side of the cylinder head (nearly all MGBs are stained with coolant along the RH side -- the new Payen gaskets have an extra thickness down the RH side to stop this leaking/weeping); and finally, there can be a leak between the cylinder and the cooling jacket, either through a crack or a faulty headgasket. If the coolant leaks into the cylinder then there is a whitish (steam) exhaust at times; if the exhaust gasses escape into the cooling system it will blow coolant out of the rad in short order.

I hope this quick course helps!

John
CoolingHeater for MGTDJohn:
I have a 1953 Mg Td and just got a heater for it,do you have any instructions manuals and parts for one. I need the hose pipes,valve and connectors ,all I got is the heater that goes inside the car.
Wayne
Wayne!

There were two popular heaters for the TD -- the Smith's heater and the Arnolt heater. I am most familiar with the Arnolt and can discuss some of the installation if you'll call during tech hour.

You want hot water, either from a tap installed on the rear plate on the cylinder head (pretty warm) or from the bypass from the thermostat assembly (hottest). You want to plumb the return line into the line coming from the bottom of the rad into the water pump. You can make these lines by adapting the originals, if you're handy; you can make them from copper pipe if you don't mind the conflict of technologies under the bonnet; and, I suppose, you can advertise for original pieces. The hot and return lines were originally plumbed through the firewall, just to the right of the back of the engine.

Someone out there probably has the original installation instructions -- perhaps you could advertise for them through TSO or one of the MG boards.

I hope this little bit has helped!

John
CoolingMGB Engine Running HotGood day, John:

I have a 72 MGB with a rebuilt engine with an alloy standard head (Pierce), 9.0 compression 0.020 oversize pistons and a slightly hotter cam. The distributor has been rebuilt. The engine has about 3000 miles on it since the rebuild. The rebuild went just fine, but I had to rotate the distributor clockwise one tooth in order to have enough advance adjustment on the timing to set it to 16 BTDC at 1600 RPM using a timing light. The engine runs hotter on the gauge than it did before the rebuild especially if the temperature is over 85 degrees, and it has a tendency to run on a bit when I turn off the
engine since the rebuild. It has never quite gotten to HOT, but it now gets very close. Before the rebuild it barely got above the N even on very hot days. I did replace the water pump and the hot water pickup on the head, but nothing else electrical. The radiator has
been recored. The new thermostat is a 185F, plugs are NGK BP6ES and the HIF carbs have free flow air filters with ABD needles. These needles feel a bit lean under hard acceleration (the slight headwind effect). The AAA needles felt a little better, but I was concerned
that they might be too rich. Everything appears to be properly adjusted and timed. The exhaust is a Monza.

Do you have any ideas on why she seems to run hot now? I wonder if the cam is not calibrated properly with the crankshaft and distributor, but I don't know whether this is the cause. I was surprised when I had to rotate the distributor to give it enough advance adjustment to set the timing. I am seeking your advice before I tear into front engine cover to expose the timing chain and
sprockets. I bought a replacement water pump with the cast iron impeller like the car originally came with to see if that would make any difference. The current water pump has the stamped metal impeller. It has not been put on yet, because I want to take care of all the work at one time. I rebuilt the engine and have done it before so I have some experience with engine mechanics. Your advice would be appreciated.
Regards,
Konrad
Konrad!

First of all, I wonder if your engine is truly getting hot. Use an infrared thermometer, pointed at the cylinder head, just below the thermostat. If the gauge is reading "N" the thermometer should be about 185-190. It is not uncommon to have an incorrect sending unit. The two units, the GTR 104 and GTR 101 look exactly the same.

If it IS getting hot, I'd check the timing. Run the engine up to a 4500 idle and set the timing at 32 BTDC, vacuum disconnected. That's maximum advance.

Hope this little bit helps.

John
CoolingPoor Heater PerformanceJohn,

I have a 1967 MGB roadster that has been "restored" (not by me). When the heat is on - It doesnt seem to be putting out hot air, just barely warm, but not as
hot as it was 2 years ago - the air comming from the heater is barely warm. The heater valve cable opens and closes - as far I I can see. Do you think the heater coil needs to be replaced? The engine temp is 180 - mater of fact last year I put the heater on to help keep the car from getting too hot. It was near 200.

I read your tech talk in the MGB driver, what a good series.

Thanks

Tom
Tom!

The heater matrix is mostly likely OK. It's probably the flow of hot water that is impeded. Remove the heater control valve from the head and the heater control valve hose from the bottom of the heater matrix. Use your garden hose and FLUSH the heater matrix by blowing the water into the head, and later, into the heater. Clear out or replace the heater control valve. That should do it!

John
CoolingWater LeakHi John
I hope that you can help me with my water leak. I am a relatively new member (joined at MG 2006 in Gatlinburg) so I don't know if you have answered this before in MG Driver, but here it is.
I drive a 1971 MGB-GT and every time it rains my passenger and I get wet legs and feet. I know the water comes in through the air intake and I have cleaned out the drain pipe but the problem always comes back. I have a magnetic cover that I use regularly so I don't believe there is a lot of debris collecting in the drain pipe either.
Can I remove the plug at the bottom of the drain pipe, and leave it off? Alternatively, what about fixing an extension to the pipe, with the plug removed, to drop down even with the undercarriage so it is not visible below the body.
Or better yet, do you have a solution?
Many thanks for your assistance.

Bob
Bob,

The drain for the fresh air vent can easily become packed with dirt and debris. The best way to clean it is to access the tube and bulb from underneath and use air to blow the stuff up and out -- continue to use the compressed air to clean out the remainder of the fresh air vent.

Then, sit inside the car with a flashlight and have your associate spray down the car. Look for leaks.

Hope this helps!

John
CoolingMGA Water PumpJohn:

I have a rebuilt 1622 MGA engine I am going to put in my 1958 MGA.

I have one of the old MGA water pumps. Do you rebuild these pumps? If yes, how much do you charge to do it?

If you do not provide this service can you tell me who does?

Thanks for your help.

Sincerely,

Reed
Reed,

We used to use Terry's Jag in Benton, Illinois, but they stopped repairing them. I know that someone must rebuild them. Our local shop here in Grand Rapids, Northwestern Auto, won't do them either. I cannot believe they're that difficult! Perhaps someone else knows. What about those twenty pages of services offered at the front of each month's Hemmings Motor News?

John
CoolingMGB OverheatingMy 66 MGB is overheating only when the engine goes above 50mph, it begins
to
cool down as soon as I slow down.

I may have written to you before about this problem, but did not get a
response. You seem to be the man who will know, so here we go, fingers
crossed.

I have flushed the radiator both ways and it appears to be equally heated
when I run my hand over it when warm.

I have replaced the thermostat, there is plenty of water in the system
with
the correct amount of coolant.

I have replaced the heater control valve, which was sludged up solid.

The water pump appears to be fine.

I have added a 123-ignition and set the timing with a strobascope.

The plugs are all new and set to the correct gap.

The only part that does not seem to be as it should is the rear drainage
tap. This is also sludged up. If I open it, nothing comes out. When I take
it off completely, nothing comes out.

Have you come across this before, with these symptoms?

I have bought a replacement head gasket set and was considering removing
the
head to see if I could scoop out any of the sludge which is blocking the
waterways from above.

When I take the head off, could you point out to me on a picture which
holes
in the block are going to be the offending ones. I assume that they are at
the back left above the drainage tap, but then again, this would be a
guess.
I do not want to start removing the head before I have this information as
I
will need to complete the job in one day. The car is my everyday driver
and
I can not afford to have it off the road any longer than needs be.

There is always a chance that the head gasket might be leaking I suppose.
Although, the car is not blowing out smoke. I did a vacuum pressure test
which did not show anything untoward.
You know, for every gallon of gasoline you use, 1/3 is spit out as
heat from the tailpipe, 1/3 is carried out as heat in the radiator, and 1/3
goes for power -- IF the engine is tuned correctly. If there is a problem
with the tune, then the power drops and the heat increases. I do believe
this is your problem.

Overheating at higher rpm usually indicates a problem with timing.
I would time the engine with what we call a "dial-back" light -- and time it
at 32 BTDC at about 4500 rpm, vacuum disconnected. That 32 degrees is
critical -- above or below that number will give less power and more heat.

If that does not solve the problem, then I would put my money on a
mismatch between the compression ratio and the octane of the gasoline you're
using. I am unfamiliar with UK octane ratings -- ours are either nominally
higher or lower than yours. Right now, the highest we can purchase at the
pump is 93.

The bottom line here is that I do not believe it's your water pump,
radiator, or cooling jacket. I think your engine is simply making more heat
than it should.

BTW, you can clean out that rear drain hole with some difficulty if
you're patient. The hole from the drain cock runs about one inch into the
block. At the top left -- about 10:00 or 11:00 there is a passage to the
cooling system. You'll need a layout scribe with a 90 bend to poke and prod
up into that area. Just a piece of wire is too soft for clearing out the
hardened rust and corrosion.
CoolingCooling System Flushing Any sage advice on the best way to drain, and subsequently refill, the
1979 MGB cooling system? How about flushing/backflushing?
About the only way to drain the system easily is to remove the inlet
hose from the water pump. By removing the top hose, you can use your garden
hose to flush out the radiator. By removing the heater hose from the heater
control valve, you can place your garden hose against that heater hose and
flush out the heater matrix. If the other hoses are still connected to the
radiator, thermo housing, and water pump, then the water pressure will clear
out the heater control valve.

This is the method we use in the shop.
CoolingMG TD Oil in Coolant Hope you can help me .Just founnd oil in my 52 MG TD coolant . Engine rebuilt two years ago. 2500 miles on it head and block smoothed by reputable machine shop. compression at 165 psi.
No coolant in oil. I am assuming head gasket , hoping it is not a crack some where. How can I avoid having to do this again when I install a new head gasket? Copper gasket spray ? Higher torque settings? ( at 50 ft / lbs now ) different gasket?
Wish I lived closer to you .I would have you do this one. After pulling the engine to replace faulty sealnt at the cam plug one year after a rebuild I am becoming .discouraged.
There is an oil plug in your head behind the plate. It is probably either unscrewed or dislodged.
CoolingMGB Heater BlowerMy 1980 MGBLE doesn't blow much on either speed. I can feel air movement on both speeds and low is definately less than high speed. Any ideas how I can get more rpm out of the blower?

I don't have a number or a test for you to find out if the heater blower is acting properly. I can tell you that the heater receives fresh air from the grille in front of the windscreen which MUST be uncovered (some owners cover them up!). Then, it travels through the heater matrix and is send down to a flapper valve which directs it to the screen or the floor. Quite frankly, there isn't a lot of air moving here. You can increase the comfort by increasing the temperature of the thermostat (which will raise the temp of the hot air coming from the heater). You can blow out the heater matrix by removing the hose from the heater valve and shooting water from your garden hose through the matrix (and then out of the heater valve -- both of which are known to plug up after years of disuse or from incompatible antifreeze solutions).

At one time, Costello, inventor of the MGB V8, had an improved fan on the market, but that was years ago. I do believe that Rob Clark, of Clark and Clark Spares in Holland, Michigan, a supplier to the MG vendors, was trying to copy that fan, but I do not think it came to fruition.
CoolingMGB Heater Regarding my 1969 MGB and lack of heat. We have a new heating core,
fan/blower switch,and a winter thermostat. These items were installed
last winter and the heat was almost too much...Currently, we are blowing
cold air. The hoses in and out of the core are hot...The dashboard dial
controlling temp appears to be operating the valve properly...We are
stumped...Any thoughts ?
Either hot water is not making it through the heater matrix (which
seems impossible since the hoses won't get hot unless water is passing
through them); or the heater flap is closed and while the motor runs, no air
is allowed out of the heater. It has to be one of those two items. Let me
know what you found.
CoolingMGB HeaterRegarding my 1969 MGB and lack of heat. We have a new heating core,
fan/blower switch,and a winter thermostat. These items were installed
last winter and the heat was almost too much...Currently, we are
blowing cold air. The hoses in and out of the core are hot...The
dashboard dial controlling temp appears to be operating the valve properly...We are stumped...Any thoughts ?
Either hot water is not making it through the heater matrix
(which seems impossible since the hoses won't get hot unless water is
passing through them); or the heater flap is closed and while the motor
runs, no air is allowed out of the heater. It has to be one of those
two items. Let me know what you found.
CoolingLeaking Thermostat The first time, I installed the Moss gasket (PN 296-380) without any RTV or sealant. After a year, it leaked (upon removal, it seemed the gasket had disintegrated!).

I saw your video on making gaskets, so I made my own gasket using a high temperature gasket material (for carburetors and water pumps). For added insurance, I used high temperature RTV to seal the gaskets (both top and bottom sides) and the base of the three threaded posts. After a week of curing the RTV, I added coolant. Bottom line - I noticed another small leak at the gasket between the head and thermostat elbow after one drive. I tried tightening the three nyloc-nuts while the engine was hot. My plan is to see if this fixes the leak (however, I'm not too confident!).

My question is, what is your tried and true method for leak free thermostat gasket installations?
When I install a thermostat gasket there are several things I do to prep the parts. Remove the studs, if you can, and scrape and/or sand the contact surface CLEAN on the head. Then, reinstall the studs with grease so they'll come out again. Surface the bottom of the thermostat housing with 100 grit paper. Use the cork gasket, as original, and coat EVERYTHING with grease. Use only flat washers and nuts on the studs -- don't use lockwashers or you'll end up pulling the nuts too tight to collapse the lockwashers and destroy the gasket in the process. Simply tighten the nuts until the cork gasket "just" begins to squeeze out.
CoolingOverheating I've been planning to run our Midget over to you for lubrication service from Saugatuck (likely on a Saturday morning), but it has been increasingly tending to run hot and I'm concerned about the heat build-up from the highway speeds on the trip over. I suspect that the thermostat may not be fully opening. Nancy and I took a drive to the beach and along Lakeshore Drive, nothing faster than 40-45 mph mind you, and through town last weekend and by the time we got back to the garage the temperature gauge was nearly pegged on the hot side. At speed the temperature drops, it is just when you slow down or idle in traffic that the temperature runs up high quickly.

Up until last year sometime in the summer months, she ran mostly cool, hardly moving the needle beyond the normal range even with a longer drive at higher speeds. No unusual noises, water pump vibrations or anything thing else obvious with the cooling system. Heater seemed to work fine in the fall, too, so I think the water is circulating okay. Fluid level looks okay to me, too. I was going to order a new thermostat and swap out the one in place along with the gasket, but before I create a bigger problem for myself with too little time to work on it, I thought I'd write.
Changing the thermostat may be a solution. Make sure that the cooling system is full by checking the filler plug on the radiator itself, not just the expansion tank. Or, it may be that the engine is producing more heat than the radiator can dissipate because the timing is too far off. It may be that the radiator is not clean, although that should evidence itself at higher speeds (and the higher amount of heat produced by the engine).

The components in the cooling system are: the engine, the water pump; the thermostat; and the radiator. The engine is producing the heat, the thermostat controls only the bottom range of the temperature (unless he thermostat is faulty); the water pumps leak and they wobble, but they rarely, very rarely, fail to pump; and the radiator can become plugged.

It is wise not to drive the car too much before you get the cooling under control. My guess is that the system is not filled with coolant or the radiator is partially plugged up. Please let me know your success with the thermostat.
DrivetrainPinion PinJohn,

1980 MGB roadster - 135,0000 miles

While replacing the thrust washers in the differential (rear-end "klonk") I found that the pinion pin roll pin had sheared and that there is evidence of galling between the two pinion gears and the pinion pin.

Obviously the pinion pin and gears need to be replaced, my question is - do I have to replace the other two gears? (the ones that go on the ends of the half-shafts). The pinion gears are pretty cheap, the other ones are expensive. Do the 4 gears need to wear in as a set?

Two comments on your web page on the rear-end "klonk".

1) My 1980 MGB does have an oil drain plug on the diff. (your page says it does not).

2) The wrench size for my oil fill plug is 3/8" hex, not 1/2" hex as stated on your page.

Anyway, thanks very much for your advice.

Steve Phillips

STEVE!

Thanks for your note -- my apologies for such a tardy reply. Your differential wheels will be just fine! Simply purchase a new shaft (that's not inexpensive!) and the pinion wheels, and be certain to use a split pin through the tension pin to increase the shear strength. You've found your faulty diff "just in time!"

Thanks for the note about the size of the hex. Most of the 1980 MGBs did not have drain plugs. Maybe yours is an earlier one.
DrivetrainDriveshaft VibrationHi John and Happy New Year!

Over the holidays I installed an OD tranny in my 77B, everything is working ok but I have a vibration in the drive shaft at certain rpm's. The manuals say to replace the drive shaft exactly the same way it came out but when the tranny is changed this is hard to do. My question is this, is there a way to know how to put the driveshaft on so that it is balanced or do you have to keep changing the mounting position untill you get it right? Also is this vibration doing any damage? As I said It only happens at lower rpm. Thanks, Don Walton in NC

DON!

You can always get your driveshaft balanced at a truck parts supply -- they seem to be the center for drive shaft construction around here!

BUT, you may be following the wrong path... Does this vibration occur ONLY when driving down the road -- or can you get it going by sitting still and bringing the rpm up to the same number (as if you were on the road)? If so, then the problem is probably the exhaust.

I have removed and refitted driveshafts for three decades and have never been concerned with the alignment of the flanges. Certainly the fixed axis MUST be parallel (and THIS could be your problem), but the flange to flange rotational alignment seems to make no difference.
DrivetrainProblems with Running Gear on MGB 1973John,

First, let me apologize up front for bothering you - I am at a loss as
to where else to turn at present.

I have recently purchased a 1973 MGB in excellent physical condition
however I have several problems with the running gear.

As near as I can tell, the person who was doing the restoration replaced
the SU carbs with carbs from an earlier model - it has twin HS-4 carbs
not the expected HIF-4 carbs.

The fuel pump never stops - I thought that it was supposed to stop when
pressure built up. My mechanic seems to think that they never stop
pumping.

The emissions gear has been all removed prior to my getting the car.

I have 3 main problems with the car:

1. The car has a tendency to fall on its face at around 3000 rpm (this
is when under load - with no load it seems to run fine).
This actually varies depending on the gear - 1st will rev to about 3700
- 4000 with no problem then it breaks down. 2nd gets to about 3300, 3rd
and 4th to about 3000. Backing down on the throttle eliminates the miss
but power is gone.

2. The car runs hot (depending on the ambient tempreture) above about 80
degrees it gets to just below the "H" on the gauge. An infrared
thermometer shows about 185 degrees at the thermostat.

3. The overdrive works some times - usually when the car is cool - I
drive 40 miles each way to work daily and after about 30 miles, the
overdrive will not engage if I have to stop in traffic. Sometime it acts
like it is trying to engage - throttle on is direct drive, backing off
the throttle drops rpm's to where they should be if the overdrive is
engaged. I don't think it is a clutch problem as it is solid when
working. The 3-4 switch does not work ad I have a hunch the vacuum swith
is not working as well.

We replaced the distributor with one from my parts car - a 1979 MGB. It
is the electronic with the separate amplifier(?). there was no
difference in the rpm problem.

Main question - could the rpm problem be related to the fuel pump? I am
getting to the point of considering a Weber downdraft carb kit to try to
get this resolved.

Glenn Vaughn


Glenn!

I apologise or taking so long to reach you and help you with your MGB problems.

The car should run just fine with those HS carburetters, as long as the timing is correct AND the needles are correct for your altitude. The dwell should be 60 degrees, the point setting is 0.015", and the timing should be 15 degrees before top dead centre AT 1500 rpm, vacuum disconnected. When you connect the vacuum, the timing should jump to nearly 30 BTDC.

Remember that 1/3 of the gasoline produces power and 2/3 produces heat (in the best of circumstances). Poor tuning changes that ratio so more heat is produced -- but an engine temperature of 195 is just fine for good running -- and that will give you a reading on your temp gauge on the right side of the letter N (not beyond it, just on the right side of the letter itself).

I wonder if your overdrive switch -- lockout switch -- is faulty. If the 3/4 lockout switch is going bad, then the O/D works ONLY consistently when you hold the gear lever to the RIGHT as you're driving. Try that, and if you're still having this problem, get back in touch and I'll give you the information about how to change the switch (no small task).

I invite you to call me during my technical time or in the evening, at home, so we can discuss your running and OD problems. Don't buy that Weber!

John
DrivetrainFront Universal Joint of '55 MGTF

John -
I spoke with you a few weeks ago to ask for your advice. The front
universal joint on my '55 MGTF suddenly took it upon itself to begin to
thump against the transmission hump. It didn't happen regularly, sometimes
it did it when in neutral between shifts, sometimes when accelerating, and
it generally did it all the time when my wife was in the car. At the same
time, the transmission began a nasty habit of slipping out of 3rd gear
whenever I let up on the throttle. I had visions of everything from the
drive shaft coming up through the floorboards to the transmission
disintegrating into pieces.
You suggested that I tighten the output flange nut and gave me good
instructions on how to go about accessing the nut, and tightening the
bolt.
The whole operation took just a few hours (including fashioning a bar to
bolt across the flange for torque). As soon as I dropped the drive shaft
and pulled the cotter pin, I found the nut would spin freely. A quick
torque with a wrench, refastened the drive shaft, and it was done. Since
the nut was a castle nut with a good pin still in place, I never would
have
imagined that it would loosen up and it would have been the last place I
would have looked to fix something.

Last night, I took my wife for a test drive. You're a genius! It
worked!
The noise is gone!

Thanks very much for your help - Now, I still need to figure out the
problem with 3rd gear.....

Ernie Crabtree

Ernie! I thought that the loose nut might improve the "falling out of gear"
problem. Good luck!

John
DrivetrainDisconnect driveshaft when towing?
Hello John,
I purchased a 1978 MGB from a lady in Baltimore Md and will be
towing it home to Jackson, Michigan. I could only get a two wheel tow
dolly to bring it home on. Could you tell me what I need to to to tow
it home- One guy said to disconnect the driveshaft, another said it's
not necessary- so I am asking you, the expert- what is the proper way
to do this? Do I need to disconnect the drive shaft?, If so how the
heck do you do that? Thanks so much John, I appreciate it.
Jason
Jason!

The gearbox is oiled when the laygear turns. The laygear turns only
when the engine is running. Therefore, towing the car turns the gears but
doesn't oil the gearbox. It's best to disconnect the driveshaft. You'll
need two 1/2" open end or box end wrenches to disconnect the bolts which
hold the rear flange of the gearbox / the front flange of the differential
to the driveshaft flanges.

John


DrivetrainVibrationHello John!


I have read your questions and answers about vibrations, and I'm pretty sure the vibration I am experiencing in my A comes from a need to buy new wheels, since I spun the wheels and they appear slightly out of round.

The thing that makes me wonder, however, is that I get
vibration at about 35 mph, but the vibration disappears
when I back off the accelerator. Does that mean the most
likely culprit is the driveshaft, or could it still be the
wheels?

Thanks for any help you can give me.

Lee

Lee!

There are only five things that can cause a
vibration: four wheels and the driveshaft. The wheels
probably don't know if you're accelerating or decelerating -- the driveshaft does. I guess if I were going to check something out first it would be the driveshaft. Are the fixed axis aligned? Does the shaft have even a hint of a dimple? You can have a driveshaft rebuilt and balanced with new U Joins for about $150.

Hope this helps!

John
DrivetrainU-jointsHello John, this is kind of a stupid question but Dad says you have to drop the rear-end to change the u-joints on his 74 midget, but the engine is getting pulled to replace the clutch so seems like this would be a good time to pull the drive shaft and have them done. Who wins the bet?



Thanks

Leon

Leon!

It is NOT necessary to remove the diff. All you have to do is disconnect the four 5/16-24 x 1 1/4" bolts from the drive shaft flange, and then, jiggle the drive shaft out of the tunnel -- I believe I usually move it out on the LH side. Reinstallation is a much more difficult matter, unless your Midget is late enough to have the little access panel at the rear of the gearbox.

Hope this helps!

John
ElectricsElectricsDear Mr. Twist: I have a 1950 MG TD. You worked on it several years ago. My question: what fuses do you recommend? Note: I replaced the generator with an alternator and replaced the points and condensor with an electronic ignition. Other than these changes the car is stock. Thank you! Larry CarlsonLarry, I remember you and your TD -- that was in November 2008. The original running fuse was a 17 amp fuse which would withstand a short 35 amp burst. I would use a 15 amp fuse -- or 20 amp if you cannot find a 15. The fuse for the horn circuit was much larger -- something like 35 amps continuous withstanding a 50 amp surge. So, a 35 amp fuse would be good here. Stay in touch!
ElectricsWiringI have a 1958 mga roadster 1500. passenger side turn signals do not work, driver side works fine. How do I trace the fault? The 1500 MGAs use that relay box on the firewall to separate the brake lights from the turn signal circuit. The problem often lies there. Here are some things you can do: Feel the relay box when your associate rotates the turn signal switch. You should feel the relay click as the switch is operated left or right. If you do feel the click, then the switch and wiring are OK. If not, there's a problem with the switch in the dash or the wiring to the turn signal box. Use a test light on the bottommost connecters on the relay box -- when the switch is operated one or the other will illuminate your test light. The top right connector on the relay box comes from the turn signal flasher unit. It should illuminate your test light. When you operate the switch on the dash for the right side, the right hand relay should operate. When it does, it disconnects the rear lamp from the brake light circuit and then connects the front bulb and the rear bulb (brake light) to the turn signal flasher. Sometimes the points corrode on the relay. Remove the cover and operate the relays by hand (push on them) and see if you can get both sides to work correctly. You can always drag a piece of fine sandpaper between the points. The turn signal flasher unit will not flash just one bulb -- so if one filament is burned out or if one bulb holder does not have a good ground, then the bulb won't illuminate -- and not enough current will pass through the flasher unit to cause it to wink on and off. If you cannot get this sorted out, give me a call. Hope this helps.
ElectricsConverting to Negative Earth John i printed your article on converting to neg earth from the net . I would like to ask a question if possible. I am assuming that my fuel pump, which looks to be orginal, would be unaffected. I also believe my tach is mechanical. (My car is a 1959 MGA). Do my assumptions sound correct?

Thanks in advance for any help,
Best Regards,
Mike Cundiff

MIKE!

The MGA fuel pump was originally bi-polar (?) -- it was unaffected by the chassis earth. Newer MGA fuel pumps are polarized! Negative earth ones have BLACK tape on their solenoids; positive earth ones have RED tape on their solenoids. These new pumps, when connected backwards, begin to burn (isn't that some safety feature in this modern age -- a burning fuel pump!!).

You are correct -- the original MGA has a mechanical rev counter. A tachometer is technically an electronic unit while the earlier chronometric or magnetic rev counter indicates engine rpm.

Hope this helps!
ElectricsBatteries: Dual-6V vs 12VJohn,

I just got a 1971 MGB that my brother has had in his garage for the last 13 years. Right now the engine won't run. To make a long story short. I have ascertained that the celunoid engages, but I don't have enough juice to do much more than that. My questions are:

1. Should I replace the two 6 volt batteries or change over to a single 12 volt battery?

2. How difficult is it to change?

3. Does this mean that I would go from negative earth to positive earth? and How does that impact the electrical system?

I would appreciate your insights as I am a novice mechanic and haven't work on an MG for over 20 years. That was a midget and another story.

Thanks again for you help.

Andy Phipps

ANDY!

A modern, single twelve volt battery will probably be more powerful than twin sixes! It will also be about half the price of twin sixes. Only the most "original" of us retain the two six volt batteries.

So, remove yours, then fit a single Group 26 into the passenger battery box. Connect the main power cable to the POSITIVE post. MOVE the EARTH CABLE from the left hand box to the passenger box and connect it to the NEGATIVE post. This MGB, as it has an alternator, MUST be wired NEGATIVE EARTH!!

I've found that it is far easier to work on the batteries by loosening the top and then folding it forwards, rather than trying to work on bended knee, sandwiched between the seat and the back shelf, while leaning through the door.

Good luck!
ElectricsRadio John - The original AM radio in my 1959 MGA is shot. What do you have -- or can recommend -- for a modern radio, at least AM-FM, that will fit in the same dashboard slot without modification. My car is still positive ground.

Gary

GARY!

There is simply no hope of finding a "modern" radio that works with a positive earth. You have three options: Get the present radio fixed -- find some ads in Hemmings Motor News; Switch the car to negative earth allowing you to fit ANY modern AM/FM/Tape/CD machine you want; or lastly, fitting a "voltage inverter."

The voltage inverter has a 24 volt + output lead. You connect this to your modern, negative earth, power lead, and allow the radio to find it's natural earth on the frame of the car (12 volts +). The difference between the 24+ and the 12+ is 12+ -- so, effectively, the 24+ lead becomes 12+ and the 12+ earth becomes neutral. Neat! They are hard to find now -- I mean, who has a positive earth car any more? Maybe you can make one from radio shack parts?

Absolutely the easiest way to take care of this is to switch the battery connexions, polarize the dynamo, and change the coil leads (but this last step really isn't necessary). Everything will work just fine! AND, you can fit that modern radio.

The last option, not listed above, is to fit the radio blanking plate -- that's only about $25 new (although I believe I've got a used one), as the sound of the engine should be music enough for your ears!
ElectricsAlternator Bolt ThreadDear Mr. Twist:

Would you be able to tell me what the bolt size is, that screws into the bottom hole of alternator. This bolt also connects to the link that lets you adjust the tension on the belt? I am having trouble sizing up this hole.

I have a 1973 MGB with a 1967 engine in it. I am now replacing this alternator since when I bought the car it had a Cadillac alternator in it.

Thanks Dave Matos

DAVE!

That bottom bolt is either 5/16-18 BSW (British Standard Whitworth) or 5/16-18 USS (American Coarse). Fortunately, these threads are nearly perfectly matched, so the American 5/16 coarse bolt will work just fine. It should be fitted with a lock washer and flat washer. It should be 3/4" long!
ElectricsBrake LightsHi John,

I have a question in regards to brake lights for my 79 MGB. My brake lights currently do not work. The switch located in the servo unit was getting extremely hot to the touch it was also not functioning properly when I would brake. I had a spare used switch, so I replaced it. That used switch would also get hot to where it doesn't want to function anymore.

Why was the switch getting hot?

Is the problem just in the switch? If I purchase a new switch will this cure the problem?

Any type of testing that I can do?

Thank you,

Tom Swerc

TOM!

If I had to guess, I'd say your car had been in a body shop recently! My best answer here is that there is a BLACK wire (earth) mixed with one of the GREEN/PURPLES which is the brake light circuit, at one of the rear corners. This would explain why the lights don't work (the current takes the path of least resistance, which is straight to ground), and why the switch is getting hot.

Let me know what you found!
ElectricsBatteries Do you supply or can you help me in sourcing suitable batteries for a 74 MGB GT? I am in your area often and would like to stop by and see your operation if possible

GEOFF!

While your car was fitted with twin six volts, only the "most original" of us would refit two expensive batteries. It is easily converted to a single 12 volt -- group 26, available here and almost everywhere. Fit the 12 volt to the passenger compartment, connect the main cable to the positive terminal; move (or add) an earth cable to that right hand box and connect it to the negative terminal. Ensure the battery is tied down and the clamps are fresh and clean! That group 26 battery is about $70, I think. Each 6volt is about that same price!
ElectricsDim Lights, Converting to Alternatorjohn,

I have a 1967 gt that is really nice, has 65000 miles and very poor headlights. I have converted the car to negative ground and one 12v battery.

Can you advise p/n and instructions for wiring an alternator? If you can, please know I am a neophyte and really thrive on simple english instruction.

If there is a conversion kit, I'll buy it. Need bracket info,too. Wish I could just drop in, but living in plano, texas it is not an easy commute. I should have come by while at MSU back in the 60s.

Thanks in advance

jack hutson

JACK!

The generator that is in your MGB is capable of providing 30 amps which is MORE than enough to run your headlights. I wonder if there is something wrong with the generator, control box, battery, or associated wiring?

If you MUST fit an alternator, I can easily provide a "kit" but it will be about $200. It will include specific instructions. If you want to go this route, just let me know! The instructions will be in plain English!!
ElectricsStarterHi,

I have a Toyota hilux which I have had refitted with an 3.5l v8 from a Rover SD1. The problem I have with this vehicle is that don't have much clearance between the front axle and the starter motor, and recently whilst 4x4ing, the two colided and smashed the face of the solenoid. I came across your articles on the net whilst looking for information on my starter motor. From your information it seems I have one of the pre-engaged lucas startmotors, with the solenoid on the bottom. My question is: Is it possible to fit another type of starter motor here which does not have the solenoid on the bottom thus giving me a couple more inches of clearance?

Many thanks for any help.

Graham Sims
Analyst/Software Developer
Computer Systems Engineering (CSE) NZ Ltd.

Graham!

There is a "high torque" starter offered by T&S Imports in Pandora, Ohio, which may solve your problem. Ask Ted Schumaker about the particulars, his Email address is in the cc line.

While serving in the army in Viet Nam in 1969, I applied to go to school in NZ, but just never got there. I later met two fellows from NZ while living in London in 1973 -- Stuart Dryburgh, whose father worked for the brewry in Auckland, and Erin Moore, a carpenter, whose mother lived in Pikakariki.

Hope this helps.
ElectricsFlasher Relay Hi there. I recently bought back my 1959 MGA that Ihad sold 16 years ago. Somewere along the way someone removed the flasher relay that mounts on the firewall. Would you by any chance have a new or used one I could purchase?

Any help would be greatly appreciated. Thanks for your time.

Tim

TIM!

I do not have this expensive device, used. I know they are available new. You can, of course, build one from two inexpensive double pole, double throw relays available from Radio Shack.

You could go to www.mgcars.org.uk and place an advert.

Hope this helps.
ElectricsStarter RelayJohn

I have a 65B and a 71 BGT. My question concerns the 71 GT. The starter relay next to the fuse box is junk. I ordered a replacement but the original style has been replaced by a round cylinder-type relay. MY problem is thatI don't know what wires from the harness go where on the replacement relay. The new unit is marked 30, 85, 86, 87. Can yu tell me
what color wire matches each number?

Thanks
Bill Snyder


BILL!
I do not have one of the "newer" relays with me, but remember that the WHITE/RED and the BLACK wires each attached to the "W" (windings)terminals of the old relay. The BROWN and the WHITE/BROWN wires each attached to the "C" (Contact) terminals of the old relay. Now, please
connect the BROWN wire to the copper colored spade terminal, the one offset in direction from the other -- the spade opposite to this receives the WHITE/BROWN. The WHITE/RED and the BLACK wires are attached to the other
two terminals in no particular order. I hope this helps! Safety Fast!
ElectricsLow Beams Also have a tech question for you. My low beams are out. High beams are ok and go on. All other lights work. Put in new headlight switch but didn't help. Before lights went out replaced the wiper switch and was trying to
get the trunk light to work. Could not fix the trunk light. Any
suggestions?
Taxiguy

About those low beams: You MUST have a test light.
Check the BLUE/RED wires at the right front of the MGB to see if they are HOT when the headlight switch is on and the dipper switch is in its "natural" position. If so, the problem lies with the wiring or the bulbs in front. If not, then remove those column covers and test the switch
right there -- again, the BLUE wire goes hot when the headlight switch is turned all the way on -- this BLUE wire is then directed into the low beams (BLUE/RED) or into the high beams (BLUE/WHITE ). Remember that "Blue with
White is Bright." If you write back for further hints, be certain to include the year and model! Hope this little bit helps:
ElectricsStarter Rubber BootHello John,
I am restoring a '67 MGB GT, and am having trouble locating the rubber boot which covers the starter solenoid & engagement lever inside the drive housing. (I need almost everything else too, but right now I'm into the starter!)
I used to live in Kalamazoo, and you did some work on my 68 Midget then (mid 70's).
Jack McInnis, Port Huron, MI

Jack! Just offhand, a 1967 MGB does not have a pre-engaged starter motor -- so I wonder what type of engine/gearbox, or what the actual year of your car truly is. Further, there are two type of pre-engaged starters. One uses a solenoid fitted with flanges to the starter; the earlier uses long studs. Which type do you have? You know, we do not sell parts by mail -- but I doubt you can find this specific part through any parts supplier.
Why not come over some day and look for that part and the others you probably need?
ElectricsRelays In most modern electrical systems, the switches on the dash that control such items as the headlights, heater blower, horn, and other big current items only switch the control current for relays that actually operate the above items. In the MGB, that is not the case, and the switches carry and switch the entire current, with consequential impact on the longevity of the contacts, wiring harness, etc. It has occurred to me that it might extend the life of my switches and harness if I were to add relays to operate big current items. I can get good individual 12 volt relays and simply stick them in where needed, but I was looking at the arrangement on my '86 300ZX and thought that something like it might be really neat. It has a relay block with plug-in relays and a cover over the whole thing. So, my question is (finally!), is the addition of relays a good idea,
and, if so, do you have any suggestions as to how it should be done.
Thanks,
John Hubbard

John! The most common relay fitted is for the horns -- and this isn't to power the units, it's to ground them! I'm trying to think of which switches we change most frequently in the shop -- and it's not the headlight switch. We do change turn signal switches and wiper switches -- the column mounted units, but more because of the abuse they suffer by careless use, rather than from the current flowing through them. I guess if I were going to place relays in any circuits, it would be just the horns. In this case, no new wires are needed. The coil on this new horn relay receives Purple (from the horn circuit) HOT, FUSED and Purple/Black (to the horn switch). So, when the horn switch is operated, the relay closes. On the relay contacts, fit a BLACK (Earth) and the Purple/Black that goes to the horns (not to the horn switch). Now, when you hit the horn switch, the relay operates, the horns are earthed, and they honk -- LOUDLY!

You'll be pleased to know, though, that I just created the T Series and MGA 1500 turn signal relay unit from two double pole, double throw relays from Radio Shack -- total price with mounting board was about $20. And, it works GREAT! Of course, it's not Lucas.
ElectricsTurn SignalsJohn,
I am considering purchasing my first mga (first mg of any type) and noticed that this car does not have turn signals. My questions is can the car be retrofitted with turn signals?

Thanks for any assistance you can offer. Best Regards,
Jim

JIM!

To my knowledge, ALL MGAs were fitted with turn signals. The 1500's used one bulb in the rear with two filaments -- necessitating the use of an expensive turn signal relay box; the 1600's and MKII's used two bulbs in the rear with three filaments -- brake, tail, turn. Now, it may be that
the former owner wired the car himself and did not provide for turn signals - in that case, fitting all the proper components would be time consuming and expensive (to do "correctly"). These are not good answers to your
question -- provide me some more info and I can advise you more easily!
ElectricsGenerator Charging Circuit Hi John, Wonderfull and immensely helpful page!!! My TD (5 post) charging system is giving me fits...Gen cuts out at around 3800 rpms. Light comes on. Slow down to 2000 rpms and it comes back on line. This is a newer Lucas regulator. Voltage was high...charging at almost 16 volts. I turned it down to 14 volts max, but it still cuts out at the same engine speed, so not voltage related. Any thoughts?? Also, I would like to convert my rearend to 4.3 and have a ring and pinion set from an MGA. Could you estimate cost if I supply the gears?
Many Thanks, Steve Tobias

I know that those charging circuits can sometimes give you fits. There are just a couple of components and a couple of important connexions -- follow me through on this: Ensure that the battery cables are tight, the fan belt is tight, and that the control box has a good earth connection
(add one if you're in doubt). Then, test the generator -- remove the YELLOW/GREEN wire from the F terminal on the control box; remove the heavy gauge YELLOW wire from the D terminal on the control box. At about 2000 rpm, hold these two wires together for several seconds, then separate them
-- you should get a BIG flashy spark. If you do, the generator is OK; if you don't the generator is faulty. Now, of course, there can be certain faults in the generator that are not evidenced in this test -- but this
gets 99% of them. If the generator is working and the control box is earthed -- and the charging is not working correctly, then THROW AWAY the old control box and purchase a new one. All attempts to adjust are just a waste of time. These thoughts are based on our labour rate of $50/hour and the cost of a new control box of about $60. Hope this helps.

The conversion takes 10 hours of labour, or $500. The only parts we'll need will be the pinion seal and the paper gasket. We've converted hundreds of these diffs -- it is really a good move! You will have to recalibrate your speedometer or install an "in-line" induction gearbox to
get the speedo to read correctly. I can advise you more at the time you send the diff. AND, that diff, without backing plates or half shafts, should come UPS -- it's under 150 lbs.
ElectricsReverse LampsJohn,
I am having a problem with my reverse lamps not working on my 1977 MGB. They haven't worked since I purchased the car five years ago. I purchased brand new light units and have checked all connections. It appears the reverse lamp plugs are getting 9.5 v of power when the car is put into reverse.
I don't have a wiring schematic for my 1977 MGB. Could you e-mail me one or suggest what I might do to make my reverse
lamps work correctly.
Thank you. K. Beatty

Mr Beatty!

Remember the first rule of Lucas electrics: approaching an electrical malfunction without a test light and a wiring diagram is a certain route to madness.

The reverse light switch is probably your problem. This switch is located on the RH side of the gearbox, just above the gearbox crossmember. It is easily grasped with pliers and rotated, then unscrewed by hand. The reverse switch receives power through a GREEN wire (ignition hot, fused),
and sends it to the rear of the car in a GREEN/BROWN wire. To ensure that this IS the problem, find the connection of the gearbox loom to the main wiring loom, at the rear of the right front inner fender (the main, rear, and gearbox loom all combine at this spot). Find the GREEN/BROWN entering the rear loom; find the GREEN exiting the main loom to the gearbox loom. Disconnect these wires and attach them with the ignition ON. I'm sure you'll find that the reverse lights illuminate. The new switch is about $30.
The problem using a voltmeter (as you have done) is that while some voltage is passed by the faulty switch, the switch cannot pass any amperage. Always use a test light --either it works, or it doesn't, and it draws current.

Hope this helps
ElectricsAlternatorHi John
I m the proud new owner of a 78 MGB. After working out most of the
minor bugs I have encountered a fault that I have not been able to solve.
I
used your Part Four on alternators as a guide but did not see My specific
problem noted. When I start my car the ignition light comes on brightly
and
remains that way for the duration. Thank you for your support and
actually
have been following your page and advice even before I became an MG
owner.
Sincerely
Rob Stachurski

Rob!

Let me restate your problem: You turn the key from off, through
accessory, to "ON" and the ignition light comes on. Lights on, lights
off, the alternator warning light remains on no matter what the engine rpm.
This indicates a problem with the alternator -- most likely the diode
pack. However, be certain to test the "surge device" which is a diode,
infinite in one direction, about 4K ohms in the other. If this goes
continuous the ignition light will not go out.
You should be having a problem with your battery charge, which you do not
mention.
ElectricsIgnition LightHi John, Jeff Rutt. I have a question I hope you can answer in maybe,
ah...let's say, fifth grade English. My ignition light glows with a real
dim
glow at all times, it will not go out. It does glow bright when started,
as it
should. But, then continues to glow. Any suggestions! Thanks in advance.
Jeff

Jeff!

The alternator is faulty. The rectifier pack has a failed diode. I'll
give you 95% on my answer. 1% chance that it's a wiring problem under the
steering column; 1% chance it's a wiring problem at the starter/battery; 3%
chance it's something else in the alternator. Send me the alternator and
I'll solder in a new diode pack and fit new brushes for 1/2 hour or $25
plus the cost of the parts (about $25) plus shipping.

Jeff, thanks very much for your poster idea. We selected the poster drawn
by Bruce Wyckoff which had a lighthouse and a dolphin (or was that a
porpoise?).

See you this summer.
ElectricsElectrical ProblemI was hoping to speak with you at the Heartland Regional on Saturday,
but you had more cars than time allowed and did not get to me. I have
an electrical problem that I was appreciate your direction on. When I
turn on my left turn signal, the back up lights flash with the turn
signal. When I use the right turn signal, everything works properly.
The back up lights do not illuminate when the car is in reverse, only
when the left turn signal is on. Everything else concerned with
lighting works properly. I have checked the wiring inside the boot
against the diagram, and this all seems to be connected properly; or at
least the colors seem to be in the right places. I would appreciate any
advise that you may be able to offer as I must take the car for a state
safety inspection soon and it will not pass in the condition. Thank you
for your anticipated assistance.


JIM!

I would first tell you to search for a faulty earth (ground)
connection, but it would take several faulty connections to get the reverse
lamps to flash with the left turn (rather than "instead of" the left turn).
The circuits are all quite separate -- and as you've inspected the wiring at
the back of the car (Green/Red is Left)(Green/Brown is Reverse), then I can
only imagine that there is mis-wiring at the rear of the right front inner
fender. There, where the main loom connects to the gearbox loom and to the
rear loom, you will find a Green/Brown entering the rear loom (the gearbox
loom has only three wires, and the main loom runs horizontally and has about
fifty -- the rear loom has about six wires). Look at where that Green/Brown
is connected! I'll bet it is pushed into the Green/Red Lucas four-way
connector. If that is NOT the case, write back and we'll take it further.

It was a real pleasure to look at and work on all those MGs at the
Heartland Regional. The next day we went to the Kansas City Zoo, and, more
impressively, to the display of the wreck of the riverboat "ARABIA." That
is a display that ALL should view!
ElectricsIgnition SwitchJohn: I've recently gotten a 1978 MGB from my Dad. He' up in years, but
still likes to tinker with the old classics. I'm just getting started
with
some of the mechanical problems that need to be addressed. The ignition
switch will not allow me to remove the key and doesn't shut the car off
when
it is turned to the off position until after a delayed period of time. I
have been told a NOS switch is not available for this model. I was
contemplating getting a used one, but thought I might be buying the same
problems. Any suggestions? Chet Edwards

Dear Chet!

You have two problems here: 1) key removal. Ensure that you press
the small oblong button at the base of the key switch while rolling the
switch "off". Only then can you withdraw the key. Sometimes it is
necessary to rotate the steering wheel allowing the pin of the locking
assembly to fall into place. Failing that, remove the key switch (use a
prick punch and a hammer to spin out the shear bolts which hold the key
switch halves together around the steering column).
2) Your vehicle is wired so that the engine will not shut down
until the anti run-on system places a vacuum on top of the gasoline in the
carburetter float bowl. If you have replaced the original carb with a
downdraught Weber this will be impossible. So, fit a diode into the
BROWN/YELLOW wire coming from the back of the alternator, with the arrow of
the diode pointing TOWARDS the alternator. Now the engine will shut down
(perhaps with a hint of dieseling) and the alternator light will work.

Moss Motors DOES have new key switch assemblies for about $200 I
believe.

Hope this helps!
ElectricsElectrical IssueGreets,

Kudos for the best ' Eliminating Rear Axel Clunk ' technical information
that has ever been 🙂 ! The url appears to be an orphan however.
other url on the site that i could find. Someone at the bulletin board

I have a Lucas mystery to solve :-/ ! My switched power lead from my CD
player is connected to the 'FUSE BOX' with a blade connector at the same
location as the 'Brake Lights'. At night, after the car has warmed up,
with the lights on, when the brakes are depressed, occasionally the power
from the switched lead is lost and the CD turns off for an instant.
Sometimes repeatedly putting on the brakes under these conditions will
repeat the CD power off. If the engine is cool at night and i am just
starting out this does not occur. This only occurs with the use of the
brakes at night, and usually just when the engine is mid range temp due to
important activity ... ... like cruising Las Vegas Strip 🙂 ! This is a
long time ongoing problem, like 3 years or so.

Yeppers ... ... I could find another switched lead and this problem would
probably go away. That would be defeating the JOYS OF LUCAS ELECTRICS
though 🙂 !

Thanks for all of your help. Especially the Clunk info. I have had one
car in the last 20 years. A 79 MGB (125k mi). MG's are amazingingly
durable ... ... ... if the owner is not negligent 🙂 .

enjoy your summer

dennis

DENNIS!

First, the basics: Half of all electrical problems in the MG is
caused by loose/corroded/high resistance battery terminal ends. So, Remove
the cable ends, clean them, clean the battery posts, open the clamps, and
resecure them. Half of the rest of the problems is caused by a dirty
fusebox. Remove the fusebox, remove the fuses, clean the fusebox in a
glassbead cabinet, with ammonia (soak it), something! Then crimp all the
female connecters before reattaching them, AND, squeeze the fuse clips to
ensure a good connection.

Please note: the "proper" power lead to your CD player is
WHITE/GREEN and is dangling out of the console loom, just waiting for you to
use it. This is an UNFUSED wire which is "ON" at the first key position
(OFF, FIRST(ACC), ON(IGN), START).

Why at night, why when the engine is warm, why not the rest of the
gauges -- these I cannot imagine without looking at the car. But follow the
rules above and expect success!

SAFETY FAST!
ElectricsBrake LightsI'm having a brake light problem (i.e., they don't work!) on my 74 B. My
voltmeter shows that I've got current in the socket when the brake pedal
is depressed, as I think it should. The light bulbs are double filament,
and the ohmmeter says that both light bulbs circuits are complete. The
tailights work properly, but even when I push in on the light bulb to
ensure proper contact, the brake lights will not light on either side.


Thanks,

Dan Hiltz

DAN!

Throw away that voltmeter! The ONLY test equipment I use for MGs is
a 12v test light and a jumper wire. (Well, almost!). The laws of physics
are this: The brake light switch has extremely high resistance (a new one
does not, but yours does) so when you check the voltage with NO LOAD on the
circuit, you read 13.2, or battery voltage. BUT, when a load is placed on
the circuit (the brake lights), the resistance is too great to allow the
passage of enough current to light the bulbs. I'll bet you that if you
check the voltage at the GREEN/PURPLE wire with both bulbs in place and
switch closed (pedal down), you'll find virtually zero voltage! A test
light draws current and avoids these errors -- the voltmeter draws no
current (well, nearly none).

Test my theory by connecting the GREEN to the GREEN/PURPLE wires at
the brake light switch. This will send uninterrupted current to the back of
the car and the lights will work. The switch you need is not inexpensive
(about $30) but all attempts to open it, rework it, and make it work in the
car will be futile.

SAFETY FAST!
ElectricsReverse LightThank you for your reply. Sure enough, the Green/Brown wire was
connected to the Green/Red wires at the four-way connector. When I
unplugged it the turn signals started working properly. However, I do
not know where the Green/Brown is to be connected, and I noticed that
the reverse lights do not work at all now. I expect that the
Green/Brown is for the reverse lights, but I'm not sure where it is to
be connected. All other systems seem to be working properly. Would you
please direct me through the final step of this process? Thank you in
advance.

Jim!

The GREEN/BROWN wire entering the rear loom should be connected o
the GREEN/BROWN wire exiting the gearbox loom -- it's the reverse light
circuit.
ElectricsLightsI have a 1980 MGB, I am having problems with the lights, the right side
will
work and the left side will not, other times all lights will work, I
replaced
the fuse block and this corrected some of the problems but I still have
problems, do you have any suggestions, When the ignition is turned on the
right side lights stay on all the time but the left side will not burn.
HELP!!! I can wiggle the wires and then the lights will sometimes work.
Thanks Steve T.

STEVE!

Let me suggest that you look carefully at your wiring again. The
new fusebox should have a bridged connection at the top of the forward side,
and to one of the four common spades a RED/GREEN should be connected. The
third fuse, front, takes the WHITE/BROWN; the fourth fuse, front, takes the
BROWN wires.

The first fuse, rear, takes a pair of REDS; the second fuse, rear,
takes a pair of REDS; the third fuse, rear, takes the GREENS; and the fourth
fuse, rear, takes PURPLES.

Remove the fuses and squeeze the little clips together so they hold
the fuses more tightly. When you remove each female spade teminal, pinch it
with pliers so that it fits more snugly.

This should take care of MOST of these lighting problems!

SAFETY FAST!
ElectricsOverdrive SwitchJohn,

Thank you for telling me about the Overdrive/ TCSA switch function.

All electrical paths checked out but that one. I checked the new
switch after I removed it from the transmission and it was OK. The
problem was the plunger that activates the switch. It was frozen inside
the shifter remote control casting and wouldn't activate the switch.

After redrilling the shaft hole to remove some burrs, it works fine
now and all electrical paths are functioning properly. Obviously, the
transmission would have to be out of the car to discover the problem.
Now I know it will function properly after I reinstall the engine and
transmission.

Thank you for warning me about this before I had put everything back
together.

Ron Tugwell

RON!

Thanks for your nice note!
ElectricsAlternator WiringI have a 73 Jensen healey which came with a delco alternator. I have
been told the Lucas a1812 will work, so I purchased one. Now I don't
know how to hook it up. The delco had + - bat and Ind connectors, the
lucas has two large brass lugs, one smaller non brass lug, and a ground
lug on the housing. Any help would be appreciated. Enjoy you page.

Thanks
Roy Burnette

ROY! I hope I can help: The Lucas alternator has the three male spade
terminals: from the inside out: WIDE - WIDE - NARROW. The first WIDE is +
sensing; the second WIDE is the + output; the third spade, the narrow one,
is the INDICATOR lead. The alternator - connection is made through the
case. Hope this helps. John Twist
ElectricsOverdrive WiringMy overdrive gave out on me few weeks ago, it stays off so not too
much trouble.

However it's managed to burn out the wiring to the front of the car so
I've replaced that. I haven't missed something though have I, there is
only one wire to the over drive (via the switch)?

Also since this did not fix the problem I drained the gear box,
drained the overdrive and removed the solenoid, the wire that goes
into the sealed unit has sanpped off leaving 3/4mm protruding.

I have found an article by you on the web refering to rewinding and
repairing a solenoid, how did you get in to it to do this??

Thank you for any help you can offer...

Philip Dagnan

PHIL! Even before you rework the solenoid, be certain to fit an in-line
fuse to the overdrive circuit. We do this on ALL the MGBs we see fitted
with O/D. That circuit is now UNFUSED and can burn up the main harness,
right back to the ignition key if the short is bad enough!

Unwrap the plastic/paper from the solenoid, unwrap one turn of wire, and
solder a new piece of 18 AWG (American Wire Gauge!) wire to the fine
solenoid wire. Then tape the works back up again. You should be able to do
this without grossly increasing the diameter of the coil. If you have the
cast black plastic solenoid, this is not possible.

Good luck!
ElectricsReverse LightsHow do I make the revese lights work?To make your reverse lights work you need an operational switch on the gearbox and good lights are the rear of the car. The circuit works like this: The GREEN (HOT / IGN ON/ FUSED) provides power to the gearbox switch (junction of the main loom and gearbox loom). The switched lead (GREEN/BROWN) comes from the switch and goes to the rear lamps (junction of the rear loom and gearbox loom). The rear lights have to be grounded (ring terminal under the licence holder).

Test the circuit be jumping through the switch: Connect the GREEN/BROWN from the rear loom directly into the GREEN at the junction of the main and gearbox looms. Now, with the key on, the reverse lights should illuminate. If they don't, look at the bulbs and sockets.

Reconnect the gearbox switch: GREEN from main loom to GREEN of gearbox loom; GREEN/BROWN from gearbox loom to GREEN/BROWN of rear loom. With the ignition on, the lights should illuminate when you engage reverse.

Problems are: plugs disconnected from lamps; faulty switch; faulty bulbs -- in that order.
ElectricsReverse Lights SuccessJohn, with your help the reverse lights are now working! Thanks again
for all your help. Little by little I'm learning about these cars, and
working on them is lots of fun. Well, almost as much fun as driving
them. The next project is a '72 B. I may have more electrical
questions as this car needs a new wiring harness. Have a good week, and
I owe you one.

JAMES! Good going! Glad it all worked out!
ElectricsElectrical IssuesDEAR JOHN,
I HAVE NOT USED THIS SERVICE BEFORE AND I DO NOT KNOW IF I AM USING IT
CORRECTLY I.E., AM I SUPPOSED TO E-MAIL YOU OR FAX YOU AND DO I NEED TO
GIVE
YOU A CREDIT CARD # TO GET AN ANSWER TO E-MAIL (IF SO JUST LET ME KNOW SO
I
CAN GET THE # TO YOU ASAP).
MY FIRST CAR (1971) WAS A 1964 MIDGET. MY NEXT CAR WAS A 1972 MGB-GT.
THAT WAS A LONG TIME AGO ANG WHILE I USED TO BE VERY HANDY UNDER THE HOOD
AND
HAVE BEEN SURPRISED HOW MUCH HAS COME BACK TO ME AFTER 23 OR 24 YEARS, I
NEVER KNEW ANYTHING ABOUT ELECTRICAL TO SPEAK OF. I HAVE RECENTLY AQUIRED
A
1976 MGB THAT APPEARS TO BE IN REALLY GOOD SHAPE. THE PROBLEM IS THAT THE
PREVIOUS OWNERS HAVE REMOVED THINGS LIKE THE WINDSHIELD WASHER UNIT AND
OTHER
THINGS UNDER THE HOOD AS WELL AS HAVING GIVEN THE CAR ONE OF THE NASTIEST
PAINT JOBS ON THE PLANET. I CAN DEAL WITH THESE THINGS. IN ADDITION TO
UNHOOKING THINGS AND THEN HOOKING THEM BACK UP, I'M NOT SURE THE THINGS
WERE
HOOKED BACK UP PROPERLY. THE HORNS WORK WHEN YOU USE A WIRE TO CROSS THE
CONNECTIONS AT THE HORNS THEMSELVES BUT WHEN YOU PUSH THE HORN BUTTON YOU
GET
NOTHING(THERE IS FIRE TO THE SWITCH) OR IF YOU TOUCH THE ONE WIRE RUNNING
TO
THE SWITCH TO THE STEERING WHEEL, YOU GET A DULL LOW NOISE FROM THE HORN
AS
THOUGH IT IS TRYING TO SOUND BUT JUST CAN'T. HELP! I HAVE FINALLY GOTTEN
ALL THE LIGHTS TO WORK, HURRAY! I ALSO HAVE A PROBLEM WITH THE BRAKE
PRESSURE SWITCH. IT HAS A HOT WIRE RUNNING TO IT, BUT DOES NOT WORK--I
HAVE
DISCOVERED THAT THE WIRE THAT RUNS FROM THE EMERGENCY BRAKE IS NOT HOOKED
UP
AND THERE IS NO CONNECTION ANYWHERE TO HOOK IT TO--HELP! THERE ARE OTHER
THINGS THAT I WILL NEED HELP ON IN THE FUTURE, ( I HAVE ALREADY GOTTEN
MUCH
HELP FROM YOUR ARCHIVE FILE) BUT FOR NOW I ALSO NEED TO KNOW HOW THE FUSE
BOX
SHOULD BE SET UP--I AM NOT SURE THAT WHO ERVER HOOKED THE WIRES BACK UP
DID
IT PROPERLY BECAUSE THE HORN LINE WHICH I BELIEVE SHOULD BE HOT ALL THE
TIME
IS ONLY HOT WHEN THE IGNITION SWITCH IS ON. WHAT COLORS GO TO WHICH POLES
ON
THE BOX--PLEASE HELP. IF I CAN JUST GET THE ELECTRICAL FINISHED THEN I
CAN
GET ON TO THE MECHANICS AND THEN THE ESTHETICS AND THEN TO DRIVING HEAVEN.
THANKS--GREG COTTON

GREG! Reading your note, all in capital letters, is a real eye burner!

The fuse box: If you look at the fuse box from the carburetter side,
then the left side, or front side of the box is the UNFUSED side. The right
side, or the rear side, is the FUSED side. Top to bottom on the front side:
1) Red with Green; 2) nothing; 3) WHITE; 4) BROWN. Top to bottom on the
rear side: 1) RED; 2 ) RED; 3) GREEN; 4) PURPLE. Half of all electrical
problems begin at the battery. CLEAN the battery, wash it down with baking
soda and water, tie it down, replace the battery clamps. Half of the
remainder of the problems come from a dirty fusebox. CLEAN your fusebox --
sandblast it, soak it in soda or ammonia -- something. Then pinch the fuse
contact together before fitting the fuses. Those two items will cover 75%
of your electrical problems.

The horn: You have a faulty contact at the center horn push. Ground
the horn brush (looks like a ball point pen with copper contacts) to see if
the horn works. If it does, then the problem is the horn push -- take it
apart and clean the metal contacts with 600 grit paper. Clean the ends of
the horn brush with the same paper. If the horn doesn't sound, earthing the
horn brush, then look further down the circuit -- is the purple/black wire
connected to the turn signal switch loom? Is the bush that wipes the back
of the steering wheel clean and in place. Simply test the circuit,
connexion to connexion until you find the high resistance, cleaning as you
go. It WILL work eventually!

The brake light switch: The brake light switch is located on the master
cylinder pedal box. It has two wires: GREEN and GREEN/PURPLE. The
pressure switch on the bottom of the master cylinder is the brake pressure
failure warning switch. This circuit is more complicated.

Remember, approaching any electrical malfunction WITHOUT a test light
and WITHOUT a schematic is a certain route to madness. Do you have both of
these?

Hope this little bit helps.

SAFETY FAST!
ElectricsCruise ControlAfternoon John

As sinful as it may seem, because of a leg problem, I must install a
cruise control in my 1951 MGTD. Has anyone done this before and what
type is recommended? Who manufacturers units that would be compatible
with the MG and how easy are they to install? I have done a minimal bit

of research and find there are types with magnets around the drive shaft

and another which goes in line with the speedometer cable for most cars.

But I don't know if either are compatible with an MG. Any information,
comment or recommendation would be appreciated.

Stu Keen

STU!

I believe there are three types of sensing units: high tension coil
wire; driveshaft magnet; and the speedo one (which is new on me!). I'm
certain you can make an attractive installation as I've seen some in MGBs
that simply disappear into the firewall. You might consider changing your
throttle to a cable design at the same time, as an MGA with a pedestal on
the firewall. I receive several inquires per year about cruise control --
I'd like to hear what you do, how you come out, on this one!
ElectricsBattery for 1971 MGB Dear Mr. Twist; I recently purchased two of the black plastic boxes to
fit
into the two battery holes in my 71 MGB roadster but am unable to find a
12
volt battery of the correct size to fit into one of the boxes. It would
have
to measure about 7 1/4 " by about 6 1/4" and this seems awful small to
start
this car. Do you have any suggestions on where to find a battery of this
size?
I just found your WEB page the other night and really enjoy all the
different things you hit on about the MGs. One of my sons just bought a
run
down 1973 MG and I am going to tell him of this site. Thanks. Ken

KEN!

I'd love to know the numbers of the cars you've purchased. I wonder
if we've seen them at the shop before?

The battery boxes are great for the six volt batteries, but not for
the twelve. I would remove the new box from the right, passenger, side of
the car and fit a group 26 twelve volt in there. Be certain to tie it down,
and to make the earth strap as short as possible (eight inches or so). Use
the one on the left to store tools or parts -- OR, fill it with ice and your
beverage cans the next time you take a trip!

If the battery box seems unusable, because of rust, simply cut a
piece of 3/4 plywood and fit that into the existing battery box -- that
should provide enough bottom support for the battery.

Come visit the next time you're downstate!

FAST FORWARD!
ElectricsCruise ControlThanks John for your reply. I have finished the installation of the cruise control in the MGTD. It went something like this:
I found that JC Whitney carried four cruise controls, but only one was applicable to the MG. Basic cost was $99 PLUS LABOR (MINE!) So what did it entail?
Well, for starters, the cruise control required a vacuum line. There are no vacuum lines in the TD. So I had to make one. Off came the hood (bonnet). Next I took out the breather and two-thirds of the intake manifold (there are three major pieces). I drilled in the center of the tubular "equalizer" intake manifold mounted to the engine block. Next I had to tap it to make threads for screwing in the vacuum hose nipple fitting. What a bear this was. Very thick aluminum or maybe it was cast iron. It took forever and I had visions of braking off the tap in the hole. I covered the bit and tap with grease to minimize metal filings falling into the manifold. I screwed the tap in and out very slowly. The diameter of the manifold was quite small thus the tap hit the opposite side before it was fully seated. Anyway, I coated the threads of the nipple with "make-a-gasket" solution and screwed the nipple in as far as it would go. I am confident it is a good seal.
Next I had to install a magnet on the drive shaft. Using a floor jack, I raised up the car and placed stationary jacks on each side. Then I crawled underneath, listening for any creaks of the 2000 pounds about to fall. I got the magnet wired on, then had to make a bracket to hold the sensor. I tapped the supports on either side of the drive shaft and mounted the pick-up sensor and routed the wires pass the master cylinder up in front of the firewall and into the cockpit through the hole where the wire harness passes.
So far so good, but then I received word from the NEMGTR that I should reverse the polarity of the MG, making the battery's Negative terminal chassis ground as is standard today. This would make the installation straight forward. Until getting the advice, I had planned to put in relays to circumvent polarity problems. I was told how simple it was to reverse, so decided to try. Initially the car would not run after making the switch. Whoops! Who says haste makes waste? I forgot the previous owner had installed a capacitive discharge ignition system and had transistorized one of the two fuel pumps (MK II has two as standard, but I have them electrically separated). I removed the cap, discharge system, which was designed for a positive ground system, and then everything ran fine. But soon I ran out of gas. I switched to the untransistorized fuel pump and I was up and running again. Upon investigation, I discovered I had fried the transistor in the old fuel pump. I removed the three component electronic circuit and restored the fuel pump back to its original mechanical configuration. It now runs fine.
Next, the servo was designed to pull the accelerator cable near the carburetor. There is NO cable in the TD, it is all metal rod linkage. This really limited where I could connect. Also, I had to find a place for the servo motor itself and the 43 inch cable attached. My main objective was to hide as much of this installation as I could so it would not appear obvious when showing the car. There were four possible locations but only one really met my objective. The manual said not to install the servo in the passenger compartment as it would be constantly operating and could be distracting. I figured the manufacturer had never considered putting it in a car with a noisy XPAG engine. Besides, the TD is a convertible and I figured the noise would not even be noticed. So I
installed the servo under the dash on the right side, passed the cable down behind the interior panel, through the floorboard, curved up over the exhaust pipe, pass the transmission and then up through the left floor board where it was attached to the accelerator pedal. I had to keep all bends in the cable to a minimum of 4 inches so it would not bind. My adrenalin might start pumping if the cable should snag and not release while going 60 mph.
Next I made all the electrical connections, to the coil, to positive 12 volts, to the brake light switch, to the ignition etc. Not knowing if this system would work, I did not cut any wires in case I had to return it. So, miles of wire were bundled up in the passenger compartment as I took off for my first test drive.
1) The servo responded only at 3500 rpm and was very erratic. I returned home and called the distributor of the Taiwanese product. I was told to change some dip switches. Off I drove again after making the changes.
2) I was able to actuate the cruise control anywhere between 2500 and 3500 rpm, but could not get it to respond above 3500. The system has a means of nudging the speed upward in half a mile an hour increments. I tried this, but it would not go any higher than 3550. I could feel the accelerator pedal being pulled by the cable but it would not hold. I returned home and made another call, getting a different technician. He said to change more dip switches and to reinstall the shorting plug which the manual said to remove for manual shift cars.
3) Vundabar! The cruise control performed flawlessly. I took the car up to 4500 rpm (the max I dare rev this 48 year old engine) and the cruise control kept it there. I did notice that sometimes when I actuate the control, it will speed up the car about 5 mph and then settle down to about where it was programmed. Probably has something to do about the magnet, the questionable smoothness of the XPAG or who knows what. Hakuna matata - not a problem. I could not even detect any noise coming from the servo. My hunches were right.
Now my project is to shorten all the wires and tidy up the installation.
The system, as installed, is virtually invisible. You see nothing in the cockpit, the controller/programmer flips down from under the dash and locks in place. In the engine compartment the ONLY thing you see is the vacuum hose. This can easily be disconnected and removed for show purposes. Then the only noticeable modification is the brass nipple on the manifold. However, it is now painted engine block red like the manifold and is directly under the breather and thus almost completely out of sight.
I read on the internet about the installation of a similar cruise control on two American cars. One guy said it took him three hours, the other said three days. In my case, I took a day planning the installation, seeing where and how everything would fit and analyzing many options. Then I took two and a half days to reverse polarity and install the system and a half day to run tests and make phone calls of distress.
The installation is fully functional.
Have a great day.
Stu,
ElectricsWiper switch question John
I have a 1973 mgb-gt manufacture date of 10/72. serial number in the
308,--- series
( sorry I do not have the entire number before me ) The car does not have
over drive.
The problem is I need a new wiper switch. and in looking through the
supply catalogs
that I have it appears that the switch is not in production.
Will a switch from a earlier year fit ? or a later year?
How about the midget series will any of those fit ?

Thanks for taking time with this minor question
Dave

DAVE!

You've probably already found a switch but this may help. A Midget
switch would work just fine. An earlier or later switch would work, too,
but you'll have to splice your plug onto the replacement switch. I cannot
believe that Moss, Victoria, or someone would NOT have that switch!

FAST FORWARD!
John H Twist
Electrics1970 MG Midget My ignition light won't go out with engine running at 2000 rpm's. I
checked
the generator. The D terminal is putting out 1.5 volts at 2000 rpm. D and
F
together put out about 20 volts at 2000 rpm. Wiring is OK. Ground is OK. I
sit the control box??? I'm on my 3rd one now!!!

Thanks,
Jeff Hughes

JEFF!

This circuit involves four things: The Battery; The Generator; The
Control Box; and The Wiring.

The battery gravity should be about 1275 when fully charged, and
fully charged, it should spin your engine for thirty seconds without
dropping below 10.5 volts. The battery clamps should be nice and fresh.

The generator works or it doesn't. When you connect D to F at the
control box -- that is, you remove the BROWN/GREEN wire (F) and the heavy
gauge BROWN/YELLOW wire, and touch them together when the engine is doing
2000 rpm, you should have a BIG, FLASHY spark when you separate the wires
several seconds later. You either get this big flashy spark, or not. If
not, a problem with the generator.

The wiring is simply, but you DO need a ground for the system to
work. Add a ground, if you must, from the E terminal right to the battery.

Start up the car, turn on the headlights, have your associate hold
the rpm at about 2000 and disconnect a battery terminal. The car should
continue to run and the headlights continue to shine (although they will
seem to flicker).

Once in a blue moon (which I understand is much less frequently than
we all believe), there is a problem with the field windings in the
generator, causing a charging problem. If there is a problem with the
armature windings, the thing quickly stops working.

Your voltmeter should show about 14 volts at the battery with the
engine at 2000 rpms.

Hope some of this helps!

FAST FORWARD!
John H Twist
ElectricsEarly 74 mgbI have a early 74 with electrical problems
1. Ignition light will not illuminate with engine not running(bulb is good
and ignition switch in the on position) and hot side seems to be on outer
jacket of bulb holder so I cannot tell if alt., is functioning
2. Head lamps are dim with engine running
3. All electrical appliances seem to run slow
Please respond if you can offer any suggestions
Philip W.Gilbert

PHILIP!

Obviously, the ignition warning light should come on when the key is
turned from OFF, through ACC, to the ON position. It should extinguish when
the engine exceeds about 800 rpm. If the light fails to illuminate there
are several possibilities: the light has burned out; the alternator is
faulty; the alternator connections have been reversed; or there are wiring
problems.

Remove the plug from the alternator -- the BROWN/YELLOW wire should
be the outermost. Take your 12v test light (like an ice pick); ground one
end on the engine; insert the other end into the BROWN/YELLOW socket of the
alternator plug; turn the ignition to ON. The test light should illuminate.
If it does not, the ignition warning lamp bulb is faulty or there are wiring
problems. Test both the other BROWN wires -- they should be HOT key ON or
OFF. If they are not, there are wiring problems.

The problem is probably a faulty alternator -- the brushes are worn
out or the regulator is fried. Contact me again when you've conducted the
tests above for the next step!

BTW! The Lucas alternators are not as durable as their American and
Japanese cousins. However, if you keep the battery posts CLEAN and TIGHT;
keep the battery clean and tied down; ensure that the wiring at the starter
solenoid is clean and not fractured, then the alternator will for for
THOUSANDS and THOUSANDS of miles.

FAST FORWARD!
John H Twist
ElectricsBackup lights on when in neutral I did have one current question I wondered if you could help with. When I put my 79B in the neutral position between 1st and 2nd gears the back up lights come on. Naturally when I shift from 1st to 2nd they flash as I go through neutral. Any idea what would cause this?

Thanks

Denny

Denny! The reverse light switch must be adjusted too deeply into the gearcase. It needs another shim (or more) underneath. This is a simple job, as the reverse light switch sits on the RH side of the gearbox, just at the position where the remote control attaches to the rear extension.

Hope this helps!

FAST FORWARD!
John H Twist, Service Manager
Electrics1977 Midget, turn signals The turn signals were operating at different speeds and I thought their
might
be a loose connection so I jiggled here and stuck a finger there. There
was
no smoke and there was no noise of fire, but the turn signals do not work
at
all. The same bulbs light for either so the bulbs are OK. The emergency
flashers do work. I checked the fuse diagram and the turn signals do not
have a dedicated fuse and all fuses were OK. I do not feel comfortable
going
into the dash for a loose wire or something else. I need help bad. I am
in
Farmington Hills, MI and would like to know if you can recommend a repair
shop in my neighborhood or give my some suggestions on trouble shooting I
may
be able to handle.
Thanks so much,
Matt Prosoli

Matt!

The problem with the turn signals is a difference in current passing
through the system, side to side. Either one of the lamps has a faulty
earth or one of the bulbs is not matched with the others, or both. Try
this: turn on the hazards and watch, carefully, at the front and at the
rear. Does one of the bulbs seem dimmer than the other?
If so, the problem is located in that lamp (either ground or bulb). Try
this: take your 12v test light, ensure a good earth, and make contact with
the four lamp bases in succession. If the test light glows, a faulty ground
is indicated. Try this: change both rear bulbs (1157 bulbs which will cost
you about $3.00). If that makes no difference, move those new bulbs to the
front.
One of these methods will diagnose or sort out your problem -- FOR
SURE!!

Contact Guy St John in Northville.

FAST FORWARD!
John H Twist, Service Manager
Electrics1953 MGTD turn signal flasher I am the proud owner of a 1953 MG-TD, and was one of John Twist's first
customers back in the Stone Age, when all of us were younger....
My car is slowly being restored to its original condition, and I finally,
after 34 years, have the original turn signals working!
The flasher unit that was installed works ( it is a three-post,
purchased
from a local auto parts store) but the turn signal indicator light stays
on
all the time (it does flash when the unit is "on"...
Do I have the wrong type of flasher? What voltage, wattage, etc does it
require, or did I wire the thing the wrong way? I have moved all three
wires
on the unit around into different configurations, and it only works when
wired one way. The lights still flash on the car, but the dash light is on
constantly. Any ideas?
Also, my flasher indicator has a green lens - I have seen other MG's with
red lens. Which is correct? My car was built on July 14th, 1953, and we
figure it has a green lens due to its late production date. Moss Motors
catalogs indicate the unit is the same one used for the fuel indicator
light,
so it is green.....any ideas?

In advance, thank you for your assistance..

John L. Russell

John!

Nice to hear from you!

The turn lense, mounted in the centre of the dash, is supposed to be
green (I think). I know the ignition light is RED; I know the fuel light is
GREEN.

The flasher unit should be wired: X or B to the GREEN (battery)
wire; L to the GREEN/BROWN (Lights) wires; the P to the LIGHT GREEN (panel)
wire. I know the LUCAS units work correctly here -- we have fitted NAPA or
similar units in the past without difficulty. I wonder if your wiring is
mixed up?

Thanks for the note -- hope this little bit helps!

John
Electrics1980 mgb electrical questionHi John,
We met once at the TMGR meet in Waco TX hosted by Clay Sawyer and you referred me to an article once on Strombergs that helped. I need help again.

Here is the problem as occurred in chronological order:

1. My Air conditioner, fuel and temp guages stoped funtioning. I checked all fuses and connections in the box. OK. Still not working. THen they started working later???

2. My ignition light stayed on when engine running and got brighter with increased rpm. My battery eventually was dead and I got a new one.

3. Alternator still not charging. I then got it rebuilt.

4. Now, ignition light glows brighter (very bright) with increased rpms still.

SUGGESTIONS?

Randy Yates

Randy!

I believe you have two separate problems. First, you've got a faulty connection for your gauges. I don't remember if you have a 77-80 B or an earlier one. All B's have a fuse box that can corrode and lose contact with the fuses. REMOVE the fusebox and clean it!! Use a sandblaster, a solution of dilute acid, even a bowl of ammonia to soak it in -- but get it CLEAN and pinch the terminals dramatically to hold those fuses fast. In the 77-80 MGBs there is an IGNITION RELAY located to the FORWARD side of the fusebox. This has a BROWN, BLACK, WHITE, and WHITE/BROWN wire. Wiggle the wires and see if you lose your GREEN circuit (wipers,heater, gauges, brake lights, turn signals). If so, change this SPST relay with a LUCAS SRB 402 unit.

To correct the problem with the alternator: Remove and replace (preferably) or at least CLEAN the battery terminals. Ensure the battery is fully charged. Remove the wires at the starter solenoid (the heavy battery wire and the BROWN wires, all on the same stud), clean them, and replace them TIGHTLY, ensure that the alternator is plugged in correctly (BROWN/YELLOW towards the outside of the unit). On some models it is possible to connect the plug upside down. If these steps don't cure the alternator problem, take it back to your shop (or, send it here) and get if fixed correctly!

Hope all this helps a little bit!

John
ElectricsGauge wiring John -
I have had a water temp/oil pressure gauge for my 1953 MG-TD, and was
wondering if you could assist me in a question? I have had the car for 34
years (you have done work on it way, way in the past, back when you were a
new business) and have never had a water temp gauge that works. Now, it
will.
But: I have no idea how the coiled sending "wire" runs to the radiator,
where it screws into the upper part of the radiator.
Any ideas? I think it was coiled around the support for the radiator on
the
left side of the engine....
Your remarkds and insight are greatly appreciated..

John Russell


The capillary tube runs from the gauge down to the bottom left of
the firewall, through a grommet in the firewall, then along the left hand
radiator support rod, then it is coiled before it is fitted into the
expansion tank. Very often, an intermediate fitting is required.

You probably have this all fitted and working -- but if you have any
more questions, my backlog of technical questions is such that I should be
able to answer your next question quickly!

FAST FORWARD!
John H Twist
ElectricsMGB Electrical Problem

Hi John,

Remember I mentioned that my nephew bought a '79 MGB? Well, now he's
encountered a problem, perhaps you can advise.

Electrical problem, this one sounds vaguely familiar to me but I don't
know
the late MGB's very well. First symptom seemed to be that the battery
would
occasionally go dead (not sure if this was related to the present
problem).
Then apparently today, he was driving the car and
the tach started bouncing around wildly, and the turn signals stopped
functioning. Then when he parked it & turned off the ignition, he noticed
that the ignition warning light and the brake warning light would not go
off
-- even with ignition off & key out. Next he noticed some smoke coming
from
under the hood -- no fire, just smoke. Looked under hood and he tells me
it
seemed to be coming from underneath the carburettor.

I seem to recall the late MGB's had some weird electrical problems, maybe
a
voltage stabilizer involved, is there an electric choke on the carb?

Any thoughts? I've cc'd my nephew on this mesage, if you have any ideas
please hit "reply all" and he will see your response. He lives 200 miles
from me so I'm not right there to look at things.

Any help appreciated.

Thanks,
Mark Palmer

Mark!

It would seem that the problem lies not under the carb but within
the alternator -- on the other side of the engine.

All MGs need regular electrical maintenance -- and this 1979 is no
exception, only that besides the maintenance, it certainly needs some repair
now!

So, start at the battery: Remove the battery clamps; clean the
terminals on the battery; clean (or replace) the clamps; fit battery post
pads (to inhibit corrosion); remove, clean, and replace the earth cable;
clean the top of the battery with baking soda and water; charge the battery
fully (one day on a "trickle charger;" and tie the battery down. To do all
this, remove the soft top from the back and work over the rear fender, DO
NOT try to work with the top up -- you'll damage the dash by lying on the
back of the passenger seat! Now the battery is serviced.

Next, work with the connections at the starter motor. Remove the
wiring from the main terminal (the heavy black from the battery and the
several heavy browns from the wiring loom). Tighten the nut on the starter
solenoid stud (13mm), then refit the wiring. CAUTION HERE -- if you're
working under the car, rear wheels on the ground, be CERTAIN to leave the
car in neutral, as it's easy to hit the connection on the solenoid which
engages the starter motor, and THUMP, you'll walk the car off the jack
stands!!!

I am more than pleased to discuss any of this, or the repairs you're
facing, if you'll call me. You can call during the technical hour -- or,
you can call me at home 616 676 1031.

Hope this little bit helps!

John

SAFETY FAST!
John H Twist
University Motors Ltd
6490 Fulton Street East
Ada, Michigan 49301
Phone: (616) 682 0800
Fax: (616) 682 0801
www.universitymotorsltd.com

John Twist is pleased to answer your technical enquiries during his
TECHNICAL HOUR. Call between 1-2 pm EST Monday-Friday.



ElectricsM.G.B 12 volt conversionJohn : I am trying to find a 12 volt batt. to fit in the passenger side of my 64 B.
but can't find one small enough to fit the frame. I read your note in the MGB Experience web site. What exactly is a Group 28, Is that the trade name, ie. Exide etc.? I reside ( winter ) near Tampa Fl. and am having a dificult time finding one to fit by any Mnfg.
Many thanks. Norm Mouldey.

NORM! You've probably already found a battery to work -- but we use group 26 (not 28). That will "just" fit into the box. Use new "American style" clamps on the battery. Move the earth cable from the left to the right side, too.

John
ElectricsHead Lamp Position On is Switched hello from southern tenn. weather may be a tad nicer,
but wet vs your snow. i have a 78 mbg. the new head
lamp switch on the left side of column shroud is at
off position when it is at a forward position toward
dash. the on positon is full rear near the steering
wheel. i had to replace to old switch and i remember
that off was at the rear, then flip it forward to park
lites and then full forward for head lamps. which is
correct since i don 't have an original owner's
manuel? have great day!

Kelly!

The switch is OFF when at its rear most position -- the same
configuration as you remember with your original switch. Simply reverse
the positions of the BROWN and the BLUE wires on the switch and you'll have
it correct!

John
Electrics69' B Roadster, Guages turn erratically while ignition is oI have a `69 B roadster that the gauges operate erratically on. I have driven the car as a daily driver for the last 3 years and 12,000+ miles with no problems. But 2 weeks ago the battery failed in the vehicle for the second time this year. After replacing the battery and starting the car I noticed that none of the gauges were working, I jiggled the wires behind the dash and they came back on. They went out once more and the same strategy solved the problem the second time. However, the problem has become much worse in the last day or so. Whenever the gauges go out a set of wires in the back of the dash (the ones that control fuel pump and ignition and plug into the tach) heat up and the radio lights flicker and then go out and the gauges follow suit. The problem appears to be heat related since when the car is cool or has sat for a few minutes the gauges work for a little while. This morning I drove the car about two miles, during the drive I left the radio on, everytime I stepped on the brake the radio would go off and come back on when I released the brake. I parked the car and turned the radio off, then I stepped on the brake, the radio clock lights went out, the guages fell to their resting places, and the brake lights went out. I drove the car home with no guages or brake lights. An hour or so later I went out and checked my fuses, they were all good. Out of curiosity I started the car to see if they would work, they did. I drove the car about three miles and then parked it. The guages, radio, and lights worked perfectly the whole time. I am baffled by this problem with the gauges and radio. Any suggestions that you may have would be greatly appreciated.
Robert Fairey

Robert!

I believe the problem is simply the fusebox. Try this for starters: Remove the fusebox from the car, sandblast it if you have access to some sort of media blaster -- or, failing that, place the fusebox into a bowl of ammonia -- something to clean the green and corrosion from the contacts. Once clean, pinch the "fingers" that hold the fuses, and, pinch the female spade terminals. With good connections and a clean fusebox, this problem should be eliminated.

John
Electrics1971 MGB Electrical ProblemJohn,

Thank you for your earlier assistance in determining that my intermittent
hesitancy and tach swing was the result of a loose ground connection to
my
starter solenoid.

A few weeks ago, I brought my 1971 B into a local body shop for some
repaint
work. Misc. scratches, nicks, etc. When I got it back, I noticed an
oddity... when driving with the lights off, it was running about 1000 rpm
on
idle, when I turned the lights on (either parking or beams) it dropped
down
to 800 rpm. At speed, the 200 rpm difference also occurred. I checked the
connections which the body shop had cut and reconnected to all the parking
lights and resoldered them. No change. This problem does not occur with
the
radio or heater fans on... cause? corrective measure to take?

Also,possibly related, when driving back from an away event, I decided to
keep up with a Porche 914 and was running 90 mph area on an open stretch
of
the Interstate for about 15 minutes. When I slowed to exit, flipped my
lights on to say "farewell", shifted to neutral and the car stalled! I
was
able to restart easily by turning the key. This issue continued all the
way
home whenever I shifted to neutral prior to stopping. When I returned
home,
I increased the slow idle back to 1000 rpms and the problem has not
repeated
itself... cause? comment?

Thank you in advance for your assistance!

Best regards,

Bart & Audrey Savino


Bart!

I've read your letter twice and cannot determine if, in fact, the
engine changes speed. I suspect it is not changing speed, it's just the
tachometer which changes the indicated rpm. If this is the case, then the
problem probably lies with the power or earth connection right at the
tachometer. The dash lights require an earth, and if that earth is
marginal, then the power required to run the dash light in the tach may be
affecting the voltage passing through the tach. So -- find the BLACK wires
which earth the tach and make certain they're connected under the knurled
knobs which hold the tach fast to the dash.

About the running problem. I wonder if one of the carb pistons is
sticking up just a bit (which would lean out the idle and cause it to
stall). I would take the suctions chambers loose, clean them THOROUGHLY
with spray carb cleaner, and set up the mixtures. Or, it may be that you
damaged the points which has closed them up, increasing the dwell, and
retarded the timing. Point gap is 0.015", dwell is 60 degrees, timing is
about 20 BTDC at idle.

Let me know what you find!

John
ElectricsAlternator Problem
John,
I replaced the alternator on a 1974 MGB GT. I am still not getting a
charging voltage at the battery. I checked the voltage at the plug that
attaches to the alternator. The center terminal reads 12 volts, the A
terminal 12 volts but the I terminal is only 1/2 volt when the ignition
switch is turned on; should that also read 12 volts? Perhaps there is
excessive resistance in that circuit. I am thinking of running a jumper
from the battery to the I terminal and then checking the charging
voltage. Is this a good move?

The schematic shows that the I terminal is connected to the Alternator
warning light. I can't recall ever seeing an alternator warning light.
Is it possible I don‚'t have one? Thanks

Fred Jacobowitz

Fred!

YES, your 1974 MGB/GT DOES have an ignition light. It lies between
the tach and speedo, next to the bright light indicator (blue). The
ignition warning light lense is red. It may be that the bulb has burned
out. You may find it helpful to remove the air control from the dash before
you try to snake your hand up behind the dash to remove the bulb. This bulb
receives power from the ignition switch on a WHITE wire which is HOT with
the ignition ON and it is UNFUSED. The bulb grounds through the
BROWN/YELLOW wire which winds it way, through the loom, to the alternator,
and should be connected to the outmost, small spade terminal. "I" is for
Indicator. When you turn the ignition ON, the bulb grounds through the
alternator rotor and then to ground. When the alternator begins spinning
and making voltage, the "I" terminal rises to charging voltage -- placing
the same voltage on each side of the indicator bulb, extinguishing the
filament.

The plug to the alternator should carry this BROWN/ YELLOW wire,
along with a heavy gauge BROWN (charging/output) wire, and perhaps a light
gauge BROWN (sensing) wire. The two BROWNS should be hot ignition ON or
OFF.

You should be able to ground the BROWN/YELLOW with a jumper and with
the key switch ON, get the ignition light to illuminate.

Some rebuilt alternators are faulty.

Let me know if I may be of more service or help.

John
Electrics1952 MGTD Fuel Warning Light John,

I hope you can take the time to answer a technical question for me. I have
a 1952 MGTD that has a problem with the fuel warning light. I removed the
float switch from the gas tank and found it to be froze-up. It had the
original cork type gaskets. I opened up the housing and found some old gas
with varnish smell inside. I have removed the rubber and insulator
material
and soaked it in carburetor cleaner. The mechanism now works OK. I bought
a
gasket set from Moss Motors. The gaskets are made of a rubber-like
material.

My question is this. Should there be some kind of oil or something inside?
If I close up the unit with air inside, will gas leak inside the unit and
if it does, will that cause an explosion when the electrical contact is
made? None of my books say anything about the switch/sending unit.

Thanks in advance,

Dave Parker

Dave!

I have never seen a fuel sending unit explode, nor have I ever heard
of one catching fire -- not in 30 years in the trade, so it must not occur.
It may be that the air/fuel mixture is too heavily fuel so there's not a
mixture to ignite. It may be that the spark is so miniscule that it just
doesn't have the heat necessary to ignite the mixture.

However, on many (most, all?) the units, there is a very thin copper
wire wound loosely around the axle that holds the copper contacts, and that
wire is attached both the to the axle and to ground. This wire then carries
the current rather than trusting an erratic contact made between the axle
and the pot metal base.

Be cautious of those neoprene (or whatever they are) gaskets.
Sometimes they'll balloon up and leak like a sieve. Moss says they've
tested these things in all sorts of fuel -- but something, sometimes, makes
them fail. We always use cork ones in the shop.

Hope this helps!

John
ElectricsMG TD Add Turn Light John,
I am rebuilding a 1952 MG TD and mine did not originally come with
turn signals, however I would like to add them to make it more
practical for everyday use. I am currently rewiring the entire car
and purchased a wiring harness with built in wiring for the turn
signals. What else do I need to do to fit turn signals to this car??
Do I have to replace the bulbs and the housing for the tail lights and
the front sidelamps, or do I need to add something new all together??
Thanks for the guidance in finishing this project.
Kate

Kate!

In addition to the wiring loom, you'll need a three pole flasher
unit; a turn signal relay; a turn signal switch; two new sockets for the
front wing lamps; and a dash indicator (if you wish to fit it). If you
don't fit the dash light, then go with a more modern two pole flasher (as a
1980 MGB turn signal flasher unit). If you don't want to purchase the
switch and relay new (probably $400 together), then find used ones on eBay
(you can always fix the old ones), OR, you can make up these parts with
non-original parts from radio shack for about $30. You have to fit those
front dual filament bulb holders, though. Hope this helps.

John
ElectricsThe Light That FlickersI hope all is well. It was a pleasure to see you again at the meet in Dallas in July. Your seminar on valve adjusting was the most easy to understand and helpful that I had ever attended.

I recently replaced the ignition relay on my 1979 'B. It would start but not run, and this seems to have fixed the problem, as it is now running fine. However, since the replacement, the ignition light on the instrument panel flickers. There seems to be no pattern to the flickering, as it flickers at all rpm levels. I had the idea that there was a loose wire, but could not find one that seemed to be loose in the area of the relay.

I would appreciate any help that you may be able to offer.


Jim Pendleton

Jim!

Thank you for a most wonderful compliment!

The circuit for the ignition warning lamp is this: One leg of the warning light is connected to the field diodes on the alternator. There are no splices or connections (LUCAS -- Loose, Unsoldered Connexions And Splices) between the lamp and the plug at the back of the alternator. If there is a problem with the alternator, the light might flicker. But, of course, the light should remain extinguished during normal running. The fact that it illuminates indicates a bad connexion either at the back of the alternator, within the alternator, or at the starter solenoid.

The other leg of the circuit provides power from the ignition switch. A WHITE wire leaves the ignition switch, runs through a plug, then to the ignition warning light. If this wire were to occasionally earth, then the light would flicker -- but, on the other hand, if it occasionally earthed, the WHITE circuit would incinerate -- so it's not that!

I'd put my money on the alternator or connexions at the starter motor solenoid.

Let me know what you've found!

Flickers: Isn't that the "full" position on the Lucas Lighting switch -- Flicker, Dim, Off?

Good luck!

John
ElectricsIgnition Warning LightMr. Twist:

Any help would be appreciated. '56 MGA 1500; Ignition Warning Light came on, found dynamo armature wrappings burned, disintegrated. Replaced dynamo, but Warning Light burned brighter and pulsed; was told likely 'fried' voltage regulator when dynamo burned up. Replaced voltage regulator, same result, warning light still brighter and pulsating.

Any advise would be greatly appreciated.

Gary Hancock

Gary!

There are four components in the system: Dynamo (Generator); Control Box (Regulator); Battery; Wiring.

First of all, polarise the dynamo. Do this by jumping between the A and F terminals on the control box. Spark, Spark! Just jump these terminals twice -- don't linger with your jumper wire (or screwdriver, or paperclip, or penny) -- just spark, spark, and it's done.

Now, remove the YELLOW/GREEN from the F terminal of the control box. Remove the heavy gauge YELLOW from the D terminal of the control box. Have your associate start up the engine and rev it to about 2000 rpm. Touch these wires together, hold them together for maybe two seconds, then separate them. You should be a LARGE, FLASHY spark (it's about 100 volts!). If you DO, then the dynamo is OK; if you don't then the dynamo (or wiring) is faulty.

If the dynamo works and the light remains on, then purchase and fit a new control box.

That should do it!

Questions? Call me in the evening.

John
ElectricsThe Light That Flickers Cont.Thanks for your quick response. I found that the brown wire with the yellow tracer was not connected. I also found that the screws that hold the plastic cover on the back of the alternator were missing. I was unable to get the spade connector on the brown with yellow tracer wire to plug into anything on the alternator. I removed the white plug from the alternator and found that three spades were intact in the back of the alternator. There doesn't seem to be anything in the white plug to hold the brown/yellow wire, although the other two wires are securely fastened. Is something missing from the plug?

Moss does not show the white plug nor the screws to hold the plastic cover on the alternator in their catalog. Any further advice that you can offer for the mechanically declined would be most appreciated.


Jim!
Just use some small (maybe #4?) Phillips screws from the hwd store to hold the cover on.

The BROWN/YELLOW spade has a barb -- fold this barb outwards and then slip the spade into the white plastic block. The barb should hold the spade in place. Now you should have three wires in the plug to connect to the three spades on the alternator.

John
ElectricsImproper wiring connections Ref:
1) Official MGB 1975-1980 Workshop Manual, Section Na.12, page 246.
2) Tech Tips in Moss Restoration Parts & Accessories Catalog MGB-16

John,

1. I would like to solicit your help in identifying the proper connections
for the two (2) wiring harnesses that connect to the Transmission on a
1977
MGB w/Overdrive.

- I can account for all the connections on Harness #1....... to the Rev
Switch, OD Inhibit Switch, OD Switch on Gear Shift, and OD Solenoid, which
is consistent with the wiring diagram in Ref 1) (above)

- The problem is with Harness #2 that connects the "Vacuum Advance Relay"
(on the Break Pedal Box) to the "Micro Switch" (mounted on the
Transmission). There are two (2) wires (a Yellow/Brown and a White/Brown)
in this bundle with no apparent place to terminate. Note: There are
"bullet
connectors on both ends of both these wires, plus there is connector
sleeve
on one end of the yellow/brown wire.

- Ref 2) indicates the yellow/brown wire goes to ....Drivers's Seat Belt
to
Time Delay Buzzer; however, I do not see any place in the transmission
tunnel (under the car) to make this connection.

2. Any advice you have to offer would be greatly appreciated.

Regards,
Paul!

Let's start at the connection between the main harness, the rear
harness, and the gearbox harness, located at the rear of the right front
inner fender. There is a four-way Lucas female connector which receives
power from a WHITE wire, and transfers that to another WHITE wire from the
rear loom to operate the fuel pump. This is an unfused circuit! Also
connected to this four way connecter is a WHITE/BROWN wire, most often
encased in a black plastic sheath. Later cars have this wire part of the
gearbox loom. This WHITE/BROWN **MUST** be fused to ensure that the loom
doesn't burn up from a dead short. Simply fit an in-line fuse between the
bullet connector and the WHITE/BROWN wire.

This WHITE/BROWN is connected to a YELLOW/PURPLE and then enters the 3/4
lockout switch, on the top left of the remote control housing. A YELLOW
(*)wire leaves this switch (which goes hot in 3rd or 4th gear) and is
connected to what looks like a "micro-switch" at the front of the remote
control assembly. This micro-switch goes continuous in reverse, 2nd, and
4th. Leaving that switch is eventually a YELLOW/RED which goes up the TCSA
(transmission controlled spark advance) switch on the brake master cylinder
box. So, the only time the TCSA switch can receive power is when the gear
lever is in 3rd or 4th AND in reverse, 2nd, or 4th. So -- that TCSA switch
is powered ONLY in 4th gear.

If you have overdrive, then there is yet another YELLOW wire which
connects to the YELLOW/RED connectors and goes to the overdrive switch in
the gear lever. From the gear lever, there is a YELLOW/PURPLE which goes to
the overdrive solenoid.

The whole point of this is to run the TCSA switch only in fourth,
and to allow the overdrive to work only in fourth.

By 1978, the two switches had been replaced by a single switch
(still located at the left top of the remote control assy).

Trying to explain all this without a wiring diagram is so very
difficult.

Send me your fax number and I'll fax back the FACTORY wiring diagram
(which is wrong), but it may be better than yours!

John
Electricsline fuse John,

Thanks.

I found the location of the Junction Connector you identified, and the
White/Brown wire that goes to the Switches/Connections on the
Transmission
& Over Drive Solenoid. It is my understanding that I only need to
install
a "line fuse" in the White/Brown line that goes to the transmission. Is
that correct?

Regards,
Paul!

Yes! Just fit an in-line fuse to that WHITE/BROWN wire and fit
about a 10amp fuse to the holder.

John
ElectricsRadioQuick question: that Sony radio you installed a few years ago has stopped working (no power). I don't see a blown fuse, and the line fuse to the radio seems intact.

Can you give me a suggested troubleshooting list? In particular I'd like to figure out whether current is reaching the radio and I don't know the best way to check that.

Thanks in advance for your reply. - Terry
Terry!

First of all, arm yourself with a 12v test light. Don't use a meter -- you'll get confusing readings. The test light either works or it doesn't. So -- test the radio power wire, then find the white/green wire behind the radio console -- that should go hot with the key is turned from off to acc. Then come back to the steering column and test that wire at the key switch. Your failure to get power to the radio lies somewhere along this circuit. Find it logically by backing up to the ignition switch.

Hope this helps!

John
ElectricsAlternator 78B
Hello , I have a 1978 MGB Roadster, and have some questions that I hope you can help me with?
After driving the car for about 2 or 3 months the regulator on the alternator goes, once its bin replaced the car runs fine again, until the 2 to 3 months is up, what is wrong??
I am also leaking anti-freeze, not from any hoses, the rad, or thermostat. It starts leaking once the car belts start moving? When the car sits it won't leak????

Thank You,
Well -- you've got an interesting problem with the alternator. Here are some "rules." The Lucas alternator is a good unit as long as the battery is never jumped; the battery cable ends are kept clean and right (that means remove them, clean the clamps and the posts, and refit); and the main connection from the battery to the wiring is tight -- at the starter solenoid.

Here are some more: The rectifier is always the unit that fails, so ALWAYS solder in a new one. Always change the brushes, as they're so inexpensive. The regulators never go bad. To every rule there is an exception.

So -- what's wrong with yours? I am loathe to diagnose it from this distance, but I simply cannot believe that your regulator keeps failing. I believe you're continuing to mis-diagnose the problem.

The water pump can (and sometimes does) leak ONLY when the car is running. So, take the car for a run then let it idle and watch under the pump. That should tell you the truth!

Hope this helps!

John

ElectricsBrushes for Lucas dynamo Dear Mr. Twist,

I have a 1925 Rover 16/50 (in the family since my grandfather bought it
new
in England) containing a Lucas "dynamo type E.418.L 12 volt" (according to
the service manual). It works, but I have no idea how old the brushes are
and feel I should try to obtain a new set (of three). In browsing the
internet, I found that you service Lucas dynamos, but possibly not ones
going back to 1925. On the other hand, the same brushes may have been
used
on many generations of dynamo. Can you help?

Regards,

Kenneth
Kenneth!

I do not know if the brushes I have would work -- but you know that
an "old fashioned" starter/generator shop in your home town will certainly
have brushes that will work. The nice thing about the carbon brushes is
that you can ALWAYS make larger ones smaller with some relatively fine
sandpaper (220 grit). The opposite, of course, is not possible! In any
case, I bet your local shop can help you out just fine!

John
Electricsre-polarise GeneratorHi John,
I wonder if you had any ideas about a problem I'm having with my B?
My friends at the body shop connected the battery with a negative ground
as opposed to the right way! It had been driven about 5 miles that way.
I replaced the bad fuse for the radio and that now works. However the
battery fails to hold a charge. The ignition light glows (1/2 bright) on
occasion at speed and certainly when the headlights are on. I have
tightened the fan belt to ensure no slippage. I have had the generator
tested too and that's OK. Help!
regards,
Marty
Marty!

At worst, both the generator and control box are damaged. At least,
you'll want to re-polarise the generator.
Follow these steps:

1) Polarise the control box -- with a jumper wire, flash twice between the
starter solenoid "hot" lead and the "F" (smaller) terminal on the back of
the alternator. Now the system should work correctly.

2) With the engine running about 2000 rpm and headlights ON, disconnect the
negative lead on the battery. If the engine continues to run, then the
charging system is working.

3) With the engine running about 2000 rpm, disconnect the D and F wires
from the back of the generator. Use your jumper wire and connect these two
terminals together for about one second, then break the connection. If you
get a large flashy spark, the generator is working. If you don't get the
spark, remove the dynamo and send it out for repair.

4) Repair of the control box is an exercise in futility. Purchase a new
one if you have to.

Hope this helps.

John
ElectricsStarter Motor In 4th gear, I can push my
car,
and the engine revolves, so it is not seized. I tried the test you
suggested, and when I touch the brown/white wire to the spade, nothing
happens-- no spark, no turning starter motor. Zip. I thjough it would be
easier to test the starter out of the car, so I pulled it. I used jumper
cables, and hooked the - cable to the starter motor case. When I touch
the
+ lead to the middle spade lug, the solonoid kicks out the gear that
engages
the flywheel. Nothing happens when I touch the + lead to the other two
spades. My Haynes says to connect a jumper between the battery and the
STA
terminal of the starter, and try it; but I haven't done so, as I don't
want
to screw anything up. Any additonal tests I can try to determine if the
starter motor or solonoid is bad? My though is that if they both pass,
it's
the relay, of course that shows what I know. I appreciate the help. Pat
Pat!

At the most, the solenoid has four connections. The bottom most
stud (as fitted to the car) is the isolated power connection -- your battery
cable and the BROWN wires to the electrical system connect here. The STA
stud is connected directly to the brushes within the starter motor. The
"normal" sized spade terminal is connected to the pull and hold coils in the
solenoid. The much smaller sized spade is the battery voltage output for
the 1974-1979 MGBs with a reduced coil voltage circuit.

Connect one jumper lead to the case (makes no difference which one).
Connect the other jumper to the isolated terminal (usually carries a spade
terminal). Use a small screwdriver, something, and jump between the HOT
stud and the spade for the solenoid. The solenoid should SLAM closed and
the starter motor should spin FAST! You an also connect one jumper to the
STA terminal -- this will spin the starter motor but NOT work the solenoid.
Let me know what you find out.

BTW -- in the second test, better to connect the jumper to the STA
terminal first, then touch the starter case second. This does not damage
the threads on the solenoid by arcing.

John

ElectricsTF Wiring
Hey John,

A few months ago I dismantled my TF dash for refinishing. I tagged or
made notes in order to rewire correctly. However I seem to have
confused myself somewhat and need some help.

The amp indicator Ihave the brown/white wire noted to the left pole
and the brown to the right, I don't know if I was looking from the front
or rear when I made that note.

The same for the ignition switch, does the brown/blue wire go to the
left when viewed from the car seat, the white to the right? There is a
faded cloth covered wire from the lite switch, which pole does this go
to?

I have a shop manual and wiring diagram but the switches are not
imprinted or marked so I can't say which is pole 36 or 9 on the
ignition switch. (None of the others are either). All the other stuff I
properly tagged or left wired.
Bob!

Ammeter: Try the connections one way -- turn on the lights, the ammeter
should show a discharge. If the ammeter shows a charge (+), then reverse
the connections. This wiring depends on the polarity of the car, too.

Light Switch: The Brown/Blue wire is the power wire and the White wire
powers the fuel pump/fusebox/ignition light. It makes NO difference which
way these are connected as the switch is simply an OFF-ON switch.


The faded wire is more difficult. The Light Switch has a Brown/Blue for
power; red goes out to the various lamps; and Blue goes to the headlight
dimmer switch (where it's switched to Blue/White for Bright; and Blue/Red
for Dip. Among the many red wires is one from the dash loom that goes to
the dash light switch (first position instrument lights/second position
"map" lights up under the cowl). So, it may be that the fabric covered wire
is the one that goes to the RED connection of the Headlight switch. If you
cannot determine the positions of the switch (A is power, S1 is the first
step in the switch (reds), S2 is the second step in the switch (Blue), then
use your 12v test light to test and Brown/Blue for power.

I hope this little bit has helped you out!

John

Electrics22258 GeneratorJohn: Did the 22258 Generator have a cooling fan installed on it typically? This one from the '57 I'm working on did not. I notice Vicky Brit only has the fan listed for the C40 Gen while Moss has fans listed for the 22258 and the C40 models.

Problems in running without it?????

Thanks again...

Marv

Marv!

All generators SHOULD have a cooling fan on them. It's a quick fit if the pulley comes off without a great struggle! I would add it if it were mine or in my shop.

John
ElectricsAlternator Mr. Twist,
I read that you will not handle these prior to 1 Sept and that is fine.
Here is my question regarding a '72 MGB. When the alternator is attached
to
the engine, but the wiring is not connected, I attached my test meter with
one lead to the center or middle terminal of the plug receiver on the back
of the alternator and the other lead to the head (for ground) and got a
complete circuit. Is this supposed to happen or does that indicate a
problem with the alternator?
Thanks for whenever you can get to it. I live in the middle of no where
so
more proximate sources of knowledge just don't exist.
Roger
Roger!

You must suspect a problem with the alternator or you wouldn't be
checking this out. You know, when you turn the ignition ON, the ignition
warning light should illuminate. When you exceed about 800-1000 rpm the
ignition warning light extinguishes, showing that the alternator is
charging.

On the plug at the back of the alternator, the inner most spade is
probably unused, even though it may have a light gauge BROWN sensing wire
from the solenoid attached to it. The center spade is the OUTPUT spade with
a heavy gauge BROWN wire. The outermost spade, the "normal" sized spade is
the indicator lead which carries a BROWN/YELLOW wire.

If you test both BROWN wires, they should be HOT. If you test the
BROWN/YELLOW wire, the earthed test light should illuminate when you turn
the ignition switch to ON.

If you place an ohmmeter between the center spade and earth, you'll
find infinite resistance in one direction (negative earth); and about 1,000
ohms in the other direction (positive earth).

If you connect your test light to a power source, then touch the
alternator case to ensure it is working, the light will illuminate when
touched to the outer, indicator lead. It will NOT light when touched to the
middle, power, or to the inner, sensor, spade.

Hope this helps.

John
ElectricsBlinkersJohn


Two weeks ago I noticed that my blinkers were not "blinking" I checked all
the lights and they are lighting even on the dash but when I turn on the
turn signal either direction the lights inside and out come on but don't
blink. Any sugestions for what I need to check?
Dave
Dave!

The turn signal flasher is very voltage sensitive. If the
alternator is not making 14 volts, the turns won't wink. If there are
faulty grounds then not enough current can pass through the turn signal
flasher unit and it won't wink. So:

Check you fan belt. Is it tight? You should not be able to rotate
the alternator pulley anti-clockwise. Do you have a voltmeter? If you do,
connect it to the bottom fuse and to ground. When the engine is doing 1000
rpm or above, the alternator should be producing 14 volts.

Turn on your hazard lights. Watch both the front and the rear
lamps. They should be BRIGHT! If they seem dimmer than normal, then check
for a good ground at each lamp. Test for the ground by using a test light.
Place one end of the test light on a good ground -- a bolt on the engine,
for instance. Then, test the test light! Use the bottom fuse for a power
source. Now, with the turn signals turned on, push the ice-pick end of the
test light onto the base of the turn signal lamp. If the test light glows,
then there is a faulty earth. It would be odd to have both earths faulty at
the same time, but it could happen.

However, the problem is probably a faulty flasher unit. You can buy
a simply turn signal flasher at NAPA for a couple of bucks. Plug it in and
see if that makes a difference!

Hope all this helps, Dave!

John

ElectricsElectricalMr. Twist,
1. I have a 1980 MGB. For quite some time now I have been having an electrical problem. It started out being a very little problem, but have very slowly, been becoming worse. In order to explain my problem, I will give some senarios.....

When I turn my heater fan on, the turn signals do not work, the blinking light just stays on.
When I have my windsheild wipers on, and I turn my headlights on, the wiper speed slows down.
If I have my headlights on, the turnsignal works very slowly.
When I have the headlights and the wipers on, the turnsignals dont work at all unless I turn the dash-lights all the way down.
When at a stop light with multiple devices running, the turnsignals do not work although when I rev the engine up, they start blinking slowly.



These are a few observations that I have made although that is not all the instances.Now here's what I have done in my quest to solve this problem.

I have replaced both the positive and negetive cables coming from the battery.
I have checked my motor-mount ground and it's fine.
My father, an electrician, checked my grounds and the multimeter determined that my grounds are fine.
I have a 1 to 2 volt drop at the fuse box. we noticed that some of the power-carrying lines at the fuse box didn't look very good so we replaced those connectors and it sped the blinker up, but did not solve the problem.
My battery is fine. It doesn't have a bad cell.
When I replaced the Battery cables, once again, it helped but did not fix the problem. It sped my starter(revs) too.



My father believes that the problem lies somewhere near the power wire that leaves the starter solinoid and that powers the components. He says that the wire is so small and carries so much that it might need to be replaced, or the terminals at the starter are also bad.

What is your opinion? Have you run accross this problem before? Do you have any advise?

Thank you very much for your help.

2. I checked the belt for tightness and it was fine. I removed the fusebox and cleaned it. It didn't look that dirty but I cleaned it up and it helped, but didn't cure the problem.

When I checked the voltage, I checked it a the fusebox, at the bottom fuse (since it was hot even when the ignition was off) and found that when the car was turned off, I had aprox. 12.47 volts. When I first started the car though the auto-choke was engaged and the idle was higher I don't know how high it was but the voltage reading was approx. 14.00 volts. when I blipped the accelerator and the Idle went down, to 500 rpm, I got the reading of 12.96.

About the ignition light on the dash. At night for example, I start the car, the light is on until i rev the engine up to 800-1000 rpm, and then the light goes off. When I turn the headlights on and rev the engine or just drive the car around. The ignition light is barely on, but as the rev's go up, the light gets much brighter. Then, when I drop back down into idle, the light fades back down to barely visible.


Sincerely,
Mike
Mike!
1. The turn signals are very voltage sensitive -- their slow blink rate or no blinking indicates that the voltage in the electrical circuit is too low. Here are some things to do:

Clean the fusebox -- actually remove it and sandblast or glassbead the unit -- or, let is soak in ammonia or dilute acid (not both!) for a little while, until the terminals return to their natural copper color. Be careful in reinstallation as the unit does have a top and bottom -- the top, front, two terminals are bridged.

Check the voltage in the circuit -- you should find 14 to 14.5 while running (vs 13 when the engine is off). Sometimes the fan belt is so loose that the alternator pulley just doesn't turn quickly enough. Sometimes there's a fault within the alternator. I suspect you have an alternator problem -- loose belt, corroded connections, faulty regulator -- something like that.

Write back when you've done the fusebox cleaning and have checked the voltage and tightened the fan belt. We'll go from there. Oh -- by the way, tell me about the ignition light. It should illuminate when you turn the key on, then extinguish when you've exceeded 800-1000 rpm, never to illuminate or glow again, no matter the condition.

2. The fact that the alternator light glows indicates a problem with the charging. Although it might be corroded battery posts or a loose connexion at the starter solenoid, it's probably the alternator. You can probably have yours rebuilt at an electric shop for less than $100. Be wary of "rebuilt" units offered in stores and through major suppliers -- they're often not very good.

Hope this helps a bit.

John
ElectricsWiring 69 MidgetJohn
I am restoring a 69 midget and i am down to rewiring it. I have a new
front and rear harness but I am not sure where to start on either the
front
or the rear? My second question is the wiring diagram in the haynes
repair book, is that enough of info to do this job and if not where can I
find the info I need?

I have done anything like this before and have outside help (Jim and other
club members) but I want to have what they need when the time comes to ask
for there help.

Thanks for your time and advice.

Carl
Carl!

The job is not as daunting as it first appears.

#1 -- get a wiring schematic for YOUR YEAR specifically, not some
generic thing from Haynes. If you want the REAL THING, I'll make a copy for
you. Now, you can either get multiple small copies, you can get multiple
larger copies, or you can get a large poster. The large poster is really
helpful, unless you still have your 20/20 vision!

#2 -- lay the wiring into place, physically. Stretch, bend, wrap --
and get is laid out.

#3 -- connect the loom wire by wire. Start at the corners (easiest)
and work towards the dash. Don't waste time "checking" each circuit as you
go. It'll be wrought with frustration -- just do the WHOLE job.

#4 -- don't connect the battery tightly at the beginning -- just a
loose connection will do. Test the lights and ignition functions (wiper,
heater, etc).

#5 -- polarize the generation (simply jump between A and F on the
control box -- twice -- briefly -- "spark, spark" and it's all done).

#6 -- Test the function of everything.

WARNING! Approaching an electrical malfunction without the proper
schematic and a test light is a certain route to madness.

John

ElectricsParking LightsMr. Twist:
Read your articles in the COMGO magazine and I hope you can help. I have a 1952 TD which I had a frame up restoration done by British Cars Ltd. of St Louis in 1998. All wiring is new. A few years ago, my parking lights would go off when I turned the switch up for the head lights. The switch was not replaced in the restoration. Either set of lights works well but, not together. It has been suggested that I may have a grounding problem. Hope you can shed some light on a solution?
Thank you, Harold
Harold!

The wiring is incorrectly connected at the rear of the lighting switch, that's all.
When you look at the back of the lighting switch, with the "A" terminal at 12:00 then the IGN terminal will be in the middle. The lighting connections will be along the bottom. From left to right, there is a "T", blank, "H", and "L". The "T" is for "T"aillights. To this screw connect an in line fuse, then connect the four or five individual RED parking light wires to the other end of the fuse. Connect the BLUE wires to "H" for Headlamps. This BLUE wire then travels to the dipper switch where it is changed to main or dip. The "L" is for Driving lamps that come on with the parking lights but NOT the headlights. Now, I may have one of these positions confused, but you'll see when you get under the dash.

Hope this helps.
John
ElectricsVoltage ConverterI read on your published comments in NAMGBR that you recommend a 24 volt voltage converter to power a 12volt negative ground radio with 12volt positive ground cars. Can you elaborate a bit on the installation, and a possible source for this device?

Have you ever run across a good "hidden" fm antenna I could install inside my B?

Regards,

Dan
Dan!

You have several options: 1)Leave well enough alone and listen to the clatter of the valves and the whispers of the dynamo brushes -- after all, the sound of the engine should be music enough to your ears; 2) switch the vehicle to negative earth (very easy but for the tachometer which will cost $75 or so); 3) find a "voltage inverter" on eBay (I just sold an original Archer unit for about $20) and install that.

Of course, there are variations. You can fit a positive earth AM radio, as originally fitted to the MGB (probably Magnavox internals); you can simply set your boom box on the seat;.....

The voltage inverter doesn't really invert anything, except your wallet, and not for very long. Right now, your MGB has a neutral frame and a -12 power source; or, your MGB has a neutral power source and a 12+ frame -- however you want to look at it. Enter the voltage inverter. This unit has an output of 24+. Couple that with the 12+ chassis frame and the frame effectively becomes neutral and the 24+ wire effectively produces 12volts+.

Quite frankly, for my money, I'd switch over the negative earth and buy a recent, decent, radio with extras.

Let me know if I can be of more assistance!

Oh! Yes! The antenna! Mount it lengthwise, under the chassis, under the passenger seat. Support the end and middle in large rubber corks; those, in turn, held fast with zip ties. I know this works!

John

Electrics72B FusesHi Mr. Twist,
Can I use north american glass fuses when Lucas 17/35 are not available ?, and @ what rating ?.
Best regards,
Barry
Barry!

Use 10amp on the top two lighting circuits; use 15amps in the other two. You can boost that bottom one to 20 or 25 if the horn draws so much current that it wants to blow.

John
ElectricsPerTronix WiringJohn,

I have referred back to your tech tips many times while restoring a 77 MGB for my 16 year old son. Not sure if you reply to questions but thought I would give it a try.
The car in question came to me with a PerTronix Ignitor installed and during restoration I began to question the wiring of the Ignitor. The car is running and is driven daily to and from Soccer practice. The reason I questioned the wiring is because I noticed the Coil was getting very HOT. The Coil is now wired hot through the resisted wire and the ignitor is fed 12 volts. Should the ignitor be fed through the original resistor? I went to the PerTronix web site for answers and learned nothing.
Kevin
Kevin!

The coil gets hot because it is "on" too long or because the primary wiring has shorted -- unless it's wired wrong to start with.

There are two coils: one has 3.5 ohms internal resistance; the other 1.5 ohms. The first receives battery voltage; the second receives a reduced voltage (about 6-8 volts). The first is powered by a WHITE wire; the second by a pair of WHITE/GREEN.

In either case, I would power the Pertronix from a 12 volts source -- the fusebox is a good point.

Hope this helps at this late date.

John
ElectricsCigarette LighterIs the hole for my cigarette lighter (just to the left of the radio) "stock" or did one of the previous owners get happy with a drill? I haven't noticed that extra hole/lighter in other '62-'67 dashes, but then again I don't see that many. Moss catalog does not show the location, but does list a lighter as "Optional". Just curious.

Regards,

Tom
Tom,

The cigarette lighters (as well as radios and antennas) were dealer installed -- so the position of the hole, the quality of the cut, etc, all hinge on the young mechanic doing the work. I believe you'll find that a stock unit will fit the hole.

Hope this helps.

John
ElectricsElectrical ProblemDear John,

1. As most "Dear John" letters begin, I am having a problem with our relationship (me and my MGB). I have a '79 MGB. For months now, when I step on the break or use my turn directional signal I lose my Tach, gas gauge, temp gauge, radiator fan and break lights. Normally, they return within a few minutes and go out again at the next touch of my break pedal. This time, however, they have not returned. I have replaced the relay switch, cleaned the fuse connections, checked wire connections. I don't know if either of these are related to the problem but, my ignition light is always on (two years), and I recently replaced the ignition switch (several months ago). Some of the greatest technical minds in our club are scratching their heads on this one. Can you help? Thanks.


2. I squeezed the fuse tabs together, even put in new fuse, cleaned tabs and connectors but problem still exists. There are two relay switches on the wall. Should I replace them?

Bill
Bill!

1. 1979 MGB. Ignition switch to "ON" closes the ignition relay. Ignition relay closed energizes the third fuse (WHITE/BROWN front side and GREEN rear side). The problem lies in one of these three components. If the ignition switch had failed the car wouldn't run. Rule that out. When the ignition relay fails the cooling fans also fail to run. Jiggling this relay will cause a faulty one to switch on and off. So, with the ignition ON and the heater motor running, shake the relay. If the relay's operation is erratic, the heater blower motor will turn on and off. This relay appears the same size as a 35mm film canister and lies in FRONT of the fusebox.

But these are not your problems. Your problem is an erratic connection at the fusebox. Remove that third fuse, pinch the tabs together -- bend them together -- then fit a new fuse (20a). I think this will do it.

If your ignition light has been on for two years and the battery has not gone dead, then the alternator must be charging -- but perhaps not charging enough. Does the light remain bright or barely glow. Does the glow change when you operate the wipers, turns, brake lights, or heater motor?

Hope this helps -- get back in touch!


2. Replace relay IN FRONT of the fusebox, SPST Normally open. White and Black run the coil, Brown and White/Brown to the contacts. Good luck. let me know!

John
Electrics69 MGCAny idea if a GM altertnator would fit my car?Jay!

You can make anything work. You can make the case that all modern
alternators are better than that Lucas one. But remember, a new part here,
a new part there, and pretty soon you've got a Miata.

The Lucas alternator will recharge the battery just fine -- it's a
good unit that requires only the cleaning of electrical connections on an
occasional basis.

If you do wish to change over, then use a Saturn 100 amp alt which
will, with some fiddling, bolt right up.

John

ElectricsWiper MotorJohn

I have a 69 midget and my wipers won't park. They are either on low or
high but will not park, they just run on low. I unplug them when they are
not needed. I was thinking that it could be my wiper switch at the
steering column or my wiper motor. I can't find anything on this subject
in any of my books. Any suggestions would be appreciated?

Carl
Carl!

I think you are telling me that the wipers run all the time and will
not shut off. There is a switch on the underside of the wiper motor that is
pushed open by a little cam on the back side of the large gear in the wiper
motor gearbox. On your car, a Circlip on the shaft of that gear has fallen
off. Now the gear rides too high in the gearbox to operate the switch.

To repair this problem, loosen the gland nut (3/4") from the wiper
rack to the wiper motor. Remove the wiper motor from the inner wheel arch.
Remove the cover of the wiper motor gearcase. Push down on the white
plastic gear while you fit a new Circlip onto the gearshaft (at the bottom
of the gearcase),.

Hope this helps.

John
ElectricsWiring HarnessesJohn
Question about my '69 MGB/GT:

Do you have a recommendation for wiring harness suppliers? My dash
harness melted all the way down to the starter. I have to rewire. Which
supplier is best in your experience?

By the way, the alternator that you rebuilt is (was) charging fine, and
the wires to it are not burned. It is probably still OK.

Fred
Fred!

Our experience has been wonderful with British Wiring in Olympia Fields, Illinois. www.britishwiring.com Contact Leslie -- she'll help you
out!

John
Electrics79BJohn
I have a 1979 MGB
I tried to charge up my car and when I started the other car the
alternaror started to get very hot in the MGB and if I keep the car
charging I think it would have started a fire. When I put the cables
on
the other car the hot cablle makes a spark which it shouldn`t do it
never did this before I don`t try to charge the the MGB anymore.
What should I look for to fix this problem?
JIM

Jim!

It sounds to me like you got the positve and negative cables
mixed
up. You know, the battery cables on the car, when original, were both
black. But, over the years it is not uncommon for us to see replacement
ground cables. These, sometimes are RED. So, it is not unusual for us
to
see a RED cable for negative and a BLACK cable for positive -- exactly
opposite of what you would expect. I'll be that's what's happened. Do
let
me know how you solved it.

John
ElectricsLucas Battery CapsJohn; I have acquired a set of dry NOS Lucas 6 volt batteries, these are black cased and not current production red-mid 70's I am guessing. The terminals are drilled to use Lucas Helment head connectors. They are perfect EXCEPT one is missing the red bar cap that covers all three cell ports. Do you think that you might come up with a couple of these in used albeit nice condition so as to have a spare and make this set of batteries functional? The car is rolling along-I just found an NOS SHELLY jack for it while rummaging through a dealer buyout of Triumph parts. My Minilites are being painted to match the Works Old EnglishWhite hardtop and all of the major projects are out of the shop so the car can soon go on a rotisserie. The welding is pretty much done with the exception of the battery boxes. The original owner had cut these out and fitted a 12V in the boot on the passenger side to distribute weight better when he autocrossed the car. I will convert back to the original set up but retain the hand-made Koni conversion as that is easily retrofitted to Armstrongs.
Tony
Tony!
I'll bet that something comes up on eBay. I've printed out your msg and if I have something at the shop I'll let you know.
How can you leave those Koni shocks on a car you're trying to make so original?
John

ElectricsBrake Lights Will Not Shut OffJohn:
I have a MG TD 1952 that the rear brake light are now staying on all the time. I have tried to wiggle the brake pedal with no success. Can you tell me where to look to solve the problem?
Wayne

Wayne!

You have one of three problems: crossed wiring (do you have a turn signal box); a faulty brake light switch (staying closed); or no brake pedal freeplay (allowing pressure to remain in the brakes).

First -- ensure you have 1/2" of pedal freeplay. If you're running real fluid you should be OK. If you're running silicone fluid then there's a problem INSIDE the master cylinder (write back and I'll go through the procedure to reposition the piston).

Disconnect the brake light switch. If the switch is the problem then dropping one wire will cause the lights to cease illuminating.

Hope this little bit helps!

John
ElectricsMGC Charging SystemWent to fire up the 1968 MGC last week..reconnected the battery ground...tried to fire it up....it was dead.

I disconnected the alternator and put the charger on it.

Yes...Negative to negative and positive to positive.

Battery appeared to re-charge on trickle...

Went to reconnect alternator and ...SPARK!

"This ain't right, I say!"

Pulled the one wire off of the alternator that I had connected (brown).

Then...

I disconnected battery at ground (negative terminal).

Reconnected alternator.

Went to reconnect ground....SPARK at battery terminal.

"This ain't right, I say!"

Any clue as to what's going on here?

OK...The saga continues....

I swapped out the battery just in case it was a short in the battery itself.

I connected the alternator back up (black wire on top, brown beneath it) and reconnected the battery.

It SPARKED at the negative terminal.

For grins, (I would say tickles and grins, but I didn't want to get shocked), I disconnected the alternator and reconnected the ground to the battery. NO SPARK.

I verified that the ignition is indeed switched OFF.

I have a feeling that the alternator, or maybe the alternator control box, is at fault.

In this model of MG, what does the Alternator Control Box do as a function? Could the fault lie here? (My '69 MGC does NOT have this feature.)

Also noticed the one time I did get the C started (a few weeks ago), that the tach would jump to 7000 rmp or so until the car started, then show normal rpm.

The 1968 MGC (and MGB) have an external voltage regulator. By 1969 it was incorporated into the alternator itself.

There is, sometimes, a tiny spark when connecting the alternator, especially on the later style (about 1977-), but there should not be a large spark -- certainly.

There must be some fault within the alternator. You can have it tested or rebuilt (or both) down there, or you can send it up here and I'll run right through it.

There are two large spade terminals on your alternator. The outermost spade is the output, the innermost is the earth. It is nearly impossible to reverse the connection -- but look at the wires at the alternator just for fun.

I doubt there is anything in the control box which would give these symptoms. That doesn't mean it's good -- but there is not a path for the current to take through this control box to give a spark like you're getting at the battery.

John
ElectricsPositive Ground, TCJohn:

My TC is a positive ground system. is there a quick reference on how to
change to negative? is there a reason not to?

Thanks much.


Bill

Bill!

The car cares not a hoot whether it's positive or negative earth. Positive earth was the convention at the time. In 1968 the MG changed to negative earth. All the components work the same except for the ammeter (which, not reversed, will read backwards) and the coil (which, not reversed, will cause the spark to jump from the "L" to the center electrode with no ill effects whatsoever). So why change? Only the modern electrical equipment -- radios, CDs, scanners, etc.

To change, reverse the battery. Polarize the dynamo -- jump between A and F on the control box, twice -- spark, spark -- and it's all done. Reverse the ammeter connections (unless the wiring is especially crusty); reverse the low tension leads on the coil; and that's about all -- UNLESS -- the fuel pump is a polarized model -- either the Halls effect style or wrapped in RED tape indicating a diode style. This is more complicated now -- write back if you have a more modern, polarized pump!



John
ElectricsMGA WiringJohn.

Someone told me that the MGA wiring is not fused throughout and there
are wires that might burn up. Do you add a fuse and where should it be
put.

Thanks.

Pete
Pete!

There are several "dangerous" unfused circuits: Ignition, parking lights, and headlights. The only circuit I've ever seen burned is the parking light (red) circuit. Here's how to fuse it:

Get an in line fuse holder. Fit one end into the headlamp switch at S1 -- where the RED wires are right now. Then, butt connect the RED wires and the other end of the fuse holder. DONE! Now the parking light circuit is fused -- use about a 10amp fuse here.


John
ElectricsIgnition RelayRecently a ground wire shorted out going to the ignition relay. I replaced the wire andattempted to start the engine. No Luck ... but the fuel pump continues to run till I pull the whitewire off of the relay. Do you think that the relay could be bad or maby another problem in the wire harness?

Thanks in Advance
Roger

Roger!

It seems that you've got the wiring to the ignition relay wrong and the BROWN wire is energizing the WHITE circuit. If you are using a LUCAS SRB 402 relay, then the BROWN wire goes to the copper spade which is 90 degrees from the other three. The opposite spade receives the WHITE/BROWN. The other two receive the WHITE and the BLACK in no particular order.

If you are using a different relay, the coil receives the WHITE and BLACK and the points (normally open) received the BROWN and WHITE/BROWN.

More questions/ problems? Call me!

John
ElectricsDiodeWhere might I find a diode to replace the one from the brake warning light?
Thanks again
Skip
Skip!

There might be something available through NAPA, but Radio Shack has all kinds of diodes. The rating seems pretty low -- maybe 16 volts (as the alternator is 14 v max) and maybe 3 watts (to power the ignition warning light).

I usually just take the one out of the wiring and leave it on the alternator, not replacing the one under the dash.

John
ElectricsHeadlights FluctuateDear John,
I have noticed that the headlights fluctuate in brightness while the car is idleing. The alternator belt is snug and the car idles reasonably smooth. Any help you could provide would be greatly appreciated.
Regards,
Anthony

Anthony

This situation is almost always caused by a problem with the voltage regulator in the alternator. You could buy another alternator -- you could change the regulator in the alternator -- but first:

Clean the battery clamps -- don't just look at them and call them clean.
Ensure that the battery is full -- top it off with distilled (de-ionized) water if necessary
Ensure the earth strap is tight to the frame in the battery box.
Remove all the BROWN wires from the starter solenoid, tighten the inner nut on the solenoid stud, clean all the wires, ensure their integrity (broken strands?), then refit.

If the problem still persists, then go for the regulator!

Hope this helps.

John
ElectricsAlternator InformationHi there,


I have a 1952 Bedford truck fitted with 12V Lucas equipment. The motor is currently being rebuilt and I am looking for replacement parts to suit the generator. I have listed the Lucas part No. below and I would like to know if you have a NOS dynamo/generator or even parts to suit. If you have anything second hand, that might also be useful. I would prefer a NOS generator or if not available, one that is reconditioned. The details for the generator are listed below;



Lucas Dynamo/Generator 12V



Lucas Model No. – C39PV-2



Lucas Type – L-O



Lucas Ordering No. – 22258B



The numbers stamped on the casing of the generator appear as follows;



LUCAS



MADE IN ENGLAND



22258B I151



C39PV2 LO 12V



I have managed to purchase a NOS armature to suit the generator, but the keyway is narrower than that on the original armature. I have filed down the woodruff key, but I‘m not too keen on utilising this method.



The part No. of the NOS armature I have bought is 227987AX. Is it possible for you to check if this is the right armature for this generator?



If you can assist me in any way,



Thanks,



Sam.

Sam!

I have printed out your letter tonight and will see if I can come up with any information to help you out. We have many starter/alternator shops that still provide good service for old generators, including Lucas. There must be similar shops in Australia. If it is just the armature that is causing a problem, I'm sure you could have yours rewound -- or -- take the newer armature to a machine shop with your pulley and ask them to deepen/widen the Woodruff key cut.

Hope this helps a little!

John
ElectricsBrake Warning Light SwitchAdvice on this one..the brake light keeps coming on...I've cleaned the brake master cylinder switch underneath it and the connecting plug three times. It appears some fluid somehow is leaking into it. Is there a repair kit or something else I can do?

Keith
Keith!

The brake warning light switch on your 1979 MGB is integral with the master cylinder. This shuttle valve earths a switch if there is a difference in pressure between the front and rear brake hydraulic circuits. If the switch is getting damp or dripping with brake fluid, then the master cylinder needs a rebuild. Hope this helps

John
ElectricsAlternator ConversionJohn:
I have an August, 1966 MGB (GHN3L 98066) on which I have just completed a major driveline rebuild. In the process, I installed an alternator conversion purchased from one of the major suppliers, with a "2-wire" alternator which retains the original RB340 regulator.

The car was already converted to negative ground. The alternator conversion calls for the brown/yellow "D" lead on the regulator to be spliced into one of the "B" leads (either to the ignition switch or the fuse box) and the "F" lead to be relocated to the "D" terminal. The alternator installation and the wiring conversion have been done according to instructions, checked and re-checked with no problems apparent.

The situation is this:
1) When the key is turned on, the warning light glows (no problem).
2) When the motor is started, the warning light goes out (no problem).
3) When the motor is shut off (and the key is off), the warning light glows (PROBLEM).

I pulled the regulator cover and noted that the cut-out is remaining closed when the key is turned off, so I disconnected the battery to open the cut-out. When running, the cut-out is closing at approximately 12.8-13 volts (no load), which as I recall is in the acceptable range.

I have checked and re-checked the conversion wiring, cleaned up all of the old regulator connections, and directly grounded the regulator. As the regulator I was using had been in service with the old generator for many years, I suspected a cut-out problem and substituted a new regulator I've been keeping as a spare, but the same problem occurred. I can't help but think that I'm missing something really obvious, but the brain is fading rapidly. Any suggestions??

Glenn

Glenn,

To keep the system working correctly, you really have to gut the old RB340 to keep the current from getting to earth. I just did one -- but you can do it too. Cut out the swamping resistors; cut out the F to D resistor (for the voltage regulator); Cut the points so there is NO WAY that any current can pass between B F or D and earth.

Connect the heavy BROWN/GREEN wire to the alternator output; connect the light BROWN/YELLOW to the alternator indicator lead, and you should be all set to go.

Hope this helps!

John
ElectricsFusebox, LEJohn,

I have the same electrical problem everybody else that signs on to your site has. I removed the fuse box and cleaned it. Checked the power on the fuses. Only the bottom two have power. The second fuse which controls tach, blinkers, etc is sporadic, but got everything going except for one tail light.

My radiator fans weren't working I touched the two ends together and they went on, so I replaced the sensor. They worked.

While I'm doing all of this, I cleaned the two pop in fuses that hang under the fuse box. Now I don't get any power to the fan sensor. I have a concern about the top two fuse, but I can't drive the car without the overheat fans working. Please Help me.

Gene
Gene!

Let's take this from the top down:

#1 fuse runs one side or one diagonal on the parking lights / side markers / licence lights
#2 fuse runs the opposite side or opposite diagonal
#3 fuse runs everything that works when the key is on -- gauges, turns, brake and reverse lights, wipers, heater motor, those kinds of things
#4 fuse runs the components that work with the key on or off -- the horn, the bright light flashers, the cigarette lighter, the trunk and interior lights.

The fusebox does NOT control the hazards, the anti run-on valve, the headlights, the fuel pump, the coil, the overdrive, NOR does it control the cooling fans.

The two in-line, pop-in fuses are the hazards and the anti run-on valve. The headlights are not fused -- neither is the fuel pump, the coil, the overdrive (although it should be and can be). The cooling fans are fused through a circuit breaker (the size of a rectangular turn signal flasher box), located just to the front and lower than the fusebox.

The connections for the fusebox are:

#1 FRONT: Top or second spade receives a RED/GREEN
#2 FRONT: See above
#3 FRONT: Receives WHITE/BROWN wires from the ignition relay
#4 FRONT: Receives a BROWN (always hot, unfused) wire from the starter motor solenoid HOT stud.

#1 REAR Pair of Reds
#2 REAR Pair of Reds
#3 REAR Three or four GREENS on two spade terminals
#4 REAR Pair or three PURPLES on two spade terminals.

The front side of the fusebox is the UNFUSED side; the rear is the FUSED side.
The top front two fuses have a bridged connection (look on the underside of the fusebox).

The cooling fan circuit runs from the ignition relay to the front side of the #3 fuse (or directly) to the circuit breaker. From the circuit breaker the heavy green runs to the thermostatic sensor. From the thermostatic sensor to the motor is GREEN/BLACK to the motor. From the motor to earth is BLACK.

WARNING: Approaching any electrical malfunction without a test light and without the wiring diagram for YOUR MGB is a certain route to madness!

Hope some of this helps.

John
ElectricsIgnition LightJohn,
I have a 1978 MBG roadster and at low idle the ignition light comes on. I just replaced my alternator and the light still seems to flicker on at low idle, being below 1000 rpm.
I had the old alternator checked and it was only putting out about 14 amps that is why I replaced it. Am I missing something I should be replacing, as I don't understand why the light is still coming on.
Please let me know
Thanks
Scott
Scott!

The alternator light usually remains on until you exceed 800 - 1000 rpm at which time it extinguishes. It should not flicker.

Here are some things to check: Battery posts; starter connexion; and alternator connexions.

Remove the clamps from the battery, clean the posts and clamps, and refit. Also, Remove the earth strap from the chassis, clean it, and refit it.

Remove the heavy BROWN wires from the starter solenoid. Tighten the nut at the solenoid, then refit the BROWN wires along with the heavy, black cable from the battery.

Lastly, work with the alternator plug so that the female spade connectors do, in fact, grip the male spades in the back of the unit tightly.

Your alternator should produce 30-40 amps -- if it's spinning quickly enough and if there is a heavy load on it. The ignition warning light is usually the only indicator you need to determine if the unit is working well. The alternator produces 14v when the engine is running over about 1000 rpm.

Hope this helps.

John
ElectricsErratic ElectricalMr. Twist,
1975 MGB
I am having troubles with my turn signals, flashers, and alternator indicator light.
Recently the alternator light did not totally go out after starting my car. It would glow and then dim as the RPMs increased, then glow brighter as the RPMs lowered. Is this a bad alternator or a dying battery? (FYI The battery is very close to its life expectancy!) Nothing like this has every happened in the 23 years I've owned the car. Also, the alternator is relatively new with only eight years and 8000 miles on it. It is a Bosch from Moss.
Then last night the turn signals would not blink - just steady on.
Next, the passenger's running lights and turn signals would not come on at all, then they would, then they wouldn't...
With the engine running and all lights off, the headlights would flash on and off like emergency lights...
Then the emergency lights would only work on driver's side...
Or not at all...
Or sometime they worked perfectly...
All fuses appear good.
Flasher units are "clicking" so I assume they are working.
Where should I begin my investigation?
Thanks,
John
John!

I have some things here for you to try. Let me know what has helped.

Clean the battery posts and cables to ensure a good connection. Pull the plug from the alternator (probably a Lucas alternator in a Bosch box), squeeze the terminals in the plug, and then refit.

Remove the fusebox, clean it in a sandblast cabinet or in vinegar or ammonia until it comes bright. Reinstall (make certain the bridged connection is at the top, forward side).

Most of your problems should be solved.

If the ignition warning light continues to glow, then the alternator is faulty.

Let me know!

John
ElectricsBattery DrainingGood Morning John

I recently noted a strong odor of rotten eggs coming from my 1975 MGB. This ultimately was found to be a bad alternator which cooked the battery.

Both replaced.

Now I have a problem with the new battery which has checked out good, completely discharging in about 2 hours when sitting in the garage. So, not being a mechanic I tried a couple things to see where the possible electricity is going. I pulled the fuses, still discharges, alternator checks ok. Before going any further, any ideas where to start?



Thanks

Tim
Tim,

Arm yourself with a 12 volt test light. Do not use a meter.

Remove the negative battery terminal and fit the test light between the battery post and the battery clamp. Now, any current coming out of the battery will illuminate the bulb.

Pull the bottom fuse, pull the plug from the back of the alternator, disconnect the anti run-on valve. If this doesn't extinguish the light, then there is a short -- VERY uncommon -- so you'll have to call me during tech time. The most common draw is the trunk light, but that takes a whole day to discharge a battery. It is not uncommon to get a faulty alternator. Your ignition light should illuminate when you turn the key to ON, and extinguish when the engine exceeds 800-1000 rpm.

Hope this helps.

John
ElectricsSeatbelt Buzzer, Engine Shuts OffI HAVE TWO BASIC PRBLEMS

I purchased a 1974 1/2 MGBGT ALL ORIGINAL AND IT WAS NOT RUNNING TOO WELL BUT WAS RUNNING. I DECIEDED AFTER TRYING TO TUNE IT THAT I WOULD HAVE A VALVE JOB DONE. OF COURSE I TOOK OFF ALL THE EMISSION CONTROLS IN THE PROCESS AND SINCE ALL THE ORIGINAL HOSES WERE CRACKED AND SPLIT I DECIDED TO LEAVE THEM OFF FOR THE TIME BEING. I LEFT THE ANTI RUNON VALVE ON HOWERVER

I GOT MY HEAD BACK AND INSTALLED IT AND ADJUSTED THE VALVE TAPPET CLEARANCE AND PUT THE SU HIF4 CARBS BACK ON.

I STARTED THE ENGINE AND AFTER ABOUT 30 SECONDS IT SHUTS OFF AND IT SEEMS TO BE FOR LACK OF FUEL BUT IVE TRIED EVERYTHING I CAN AND IT STILL SHUTS OFF MAYBE YOU HAVE THE ANSWER

PROBLEM NUMBER TWO IS THE WARNING HORN GOES OF UNDER THE DASH I THINK IT MAY BE THE SEATBELT ALARM . HOW DO I JUMPER THIS OUT.
GIL
Gil,

The seat belt warning buzzer is the easier of these two problems. Remove the column covers, and pull the purplish wire from the exposed spade terminal on the side or bottom of the key switch. Now the buzzer will be silent.

The smog system is composed of the air pump, the injector rail, and the gulp valve. Block the injector holes with 7/16-20 Allen set screws -- it looks good like that. Remove the gulp valve and bracket. Remove the 90 degree fitting in the center of the intake manifold -- tap that 1/4" NPT and fit an Allen pipe plug -- then it looks finished and won't leak air.

The ELC or Evaporative Loss Control system is helpful to keep in place. I believe this may also be the source of your problems. Let's use the charcoal canister as the starting point. There are three lines at the top of the canister. One loops to a steel line that goes back to the gas tank. Make sure the line is free into the tank -- blow through it and you should feel air/fuel escaping through the filler neck. One runs over to the HIF carbs, to the float bowls. Make sure that line is clear. One fits to the valve cover. Make sure that line is not cracked.

During engine operation, fresh air enters the tube below the anti run-on valve, travels through that valve and into the bottom of the canister. It is drawn out of the canister and into the engine, then out of the engine and into the carburetters (from the front tappet inspection cover hose). In this way, the charcoal within the canister is continually being washed with fresh air and the unburned hydrocarbons (gasoline) is purged from the charcoal. If the canister plugs up then the engine places a vacuum in the gasoline tank and in the float bowls and the car will quit running. That's just what the anti run-on valve does when you turn the key off.

The anti run-on valve is HOT when the key is off and is grounded only when there's oil pressure -- that's in those two to ten seconds after you turn the car off. So the valve only works for a couple of seconds. You can hear is CLICK off after you've turned the key off and the engine quits running. When the valve operates, it blocks the free flow of air and the canister begins to evacuate. Further, by the valve's operation, manifold vacuum is routed to the canister which creates a tremendous depression. That vacuum is transferred over to the carbs, on top of the gasoline in the float bowl. Now the vacuum created inside the carb at the jet is not enough to draw gasoline from the float bowl and the engine stops dead.

I suspect this may be occurring to your car right now -- not properly -- but from incorrectly connected hoses or a plugged canister.

Hope this helps!

John
ElectricsBlowing the Fuse QuestionHello John,


I enjoy your Youtube videos - they are the best. My problem is that my newly bought 76 MGB keeps blowing the 3rd fuse. It started when I turned on the lights and used the turn signals. The turn signals stopped working along with the tach, gas gauge and temp gauge. I replaced the turn signal switch. The fuse still blows and the shop where I have says that about 40 amps are going thru it. Any ideas to where to look?


Thanks for your help as I know you are a very busy shopowner.


Frank
Frank,

The most common cause for an excessive draw on the 3rd fuse is that
the wire which should be attached to the manifold heater (between the carb
and the intake manifold) has been left loose and it's touching ground. It's
a heavy green wire, sheathed for some of its length in a black plastic
covering.

John
ElectricsReplacing Two 6Volts with One 12Volt BatteryHi John,

Quick question. I just purchased a 62 MKII MGA that has been off the road
for about 10 years. I don't know if the motor will even turn, but I do
know the batteries are dead. It still has 2 6 volts installed. My
question is simply: Is there any reason to put 2 sixes back in it, or is
it a no brainer to go ahead and put a good 12 volt in it? If so, is there
anything else I need to do with the electrical system while I'm at it?

Thanks,

Greg

Greg,

I used to be a member of the positive earth club! I had twin sixes
in my 1962 MGA 1600 Mark II Deluxe. I had helmet clamps on the cables.
Then I wanted to fit an electronic ignition......

One of my six volts was faulty so I joined the dark side. Besides,
those 17HF batteries from Interstate are very difficult to get now and
they're very expensive.

A single group 26 battery, supported on a piece of plywood about 7
1/4 by 7 1/4
will keep the bottom of the battery from chafing against the edge of battery
box.

There is no inherent advantage between positive or negative earth.
Negative earth is "modern" and will allow you to use modern electronic
devices without the fear of a dead short.

Place the battery on the passenger side and shorten up the earth
cable to fit on that side also.

Hope this helps!

John
ElectricsDamaged BatteriesMr. Twist,


I am writing to inquire about a possible electrical problem I am experiencing with the MGA your company worked on a couple of years ago. Otto Green told me to ask you if you thought there could be a problem with the alternator or coil that could be damaging the battery in the car. I have replaced two batteries, 1 each year of ownership. If you believe the alternator could be the problem, could you please tell me where I can get an alternator for a 1958 MGA? I believe you told me before that you sold coils. If that is incorrect, could you please also tell me where to purchase one?



Thanks,

Steve
Steve,


The MGA is fitted with a generator and control box. The generator only does what the control box, or regulator, tells it to do. If the battery is overcharging, boiling out the electrolyte, and forcing you to purchase a new battery, then changing the control box might be in order.

Give me a call if you're still working with this problem.

John
ElectricsPuchasing A Starter MotorJohn,

Do you sell a starter motor for a 1973 spitfire, or can you recommend someone you trust who does?

Thank You

Peter
Peter,

That starter motor is very common -- it's the M35G unit used on T series MGs, MGAs, Midgets and Sprites, as well as the Spitfires and GT6 models. You should be able to purchase a rebuilt unit from your local auto supplier for around $100.

John
ElectricsMGB Electrical Short?When I was driving 'B' around at night with lights on, everything shut down, engine, lights, etc. It would shut down for 5 secs, then come back on, then shot off again and come back on. I made it home and parked it. I have changed the engine to body ground wire and wonder what you thought of the 'complete' shut down' problem. Thanks and any help would be appreciated



If everything winked out, then there must have been a disconnect at the battery or at the starter motor solenoid (where all the BROWN wires connect to the main battery power cable). You can eliminate this problem by going just a bit further than you did -- at least remove, clean, and replace the connection at the positive side of the battery. And, then, go to the starter motor, remove all the BROWN wires, tighten up the stud, then refit all the BROWN wires. One more thing -- there is a white rectangular connector on the later MGBs, just to the rear of the fusebox, into which four BROWN wires are fitted. Pull those wires out, crimp the ends with pliers, and refit them.

Somewhere in all of this you will have fixed your faulty connection.
ElectricsMGA Charging ProblemSo as to not waste your time, I'll get right to the point:
My MGA 1500's charging light came on yesterday. I spent some time
(probably not enough) viewing some of your online videos. In my
'diagnosis' phase, I connected the field terminal on the generator direct
to the battery for a short time, and checked to see if the charging light
was extinguished (it wasn't)

Then I monkeyed some with the regulator, including pushing on the two
contacts once or twice (this was BEFORE I read your admonishment not to do
this)

Finally I followed your guidance to jumper the Dynamo and Field terminals
together, and take a voltage reading to ground.. Nothing.. then your
second advice to momentarily touch those connections together and look for
a spark... again nothing.

So, removed the generator, and found in both brushes severely worn, one
had broken up in its holder. Aha... I carefully replaced with new brushes
I had on hand, and reassembled, using a bit of Dielectric grease on the
brush screw terminals. After assembly, I spun it by hand, and visually
checked that the brushes were seating on the commutator.

Alas, after reinstalling the generator, cleaning the contacts on the
control box, resetting the regulator contacts to .015, and polarizing
twice, I'm still getting no voltage output from the generator, using the
two methods described above.

1) Do you think I may have damaged the windings in my ham-handed
checkout?

2) I'm not averse to just springing for a new generator, but first
wondering if you have any other possible actions I could take to revive
it? (At just a bit over $100, it just doesn't seem worth it to try my
luck again with one of the auto electric rebuild shops around here)

3) If a new generator seems to be the advice, will I encounter any
difficulties removing the pulley from the old?

4) Although my car is in superb physical condition, I am finding that
basic preventative maintenance tasks seem to have been deferred by the
P.O. Based on my generator brush discovery, should I just go ahead and
yank the starter and check those brushes, or assume that the intermittent
starter usage might result in longer lived brushes?
There are four components in the charging system: generator,
control box (regulator), wiring, and battery. Polarize your rebuilt
generator and test it on the car by jumping between the D and F. You should
get a big flash when the engine is doing anything above an idle. If you
don't, then perhaps the brushes have hung up somehow and are not following
the commutator, or perhaps something has grounded. Work with the generator
until you can do no more yourself. You should be able to have it rebuilt by
some local shop for under $100. Once that's working, then you can, by
elimination, discover if the control box is working OK.
ElectricsRadio Static Here's a strange one, I think. I just put a new radio in my '79 MGB.
FM is fine, but there's a bit of popping static on AM that seems to
increase with speed. I remember years ago it had something to do with
the ignition system, but can't remember the fix. The mystery - it goes
away upon acceleration, but as soon as I let of the gas, it comes
back. What can I do about it?
Since the static follows the speed of the engine, then the source is
either the ignition system or the alternator. The common source is the
ignition system. You can change to resistance plugs (Champion RN9YC or
#415) if you have a non-resistor plug in there now. You can change the
wires and/or cap and rotor. I don't have any tricks for you to follow to
find the problem -- so it's only by substitution that you can achieve a zzzz
free am reception. Let me know what you found.
ElectricsTD GeneratorI have a few questions about the oiler on an MG TD generator.
I ordered the felt from a parts supplier, and it's longer than the oiler - so, how much of it should I use?
The operation manual for the TD says to unscrew the lubricator, take out the spring and the felt, fill the tube with grease and reinstall it. That sounds like the grease would be above the felt, in the top end of the oiler when it's installed. Is that correct? It would seem more logical to put the grease in the opening in the generator, where the lubricator screws on.
What grease would you recommend?
The bushing at the rear of the armature is an oil impregnated bushing. Oil applied on the outside of the bearing will seep through and oil the contact area between the steel in the armature and the bronze on the inside of the bearing. So, I would stuff that wick through the spring and then oil it up. Then, place a slug of grease between the bushing and the oiler and screw it in. We use NGLI #2 lithium grease for nearly every application on the car.
ElectricsAH Negative Ground Conversion I have a1963 AH 3000 positive ground. On e-bay there is an ad for a fuel pump and tack,positive ground,it says replace these two items and rewire the battery and all will work? Is this true
Converting to negative ground is only necessary if you're going to fit a modern radio into the car.

The steps are relatively easy:

Reverse the battery
Polarize the generator (use a jumper wire and flash twice between A and F on the control box)
ENSURE that you have a negative earth fuel pump -- the original fuel pumps were not polarized, but the new and improved ones have diodes. If you fit a positive earth pump to a negative earth car it can catch on fire!
Convert the tachometer -- this is a step by step process which requires calibration at the end, but you can do it at home. If you want to send it out, we'll do it for $50 -- you can call Nisonger Instruments in Mamaroneck NY to get their rebuild price.
Reverse the ignition coil leads. - to the coil, + to the white power wire; or SW to the coil and CB to the power wire.
ElectricsTD FusesMy 53 MG TD has a five lug regulator and a separate fuse block for two fuses. Are both fuses to be rated at 35 amps or a combination of 35 and 50 amps? One fuse, the one with the most wires, is the WHITE/GREEN fuse (stop lights,turn signals, fuel light, wiper motor). That one is a 20 amp (Lucas says 17 with a 35 amp surge).

The other fuse, the one with two or three wires, is the horn. The horn draws more current than anything else in the car -- it's not even wired through the ammeter. That one will also work OK with a 20 amp (usually), but better to use a 30 -- again, Lucas has a "surge" protection of about 50.

It's always best to use the lowest amperage that will work -- but a dead short, in all but the turn signal circuit, will snap even a 50 amp fuse.

Speaking of the turn circuit -- be sure to fuse that RED circuit coming from the back of the lighting switch. Pull all the RED wires from the "T" terminal. Fit one end of an in-line fuse into that slot on the switch, and connect the other end of the fuse holder to the five or so RED wires. Use a ten amp fuse here.
ElectricsBallast Resistor Wiring / Head Work EstimateI was out today to pick my B after it had an ignition failure this past weekend. I had a spare coil, which I felt was not the problem but I changed it anyway. I also thought it could have been the ignition switch, the relay, or even the ballast resistor. I wish I had replaced the relay I gave away a couple of summers ago to someone in trouble! Now that I am back on the road I have a few questions. Is the ballast resistor connection just to the right of the ignition coil? I see a green wire to the right and a white and white with brown coming out the other side. I know the green is the ignition circuit. The other question involves some engine work that I am contemplating in the future. The bottom of the engine seems to be solid with good oil pressure and really no problems with burning oil. But after 76,000 I am wondering about the condition of the cam shaft and the overall condition of the cylinder head. I do notice a little slop between the valves and rockers the last time I was checking the valve gap. From the outside the head looks good, but as far as the underside who knows. I have also heard that the later cams tended to be a softer alloy and that sometime after 60,000 miles they began to show significant wear. If my head was still in good shape, what would it cost in time and labor to change out the valve assembly, seats, guides, polish it up to increase the flow of gasses in and out, and to replace the cam and associated lifters and push rods? I know this is an estimate, and I am basing it on your experience. If my head had problems, what does a replacement run?
There is a ballast resistor within the wiring loom itself. This pinkish wire connects to the WHITE or the WHITE/BROWN circuit on the outside of the wiring loom, just below the fusebox . This resistance wire then travels to the left front of the car where it exits the loom, is connected to a WHITE/GREEN wire which then runs all the way back to the ignition coil. This delivers 6-8 volts to the ignition coil during operation. WHY?

The gov't wants to eliminate unburned hydrocarbons. They want the car to start quickly, stop quickly, accelerate slowly and decelerate slowly -- all to lessen the quantity of unburned hydrocarbons spewed into the air.

At start up you need a really good, hot, intense spark. In a "normal" car, the 12 volt coil delivers an 18,000 volt spark. But, when the starter motor is running, the voltage in the car is depressed to about 10 volts, so the resulting spark voltage is less than normal. Again, you want the hottest spark at startup. So, the engineers designed the coil to run on 6-8 volts -- except at startup. When you turn the key to START, the starter solenoid sends battery voltage (about 10 volts) to the coil through the second WHITE/GREEN wire. Now the coil is receiving MORE voltage than usual and producing a spark which is much hotter than usual -- but just at startup.

The rear side of the coil has a pair of WHITE/BLACK wires -- one from the distributor switching, one to the tachometer.

Just changing the cam in your engine, in place, would be about $1200. Changing the bearings and oil pump would be, in place, about $600. Removing the cylinder head, getting it upgraded, and replacing it would be about $1200. Getting the head ported and polished is another $350 on top of that. If we were to do all these jobs at the same time, there would be come savings, certainly. Give me a call or stop out and Lisa or I can go over these jobs with you.
Electrics1973 Spitfire Starter MotorDo you sell a starter motor for a 1973 spitfire, or can you recommend someone you trust who does? That starter motor is very common -- it's the M35G unit used on T series MGs, MGAs, Midgets and Sprites, as well as the Spitfires and GT6 models. You should be able to purchase a rebuilt unit from your local auto supplier for around $100.
ElectricsFuel Pump Wiring
ElectricsMGB Battery ChargingMy '77 B (you worked on this car when I was on the
faculty at University of Michigan) was totaled this summer in
a parking lot, I replaced it with a '75 B, and I am getting to
know a new car...one quirk is that the polarity in the electrical
system is reversed (discovered when I replaced the battery), when
the alternator went out, my local guy said rewired the car to get
polarity back to normal, but when I attached my trickle charger this
winter, no go--lead me to check and the battery was still hooked up
neg-pos...pos-neg...I called the guy, he is not concerned...should I
be? (I reversed wires on charger to try to charge up...power is out right
now so don't know outcome yet...) Thanks
Your MGB is negative earth, negative ground. This is common with
all modern vehicles. Sometimes the ground cable has been replaced with a
red cable, making ground red and power black -- just opposite of what you
would expect -- but the important thing is that the battery is hooked up
with the negative (-) terminal connected to ground. If you hook it up
backwards, the alternator will cook -- sometimes even catch on fire!

When you connect your trickle charger, the easiest way to do it is
to go under the bonnet. Connect the black lead from the charger to a bolt
or stud on the engine. Connect the red lead to the clips that hold the
bottom fuse in the fuse box. You should see a little spark if the charger
is plugged in and you make the second connection with the alligator clips.

This is a perfectly acceptable method of charging your car and will
not over tax the wiring -- and it's easier than trying to gain access to the
battery.
ElectricsBenefits of Converting to Negative GroundLast year I purchased a beautiful older restoration of an OEW 1967 MGB/GT Special with overdrive which is both cosmetically and mechanically close to original specs. The car has the original positive ground system with twin 6 volt batterys and thev original dynamo. This year I plan to do some upgrades to make the car more reliable. These include putting in a S U electronic fuel pump, a petronix electronic ignition and put in a high torque starter. The question is will the original electrical system handle these changes or do I need a twelve volt battery and a negative earth system? The car does not have a radio and everthing on the car is as original except I put in halogen lights. The car is not a trailer queen and I expect to drive it on nice days putting on about 1500 miles per year. The car has been trouble free so far and I want to keep it that way.

After over 30 years of owning my 1962 MGA 1600 Mark Ii Deluxe, I finally converted it to negative earth and a single twelve volt. Why? One of the sixes was bad -- and new ones are harder to come by -- plus, they're made with 1950's technology and the new batteries are much, much better. I wanted to change to Pertonix and didn't want to deal with the positive earth system. So, are you geeked on originality or is it of little matter?

There is no inherent advantage of negative earth over positive earth. The group 26 twelve volt sits in the passenger battery compartment just fine. If you ever wanted to add something modern (a radio, for example), or if someone besdies you was driving the car and needed a jump, the negative earth is so much more common.

The only disadvantage to the high torque starters is that the power lug sits very close to the distributor, so pay attention to that.
ElectricsPolarizing / Generator Testing Restoring a 61 MGA 1600. Tried checking out the Lucas 22744B C40 generator that is out of the car and unused for years. Hooked up a DC volt meter to the D (fat flat spade) and grounded to the casing, then turned the armature with a brush on a drill - got nothing at all. I read an article that talked about the magnetic field being lost over time so I wanted to be sure I do this properly if that is indeed the next thing to try.
Found articles that talk about polarizing and jumper wires which weren't entirely clear to me on where to "touch" the wires and they all have me doing it with the generator and regulator in the car usiing the hot side of the starter solenoid.....so that is why I'm asking for your help. Can you advise me on how to establish the magnetic field and bench check the generator unit? By the way I intend to convert to a negative grounded system in my restore.
I'm thinking this 22744 was a replacement unit as I'm only finding references to it in Midget/Sprite and TC/TD applications. I would intend to replace it with the appropriate generator from MOSS if this one turns out to be bad. Any thoughts about going for an alternator if a replacement is required?
First polarize the generator by grounding the case and energizing the small spade, the "F" terminal, with the hot wire from your battery. This magnetizes the poles on the field windings.

Now, when you spin the generator with your wire wheel you should pick up a voltage of 1-2 volts between the larger terminal, "D," and ground. To make the generator work more powerfully, connect D and F and run your voltmeter between that connection and ground. If you can spin the pulley fast enough you can get up to 100 volts!
ElectricsLight Grounding You have inspired me to get the old ragtop out and look at it again. I had almost given up and was going to put it on ebay. I recently put a new haz. switch on the 79 mgb. The left rear light was not flashing but the tail lights worked so I figured - put a new 1156 bulb. The existing bulb was ok. I took the fixture off and found that the ground was bad. Sanding the inside did not work. Why would the light fixture itself be insulated from the frame? Even the "nuts" holding the fixture in have plastic insulating washers. I jury rigged it by stripping wire and wrapping it around the outiside ot the bulb holder (taping it on) and running the other end to an attachment stud. Any advise will be appreciated. It is not a driver yet but may be with your inspiration. You seem to be close to understanding Lucas! I'm surprised that you'd find such a fault in your climate -- up here in the cold, wet, and salty winter we've encountered all sorts of disconnects. In the case of a socket isolating itself from the lamp base, peening the little tabs usually does it. It does seem odd that the nuts holding the lamp base to the body are isolated with plastic, but the ends of those nuts have little sharp points which I've suspected ensure the earth connection.
ElectricsMidget Radio Wondered about the AM radio. It squeeks - no music ( ok there probably isn't any music on AM ). My wife thinks it worked before its 25 year hibernation. I did get it removed, hoping to figure out the problem. Wondered if our car a negative ground? There is a local "radio guy" to take a look at it. Any suggestions? Many of those BMC radios were Motorola underneath. Yes, your Midget is negative ground. If your local guy cannot make it work, there are a host of repair shops listed in "Services" in Hemmings Motor News.
ElectricsWiring Harness Installation / Overheating1) I am going to install a new wiring harness in a 1972 MGB. Do yuo have any tips that might make the jobs easier or more fool-proof?

2) My car,, 1972 MGB, continues to run after I shut the key off. What could be the problem and how can I fix it? I dont think it has a anti-runon valve?

3) I am having problems with overheating. I am lossing antifreeze. It seems to just be boiling out some. At high way speeds it seems ok. I assume that tis is because of the greater air flow in the engine compartment. What sould I do? Flush and fill? How can I tell if the water pump is good? Should I be able to smell it if is is burning in the cylinders? See it if it is in the oil?
For your wiring harness, it is best if you physically placed it into the car then hooked up one connection at a time. With your year car you should have a anti run-on valve, it is powered with a slate with purple wire. Watch the youtube video for help. Over heating is very common with bad timing. your timing should be 32 DEG MAX with the vacuum disconnected.
ElectricsTCSA SwitchI'm De-toxing my 1980 MGB. I'm not understanding DT13. on page 310 in the book Haynes Restoration Manual MGB. I know where the vacuum advance is (it is on the distributor) What is TCSA switch? Than were is the inlet manifold? The picture in my book is real dark and I can't see it! TCSA is the Transmission Control Spark Advance. The inlet to the manifold is between the head and the carb and takes 1/4" NPT plug.
ElectricsFaulty Wiper SwitchAbout a week or so ago, I purchased a new wiper switch for my ’79 MGB. It arrived a couple days ago, and I attempted to install it today. As you know, it appears to be a very straightforward installation – remove the cowling, unplug the old switch, remove the old switch, attach the new switch, plug it in, replace the cowling.



I did this, but the wiper switch doesn’t work as the original did (both are Lucas, and appear identical). First of all, in the “off” position, the wipers appear to wipe intermittently – sweep, 1-second pause, sweep, repeat. In the “single wipe” position (pushing the lever up), the wipers stop completely – and the lever won’t stay in this position, so the wipers are always on. The “low speed” position appears to work normally, as does the “high speed” position – although the switch doesn’t want to stay in the “high speed” position, and jumps back to the “low speed” position – like the spring is too strong.



Any ideas of what I’ve done wrong?

We have made a YouTube video pertaining to your problem. it can be found at http://www.youtube.com/watch?v=X9_C2QAnk9A&feature=channel_page.
ElectricsMGA Turn Signals I have a 1960 MGA 1600 and want to ask you a question regarding
directionals. I was having trouble with the right side front
directional.
I checked the wires and they seemed OK. Now, the the directionals
started
blinking at all four bulbs. This occurs even when the dash switch is
turned
right or left. I installed a new flasher unit to no avail. I'm thinking
its
a wiring issue. Can you help?
You do have a wiring issue in the rear of your car. I
think that your wires are confused. Your green with white should be for
the right side, the green with red should be for the left and the green
with purple should be for the brakes. Any other questions, please call
during my tech hour.
ElectricsMGB Loud Horn
ElectricsMidget FuseboxThere are several brown wires that have what looks like a heat shrink covering on them that are in the area of the fuse box. We think we have identified all of the wires that do go to the fuses box, but these are extras. The fuse box had been relocated and all of the original wires had been spliced so not many of the original wire colors were present. We have put it back in it's proper location and connected the wires to the correct terminals according to the wiring diagram. Again this is on a 1978 Midget.

I think there is a top and a bottom when looking at the fuse box like on a B. How do tell the correct orientation when installing the fuse box?
The fusebox is fitted upside down from the MGB orientation. That is, the two bridged connections are at the bottom. The wires from the top to the bottom on the battery side should be: Brown; White; Empty; Red/Green. The wires from the top to the bottom on the fender side should be: Purple; Green; Red; Red. Those Brown wires with the black shrink tubing on them should all be common. The original loom had a translucent whitish four way connector into which these were fitted.
ElectricsAlternator WiringI'm in the process of changing out a Lucas ACR 16 34 Amp Alternator for a
Delco CS130 96 Amp Alternator.
My Lucas has 3 wires coming out. From what I can tell from colors, 2 are
heavy gage Brown w/Black and 1 thin Yellow w.Black. Obviously the colors
are really worn and hard to distinguish color wise.
My new Delco has wiring instructions that say Large & Small Solid Brown
along with Large Red from Alternator to the battery post on the
alternator. The Small Brown on the new plug to the Brown w/Yellow tracer
from the wire harness.
I've been on the web trying to find wiring diagrams for both alternators
with absolutely no luck. I've also tried several wiring combinations and
all I have succeeded in doing was the lock the starter up.
Any info will be much appreciated.
The BROWN wires are always hot and are connected directly to the
starter solenoid. The BROWN/YELLOW is the indicator light. That's about as
much as I can tell you. You can call, and that might be helpful if you
haven't already got this sorted out.
ElectricsMGA Rheostat / Potentiometer ohmsDoes anyone know the resistance value (0 - x ohms) of the panel light dimmer rheostat/potentiometer, or where to find it?I just checked an MGA potentiometer to find a range of 0-12 ohms. Doesn't seem like much, but I checked it thrice. It must be the same as an MGB.
ElectricsMidget Ignition WiringI recently dragged home a refugee midget that with a little clean up, should be running for this summer. My first hurdle is electrical. The previous owner replaced the battery, ignition switch, points/ condenser, cap and rotor, coil, plugs and wires--but had not gotten it running. At first, I had no spark whatsoever. By switching to known good wires, cap, rotor, and coil from my other midget, i got a feeble spark when i first started cranking, then nothing until just as I released the key. I decided to try jumpering 12v directly to the hot side of the coil and then I did get a nice steady stream of spark--so I suspect a wiring problem. My next plan is to try and trace the circuit back thru the harness and clean/ tighten each connection. I swapped the fuse box for a freshly cleaned (not new) unit. I am crossing my fingers that the car is not simply diabolically possessed! My problem is, I cannot find a wiring diagram that exactly matches my car--it appears that my coil is powered directly thru the ignition switch while the negative side (white with black tracer?) leads from distributor to coil and then the negative side of the tach. (I disconnected the tach suspecting a short in this circuit.) I did find one such diagram for the primary circuit, but other parts of the same diagram don't seem to match this car. (?)

At the aftermarket ignition switch, I have green/white, light brown/grey, dark brown, and white/ red--how do these align correctly with the harness? Also, what is the relay looking box on the rh fenderwell near/ outboard of the fusebox?
There is a direct connection from the key switch to the hot side of the ignition coil. The negative side of the coil is correctly connected to the distributor and to the tachometer.

The fusebox is wired "upside down" from the MGB. From the top, down, it's BROWN, WHITE, and RED/GREEN on the unfused side (pay attention to the buss between the two terminals at the bottom right); and PURPLE, GREEN, RED, and RED on the fused side.

From the ignition switch you have: BROWN - Hot, unfused, power INTO the ignition switch; WHITE/GREEN - first position, unfused, power to the radio; WHITE - second position, unfused, power out to the fusebox, coil, and fuel pump; WHITE/RED - start position, unfused, power to the starter relay. You may also have a SLATE wire which is hot, fused, when the key is OFF to work the anti-run on circuit.
ElectricsWiring HarnessDo you have a recommendation for wiring harness suppliers? My dash
harness melted all the way down to the starter. I have to rewire. Which
supplier is best in your experience?

By the way, the alternator that you rebuilt is (was) charging fine, and
the wires to it are not burned. It is probably still OK.
Our experience has been wonderful with British Wiring in Olympia Fields, Illinois. www.britishwiring.com Contact Leslie -- she'll help you out!
EngineEngineyes i have a 1973 mgb it have a newer mottor in it i think it is a 75 to a 78 it dont have the tack gear on the driver side and it has the weber carb on it the quist is on the rocker a semb the is a shem that was on it beteewn the head and rocker bracket i need to now what bracket it goes under are is all of then need this From 1972 through 1980 there were two shims fitted under the rocker assembly -- on the middle two pedestals. This was to place a bit of tension on the rocker shaft so it would prevent tramping -- vibration under certain conditions. The earlier engines did not have these shims -- but they did have much stronger valve springs. I have found them in the wrong places or non at all. It is not critical that they be fitted.
EngineOil PassageI was watching one of the videos that John made where he was talking about the 1500 cc engine and how the #3 bearing is not lubricated well. He recommended boring out the oil passage to help. What if during the rebuild the oil passage was not bored out, what can I do now or what should I avoid during driving? High speeds or high revving? Once the engine is assembled there is nothing more you can do, save keeping the oil clean and fresh. We use 20W/50 on all our engines. Change the oil at least once a season (in the fall before storage) and at 2500 mile increments. Watch your oil pressure gauge – you should always have at least 60 psi when you’re running at high speed. Hope this helps!
EngineEngine Smoking After RebuildHi John, Sorry to bother you. If I lived closer than the east side of Toronto I would just drop the car off with a blank cheque and have you fix it. I have just rebuilt the engine ( 1952 ) new >030 areolite piston with hastings rings , new bronze valve guides at .002 clearance ( a bit tight ) 30 weight non detergent oil for first 20 miles of break in . Problem is it smokes quite badly , especial;y when hot . I am told the piston andring clearances were to spec as provided to the engine shop . Rings were set at 120 degrees apart on insertion into bores . All spark plugs show wet and black. Timing is 10 degrees advanced . Roller cam kit installed compression 165psi on all cylinders wet or dry. All cylinders fire dwell at 60 degrees. Carbs rebuilt by joe Curto. at 5 flats down. At the first rebuild seven years ago using County four ring pistons there was no smoke at start up at all . I am quite confused by all this and more than a little frustrated . Hope you can help, thanks , Keith Keith! It is normal for engines to smoke for a short time after a rebuild. The inexpensive solution to your problem may simply be a 200 mile run up and down the 401 (carrying extra oil with you, for sure) to help the engine break in. The engine smokes for three reasons: the PCV system is plugged causing internal pressure; the valve guides are leaking; or the rings are not doing their job. The TD engine has an oil draught tube on the left side of the engine. These were sometimes replaced by finned side covers with very restricted breather vents which can cause smoking by allowing the sump to pressurize. If the oil draught tube is original there should be no problem. You can always remove the oil filler and blow into the engine. There should be absolutely no restriction to any air pressure. If the valve guides are faulty the smoking is exacerbated by high manifold vacuum -- it will smoke much worse idling or after a deceleration. But, in the end, it's almost always the rings. Faced with the prospect of removing the head and sump to hone the cylinders and change the rings, I'd drive it for several hundred miles at highway speed. Set your timing to 32 degrees before top dead center at maximum advance. Your original 40152 distributor has a 16 degree advance which translates to 32 degrees on the crank. I believe ten degrees at idle is probably too little advance, especially if the springs are even a bit loose or stretched. It is essential to dial in the carbs. After matching the air flow, test the mixture. As you lift the air piston about 1/8 inch three things may occur. The engine may run faster and faster -- alerting you that the carbs are set too rich. The engine may stumble and fall -- alerting you that the carbs are set too lean. The "perfect" mixture allows the engine to rise about 50 rpm and then fall off. Work one carb, then the other. You may have to adjust the idle speed several times as you achieve the best mixture. Rev the engine between every adjustment. Hope this little bit helps.
EngineOil Leak / PCVI\'m having trouble with oil coming out of the side cover vent on my 75 MGB. It is extreme at highway speeds. I have alot of moisture (white slim) in the valve cover. New valves were fitted last year and I\'m wondering if the head gasket might be leaking. There is no smoke coming out of the exhaust so I don\'t necessarily think it is blow-by from worn rings. The car is a daily driver for my 17 yr old daughter. Tom, Your 1975 MGB has a PCV system that works this way: Filtered air enters the engine through the 1/2" tube from the charcoal adsorption canister. Dirty air and blowby exits the front tappet inspection cover and is vented into the carburetter. This draft keeps the inside of the engine clean. If the tappet cover is blocked, intentionally or because the metal gauze inside has been baked (an overly hot catalytic converter perhaps years ago), then the engine will leak and blow oil out of nearly every gasket and seal. If the tappet cover is open and vented to a carb or the atmosphere, then excessive blowby is mostly likely the cause of worn compression rings. Make sure there is no impediment for the gasses to exit the engine. The milky white is the water/oil mix, again from the combustion. I doubt there is a head gasket problem.
EngineSmog System> Question: Hi John, > I'm a new 1979 MGB owner and found that the car has been been substantially de-smogged and many lines and intakes related to the emission controls have been blocked and plugged. I have a 2 part question. I'm wonderring how much of these changes are affecting the performance of my Zenith carburator and should I just leave it alone, though it looks unsightly and unusual. My second question is, if I chooose to remove all smog related apparatice from the engine and manifold, do you think a Weber carburator is a reasonable alternative that will require less maintenance. > Thank you and I enjoy your videos. > PeterPeter, There are three large sections of the smog system. One is the airpump; one is the Positive Crankcase Ventilation system; and one is the Evaporative Loss Control System. The car does run better with the airpump and its associated plumbing removed. But, the remainder of the system is passive, does not impact performance, and should be left in place. If you will send me digital pictures of your underbonnet and then call me at tech time I can go over each hose and tell you if and where it should be connected. You may also find some of my YouTube videos helpful -- search YouTube for and scan the titles. Hope this helps!
EngineEngine Rebuild Cost> Question: How much should I expect to pay for a really serious engine rebuild? Do you know of a good shop in the Denver area?2012: Bob, Including a new clutch, installation, and tuning, you could spend as much as $5,000. We are in the $4000 -$4500 range here. You have the wonderful advantage of having Sportscar Craftsmen in Arvada. They are an excellent shop. John
EngineValve Stem SealsHi John,

I am going through the cylinder head from my 1960 MGA 1600, recovering from a coolant-to-oil leak. A friend of mine said he used Felpro valve stem seals rather than replacement originals. He thinks you may have given him the recommendation, but his memory is foggy.

So, the question: What should I use for valve stem seals? Do you have a recommended supplier?

Thanks a lot for the help. Happy spring time motoring.

Jay Fluehr

JAY!

Yes, use FEL-PRO seals, part Number SS 70373. These are for some sort of Chevy truck or something.

You'll not be able to use the internal cone (oil deflector) which sits inside the inner spring. Also, don't use the rubber O ring (which is nearly useless anyway).

These Felpro umbrella seals fit tightly around the valve guide and the stem and eliminate ALL oil leaking from the valve guides.

Hope this helps!
EngineHigh RPM'Morning John,

I hope this e-mail finds you well.

Got a question for you if you have time. I rebuilt the SU carbs and changed points/plugs/wires on my '68 B a few weeks ago. Everything is running great, it idles better and pick-up is much improved. The situation is now when I'm going about 60mph, the tach hovers around 4000. Before I did all of the above, it hovered around 3000rpm. What did I do? or what didn't I do?

Any quidence would be greatly appreciated as always. Also, do you still have the book for sale? I believe it was around $30 and have tons of tech tips. If so, I think I'd like to get a copy.

Comming down to MG2000 this year? I work in Cleveland and they have really done some great things the last 10 years. You'll have a good time and the Emerald Necklace does a good job at whatever they do.

Thanks again, John. Take care.

- Tony

TONY!

I cannot imagine what you did (or didn't do) to cause the tachometer to read differently than before the tune up. If the tach reading really drives you nuts, you can send it to me for calibration, or to Bob at Nisonger Instruments, Mamaroneck New York. I tell people to expect a reading of about 3500 at about 65 mph.

The technical book IS available for $30. Either call with your charge card number (try to call between 1-2 EST Mon - Fri -- that's my technical hour), or fax the particulars to: 616 682 0801.

YES, we'll see you in Cleveland!
EngineStarting Stored EngineJohn,

I have one more question. This MGB has been sitting for at least 13 years, and a friend told me before I try to start it I should remove the spark plugs and turn the cam shaft to make sure that the enginge isn't locked up.

I did and it isn't. He also said to pour a small amount of auto transmission fluid into where the spark go to coat the pistons and help remove any corrosion that might have built up over time. What do you think about this suggestion?

Thanks for your input.

Andy Phipps

ANDY!

The most important thing is to spin the engine to get oil pressure before trying to restart it after such a long time. The engine will spin more freely, and you'll get oil pressure more quickly, if you remove the spark plugs before spinning it with the starter motor. Oil down the cylinders will make little difference now -- had you done this when storing it, it would have prevented rust and corrosion -- but whatever has rusted and corroded has already done so. Oil down the cylinders will not hurt anything -- but if you get too much in there, it will make a real mess when you start spinning the motor!
EngineMotor MountsJohn

My motor mounts are getting a little soft from the oil that leaked from the engine. I have the engine pulled now and was wondering what is the best way to replace the drivers side mount?

Thank you

Michael Cerny

MICHAEL!

First, make certain you've purchased the "competition" mounts which are stronger and more durable.

Second, fit the rear / lower / innermost bolt into the motor mount bracket and WELD it into place -- that bolt is nothing but trouble trying to fit!

Third, it's necessary to remove the pinion from the rack and pinion to gain access to the nut on the bottom of the mount. Remove the shim pack from the top of the rack, remove the bolt at the steering U Joint, then slide the pinion out. This sounds like the workshop manual -- easy!! It's not. You'll probably have to grasp the pinion with vise-grips and drive it out.

Leave the pinion out until the engine is fitted, then when all is tight, replace the pinion and then center the steering wheel.
EngineRun-on, Hard Start77 MGB, Z/S carb, full emission equipment

Electronic Ignition Allison - been using it for the past 10 years (56,000 miles)

Recently had the engine rebuilt. I had not been using the vaccum advance since it was not connect when I purchased the car over ten years ago. The rebuilder reconnected the vaccum advance via a tee in the run-on control pipe and the manifold said it work correctly and I should use it. Engine does not ping under any driving conditions.

Engine now has about 1200 miles on the rebuild and runs great. EXCEPT when I want to shut it down or start it up when it is hot.

Likes to run on when I shut it down. Oil pressure switch, Ignition switch and run-on valve all work correctly , verified pressure switch ground, verified ignition (off) switching voltage, verified run on value switching (it clicks when I shut down and the oil pressure drops back to 0), cleaned connections.

When I start the engine hot it is very hard to start, starts ok if cold or cooled down for half hour or more.

Neither of these conditions is 100%, sometimes it shuts down quickly and sometimes it starts OK. I have renewed the carbon in the canistor. All hose connections are tight. I had the carb check by a local rebuilder who is experienced on Z/S he gave it a OK and I replaced the fuel line filter, has new plugs, new plug wiring, new distributor cap. A lot (most) of the tubing is also new. Once started purrs..... Just does not want to stop running and I am afraid I am going to pull in someplace for a coke or gas and not be able to restart it.

I have ran out of things to check. Any suggestions ? Thanks, Stan

STAN!

Your problems of run-on and hard start may be related. Look at the anti run-on system first.

When you place your finger over the end of the anti run-on valve inlet tube (located to the right of the radiator, on the front side of the radiator diaphragm) the engine should momentarily rise in rpm, then kill. If stopping the air flow into this tube does NOT kill the engine, then there IS a leak in the evaporative loss control system or in the positive crankcase ventilation system. Work with EVERY hose until you can get the engine to kill! Then the anti run-on system should work without hesitation.

If the engine DOES kill when the tube is blocked, but the engine doesn't kill when the key is turned off -- well, I'll have to think on that one!

To understand the system, follow the flow of the air: The gas tank is NOT vented to the atmosphere, but instead pushes air/fuel mixture into the charcoal adsorption canister when the fuel expands (when it warms up). Or, air is drawn through the canister and into the tank to replace gasoline which has been drawn out by the fuel pump.

The carburettor float bowl is NOT vented to the atmosphere, but instead pushes air/fuel mixture into the charcoal adsorption canister when the fuel in the bowl expands (after the engine is turned off and the heat causes the fuel to expand). For the carburettor to work correctly, atmospheric pressure MUST sit on top of the gasoline in the float bowl so that the gasoline can be pushed up and out of the jet when the air pressure there is depressed at the venturi (during running).

So, both of these are connected to the ADsorption canister, where fuel is ADsorped by the charcoal. This is the ELC (evaporative loss control) system. The gov't doesn't want raw fuel in the atmosphere.

During engine operation, air enters the anti run-on valve ventilation tube (at the radiator diaphragm), passes through the valve, into the bottom of the canister and through the charcoal (to purge it of fuel fumes), into the valve cover, through the engine, out of the front tappet inspection cover, and into the carburettor between the air piston and the throttle disc. Air is ALWAYS in motion through this system while the engine is running.

When you stop the air entering the system, the engine and the canister begins to evacuate. This, eventually, places a vacuum on top of the gasoline in the float bowl and starves the engine of the fuel in the "air/fuel" mixture.

When you energize the anti run-on valve, not only is this vent tube blocked, BUT, manifold vacuum REALLY evacuates the system and the engine is killed INSTANTLY for lack of fuel. You can energize the anti run-on valve (hot wire from the bottom of the fusebox to the stud which carries the SLATE/PURPLE wire on the valve) and test the integrity of the hoses.

Without a diagram, I know this is difficult to visualize.

The problem in the 1977 models and early 1978's is that the ignition coil is powered through the ignition relay. When you turn the key OFF, the ignition relay should turn off, of course -- BUT... The electricity coming out of the alternator, on the BROWN/YELLOW wire, which extinguishes the ignition light, now is free to pass through the ignition light, and continue to energize the WHITE circuit. When the fuel pump operates (WHITE CIRCUIT) the voltage drop is usually great enough of open the ignition relay. SO, fitting a diode into the BROWN/YELLOW wire (arrow of the diode pointed towards the alternator) also fixes your problem!

I suspect that the mixture is too rich, and the engine is flooding when trying to do a hot restart. Lean out the carb and try some more hot starts.

This was lengthy, but I hope it helps! Good luck!
EngineIdentifying EngineHi John;

I am hoping you can help with deciphering my engine number. I have a 1973 MGB GT that I purchased last October. My engine number is: 18V658M-L17025. I have checked this number against what is listed in Clausager's book "Original MGB" and cannot identify what 658M stands for. According to Clausager this engine was never put in MGBs on the assembly line. The engine does have AUD 550 SU carburetors which is right for the year. I have not sent of the BMIHT certificate to see if it is the original engine. If it is not then it would be of no help in determining what 658M stands for. Any suggestions?

Also, are you still running your workshop seminars?

Thank you in advance for your help.

Sincerely,

Mark Jones
New Brunswick, Canada

Mark!

The engine is one from an Austin Marina (sold in the UK as a Morris Marina). It is a severely detuned B series engine -- but who knows what has been changed in the meantime. In the end, it is the camshaft, valve size, distributor, and carbs that make the engine an MGB engine.

Watch our website for notes about next years technical seminars.
EngineGB Engine I am installing a GB engine in an MGA. All the info I have seen, and all the advise on the websites, says that I need to install an early MGB front cover and clutch fork on the MGA transmission ( 1600 model). However, after assembling the new engine/clutch, I compared it to the MGA 1622 which I had removed. The MGA with a used clutch measured 3-1/2" from the backplate to the actuation ring on the pressure plate. The GB, with a new clutch disc, measured 3-3/8". This 1/8" difference would be somewhat expected due to the clutch wear.

Am I missing something? Do I really need to change to the early B front cover or is the information wrong and the MGA front cover/fork ok?

ART!

You have probably solved your problems, but here is some more information. You have parts of two interchanges mixed up:

An MGA clutch can be upgraded to an MGB clutch. To do this, it is necessary to change the front cover of the gearbox to the MGB style, change the release bearing fork (and bearing), and, of course, change the clutch cover and disc to the MGB type.

An MGB engine can be fitted to an MGA, but you must change the rear plate, and have that plate opened to accept the MGB rear oil seal. Further, you have to fit an MGB flywheel which will accept the MGA clutch (65-67 MGB) so that the crash starter works.

In practice, I've seen all sorts of combinations -- some of which I would have sworn could not work -- but there they were, mashed and screwed together, working.
EngineLow Oil PressureMr. Twist,

I spoke with you on the telephone a couple of days ago about an MGA I recently purchased. The previous owner said that it probably needed to have it's engine overhauled. On the phone you had asked about the oil pressure, and it is about 35 lbs at regular running speeds. You said that was pretty low, and mentioned a couple of "not drastic" things that could cause that. I think I did pretty good with the purchase price, and I wouldn't want to run into any major engine problems in the near future, especially if I have the car sent from St. Louis, MO, up to you, so I wouldn't be against a complete engine rebuild. Can you give me a description of what you do in an engine rebuild, and some sort of prices. I have heard that these cars can be a bit quirky, so I know an estimate won't be exact.

Thank you for you time,

Jason J. Buchek

JASON!

The route to "proper" oil pressure is as follows:

1. Change the oil and filter -- use Castrol 20W/50 GTX
2. Change the oil pressure relief valve on the left rear of the block
3. Remove the sump and change the rod bearings and center main bearings (the first and last mains cannot be changed in the car), and replace the oil pump.
4. Remove the engine and replace the crank
5. Remove the engine and rebuild the engine.

1. $50
2. $50
3. $400
4. $1600
5. $4000

Since the prices begin to jump so dramatically, it's best to work UP! Yet, an examination of the rod bearings can determine the condition of the crank.

Hope this helps!
Engine1500cc EngineHello,

I have a '55 MG TF and have reason to think that the engine is the 1250cc engine and not the 1500cc engine. The car has been in my family for years and is now in my care. The brass plate on the block has been tampered with and the numbers cannot be read.

On the block is a casting number 168421 which matches numbers I have seen on other 1250cc engines. My dad never checked the numbers on the car when he bought it in 1979. Anyway, I am going to restore the car and may need to find an XPEG engine block. I am sure that is not an easy item to find. Any suggestions?

Is it true that the only difference between the 1250cc engine and the 1500cc engine is the block and pistons? The head, cam, etc are the same. Well, this is my situation. The car has the 1500 TF badges on the side, but I think the engine was changed before my dad bought the car. I would like to rebuild the correct engine when the time comes.

I would welcome your advice. Also, do you guys have a correct TF valve cover as mine is aftermarket?

Marty Ennis

MARTY!

Your suspicions are correct -- the 1250 block has a numerical casting number, the 1500 carries an alpha-numeric casting code ( I want to say it's an AEG prefix on the 1500, but I'm not certain). YET, in the end, this will bother only YOU! Continue to advertise for the 1500 block, but expect to pay handsomely! I would keep an advert up on www.mgcars.org.uk.

We do not have the correct TF valve cover.
EngineEmission ControlsDear Mr John H. Twist

I have just bought an MGB Roadster(Built May 1978) that has been imported in to the UK from southern California so it has the full nine yards when it comes to emission control systems installed. My girlfriend has given me the Haynes Restoration Manual For MGB's for a Christmas present that has a section in it written by you regarding "De-Toxing" US Cars. The excerpt that is in the book covers removal of the EEC system do you have anymore information regarding the removal of any other systems that were incorporated for the US market (Californian) (e.g. the Evaporation Loss Control System) so that I can get the car back to a basic engine

Gavin Hunt

New MGB Roadster owner

GAVIN!

My suggestion is to remove the air pump, air manifold, gulp valve, and associated plumbing -- but leave the ELC (evaporative loss control) system alone. That ELC system incorporates the charcoal canister, the evaporative canister in the boot -- and really does help keep the air clean without affecting the operation of the engine (much).

You can, of course, remove the carburettor, and solder shut the spring loaded poppet valve (the overrun valve) which will give you better throttle response on deceleration.

If you have any further questions, please get back in touch.
EngineValve Seat Machine DimensionsDear Sir,

I am in the process of rebuilding the head of my 73 MGB and in need of the valve seat machine dimensions for the intake valves. The engine # is 18V672 Z L9507 and from what I read, the intake valves are larger on that engine than the others. My "The Complete Official MGB" manual only provides the dimensions for what appears to be the smaller intake valve. I have just sent for your Tech Manual and as they say "the check is in the mail". I noted there was a section "MGB cylinder head data", perhaps that information is in the manual.

Thankyou

Sincerely
Earl A. Epps

EARL!

The head probably takes the 1 5/8" intake valve -- that is 1.625" Interestingly, this valve (minus the 5/16" stem) yields almost exactly 2.0 square inches of cross section. Note, too, that this valve is LARGER than the 1 1/2" carburettor!

Much more information than this is in the book. Hope you like it!
EngineHousing Bore SizesMr. Twist,

My name is Pete Ingwersen, AMGCR #1295 (I think), and I have my MGC engine in the shop for a complete rebuild. One question the shop has that the manual does not answer is the following: What are the housing bore sizes of the Main Caps and the Big End Rod Caps? These are not the journal or bearing diameters, but the actual diameter of the hole formed by the block and cap or rod and cap in which the bearing set. Where can I find these specifications? I need them in a hurry. Can you help me? Thanks for your time.

Pete Ingwersen

PETE!

The housing diameter for the main bearings is: 2.5210 - 2.5215
The housing diameter for the big end is: 2.1140 - 2.1145

This is not an uncommon question! Hope this helps!
EngineDetoxHi John,

I bought my first MG in September of 1999 from a couple in NC. It's a 73 Midget. They knew I was going to drive it home when they saw the smile on my face after the test-drive. It was fitted with pollution control equipment to pass NC inspection. I'm not required to e-test here in GA. I'd like to detox the engine but I can't find the information on your site. If you could point me in the right direction I would surely appreciate your help.


JIM! Quickly: Remove the air pump and air manifold -- plug the head with 7/16" Allen set screws (looks nice). Pull the 90 degree fitting from the intake manifold and tap it 1/4 NPT and fit an Allen pipe plug (looks nice). Remove the carbs and 1) solder the overrun valves from the button side, or 2) replace the throttle discs with new ones (non pollution). The new discs are, by far, the best solution because of air flow. Remove the gulp valve from the intake manifold and plumb the vacuum advance line directly from the manifold to the distributor.

That's all!
EngineEngine OptionsJohn,

I have a 1979 MGB that has been raped over the years and is in poor condition. I want to put a new carb, exhaust, and distributor in it. Right now there is no air pump, converter, or heater. It has a 25d distributor and the original carb. The car runs ok but it does not have any pickup or power from a stand still. The compression on the engine is good,so I am thinking about getting a weber DGV carb, big bore stainless steel exhaust, and a mallory dual point distributor. What do you think of this and what would you recommend with the options that are available(weber DCOE, header, lucas distributor, etc).

Thanks for your time,

Michael T. McLaughlin

Michael!

The first step in your search for power, reliability, and efficiency is a good tune up by someone who knows what they're doing. This can ("can") be a professional, but it can be YOU, too!

If you brought your MGB to my shop, we'd charge you around $250 for a "complete" tune up. You would be pleased. But, IF you wanted more, then you could elect to do some of this radical stuff you're fantasizing about.

Remember that Webers say "Bologna" on top; All Headers are LOUD, all headers leak, all headers are headaches; you do not need a dual point distributor -- no MG runs out of spark.

Where do you live? Do you want a step by step so that YOU can tune your MG. Maybe you'd fly me out to your house? (It might be less expensive than all this other stuff!).
EngineOil Leak, TimingDear John,

I need your help for engine reconstruction. I recently pulled the engine out for not a rebuild but for a rear engine leak. I think I have this problem solved. It's either because the rear plate was not tightened down good or the rear crank bearing cap was not smeared with a sealer before it was tightened down. By the way, what are your thoughts on this and what kind of sealer do you usually use on the bearing caps. On to my real problem- After getting all my new gaskets, I'm ready to set the motor at TDC and put the fly wheel back on. Following my shop manual, I rock the 4th lifter-exhaust just closing and inlet just opening. That should be TDC. Viewing the timing gears, the dimples should line up. Mine don't - does it really matter if they do or don't? The crank dimple points toward the cam but the cam dimple points 180 degrees away from where it should. Does it mean that I should undo the cam nut and rotate the cam 180 degrees?

Or just leave it. Now on to the flywheel orientation. The manual says the number 4 on the flywheel should be pointing to the number 4 and throws of the crank. What are the throws?

Thats about it. I would appreciate your expert opinion on my problems. I would love to get the car on the road come this Spring.

Sincerly yours,

Rick Davis

RICK!

You have two considerations -- a leaking rear oil seal and a problem understanding the workshop manual.

The engine has a problem not leaking out the rear. All there is there is that scroll thread which attempts to screw the oil back into the rear main cap. IF, IF you have had the engine "align bored" or "align honed" then the rear slinger will fit concentrically about the scroll thread and allow about 0.003 clearance, and it will not leak (at least, not much). By the way, there is a NEW rear seal soon on the market, which will offer a POSITIVE seal.

We use silicone gasket goo (RTV silicone sealant) on the rear gasket and on the block cork used between the rear cap and the sump. We use silicone goo on ONE SIDE of the sump gasket, and GREASE on the other -- in case the sump has to be removed at some time in the future.

When the dimples on the timing gear are NEXT to each other, the engine is firing on #4. When the dimple on the cam gear is at about 2:00 (opposite of the above), then the engine is firing on #1. When the rockers are "rocking" they are both open and the other cylinder is firing.
EngineHigh-RPM ScreechingDear Mr. Twist,

I got your name from my former mechanic (I had to move... military, you know how it is...). Since he revered your wisdom, I humbly ask for your technical assistance. I have a 1971 MGB. I just had the engine and transmission rebuilt and new U-Joints installed. I followed my mechanic's recommendations for engine break in and have recently finished it. I now have about 2000 miles on it and whenever I exceed approximately 3700 RPM, the engine starts to screech! I thought it might have been a belt, or my air pump seizing. I sprayed silicone lubricant onto the belts, no help. I removed the belt from the air pump, no help. Next I noticed that it didn't happen only at 3700, but if I down-shifted and popped the clutch, it would do it. Also, sometimes I can exceed 3700 RPM, only to have it start at a higher speed. It doesn't matter if the car is moving or not, so I think it's not the transmission. Could this be the water pump? or alternator? HELP!!!!

Michael Burman, SrA, USAF

Michael!

OK, it seems that your engine screams when it hits a certain rpm, whether you're on the road or not. So, disconnect the fan belt, drop it away from the engine, and run the engine up through that rpm range where the noise occurs. If it is gone, then the problem is the alternator or water pump. If it is not, then it's within the engine. I'd put my money on the alternator, but let me know!
EngineMGB Big Valve HeadHi There,

I am looking for an MGB big valve head (c. 1972-1974, with and 'L' cast in the back of the head). If you happen to have one laying around, would you please forward price and condition to:
Mike Franey
Thanks for your time, much appreciated.

Mike!

You know that you can install the larger valves into the older heads, at the same time that you have hardened valve seats installed. This is your easiest solution. However, I might have something lying around. If so, I'd want $250 for the head -- I would have it crack checked first to ensure that the cracks would be smaller than the size of the replacement valve seats. If you wanted me to prepare a head -- 100% done and set to install, with bronze silicone guides, hardened seals, umbrella seals, surfaced,
triple cut valve seats, then the final price would be about $600.
Let me know!
EngineDetoxI read your detox instructions for a 75-80 'B. How much of that applies
to my low-compression '72 'B?
Thanks J Donoghue

Mr Donoghue!
Just about all the information. The important things are to keep the evaporative loss control system in place -- that keeps the engine clean; to block off the fittings on the intake manifold so that the induction system
cannot leak; to clean the right side of the engine so that it looks nice. Set your timing at 15 BTDC at 1500, vacuum disconnected. I believe you'll find that the car will have a little more zip -- and that slowing down will be faster. If you really want to make a difference in the slow down,
solder the overrun valves shut (the carb butterflies). Heat the button side and flow solder onto the disc from the spring side.
Good luck!
engineWinter OilJohn
As you may or may not know I drive my 74 BGT year round - New Jersey. I normally use 20-50 oil in the engine and dashpots. What do you suggest for winter driving - 10-30?
Thanks Rick

Rick!

I drive my wife's MGB/GT all year round. Here, it gets just as cold as it does in New Jersey. I use Castrol 20W/50 all year round -- and in the carbs, too. Sometimes, on VERY COLD mornings, it'll take several minutes of driving before I get full oil pressure -- that oil must be like syrup on the bottom of the sump. But, I've done that for years and years. In fact, Caroline's car has 180,000 on the engine and the CRANK HAS NEVER BEEN OUT OF THE BLOCK!
Rick, thanks for all of your work on the MG Council!
EngineRear Engine Oil SealDear Mr. Twist,
The rear engine oil seal on my 1950 MGTD leaks badly and I would like to replace it with the Moss Motor seal. Do you know anyone you would recommend to do this work in the Philadelphia / Reading area
Thank you for your time.
Best Wishes, Michael B. Simson, MD

Dr Simson!

Let me suggest that you call Steve Harding, chairman of the Philadelphia MG club for a recommendation -- he lives at 1913-D Darby Road, Havertown -- he has an Email address, but I don't have it right here. Let me also suggest that you do not fit the Moss seal, but instead "do the right thing." You know that the crankshaft does not have a modern lip type seal. Instead, it has a scroll thread, or archimedes screw, that spins the oil back into the engine. Over a long period (fifty years!), the saddles that hold the main bearings, the slinger that surrounds the scroll
thread, and the crankshaft lose their common concentricity. The "real" solution is to disassemble the engine, get the lower end ALIGN BORED or ALIGN HONED. This will place all three circles with a common center, and
the original scroll thread will work wonderfully well. However, you can easily make the case that this work would far exceed the Moss rear seal in cost!

Good luck!
EngineRod IdentificationJohn
If you have time to dispense information.....I have a dismantled 1622 engine with various connecting rods, some from a 1622 and others from early Bs. Trying to sort out which rods belong to the 1622. Looking at casting numbers, I am assuming that 12H425 belong to cylinders 2 & 4 and 12H427 belong to cyls 1 & 3. Are these casting numbers
something I can use for positive identification or should I get out the micrometers.

Sincerely, George Horton - Anchorage, Alaska

GEORGE!

It is my understanding that the rods are the same between the 1622 and the MGB. Of course there are two different types of rods -- 1&3 and 2&4 because of the offset of the crank to the cylinders. Yet, I had a fellow call not too long ago concerned about the weight difference between his
rods -- about 16 grams. Remember on reassembly that the small oiling hole at the top of the rod bearing points AWAY from the camshaft. This isn't much help this late in the game, but I'm catching up on letters -- if you write again the answer will be a little more quickly forthcoming!
EngineDetoxingMr. Twist
I'm trying to finish detoxing my 1979 MGB with a single Zenith Stromberg carburetor. Two questions:
1) Your instructions state "Close down the air bleed by unscrewing the brass screw, then tightening the white plastic nut, then retightening the brass screw". Which screw is the "air bleed" screw? Is this component #15 (idle air regulator) as pictured on page 140 of the Complete Official MGB 1975-1980?
2) I'm fitting a gasket and plate to replace the removed EGR valve. Can I replace the EGR brass carburetor connection with a set screw?

Thank you, Russ Holder

RUSS! I thought that Alaska still had emission control inspections. The air bleed screw is the idle air regulator, which allows fresh air to bypass the jet/needle and lean out the idle mixture to achieve the correct CO
level. Just close it off and then tune the Stromberg as you would an SU -- by lifting the piston and judging the change in rpm. You certainly could replace the EGR port on the carburetter with a plug -- but you might need high speed (ported) vacuum sometime in the future for a
different distributor. Better just to cover the end of the brass port with a rubber nipple which you can purchase at the auto parts store. Hope this helps!
EngineValve ClearancesI didn't invent this one, so please don't give me any credit.

It involves a method to check clearances on MG valves using "The Rule of
Nine." When a particular valve is fully open, then the corresponding
number
valve is fully closed and the two numbers (of the two valves) add up to
nine.

e.g. when valve number 8 is fully open, then valve number one should be
fully closed and tappet clearances may be checked and adjusted on number
one. 8 + 1 = 9

Craig! Thanks so much for thinking of me on this one. It's much more
printable than the last one I got which was entitled "nipples up." I
believe I probably have included this in the tune-up section of my
technical book, but I'll make certain. As you know, most of my ditties
are just that. We just had our electrical technical seminar and I stumbled
on identifying the correct wire and placement as it enters the back of the
headlight bulb "Blue with White is Bright is Right."
EnginePistonJohn,
I am looking for a +.060 Piston for a 1098cc Midget engine. It
carries the
AE part number of 16179 and has 5 rings. Would you have one (or a set or
5)
in stock with rings? I can be reached at glownsdale@aol.com.
Thank you.
Gary Lownsdale

Gary!

Sorry, but try Pierce Manifolds -- they're in California, maybe 90 miles
south of San Francisco. Cannot remember the city name. He has quite a
quantity of NEW, OEM parts.
EngineLightening FlywheelHi,

Can you give me any advice on lightening a 1275 flywheel? I recently
purchased a used one that I'd like to remove a few pounds from. I
autocross my '60 Bugeye and believe the reduced reciprocating weight
would help.

TIA Herb

Herb!

Contact S Mark Palmer in Bethlehem, PA, chairman of the MG Vintage Racers
-- he may be able to help. Also, please contact Jeff Burns at Motorhead,
in Alexandria, Virginia. BTW Jeff used to pass out green covered book
matches titled "World Peace through British Cars." He's a good guy. Or,
go right to Brown and Gammons in Baldock, Herts, England. Sorry I don't
have the info at my fingertips.
EngineIdentifying EngineMr. Twist,

I sent an Email to you about a week ago. It was in reference to the Engine
in my 1977 MG Midget. It appears that my engine was a transplant but I
have
yet to determine what it is. It looks like the 1500 Spitfire but...the
serial number is DM 735E SS.
This is neither MG or Triumph so it seems. The Engine block is stamped
STANPART below the intake and exhaust ports.

I'm hoping that you could put some light on this thing. I'd like to know
what it is and where it comes from.

Thank you in advance.

Sincerely,
Dan Dwelley

Dan! I have absolutely no information about the TR engines, other than
some notes from the MG workshop manuals. I would expect to find a FM
prefix, followed by a UE suffix. Whether this is from an earlier TR sedan,
I don't know -- but I bet that if you contact the Roadster Factory in
Armagh, PA, they can give you some direction. You could also contact a TR
club in your area -- there must be a big one in the DC area.
EngineHeadsHi John, I have a cracked cylinder head on my stock 70 Mgbgt. Engine has
about 18k miles since rebuild by previous owner. Is it worthwhile
performance
wise to replace this head with one of the new alloy heads , standard or
crossflow? I use the car regularly for street use but find the performance
lacking when accelerating . Do I have to go for larger SUs and larger bore
exhaust system or will the stock system be adequate? Moss and Victoria
stock
these heads. Do you also and what would be the price?
Thanks, Leonard

Leonard!

You have three options, in increasing price: find an original cast
iron head (perhaps I can supply one at about $600), fit your original
equipment, ensure a GOOD tune-up, and be satisfied with "stock"
performance -- very well much greater than now. Second, fit the new
aluminium head, but ensure that it is smoothed prior to fitting -- these are
available from Moss and Victoria (I do not sell new parts by mail) for about
$800 plus the machine shop charge to set it all up -- you may get slightly
increased performance here. Third, the cross flow head will cost you nearly
$2000 or so by the time you're done with the manifolding, carbs, etc, but it
will provide a GREAT boost to power.
I am "Mr Original" and would advise you to find and fit a cast iron
head. That not being available, I would go with the aluminium replacement.

Hope this helps a bit!
EngineOil Pressure I have a 1968 MGB which has approx. 900 miles on it since it's engine
rebuild. It performs very well. My concern is with the oil pressure. It
has been running at 70 psi +/- but last week end it dropped to 55 psi
while
cruising at 2500 rpm. Now it usually stays at 70 but occasionally drops
to
55. If I accelerate or gear down it returns to 65 or 70. I have changed
the oil at 500 miles and examined it as well as the coolant. everything
appears to be normal.

There is a new oil pump in place and relief valve kit. The only other
possibilities that I can think of are the rocker arm shaft is worn. Their
were no holes in it when I cleaned it in the spring. And maybe the sensor
or the gauge. But why would it respond to higher rpms

Terry E. Carr

TERRY!

Your engine should hold about #70psi above about 1500 rpm. But, I
would NOT trust your oil pressure gauge if it is the original, electric
unit. The oil gauge will read higher or lower, depending on the output of
the alternator (which SHOULD be fixed) -- but the sending units are
notorious for being wrong. New sending units are about $US120. SO -- if
you have the opportunity and/or ability, change to a mechanical gauge
(71-76).

Low oil pressure can be caused by diluted oil, a sticky or unshimmed
oil pressure relief valve, or extreme use (loose bearings). The way you
describe your problem -- that is, the oil pressure sometimes reads like the
tachometer -- is usually caused by faulty rod bearings -- the crank is not
smooth or the rod caps have been switched from rod to rod.

Let me know more about your rebuild and I'll try to give you more
hints.
Remember, you CAN remove the sump and the OP relief valve without removing
the engine from the car.

FAST FORWARD!
EngineMotor NoiseMorning John,

Got a curious "question" about my 1968 MGB. Its got
a 1965 5-bolt main motor that seems to be making a
little more noise than usual in the block. The car
accelerates fine and have noticed no excessive leaking
of any kind of fluid. The noise isn't comming from
the valve cover area, it sounds further down. There
also isn't any additional smoking from the exhaust
than usual. The oil pressure is fine and no leaking
from the water pump - its seems to be cooling fine.

The car's got over 80,000+ miles with a minor rebuild
on the motor. The carb's were rebuilt about a month
ago. The timing belt and associated parts were
replaced about three years ago.

What else can I investigate? I know you are busy, but
really appreciate your time.

Thank you again.

- Tony Godfrey

TONY!

You should expect #65-75psi at highway speed with your engine, and a
pressure of 40 or so at idle. Ensure that you're using Castrol 20W/50 GTX.
Rod bearing noises evidence themselves by rapping, which dramatically
increases during acceleration (load). Wrist pin noises evidence themselves
by a slight rapping, heard during deceleration. Piston slap (a looseness in
the
bore) is worst at idle and silences as the rpm increases.

Ensure then engine is coming from the block by disconnecting the fan
belt and running the engine (maybe only for a minute) so that the water pump
and alternator are not turning.

Listen for the noise when the clutch is out, and when the clutch is
depressed (that can shift the crankshaft fore and aft slightly).

Rev the engine up to 5000 while sitting still and listen to see if
the noise is a szzzzzzz or a ringing -- this could be exhaust. These noises
are also harmonics, so that if it occurs at 2000 it will probably also
occur at 4000.

Ensure that the tappets are adjusted correctly -- even run the
engine with the valve cover off -- use a 0.010 feeler between the valve and
rocker on each valve. If the noise disappears, then the problem is a faulty
cam follower (lifter) or cam.

Hope some of this helps.

SAFETY FAST!
EngineOil Cooler John:

I hope the time you spent in Iowa was restful. I am Paul Brown, Willard
Brown's brother I live in Montclair. I own a 1967 Mineral Blue MGB.

After many tries to stop my "B" from smoking I have decided to have the
engine rebuilt. It is being done as I write this Email to you. My mechanic
says that I do not need an oil cooler after the rebuild because today's
motor
oils are much better than they were years ago. So, he is not attaching an
oil
cooler. Is that advisable? He tells me that if oil dose not reach a
certain
temperature it can actually be harmful to the engine. What are your
thoughts
on his advisement? He also says that after breaking the engine in with a
1000
miles of driving. The engine can be lubricated with a synthetic lubricant
like Mobil One. Is that possible? If so please advise. Is Mobil One the
best
synthetic? If not, please make a suggestion.

I am also replacing the Weber down draft with the original SU's. A bonus
the
he is rebuilding is a 18GB-U-H (5 bearing).

Please advise, I value your expert professional opinion.

Paul Brown

PAUL!

I have never seen a correlation between oil cooler use and engine
longevity. This I know: All (there are always exceptions) MGBs imported to
the US were fitted with oil coolers from 1962 - 1974/2. The 18V engines
with three piston rings and single row chains get more miles on them before
a rebuild is necessary than the older 18G engines.
Do you NEED an oil cooler? The answer is NO. Would I fit an oil
cooler to a 1967 MGB? The answer is YES -- because it is original, and
because those engines DO develop more heat than the later ones.
After your massive investment (a "total" engine easily costs $3000)
what's another $150 or so for the cooler and hoses?

Say hello to Willard!
EngineTicking SoundHere is a thorny one for you to cogitate!

READ THIS AND CONSIDER. YOUR INPUT IS VALUED.

The TiF (1955 TF 1500) is making a ticking sound, prominent at idle.
It sounds like a valve lash set way too wide. Here are some
observations related to this sound:
1. It occurs regularly at cam speed (I think, this is hard to tell),
and is most prominent at lower rpms, such as idle.
2. It lessens as the engine warms, but is still present. With a warm
engine, the intensity of the sound waxes and wanes.
3. It goes away under heavy load (such as starting away from a dead
stop), and quickly returns as the load lessens.
4. It is somewhat louder as the engine decellerates after
accellerating.
5. The sound is more prominent on the right side of the engine.
6. Using a screwdriver as a stethoscope, the sound seems loudest with
the screwdriver held against the head just in front of #2 sparking
plug and at the middle tappet cover bolt. It is not audible via
screwdriver anywhere else.
7. Pulling sparking plug wires reveals that the sound goes away if #2
has no spark, and returns immediately upon returning spark to #2.
8. Compression testing reveals: (pump-up pressure, amount of time
required to then decline to 100#) #1 - 160#, 12 sec.: #2 - 170#, 11
sec.:
#3 - 170#, 11 sec.: #4 - 170#, 12 sec.
9. Sound persists after ensuring correct valve lash settings.
10. By decreasing valve lash setting until it is just eliminated, the
sound disappears. In particular, eliminating valve lash on #3 valve
(intake
for #2 cylinder) eliminates the sound.
11. Observation of rocker action suggests all cam lobes functioning.

12. Inspection of rocker assembly reveals: 1. bushings and shaft in
good shape. 2. rocker pads (where they contact the valve) are pitted
on #2 intake and exhaust, and #4 exhaust. #2 exhaust is particularly
bad. These were then ground to present a smooth surface to the valve
stem, without any resultant change in the sound.
13. Lifters removed and inspected. #1 and #8 severly worn.
Inspection of cam (as best possible without actual cam removal) fails
to reveal
any obvious defect of the cam. New lifters installed using lots of
cam lube on the cam lobes and lifter faces. This does not eliminate
the
sound.
14. #2 intake pushrod slightly bent (about 1/16" out of straight).
Replaced, without impact on the sound.
15. All pushrods inspected and are otherwise free of galling
scraping, or cracks. Ends tight.
16. Engine rotated by hand (wrench on the front pulley bolt) until
piston #2 just starting to descend, as observed through spark plug
hole.
A screwdriver was then used to push down on the piston, looking for
any free play in the small end. None noted. Top of piston noted to
be carboned up (as are the other 3, as well).
16. With rocker assembly removed, intake and exhaust valves on cyl.
#2 do not wiggle back and forth.
(17. I considered removing I2 and E2 valves to inspect guides, but
cannot do so with engine in the car. However, looking through the
springs, the guides seem intact, although adequacy of this exam is
doubtful.)

SO!!!
The problem seems to be in cylinder #2. Is it a bad small end? Is it
a cracked rod? Is it cam-related? I am baffled why removal of valve
lash
AND removal of #2 spark both relieve the sound. ANY HELP IS
APPRECIATED!

P Smith

PHIL!

Run the engine at idle, noting the noise. Place a 0.010 feeler
between the rocker and valve stem -- if the noise goes away, then the
problem is cam/lifter/pushrod related.

A rapping on deceleration, is a loose gudgeon pin to con rod fit.

Please let me know what you find.

We now ALWAYS have the rods crack checked!
EngineRebuilding MotorI am rebuilding a 77 'B', the motor has to badly burned pistons. I
would like to rebuild it my self. Could you recommend a step by step
guide. I has gotten lists to parts for verious rebuilds, but I need
more guidance.

George!

Let me be so bold as to propose that you purchase about three books,
then use the information in all to determine your best route. The factory
workshop manual is essential (available as a Bentley reprint); my own
University Motors Technical Book is a GREAT help, as it has a step by step;
and the MGB Engine video is great.

I believe all are available from Ron Embling at Britbooks
1-800-READ-MGM. He's in upstate New York. My book is at the printers,
AGAIN!, and will be available in a week or so. Send me your snail mail
address and card number -- the book is $30.
EngineObtaining Original Engine NumberHello,

I'm currently having my 1976 MGB restored. During the engine rebuild, my
engine id plate must have been cooked and melted. I understand that it is
possible to obtain the history your car (engine number, chasis number, and
car specs) by writing to the British Motor Heritage Trust. I have two
questions. Is that the only way to obtain the original engine number?
Once I receive the engine number, is there a place you know of where I can
then get the number stamped onto the id plate?

Any input you can give me would be greatly appreciated!!

Thank you,

Bill

BILL!

Get the engine number from:

Anders Clausager, Archivist
British Motor Heritage
Archive Center
British Motor Industry Heritage Trust
Banbury Road
Gaydon, Warwickshire CV35 0BJ
ENGLAND

This service costs $40. You receive a certificate suitable for framing.

Then, send the number to Todd Clark, Clark Spares and Restoration, Swamp
Road, Doylestown (philadelphia area), PA. He can do the reverse stamping.

Hope this helps!

SAFETY FAST!
EngineRun-on ValvesGood Afternoon John

I have a1979/80 MGB LE. Recently my car would keep running on after I
shut
the engine off. I decided to order a new Anti-Run-on valve from Moss
after
testing the one I have by grounding the slate/yellow wire connected to the
oil pressue sending unit. I know the wires are good because I tested
them.
However, when I grounded my old run-on valve and the TWO new one I
oredered
from Moss, I did not hear the valve operate as apparently I should. Is
there a reason I would not hear the valve operate for my year car, or is
it
really possible that the TWO new valves that I ordered from Moss could be
bad? Thanks for your input.

Most Cordially,

Robert L.F. Clarke
Immigration Paralegal

Rose Rix & Bennett LLP

Robert!

Let me explain how the system works -- then you can re-check your
system. The anti run-on valve is designed to place a vacuum on top of the
gasoline in the float bowl at the instant the car is turned off. This
vacuum prohibits any gasoline from mixing with the air that is still being
drawn through the carburettor causing the engine STOP DEAD.

The SLATE wiring is HOT with the ignition switch turned OFF. The
SLATE circuit is wired through a fuse where it becomes SLATE/PURPLE. This
wire is connected to the anti run on valve. The other wire, SLATE/YELLOW,
connects the anti run-on valve to the oil pressure switch, which is normally
open -- that is, it closes only with oil pressure. Now the only time the
valve operates is when the key is turned off AND you have oil pressure --
that ten seconds or so after the engine has been shut off. You will not
hear the valve close, but you will hear it open when the oil pressure drops
to zip.

If you're still unclear, give me a call during my technical hour
1-2pm EST Mon-Fri, or Email me again.

SAFETY FAST!
EngineSuccessful Engine Replacement I have finished replacing the engine in my MG-TD. Took it on a 50 mile test run, one small seep was only problem.(mine). I must tell you that the work you did made a dramatic difference. It starts instantly, runs smooth(as smoothly as a 4 banger can) and is as solid as I have ever felt.
Thank you and your staff for a job well done and I'll be using you again if needed. Nice to deal with a business that offers good respectable service; hard to find these days.

VR, Skip Fritz

PS: Engine box badly damaged - I am glad I built it - not worth repairing, sorry.

SKIP!

Glad to know everything worked out well! Keep the oil changed and be sure to adjust the valves again after about 500 miles!
EngineReplacing EngineDear Mr. twist
I own a 1956 mga Ihave the old 1500 engine, its in very bad shape. I
would like to insert a datsun A14 engine and the macthing 5 speed
Trany Is there any information on this type of project.

Any help would be greatly enjoyed

Mike Alley

MIKE!

If this Datsun engine is the "J" series, then it is virtually the
same engine as the B series engine you have in the MGA right now. Let me
caution you. You will severely diminish the value of your MGA by fitting
non-standard parts. This is even more a problem if you have little
experience in engineering and this type of work -- as the finished product
will never "look right."

Why not rebuild the MGA engine -- or even fit a later model MGB
engine? I think you would be happier with the result!
EngineFreeze Out PlugDear Mr. Twist,
Thank you very much. It is the rear freeze out plug. Now all I
have
to do is read up on fixing the problem; since I never have had any
dealings
with freeze out plugs.
Thanks again
dave matos

DAVE! You'll have to remove both intake and exhaust manifolds, renewing the
manifold gasket, carb gaskets, and cleaning everything as you go. Take the
manifold to the auto parts store (NAPA, for instance), and they can get you
the right freeze plug.
These plugs are called freeze plugs, core plugs, or Welch plugs. They come
in dish or cup style -- you want the dish. And, the size you want it
fractional, not metric.
EngineValve Train NoiseJohn, a quick synopsis before my question: I by a 68MGB-GT not running.
Get
it running. Excessive valve train noise. Pull CAM, chunk of first lobe
missing. Tappets look like 50 year old hammers. Bore of #1 tappet appears
to
have small shiny flecks of metal imbedded into walls. Replace CAM,
tappets,
push rods, rocker assembly. Only minor help. Have engine rebuild performed
($2500) foolishly thinking block will get visual examination, etc. Rebuilt
engine sounds the same as before rebuild. Conclude only cylinders rebored,
tappet bores probably NOT rebored and then fitted with oversize tappets.

So here's the question. ARE there oversize tappets available for the MG
series B engines? Is the famous remark "oh, some of them just sound like
that" caused by worn tappet bores?

The first question is: what is making the noise in your engine? The second
question is: Does this noise indicate some fault with the engine or is it
just bothersome? The third question is: How can I quiet the engine?

So, first things first: disconnect the fan belt and run the engine. Is the
noise still there? If not, the cause is the alternator or water pump.
Next, plug the exhaust with a handful of rags while the engine is idling.
Does the noise increase or change? If so, then the problem is associated
with the exhaust systems or gaskets. Next, remove the valve cover and start
up the engine. Insert a 0.010 feeler gauge between the valve stem and
rocker on each of the eight valves. If one or more of these insertions
quiets the engine, then you know that the noise IS, in fact, coming from the
valve train. A clicky noise usually indicates a faulty cam follower or cam
lobe. However, excessively worn rockers and rocker bushings can interfere
with proper valve adjustment and can leave a clickity-clickity noise. A
renewed rocker shaft can cost $200 or so. The proper valve adjustment for
an 18GK engine is 0.015" HOT. BTW, oversize cam followers are probably not
available -- I've never heard of such an item (although it does make sense)
in my 30 years of MGing.

Hope this points you in the right direction to find the noise!

FAST FORWARD!
EngineDe-toxing Mr. Twist,

I recently purchased a copy of your excellent Technical Manual and
enjoyed
reading the many informative articles. I have a question concerning the
article
on "De-Toxing" the MGB engine. I have been cautioned by an experienced
mechanic
that blanking of the Exhaust Gas Recirculation Valve could possibly result
in
overheating problems in some parts of an engine. I was wondering if you
have
ever experienced this problem in a de-toxed MGB engine?

Also, as part of a complete engine and transmission overhaul that I
am
engaged in, I have purchased a Transmission / Overdrive unit from MG Cosas
in
Texas. My intention is to salvage a few needed internal transmission / OD
parts
that are no longer in production or available from Moss Motors. I would
like to
offer the remaining parts to someone who could put them to use, and I was
wondering if you might have a need for them at University Motors?

Thanks for your time and consideration.

John McCarthy

JOHN!

The EGR valves ALWAYS leak into the intake manifold -- so blocking
it off can only assure you that the mixture is not leaning out at idle.
You'll find that you can tap the original Stromberg, combination manifold
with a 1/4 NPT taper pipe tap and fit a 1/4 NPT allen set screw -- this
looks better than a condenser or bolt hanging on the end of a hose (which
will then leak). Also, you'll find that 7/16-20 allen set screws look good
in the air injection ports in the cylinder head. Anyway, I , personally, am
convinced that the car runs better without all those leaking
"anti-pollution" hoses and fittings.

I would be pleased to receive any extra OD parts you have -- we do a
fair number of OD rebuilds here at the shop.
I have attached a step by step for the all synchro gearbox -- but it's for
the STD box, not the OD (I think). We use this in our technical seminars in
February.

Thanks again!

SAFETY FAST!
EngineDesmoggingDear John,

I've been following your desmogging how-to and have a couple of
questions about the vent lines leading to the cannisters (and removing
the cans). My B is an 80.

Is it okay to plug the fuel tank vent line way back in the trunk if I
drill a small hole in the underside of the gas cap?

Plugging the vent off the top of the valve cover will not cause any
harmful effects to the engine. True or false?

About the third vent line--the one off my Zenith carb. Surely you can't
just plug that one can you? Won't it upset the proper function of the
thing, such as it is? I've heard about fuel backing up in that line and
getting right into the cannisters.

Thanks for all the help to so many over the years.

pete in Toronto

ps: The four 7/16 by 1 inch bolts that I used to plug the air manifold
holes on the block stick out pretty far, a la the Frankenstein monster's
neck. How come you suggest 1 inch and not shorter? Just curious. Would
it work to braze fill the original screws?

DEAR PETE!

I should really update that "desmogging" article. We've used
7/16-20 x 1/2 socket set screws for years -- they give a nice flush
appearance.

DO NOT remove the charcoal canisters! There is no need to remove
the expansion tank can in the boot, either! Ensure that all the lines are
in good condition! The original factory fuel lines and evaporative lines
rupture lengthwise without warning, so you're best advised to change ALL of
them (except for the formed hoses between the anti run-on valve and the
charcoal adsorption canisters).

Leave ALL the ELC (Evaporative Loss Control) lines in place
underbonnet! This system keeps the inside of the engine clean and allows
you to shut the car off without it dieseling. Leave all the PCV (Positive
Crankcase Ventilation) lines in place for the same reason.

So, only remove the air pump, the air injection manifold, the gulp
valve. Blocking off the EGR (Exhaust Gas Recirculation) valve is helpful,
and soldering shut the spring loaded button on the throttle disc will assist
a more speedy de-celeration.

Hope this helps!
EngineStarter Pinion & Flywheel Meshed TogetherGreetings John!

You may recall that I am the one who bought Barry Rutheiser's '53 TD about
a
year ago, and I have been enjoying it a great deal--until about 3:00 this
afternoon.

While trying to start it, the starter pinion and flywheel seem to have
gotten meshed together. I thought that the "cure" for this was to put the
car in gear and roll it forward. I am able to get the car into gear, but
I
seem to not be able to get the car to move when I push it. I can only get
it to rock back and forth.

I realize that this is a question you've probably answered many, many
times
before for stupid newbie owners like myself, but I am hoping that you
might
be willing to help me out with some advice as to what to do next. Help!!!

Thanks very much!

Dennis Leipold

DENNIS!

You've got the right idea but the wrong direction!! Change the
gearlever into FOURTH gear and push the car BACKWARDS about three feet.
This will unscrew the starter pinion from the flywheel ring gear teeth.
Pushing the car forward only makes the condition worse, and can bend the
starter armature. Hope this helps!
EngineHand CrankHello, do have a decent hand crank for my 55 TF ???. Thanks , Dave
Cates /POR/xpeg/2527/hde43/8678

DAVE!

Sorry, no I do not. Try Bill Hinkle in North Carolina, Gerry Goguen
at Abingdon Spares, Ship Kelsey at Shadetree Auto in California,
www.mgcars.org.uk, or run an ad in TSO, British Car, Safety Fast, Enjoying
MG, MG Enthusiast, or MG WORLD. Good luck!
EngineSeats, Unlocking Seized EngineHello John:
I am currently restoring a MGA and have Deluxe Seats for it. Do you know
whether standard seat rails fit the deluxe seats? I looked in a 1600 parts
book and it did not seem to have a separate listing for seat rails for
Deluxe
Seats.
Also, I have acquired a Twin Cam that had sat in a barn for ten + years.
The
hydraulics are shot, of course, and the engine is locked up. Do you know
of
any trick way to unlock a seized engine. I realize that the rings are
probably shot but I wanted to get the car running and driving before I did
extensive restoration work on it. Any suggestions? The car itself looks to
be
in really good shape and would be considered a nice "driver" if it were
running!
Sorry to hear that you are no longer doing your "summer party."
I did get to go to one of them a few years ago (without my car) and really
enjoyed it.
Thanks for everything you do to promote the MG marque.
Sincerely,
Brian Findley

BRIAN!

The method we've used successfully in 100% of the "frozen engines"
with which we've had to free up -- except for the last which was a horribly
rusty MG Midget 1500 -- is this:

Remove the plugs and drool in diesel fuel, WD40, Marvel Mystery Oil,
Breakaway -- some sort of penetrating solvent.
Then, strip off the starter motor, carbs, maybe the dynamo so that the
entire right hand side of the engine is exposed. Use a LONG prybar (we
purchase ours from the tool man -- they look like GIANT screwdrivers), and
work between the rear engine bearing plate and the flywheel teeth, trying to
move the engine clockwise or anti-clockwise. Once you get it to move, even
a little bit, you're nearly home free. Rotate the engine completely, by
hand, maybe twice. Then, with a chain, rope, or strap, tow the car at 20mph
in second or third gear. By the time you've towed it a mile, the engine
will be free enough to turn by hand! Then, reassemble, start it up and
drive it for several hundred miles to free up the rings.

As I wrote before, if you need more info, call me at home.
EngineOil CoolerJohn:

Even though I have a very able mechanic Peter McCarthy of Midnight Auto
Inc. who
has rebuilt my MGB engine. It seems to be running well to date. I do have
some
questions and hope you will reply. I look on you as the ultimate
repository of
knowledge for MGB's. As you know during the rebuild it was decided not to
reinstall old oil cooler for a few reasons sledge from old engine and
advisement
from mechanic (Peter) that it is not needed due to quality of today's
oils. Will
not having a oil cooler effect the engine temperature? i.e. water and
engine
temperature. I drove my car over the weekend (10/31/99) and the
water/engine
temperature was above 190 degrees at 201 degrees. Is this normal? I don't
want
to over heat engine and burn it up.

Oh by the why, the compression ratio has been increased from 8:5:1~9:4:1.
Please advise as soon as possible. Can I buy a larger radiator? I am
having
troulbe with my techometer (negative ground) and speedometer. Do you
rebuild
them? What are the cost?

Paul M. Brown

Paul!

If you have very few miles on the rebuild (under 1000), then expect
a higher running temperature in the beginning as there is so much more
friction during the run-in time. I believe, as does your mechanic, that the
oil coolers offer no great advantage. However, the high compression of your
engine will result in MORE HEAT produced if you continue to burn low octane
fuel. So, purchase that 92 or 94 stuff at those inflated prices -- as your
engine really needs something around 100 octane to run well. Remember that
of all that gasoline you purchase, only about 1/3 is converted to power, and
some 2/3 is expelled in heat. A mismatch of compression and octane
exacerbates that problem. You can purchase octane enhancers -- but they
only last a short time in the tank (they are lightweight, volatile compounds
that boil away at atmospheric pressure). On the other hand, I'd wait until
you've got a solid 1000 miles on the engine before making any dramatic
changes in anything. Remember, too, that those gauges are not always
accurate, despite their precision.

There are a number of potential problems with the tach (wiring,
power, earth, and ignition system changes), as with the speedo (90 degree
drive unit, cable, speedo, and speedo gears). Without knowing more, it is
too soon to call for a rebuild of the gauges themselves. However, use
Nisonger Instruments in Mamaroneck, NY.

Hope this helps.
Engine'69 MGB-GT fuel hoses; oil cooler hose Hello, and thanks for your tech manual. I have the 18GH eng. Is it
preferable to replace the braided fuel hoses (from the "T" to the carbs)
with regular nitrile/neoprene hoses? And any comments re installing a
fuel filter in the eng compartment?

The Moss catalog and Bentley manual, p. 453, show the oil hose from rear
eng block connected to the RHS fitting on the oil cooler. Does it
matter that PO installed hose from eng block to the LHS/driver's side of
the oil cooler?

Kent

KENT!

You can use the braided fuel lines and the modern neoprene hoses
interchangeably. The neoprene are the right price. The braided look best.

It make no difference which way the oil travels through the oil
cooler! If you have the opportunity, slacken those fittings and coat them
with ANTI-SEIZE so that, in the distance future, they're come apart! If
they do not want to turn, don't force them or you'll wreck them. There is a
neat way to get them loose, though.

You'll need your torch and a bucket of cold water and a couple of
handfuls of rags. Soak the rags in the water. Heat the joint between the
hose and the oil cooler with your torch until the nut just starts blowing
some red in the flame (not red from junk burning away, but a minute later
when it's REALLY hot). Then, hand the torch to your assistant, collect as
many rags as you can in both hands, and quench the heated joint as quickly
and as thoroughly as possible. Now the nut will spin off the cooler,
virtually by hand!

FAST FORWARD!
John H Twist
EngineRemoval of Emissions Equipment Hello John, My name is Rich Bartner and I am the new owner of a like-new
1980
MGB roadster which I've just purchased here in Florida. My question is:
Can
the emissions hardware factory installed on the engine, be removed and
replaced by either OEM or aftermarket parts to upgrade the performance and
improve the appearance and serviceability of the engine? Is there any
written
material describing what and how? Do you know of any shops which could
undertake this conversion, and the approximate cost? Am I better off
thinking
about a Rover V8 conversion? I know I've thrown many questions all at
once,
and I apologize for that, but I do want to seriously think about this
point.
Regards, and thank you, Rich Bartner

RICH!

RICH!

You want to join the North American MGB Register -- 1-800-NAMGBR-1
as a nearly first step in your ownership of that 1980 MGB! Also, visit
www.mgcars.org.uk as that site is SO good, and it links to nearly every
other MG site around!

About that emission control equipment: Your car will run better
without it; it will look better, underbonnet without it; and the chances of
underbonnet fire will be greatly reduced with it missing. It is a violation
of Federal Law for a mechanic to remove it, but the whole job shouldn't cost
you over $60. You can remove it yourself with your Craftsmen tools
(remember, nearly the WHOLE car is American thread). I have a technical
book for $30 postpaid, which among some 250 pages, details the removal.

A V8 conversion is nice, but expect to pay around $10,000 for the
job. I'd try the emission equipment removal first!

Call during my technical hour: 1-2pm EST Monday-Friday for more
advice!

SAFETY FAST!
John Twist, Service Manager
EnginePistonsWhy are the pistons marked "front"

Some pistons have the gudgeon pin (wrist pin) hole offset to effectively give the engine a longer stroke. These pistons have an arrow and must be fitted with the arrow pointed towards the front. Most of our pistons are not made in this manner. The oil hole is pointed AWAY from the cam and is designed to oil the underside of the piston.
Hope this helps!
SAFETY FAST!
John H Twist
EngineTwin Cam crank measurements Hi John:

As requested, this is a quick reminder to ask you to please take the
measurements on the Twin Cam crank presently for sale on ebay:

Steve! Remind me again in case your request ends up where some of my
"memories" go -- I'll try to do that tomorrow for you. You know, Lyle
York
knew a guy who made an MGB 5 main twin cam using all Twin Cam parts but
added that nose on the crank.

I have been in contact with this person, he being Bill Spohn form the
northwest US; Washington, maybe? Anyway, he did build up such an engine,
with a 5-main MGB block and cross-drilled / nitrided crank, and the
balance
being Twin Cam. Bill wanted a large capacity and strong crank for racing
purposes. Since I'm building a street engine, and since I wanted an
original appearance, Bill recommended that I find a 1622 block and crank.
I
found a nice set, it passed the magnaflux test, so I'm now accumulating
the
Twin Cam bits and saving for the machine work in a few years.

Well, thanks in advance for taking the measurements.

Regards,
Steve Johnson

From the rear side of the front main bearing:

First Diameter (the main bearing)
Ends 1.520 from rear
2.000 diameter

Second Diameter
Ends 3.174 from rear
1.749 diameter

Third Diameter
Ends 4.257 from rear
1.489 diameter and keyed

Fourth Diameter (front pulley)
Ends 5.620 from rear
1.125 diameter and keyed

Hope this helps.
EngineMidget Blown Head Gasket John,

I recently Rebuilt 75 Midget 1500 Engine (Calif low comp dished pistons)
inlcuding
head. Weber carb....runs fine for few month or so and then blows head
gasket between 1&2 (twice). I checked block "deck" and head with
steel straight edge and appears flat. I initally torque as per spec and
then re-torque after 500 miles.

My next thought is to mill the head just in case it is the
culprit. I used stock gasket and copper spray sealant. If milling is the
right thing...how much can I take off? Also..any sources for better
gasket?

Maybe not related, but I put several thousand miles on this engine
before rebuild and even though the valve guides were worn causing
heavy oil consumption(I replaced them and ground valve/seats),
everything else "miked" out dead in middle of specs including
cylinders.

I'll try to call you tomorrow from work.
Cheers! Dave Testerman

DAVE!

The problem is simply a warped head or a warped block. Hope that
it's the former!! I would have the head surfaced (the shop might have to
remove 0.005 or 0.010" or so to ensure a flat surface). There are two types
of head gaskets, but the earlier ones simply don't work at all, so I don't
think that's your problem. The surfacing should do the trick!

SAFETY FAST!
John H Twist
Engine'79 B Cylinder Head John,

I have a '79 MGB with 62,000 miles. As far as I know, the cylinder head
has never been removed or serviced. I am in the process of removing the
intake/exhaust manifold to fix a vacuum leak. (I found the leak using
info from your 2000 edition of the UML Technical Book. Thanks.)

What's the likelihood that the head could use preventive maintenance or
other service after 21 years and 62,000 miles? I'll only be 11 bolts
away from pulling it off. The last time I checked the hot compression
(10,000 miles ago) it was not low: 1155 dry, 190 wet (with a shot of
oil), 2150 dry, 195 wet, 3 145 dry, 185 wet, 4 145 dry, 185 wet. I
was a little puzzled at the readings because the spec is 130 psi. I got
similar readings with a different gauge.

Thanks for any help,

Tony Campbell
Tony Campbell


Tony! Try that compression test before you go further! Although it's not
possible to warm up the engine at this time, if the figures exceed 10% in
variation, then adjust the valves and try it again. The valve clearance is
0.013" HOT, so I'd adjust them about 0.014" COLD. Don't worry about the
actual pressure readings -- about 150 is a good figure. Gauges are
different; the speed of the engine is a factor -- just look for a max of
10%. If you find that the adjusted valves give a difference of greater than
10%, then it's time to remove the head. When you do decide to have the
valve job, have the machine shop fit hardened seats, umbrella oil seals,
silicone bronze valve guides (allowing 0.002" working clearance), along with
a crack check and valve job. You DON'T need exotic valves -- the factory
ones are just fine. Expect to pay around $400 for all this work on the
head.

Hope this helps!

SAFETY FAST!
John H Twist
EngineValve ticking noise A few miles back, my 69B developed a valve ticking noise when under load.
If I'm in third or fourth gear and start going up a hill, I get this
ticking sound. Some advice from friends sugggested an ignition problem.
Gave the car a good tune up (cap, rotor, points, condensor, plugs, wires,
oil, filter, and air filter), reset the timing, tuned the carb. It now
starts and idles better than ever. But the tick persists. It now also
appears if I'm driving along at mid throttle and then suddenly let off the
gas. The oil pressure stays around 55-60, I assume the gauge is
functioning. Should I be considering a new oil pump or clogged strainer?




You very well have sorted this out -- I apologise for the long delay
answering; my computer was down and I got soooo far behind!

Ticks in the engine are caused by: valve lash (but that's regardless of
acceleration/deceleration/free-float); spark knock (acceleration) -- test by
changing the timing (retard it by 10 degrees); faulty rod bearings (clatters
on heavy acceleration only, quickly develops into a KNOCK); faulty wrist
pins (usually ticky on deceleration).

I've enclosed an article I wrote some time ago that may be helpful. Let me
know what you found!

John
Enginecrankshaft nuthi, do you know what is the socket size for crankshaft nut? I have a 32mm that is to small and 36mm that is to big. thank you very much.
my e-mail is

Use a 1 5/16" socket. Remember, this car has very, very few metric threads!
EngineThreading Oil Galley Passage Holes for Pipe PlugsDear John,

There is currently a thread on the MG Enthusiast's BBS, MGB Technical, concerning the threading of the oil galley holes, normally plugged with a brass plug, for use with a pipe plug. This is mentioned in your Technical Book, but not in any depth nor with any real information about the process. Would you be so kind as to post a response on the BBS. Thanks, Les Bengtson

Les!

The two "main" oil galleries must be opened and cleaned, no matter what type of cleaning you plan to do -- caustic soda or baking. Drill out the brass plugs on the front (or rear) then use a long shaft or rod to tap out the plugs from the other end. You can re-use the two plugs you've saved -- at the BACK of the block. The front of the two galleries should be tapped 1/4" NPT, then we use socket set screws. Careful use of the tap allows the plug to sit just under the surface of the block.

If you are to bake the block, then the machine shop will probably want to shot peen it to clean off all the ash. Now you need to remove ALL, ALL, ALL the brass plugs. Let me explain just where they are:

Rear of block -- two on main gallery, one on gallery from oil pump to diagonal feed. Tap the last (or all three) 1/4" NPT.

Top of Block -- None

Front of Block -- two on main galleries -- tap 1/4" NPT

Bottom of Block -- two at oil pressure relief valve. Tap these 1/8" NPT. Mark these holes so that you replace the plugs in the correct location -- wrong gets you ZERO oil pressure or 400 psi!

Right side of Block -- 5 main has two plugs under the distributor boss; all have a plug for the cross drilling from the cam to the chain tensioner. Tap these 1/8" NPT.

Left side of Block -- the large brass plug at the bottom of the distributor drive gear need not be removed -- but clean this THOROUGHLY!! There may be another small plug on this side for the camshaft oiling -- 1/8" NPT.

Run the NPT tap into the hole about 1/2 down the threads, then test fit the pipe plug. Do this again and again until the top of the plug sits BELOW the surface of the block on those holes which have a plate on top (front, rear, bottom).

I hope this helps you out a little bit!!

John

FAST FORWARD!
John H Twist
EngineRe: MG Q&AJohn,
Can you give me a "rough idea" of how much you would charge for an engine rebuild (major short block and head, new pistons etc.) assuming you dont find a cracked crank, cracked block or head etc.. This is the 1950 xpag 1250 engine serial number lhx 1643. I did run this car on the road before I tore it apart and it had no unusuall sounds. It did blow some oil past the rings when cold. The transmission worked well but does need seals etc. so I need you to "go through" it as well as the clutch and pressure plate (I have new clutch disc and roller throw out bearing and springs. The biggest issue here is that it will need to be in show condition so the cosmetics are a big deal and I prefer to do that myself. If you could short block it and refurbish the head and go through the trans and clutch I can do the rest. I do want the upgraded Moss seals to prevent oiling up the chassis and clutch. I would bring the engine and trans to your shop and pick it up when done. Again, I ask for a rough idea only of the cost and would not hold you to any pre discussed price estimates.

Awaiting your kind reply,

Dallas A. Cook

Dallas!

Your letter arrived a couple of days after my father passed away. That, coupled with the rush of the holidays left your important questions unanswered. I would be pleased to give you some prices -- unless you've given up on me and have already found another shop.

The first thing is, we can make it RIGHT! The second thing is, we can make it look GREAT -- BEAUTIFUL, in fact.

The engine, complete, is easily $4500 -- but some of this depends on the condition of various components. The gearbox is easily $900 -- to rebuild the box with new bearings, needles, seals and gaskets -- and to make it BEAUTIFUL. Also, in that $900 is enough to rebush the bell housing and the main case, if necessary.

Again, my apologies for the long delay in answering. If you're still interested, just write back. I'm getting close to catching up on my older emails and have been answering the new ones each day.

John
Engine1976 MGB - losing oil Also, I just had the engine rebuilt on my '76 B. I recently took it for a
50 or so mile trek that had me going up a mountain twice...not a steep
mountain, but one that i could still run it in 4th gear comfortably. when i
got back, the oil level was down about 1/2 - 3/4 of a quart. the engine has
less than 2,500 miles since the rebuild. the rebuild consisted of new
pistons, rings, oil pump, valves , the whole works...a basic complete
engine rebuild. i did not, however, put the Felpro SS70373 umbrella oil
seals on the car that you mention in your tech tips page. Do you think that
it would be a good idea to install them now? If so, how much do you sell
them for and would you be able to provide a tech sheet for my mechanic so
they would be installed properly? or, aren't they that difficult to
install?
Bill Etter

BILL!

It is not uncommon for a freshly rebuilt engine to consume more oil
than it "should" -- but this condition eventually disappears as the rings
bed in. I doubt the problem you have is caused by the lack of valve
seals -- but it IS possible to fit them. Follow this: Remove the rocker
assy, remove the rockers and retorque to the cylinder head. Remove the
plugs. Either pressurise the each cylinder in succession with air -- or --
feet rope into the cylinder when the piston is at BDC, then rotate the
engine until the rope is pushed up against the bottom of the valves. Use a
pair of long screwdrivers to lever the collet retaining plate down, remove
the collets (keepers), remove the plate, and the spring(s). Use the
prophylactic in the valve seal kit, use a lot of grease, and fit the
umbrella seal. Then, reassemble.

If your car was in our shop, I would charge three hours to do this
job ($180) plus the parts. Good luck!

John
EngineMGA 1500 Rear Main Cap (Broken Crank)Hi John,

We've met before at Namgar events and you've helped with a few questions in the past. Here's my situation and question.

My crank (MGA 1500) just broke beneath the rear main cap. The cap was ruined but the block appears to be okay (visually).

My first reaction was to try to locate another cap, then it dawned on me that due to necessary alignment these were probably line-bored, and thus unique to each engine. Is there anything I can do to save the block as the rest of the engine is in top condition? I was thinking it may be possible to get a replacement cap, then bore all three mains oversize. I have never seen bearings, however, that were oversized in their outer diameter. Any thoughts? Hope all is well.

Best Regards,

Greg Snooks

Greg!

The cap truly is part of the block and the rule is that you cannot switch caps, block to block. Consider that you have to completely disassemble the engine anyway and that fixing a cap to the rear main requires at least an align bore. Consider that anyone who will sell you a rear main cap will loose any value in the block he has. So, it's probably easier to get another block. You'll still want to have it aligned bored or align honed -- and you'll have to fit cam bearings and have the bores changed to meet your pistons. It's an expensive operation no matter how you look at it!

Remember that 1500 and 1600 cranks are the same, whether they're from MGAs or Nash Metropolitans! Those new ones offered by Moss are products from India, and you may find that an original one is a better piece.

Hope this helps.

John
EngineThreading Oil Galley Passage Holes for Pipe PlugsDear John,

There is currently a thread on the MG Enthusiast's BBS, MGB Technical, concerning the threading of the oil galley holes, normally plugged with a brass plug, for use with a pipe plug. This is mentioned in your Technical Book, but not in any depth nor with any real information about the process. Would you be so kind as to post a response on the BBS. Thanks, Les Bengtson



Les!

The two "main" oil galleries must be opened and cleaned, no matter what type of cleaning you plan to do -- caustic soda or baking. Drill out the brass plugs on the front (or rear) then use a long shaft or rod to tap out the plugs from the other end. You can re-use the two plugs you've saved -- at the BACK of the block. The front of the two galleries should be tapped 1/4" NPT, then we use socket set screws. Careful use of the tap allows the plug to sit just under the surface of the block.

If you are to bake the block, then the machine shop will probably want to shot peen it to clean off all the ash. Now you need to remove ALL, ALL, ALL the brass plugs. Let me explain just where they are:

Rear of block -- two on main gallery, one on gallery from oil pump to diagonal feed. Tap the last (or all three) 1/4" NPT.

Top of Block -- None

Front of Block -- two on main galleries -- tap 1/4" NPT

Bottom of Block -- two at oil pressure relief valve. Tap these 1/8" NPT. Mark these holes so that you replace the plugs in the correct location -- wrong gets you ZERO oil pressure or 400 psi!

Right side of Block -- 5 main has two plugs under the distributor boss; all have a plug for the cross drilling from the cam to the chain tensioner. Tap these 1/8" NPT.

Left side of Block -- the large brass plug at the bottom of the distributor drive gear need not be removed -- but clean this THOROUGHLY!! There may be another small plug on this side for the camshaft oiling -- 1/8" NPT.

Run the NPT tap into the hole about 1/2 down the threads, then test fit the pipe plug. Do this again and again until the top of the plug sits BELOW the surface of the block on those holes which have a plate on top (front, rear, bottom).

I hope this helps you out a little bit!!

John



EngineMG Rocker Arm BushingsJohn, I am preparing to have 2 sets of rockers rebushed 1 "A" & 1 "B". I have noticed that the B has only one oil hole and the A has two with the one requiring the rivet to be drilled out. Is it necessary to use both holes or did the factory decide the one is enough as the B? It look as if the second hole is lubing the pushrod tip.
Thanks,
Scott Shirk
TX

SCOTT!

The earlier set of rockers is drilled so that oil can move from the shaft over to the top of the pushrod. It obviously oils the pushrod BETTER than the later style. All throughout production small changes were made when it was realized that the original designs were too expensive (and unnecessary) to continue. This is one of those "changes" that was not an improvement -- the older ones ARE better!

John
EngineEGR ValvesRecently the EGR valve on my 76 Midget failed. So I blocked the vacuum line and went on my way till I could find a replacement. But there seem to be none available. The same EGR is used on the Spitfire and TR8 I believe. Do you know of a source for replacements or where I could find a suitable diaphram to replace the one in mine that has disintegrated? Surely someone makes these or rebuilds them but if so I haven't been able to locate them using the Internet. What do folks who drive their cars in states with strict emission laws do if critical emission parts aren't available? Steve Olson

Steve!

The EGR valve has little or no effect on performance -- it is nearly completely an emissions related "add-on" so you won't run poorly because it's now inoperative. If you fail an emissions test, then, yes, you can probably find one. I might have a good used one. But fitting these things is problemsome. I think you'll find everything is just fine the way it is right now.

John
EngineRe-Torque on Heads

John
I am under the impression that a "C" head should be retorqued after a hundred miles or so. Once the initial torque is set at 75lbs. What is the correct procedure. Obviously the sequence of torque should be followed. But do you loosen all and then re-torque or does one just check that they have not moved?
Also should the threads be lubricated on the studs before fitted to the block?
Ed


Ed!

To ensure a consistent force at the cylinder head stud, each nut and stud must have the same resistance to turn -- hence I wire wheel and oil the studs before fitting them. I run them, oiled, into the block to about 5 lb-ft, and then torque the head in an ascending pattern of 10 - 20 - 30 - 40 - and finally 50 lb-ft on the MGB. The factory calls for 55 lb-ft, but that's a dry torque (and I've snapped studs at 55#) so I go just a bit lower. I would stop at 70 on the MGC. The retorque, done so soon after the running-in, would not require loosening, re-oiling, and torquing -- I would simply pull the studs down to the proper torque (in this case 75) in the spiral pattern in the workshop manual. I hope this helps!

Hope this helps!

John
EngineMG TD Oil and OdometerJohn:
I recently purchased a 1951 TD that was restored about 10 years ago.
The guages were refurbished in England about four years ago and showed 300 miles when I bought the car. After driving this year for about 500 miles I noticed oil obscurring the trip odometer. Oil was coming up the speedo cable and dripping inside the housing and showing up on the lower mounted trip odometer. The level of oil in the trans is not too high, and I am baffled. Any thoughts?
Sandy Bates

Sandy!

The problem lies not in your gauge or in the speedo cable, but in the speedo drive at the gearbox. The gearbox oil must be slipping between the speedo pinion and its housing. You'll want to remove these pieces from the gearbox, then polish the shaft of the pinion gear. Or, you may want to find another housing and gear. You could also, of course, drill a very small hole 3/32? through the bottom of the housing, just in front of the speedo cable, to allow the oil to drain onto the ground -- rather than work up the cable -- but that's the only $1.00 solution I can think of.

John
EngineMotor UpgradeHi John,

I have the opportunity to purchase a 1955 MG-TF 1500 without a engine or transmission. I have a 1967 MGB parts car with the engine and o/d trans in good condition. Is putting the B engine and trans into the TF a possibility? Do you have any knowledge or is there a website or printed material with information on how to do this or am I flying by the seat of my pants?

Any thoughts would be greatly appreciated.

Sincerely, Jim Hearne

Jim!

You will not have to re-invent the wheel on this project, but it will be tedious. Your first step is to find some people who have this combination in their TD/TF, who have done the work themselves, and can offer you tips, hints, etc. You might find someone through the internet, but more likely through the New England MG T Register. Try them at: www.nemgt.org.

You know, when it's done, it won't be worth as much as a "real" TF, no matter how nice you make it. If you really want a TF, wait for a complete one.

John
EngineReplacing My Crank PulleyJohn,
At GT-25 it became necessary to replace my crank pulley on my MGA 1600. The only available replacement was from an MGB. I asked you about the feasibility of that; and you said keep the B pulley on the engine: it would be better for the car.

Now I can not set the timing of the motor. Is it necessary to install a B timing chain cover? If not, please advise about setting the timing. What preventative actions should I take while this tear-down occurs?

What strobe setting should I use?

Les Bari and his two younger daughters have become a 4 MG family: 1500 A, chrome B, C tourer, rubber B. They say Hello to you and yours.

Safety Fast!

Jeff Fields

Jeff!

Sorry for the delay!

You must have fitted a pulley from the 18V engines (with the timing mark at 11:00 instead of 6:00). I measured this the other day, and I think I remember that the distance, along the circumference was seven inches from that 11:00 mark back down to the 6:00 position. I would set the timing at 7 degrees BTDC static, or about 20 BTDC at idle (800).

If you fit a later MGB front cover (with matching timing marks) you'll not only be able to time the car from above!!!! but you'll have the advantage of a rear mounted rubber seal! (Remember to fit the newer splash shield with this cover).

Best to you and Les! My daughter (16) has use of her uncle's 73 Mallard Green MGB; and my son (14) has a 1971 MGB/GT of his own which he's working on.

John
EngineEngines for '57 MGAJohn,

In your opinion, which year mgb 5main engine would you think is the better? I am looking to place this in my 57 A
I have heard stories of austin marina engines fitted into certain mgb from the factory. These engines I hear are not as sturdy as mgb. www.mgcars.org.uk/mgcc/sf/990303.htm
I am seeking reliability as well as performance. Also, I have read and heard so many different opinions on engine swaps I do not know which is right. If you could point me to some successful swaps, I would be in your debt.

First of all, consider originality -- your 1500 engine is the better engine for your car from that standpoint and requires no changes to anything!

Then, consider the 1800 G or GA engine -- the three main MGB engine. This has the increased displacement and will fit right into your car, needing only the rear engine backing plate changed to the one that was on the original engine.

The 1800 GB (and newer) engine is the better engine, no question, but it requires a lot of fiddling: You have to take YOUR rear engine plate and have it opened up to accept the rear seal for the 1800 MGB engine (the opposite side of that is the engine won't leak oil from the rear main!). Then, you need a flywheel from a 1965-1967 MGB (this one has the correct ring gear for your car). Then you have to get the tachometer from that same MGB (65-67) and fit it in place of your rev counter, as the later MGB engines do not have a tachometer take off.

The Marina engines use a MUCH smaller input shaft than the MGBs, plus their sumps are on an angle because the Marina engines were fitted nose up in those sedans (plus, where are you going to find a Marina engine?)

You can run an 1800 five main crank in a 1800 three main block and use the lighter con rods and lighter (better) pistons.

Again, I'd rebuild the 1500.

John
Engine1977 MGB Emission Testing in Arizona John:
Have reviewed your Q & A's. Like to ask this question. I have a 1977
MGB.
Have owned since 1988 and is quite nicely restored. I moved to Arizona
and
now must pass Phoenix emissions. I have all the emissions gear on the car
and all seems to be working. I have had the Carburetor apart twice in
last
2 weeks checking needles, O rings, floats, etc. This work was done by a
Carb shop on the bench. The spark plugs, wires and rotor were changed.
Problem is at idle the car will not pass CO and/or HC. It is close. Az
requires Idle HC of 250 and CO of 2.20 for my year MGB. My car is
presently at 243 for HC and 3.65 for CO. Problem is when we adjust the
lean/rich with the adjusting tool, the numbers swing the other way and CO
will be good but HC is not.
The mechanic I use is using a CO analyzer but not certain how reliable it
is.

The catalytic converter is on the car but is probably original and has
nothing in it. It is a straight pipe. My guess is this will impact the
HC
reading out the tail pipe no matter how lean/rich the Carb gets set? Also
it is noted that the oil does not seem to stay in the dashpot very long.
not sure where it goes.
The upside is this car has run very well for the last 14 years and has
received much TLC but new need to get by the AZ. emissions requirements.
Any insight you can provide will be appreciated by all of us who have MG's
in Maricopa county, Az.
Thanks. Happy New Year
Carl Mitchell


Carl!

Of course, the gub'mint doesn't want your car to run well, it wants
it to pollute correctly at idle. What to do?

The car runs better with advanced timing at idle -- but for
emissions, make sure the vacuum advance is NOT working at idle. Make
certain you have FRESH oil -- heavier rather than lighter weight. In some
cases, you can block off the hose from the front tappet inspection cover to
the carb by inserting a ball bearing into the hose (not to be seen).
Usually, lean out the mixture as much as you can.

We don't have those stupid emission control laws here in Michigan,
so I have little first hand experience with setting these things up -- what
I've told you is about all I know.

When YOU get it sorted out, write back and tell me what you found so
that when the next person writes, I have something to say.

BTW -- I've included my Stromberg article for your interest!

Happy New Year!

John

EngineZB Magnette Oil Pressure & Effect
John,
After the rebuild of the 1500 engine in my ZB Magnette I am now
experiencing
engine oil pressure of 80psi @ speed and 50psi @idle. My
concern is this - I am losing oil thru the "slinger" oil return at the rear
of
the engine which in turn leaks out thru the bottom of the trans. housing
(small hole with cotter pin). Research shows that this engine as provided
from
the factory would produce 50psi @ speed and 15-25psi @ idle. From your
experience is the oil return system on these engines adequate enough to
handle
the pressure I described? If not how can I reduce the pressure so as to stop
the oil being lost? Also if you have any other ideas or recommendations
concerning this situation I would greatly appreciate any or all input.

Thank you very much,
Ed
I wonder what you've done to reduce the oil leaking. Were you
successful?

When we rebuild a three main B series engine, we always have the
bottom end of the engine align bored (or align honed). This ensures that
the groove on the crank is concentric with the hole at the rear main. Once
the engine is together, any fitting is impossible.

You can reduce the oil pressure by working with the oil pressure
relief valve at the left rear of the block. Either remove the shims,
shorten the spring, or weaken the spring. But, I'd suffer some oil leaking
rather than dropping the OP.

There is no easy oil recovery system I know. BUT, there is a rear
seal available through Peter Alberda of Zeeland, Michigan. Peter has a rear
seal that WORKS!

Hope to see you this year!

John

EngineUmbrella Sleeves
John,

I met you at the recent GOF in St Augustine, FL - I have the yellow TC
that
was fogging for mosquitoes during your rolling tech session. You
mentioned
umbrella seals for the valves but didn't have a NAPA part number handy.
Do
you have it available now?

Thanks,

Gene Gillam
Gene!

I've just rediscovered your note. The Felpro number is SS 72522.
Hope this helps at this late date!

John

EngineOil Leak in Engine Block
John,
How would you like to hear another MG adventure. I recently started up a
TD
that had the engine rebuilt several years ago. Went through the start-up
sequence to make sure I had oil coming to the rocker, but was concerned
that
it took a long time to prime the pump and get oil to the upper engine. I
started the engine for a short run without water in the radiator and was
lucky I took this calculated risk. Within seconds oil began dripping from
the right side of the engine block. Shut down and started searching for
the
leak. I don't usually get excited about finding a leak with a new engine,
it's part of the process. However, this oil was coming out of the water
drain spigot on the right side of the block. This boggled my somewhat
frozen Alaskan mind. First thought was cracked block or head allowing oil
to seep into the water galleries.

First I pulled the cylinder head and began searching for answers. After
considerable time, I noticed oil in the two banana shaped water galleries
in
the rear of the block. Since these match the two on the back of the head,
I
looked harder at the head. Could not see anything that would cause a leak
until I removed the rectangular rear cover plate. It appears that the
machine shop had removed the set plug that fills the rear oil gallery
hole -
oil was coming up at 50psi and turning towards the rear of the cyl head
where it flowed freely out of this 1/4 inch hole and down into the water
gallery.

Using a proper thread pitch bolt, I cut it to proper length and notched
the
end with a Dremel. Put this in as a plug and replaced the cylinder head.
Now my problem was removing oil from the water gallery. First paint
thinner
was injected until it flowed freely from the water drain spigot, followed
by
hot soapy water, and finally flushed with just hot water. I have a well
oiled water system!!

Overall, I was lucky on two counts. I had not filled the radiator so I
didn't wind up with water and oil circulating throughout the engine, and
second, I had left the water drain tap open by mistake - otherwise we
would
have never noticed the oil dripping out of it.

Is this the first time you have heard of this gigantic screw-up?

Take care and thanks for your note. If ever in Alaska, stop by. I have
several MGs including two As, a TD, and a TF. We started a British Sports
Car club here in Anchorage, and after two years have almost 80 members.
It
is amazing what's up here. We have members with TAs, PBs, several Ts and
As, A-Healeys of every size, E-Jags and a pristine 120.


Sincerely, George
George!

This is the second time I've heard this story. The first was with a
fellow who didn't have the water pump installed and was getting oil running
from one of the bolt or stud holes where the pump mounts. He was certain he
had a cracked block. I kept talking to him and eventually hazarded upon the
cause of the problem -- same as yours! Good thing you had the drain open!

EngineSwap Front and End Plates in 76 and 68 Engines?I AM PUTTING A 1976 MGB EGINE INTO A 68 MGB. DO I SWAP FRONT AND END PLATES FROM THE 68 ENGINE ONTO THE 76 ENGINE?
THANKS,

JIM

Jim! Change the front plate only -- you might want to save the dual chain from the 68 and fit it to the 76 engine, but it's not necessary.

John
EngineRPM in MGCabout my 69 MGC. In first and second gear when I hit 3500rpm it seems to be starving for gas and begins to sputter. I can't get it to smooth out or go any faster. I've replaced the carb jets, pulled the choke at 3500rpm, played with timing etc. It doesn't seen to do it in 3 or 4 gear but id have to pay more attention while in third. Any suggestions would be appreciated.

Thanks,

Jim
Jim!

You complain of sputtering at 3500rpm in 1st and 2nd. You are certain that this fault occurs at a certain rpm, NOT a certain road speed. I would imagine that you'd have the same problem in 3rd and 4th at 3500.

I do not believe the problem is fuel related -- rather ignition. I'd change the points, test the plug wires, clean the coil -- and test it --, and clean/replace the Champion spark plugs with RN9YC gapped at 0.035". Test the coil? Remove the plugs so the engine spins over quickly. Have your associate spin the engine with the key. Use your grounded test light and move the tip of the test light around the top of the coil -- inspecting for the intensity of the spark AND for tracks along the coil tower.

I'll put my bet on the ignition side of this problem. Let me know what you find out!

John
EngineConvert to a Tickford
I need some advice. I have two MG TAs, a '36 and a '38. The '36 is a
basket case and the '38 requires total restoration. A fellow that I bought
an engine and transmission from suggested that I convert one of these cars
to a Tickford. Is this a good idea? I know that some of the specialized
parts would be hard to find and probably very expensive, but would a built
up Tickford be worth the extra cost and effort? Also, do you do babbet
bearings, and if so what does it cost to rebabbet the mains and rods? Thank
you. William
William!

It is NEVER "worth" restoring an MG (or probably any car, for that
matter). If you want a nicely restored TA, go out and buy one -- you'll
have less time and money invested than re-doing your own. But ----- if you
love the process ---- well then, you're in our camp!

Creating a Tickford would be a tremendous job -- but there is a man
who has most of the parts -- a dentist from Horton, Michigan, phone 517 563
2740 / work 517 563 2314.

Expect to pay about $1200 to have the bearings poured for the three
mains, the cam, and the four rods!

John
Engine60A Timing Cover

Hello John, I am a friend and car club member with Jim Swenson at British Car Service INC. in Powhatan, VA. He told me if anyone would know the answer to this question it would be you. I have a 1960 MGA that I restored. I have found a timing cover to an MGB that I would like to install to reduce the oil leak from the cloth ring. My question would be in regard to the oil thrower. I have heard mixed opinions. One is that I can use the same thrower and the other is I should use one from an MGB. However when I call Moss or Jim looked in the part magazine the parts numbers are the same. It takes a bit to take everything off to get this done and I would rather not put it back together and find the thrower making noise because it hits the timing cover. What are your thoughts?

Mark!

There are several different varieties of front timing covers: Felt Seal, timing marks at 6:00; Rubber front fitting seal, timing marks at 6:00; Rubber rear fitting seal, timing marks at 6:00; Rubber rear fitting seal, timing marks at 11:00. Avoid the front fitting rubber seal -- they discovered those didn't work! The timing marks at 11:00 is the "best" cover, but should be fitted with a later, harmonic balancer with corresponding marks. In any case, you MUST use the later style of oil thrower with the rubber seal front covers. The earlier style will rub against the cover!

John
EngineEngine Rebuild
I took my dismantled 79 mgb engine to a machine shop this morning for
analysis. He is going to clean and then measure, then let me know what
is needed. Was told I needed replacement parts before boring and other
repairs could be done. Apparently he wants to custom fit pistons,
bearings etc. Does that make sense? Question #2, do you reccomend
particular manufacturers pistons, rings ,etc. Is it possible to buy a
reliable " lower engine rebuild kit"?

Thanks for your time Bob
Bob!

We purchase nearly all of our parts through Moss -- so I am not
aware of all the different parts sources you can use to get parts -- but
"custom" parts doesn't make any sense. I know that most machine shops can
order, right through their own suppliers, parts for the MGB engines. As he
is the one assembling the engine, he is the one who has to take
responsibility for the parts. On top of that, he supplements what he makes
with a little mark-up on the parts. Don't begrudge him that!

Nearly all of the pistons and bearings which we have purchased
through Moss have been high quality. Let your shop know that he can get
them directly from Moss.

When we perform an engine rebuild, we often include: cylinder head
work -- hardened seats, bronze-silicone guides, but standard valves!
Clutch, rod/main/thrust/cam bearings, pistons or rings, cam, lifters, chain,
tensioner, all gaskets and seals.

I've got a nice section in the Technical Book about the MGB engine.
If you're doing the work yourself, it may be very helpful!

John

EnginePiston Sizes The machinist suggested that he had seen ,as an example, +.030 pistons
come as +.029 and +.030, he wants to bore each cylinder to fit each
piston in that instance. That didn't sound quite right to me.

I am going to reassemble the engine the engine myself. I have the 97
version of your tec. manual and have used it in the past.

Again thanks and yours in Brit cars

Bob
Bob!

You'll notice on the top of the block there are numbers in diamonds
(rhombuses) -- these are the original size measurements to allow the factory
to fit corresponding sized pistons (which were also marked with their ten
thousandths oversize). I've not heard of a machinist doing this before. It
is a very delicate job -- he obviously knows what he's doing!

John


EngineLost screw in Engine?Dear John:

I have a 1974 MGB chrome bumper with the air pump and air manifold removed. I used setscrews to plug up the manifold holds.

While driving, suddenly I heard a loud tapping there was no change in the car's performance and at first I thought maybe I had hit something and created a hole in the exhaust system.

Home was about 15 minutes away and when I got there and investigated I found that one of the set screw, the first one, was not longer there and I'm assuming in has fallen into the engine.

What, if anything can I do?

Thanks

Butch

BUTCH! I believe you'll find that the plug fell OUT of the engine, not into it. The result is that there is now a hole from the exhaust into the engine bay -- that "tapping" sound which is really an exhaust sound. Simply fit another plug -- and tighten up those other three.

John
EngineOil FiltersIs there a way to convert a 68B paper filter to an inverted spin on filter?
all the kits I have seen only go up to 67

Tom
Tom!

Fit the top loading spin-on filter adaptor from a 1970 - 1980 MGB.

John
Engine80LEJohn I got my car apart last night from the fire, it was this way when I bought it, the exhaust manifold was cracked open about a 1/4 inch between the 1st and 2nd cylinder, what caused that and is that probably where the fire started ?
thanks
Ronald
Ron!

The casting on the manifolds was not good, and some of them continued to bend while "curing" on the engine blocks. Later in production -- about 1977, BL replaced that earlier manifold with a more durable one which included a very large boss for strengthening. You can purchase a new manifold; you can purchase a used manifold (I have one). When you install it make CERTAIN to strap the exhaust to the joint between the engine & gearbox!

That leak probably ignited the fire, but the fires were most often caused by a loose automatic choke assy which allowed raw gasoline to drip onto the catalytic converter. Once the choke came loose, the car would begin to run rich, which would cause the converter to glow red hot. Drip...Drip...Drip..... It's a wonder more did not incinerate!

John
EngineRocker Arm LubricationHello John - I've have been browsing through your tech tips and find them very informative. I have a newly aquired 1974 MGB. I have replaced the worn rocker arm shaft and rebushed the rockers. appear to have good oil flow to the pushrod ball and socket but no oil "squirting" out of the front bleed hole for valve stem lubrication. I rebushed and drilled the bushings as per the original. Also, as per the origianal, the depression in the bushing I.D is located at the bottom of the rocker shaft. The front lubricating hole does not appear to line up to any holes in the rocker arm shaft. What am I missing here??? How does the oil get to the forward hole to lubricate the valves?
Doug!

You have assembled the rockers correctly. The relief on the bushing should be at the bottom as that groove holds the oil and the pressure on the bushing is at the bottom. Oil "oozes" out the pushrod end and down the threads; it "oozes" out the squirter hole, and down the end of the rocker to the valve stem. If you were to bring the idle rpm up to 3000 with the valve cover off, I believe you'd see a lot more oil moving than you see now! Of course, you'd nearly have to take a bath when you were through!

Hope this little bit helps!

John
Engine John,
Quick and easy question.

Have just completed reinstallation of the proper emissions set up on a
'71B.

Looking for FACTORY correct clamps. Are they the double wire british,
solid jubilee or flat copper fuel line type? ,... or something
different?

Also, I've ordered some from Moss and consistently get the copper fuel
line
type which are too small in diameter; a proper source would be
appreciated.

2 more questions:

1, Where can I get the proper sized 2 wire clamps?
2, When the MG's came from the factory, I know they had no radios, but
were
there antenna installed? Hole cut for the antennas? or just a solid
fender?

Best regards,


Bart
Bart!


The hoses associated with the air pump, air manifold, and gulp
valve
are all double wire. The smaller clamps -- vacuum to the gulp valve --
are
solid band (with screw and nut). Hope this helps!


Tell me which clamps you want for which application and their
esign -- and I'll send them to you! Make it about $10 for a small handful
of clamps.

The factory did not install the radios -- they were dealer
installed -- hence the discrepancies in positioning of the antennas. Me? I
prefer the RH front fender, at the very crest, left and right; immediately
right of the rear line of the bonnet.


John
EnginePressure Failure Switch Hi John
The car is just a
shell at this stage.One question of many but I don't understand the
brake pressure failure switch.I am trying to determine if the switch I
have is good or not. It has two (terminals) pin connectors which my
meter indicates 0 resistance(as if the switch contacts were closed) no
matter which way you move the lever (which I believe would normally be
moved by the spool in the body caused by front or back brake failure).
To me when this switch is in the center position the switch should be
open but my meter indicates it is always closed (0 resistance). I just
noticed a wire at the bottom of the two pin connectors joining them
together which to me explains why my meter indicates the 0 resistance.
Should that wire be there? If it should then I guess I don't understand
how this switch functions. Hope you can help! Do you have replacement
switches?
Many Thanks
Don
Don!
The switch is a mandated safety item. When the piston in the
cylinder moves fore or aft, because of the loss of pressure in the front or
rear circuit, the piston contacts the pin from the bottom of the switch,
grounding it. The lamp in the brake pressure failure light is wired hot --
therefore, when the switch is grounded, the lamp illuminates. So why two
wires? A safety warning light is no good if it doesn't work! So -- you
have to be able to check the circuit. When you push the switch, you ground
the second wire! From the battery: current to the bulb, from the bulb to
the switch, across the switch, from the switch to the failure light switch,
from there to ground.

I hope I've made this clear. If not, I can sketch the circuit and
send it along.

John
Engine"S" in Engine NumberI have 64 mgb. Car number GHN3L 321
engine number 18S-G-U-H 425

I have been trying to find out what the "S" designates. Any help would be appreciated.
The originally delivered MG engines were 18G. At the introduction of the Smith's PCV valve the prefix was changed to 18GA. Of course, the five main bearing brought the 18GB.

The MGBs which were imported through the northwest, maybe the west altogether, had some sort of problem with the engines, what I do not know. These engines were changed by the dealers to the 18S engines. Only several hundred were so changed. I've always attributed the "S" to "substitute," but my British motor lexicon is limited, so it probably means something else!

We have more than several of these 18S engines in our database.

John


EngineEngine PaintJohn-

I have been looking all over for MGC green engine paint (not 'Healey
Green,'
but the silver gray-green used on C engines) without success. Do you know
of a
source or a reasonable substitute?

Thanks
Steve

Steve!

Contact Keith Sanders in the cc line. Keith's the chairman of the
American MGC Register and I'll bet that somewhere in their archives, someone
has already done all the research. I, myself, do not have an answer.

John

Extra Information:
1. To my knowledge the AH color is the same one used on the C. I used it on my cars for years.
Tom

2. A little more paint info from Rick Ingrm
I have seen various shades of the "Healey green". Perhaps the original post referred to the dark healey green that was used on some of the Sprites, etc.

I feel that the true MGC/Healey green is the silver/green shade. When I repainted the block on my C, I ordered the paint from the East Coast (can't remember the name, but it's something like Hirsch). I came in identical to my needs...and matched what was already on the block...an unrestored example....But when I loaned it to a friend with a 1968 MGC, he added some additional silver to lighten the green on his block and match the paint....hence, my Healey green 1969 MGC has an engine block with a deeper shade of Healey green than Dane's 1968 MGC engine block.

Knowing the variances throughout the builds of many BL products, I kind of wonder if there were different shades used for this paint throughout the build...Joe may mix the paint different than Sam....

rick
EngineOilQuestion----what type/weight oil do you recommend putting in shock absorbers for my 1977 MGB? I have never added any oil to the shocks, & I have owned the car since 1980. I was not aware that the shocks required oil. Is it necessary to remove the shock(s) from the car, drain it, & refill it?

Thanks in advance.
Shock oil is a 50 weight hydraulic oil with a seal sweller and an anti-foaming agent. Most of the oils available are a much light viscosity -- but with all the wear and tear on our shocks, that heavier weight is better than lighter weight -- but any weight is better than none at all!

Front shocks have a filler -- a 5/16" BSF nut which you can see, looking straight in above the front tire; the rear shocks the same filler, just under those white plastic plugs on the far outside of the rear shelf area behind the seats.

Moss sells the shockoil.

Hope this helps!

John



EngineEngine NoiseI have a 1955 MG TF 1500. The engine is making a
tapping/clicking/clacking
noise after the engine warms up. It sounds good when first started but as
it warms up it starts making more noise. The noise seems to be coming
from
under the valve cover. The valve clearances are set to the recommended
gaps. What might be making this noise? What can be done to solve the
noise problem? I'd appreciate your help.

Howard!

Use a 0.010" feeler, and with the engine idling, slide that feeler
between each rocker and valve stem from front to rear. When the clacking
noise disappears, you've found the valve that is the source of the problem.

It could be a bad cam follower and cam (common on the MGB), but I
suspect that one of the ends of the pushrod has come loose (common on the T
type). Remove that one pushrod and get it crimped and spot welded -- or
simply purchase a new one.

Hope this helps.

John
Engine80B Motor RebuildJohn

Met you at GOF South in April, (I proudly received a 2nd in class), you diagnosed my 80B as needing a cam. Well I have decided to have the motor completely gone through and would like your input on some thoughts.
1. Replace Weber DGAV w/Twin SU's
2. Replace with 1.5 or 1.75 SU's
3. Cam to use w/either size SU's
4. Cylinder Head port modifications required
5. Compression Ratio recommended
6. Exhaust system recommended
7. 5 speed Ford Sierra type 9 gearbox, (no modification to car), bolt-in conversion, from The Five Speed Co.

Sincerely
Dave
Dave!

If I were you, these are the steps I would take:

Return the engine to original condition. Fit a new cam (an earlier cam) but keep the Stromberg carb etc. All renewed, this will work very well.

More power: Two things: change to dual SUs and have some porting and polishing on the cylinder head.

Real power: Fit the Moss Supercharger.

Horsepower = torque x rpm. The RPM is easy -- you just use your right foot. It's the torque that's expensive.

The engine wants to breathe, but it doesn't need larger carbs as the #1 restriction to power is the size and shape of the inlet valve ports.

That five speed gearbox is nice, but remember that there are no parts easily available.

Give me a call sometime and we can discuss this further!

John

EngineCompression RatioJohn,

I attended the GOF and was present for your Tech Session on the lawn at the Palm Coast and We all really enjoyed.

While there I read in the new issue of the Classic Motorsport magazine about the MGB.
To be to the Point: What do I need to do to change my "73" B motor from a 78 HP to a
98 HP (66-67 vintage) Block. The only difference I can see is the Compression Ratio. I suspect that it is either the head or the Pistons (or both), and removal of the emissions stuff, but I am not sure how to accomplish that.

Thanks

Gregg
Gregg!

Horsepower = RPM x Torque. RPM is cheap -- just use your right foot and rev the engine to 5500. Torque is expensive, but these are the steps I would take:

Tune the car as well as possible. A single Stromberg carbed MGB will run pretty well -- and the cost is pretty low. Professionally, about $350.

Fit dual SU carbs. My preference is the HS carb from 1963-1971. Professionally, about $1250.

Fit a better cam. Professionally, about $1000.

Flow the cylinder head -- that is port and polish, matching manifolding, etc. Professionally, about $2000.

Finally, fit the Moss supercharger. Professionally, about $3500.

Combining steps will drop the price of each step, of course.
You are right about the engine -- the higher the compression, the more power you can get -- but the higher octane you'll need. Best to stay right in the 8:1 to 9:1 range.

Hope this little bit helps!

John
EngineAnsa Exhaust I have a 1979 MGB. I have installed an original 1974 cast iron exhaust
manifold and the matching downpipe. I'm confused about how to put an Ansa
exhaust on it. At the recommendation of a friend, I bought the MG0125
(old center) and MG0227 (the new rear).

Will this fit? My friend says he has done several this way. I'm having
difficulty getting it to fit. the MG0125 will fit, but its outlet is then
point at the rear axle housing. There is no way to connect the MG0227 to
it. I'm going to ask my friend how he did it.

On the other side, the guy at the parts store that sales Ansa says only
the combination of the MG0225 and MG0227 will work togother on this car.
He says the old exhaust manifold and downpipe have nothing to do with it.

What combination of Ansa has worked for you on a 1979 MGB with the old
manifold?

--
That combination would be difficult to fit, to be sure. If you have a 1979,
then you want the 225 and the 227. It will connect right up to your down
pipe (from a 1968-1974). Or, ask your buddy there to come over and fit
this hybrid system for you!

We've fit ANSA's for 25 years. They are the best exhaust you can purchase
for the car, hands down!

John
EngineMGA Engine to 5 Main MGBIs there a supplier you recommend for an electronic tach or a place to send the original mechanical tach for an upgrade conversion since I am converting to a 5 main bearing MGB engine? Where can I find the conversion plate to match the engine and transmission (using the MGA Transmission)?

Thank you,

Don
Don!

Try an MGB or Midget, 1964 through 1967 for that tachometer -- perhaps eBay. Nisonger Instruments in Mamaroneck often has units.

My suggestion on the rear plate is to have the plate from the MGA engine opened up to 3 1/2" to accept the five main seal. This is a job for a machine shop. You'll need that flywheel from the five main - three synchro gearbox MGB combination, too, along with the front cover for the gearbox and release bearing fork.

I did this on my MGA about 25 years ago -- it provided me with wonderfully reliable power until I decided to go "original" and find a proper 1622.

Hope this helps!

John
EngineAccelerator is StickyJohn,
Hi! I’ve heard and read a lot about you . . . all good.

I’m a new owner of a ’62 MGA Mk II. Can you tell me why the accelerator pedal has a sticky feel or movement to it? I’ve lubed the mechanical pieces under the dash from side to side but no luck?

Best regards,
Mark
Mark!

Three reasons for the sticky feeling: welded cable; misaligned parts; lack of lubrication; overly strong return spring.

Welded cable: lack of a good ground between chassis and engine cause the throttle cable to carry some of the current, so the inner cable welds itself to the outer cable.

Misaligned parts: As the inner throttle cable exits the outer cable, it should not exit on the bias -- it should be straight out.

Lack of lubrication: pivot bearings on the throttle pedal shaft (inside the car).

The throttle pedal shaft has a small spring (on the right side of the cockpit floor), and a moderately strong spring at the carbs.

I cannot imagine another reason.

Hope this helps.

John
EnginePayen head gaskets hello,
thank you for your great posts.....Do you have an
opinion on the 'payen' head gaskets please and do you
believe that they solve the leaky head problem in the
b-series please?
thank you,
-Jeremy
Jeremy!

The new Payen gaskets include a strip along the RH side, I suppose
to stop the water weeping endemic to all our engines. Does this strip work?
We've stopped adding the copper wire and just fit the gaskets as they are
provided. So far, so good!

John

Engine10CG EngineI understand from some of the literature I've read that my 10CG engine
has inherent problems (crankshaft bearings?). My goal is to restore
the car (not running since purchase) to a "reliable" street/pleasure
vehicle.
If the engine proves to need a rebuild, can the weak spots be upgraded
economically or should I look for a 1275 substitute? I have had no
success locating a British shop in Montana--know where 1275's are
available if that's a better choice? (We'll be coming to the Midwest
this summer if that helps.)
Thanks.
Herb
Herb!

The 10 CG engine is really just a bored out 948cc (9CG) with a
longer stroke which continues to use the 1.75" main journals. The 10CC and
the 12CC-12V use a 2.00" main journal. That larger diameter bearing
offers about 15% more surface area in the 10CC engine which is not really a
dramatic increase. The main advantage to the 1250 engine is the increase in
displacement, which, still around 15%, is not negligible. Plus, that 1275
engine is a really refined workhorse!

The 10CG engine, if properly machined, will keep your early Midget
original, and I doubt you would encounter any real difficulties. That
"proper machining" includes align honing of the main bearing saddles and the
rear oil slinger. If you cannot find a shop in your area that can do a
proper job, then send the block to a shop who can do the work -- this
machining is a very critical step!

At one time, 1275 engines were fairly plentiful, but it's
increasingly difficult to find them.

We can organize the machining for you if you want to keep the car
original.

John
EngineTorque SettingHI JOHN!; I HAVE MY 74 BGT THAT I SUPERCHARGED LAST YEAR, I ALSO HAVE A MOSS MOTORS ALUMINIUM CYLINDER HEAD. I RECENTLY BLEW THE HEAD GASKET, AND I WAS WONDERING IF THERE IS A DIFFERENT TORQUE SETTING FOR THE ALLOY HEAD, OR IS 50 LBS OK?

Chris
Chris!

If you are using original studs, or the "competition studs" offered by APT, then you can go higher with that head torque. I always use 55 lb-ft on the original studs, and that's with the studs oiled which translates to a greater downward force. Of course, you have to "feel" each stud and if one begins to turn (to stretch) more than it should, you should replace it with another. Those APT studs take a much higher torque than the factory studs. Be wary of the Moss studs, as our experience is that they can snap at as little as 35 lb-ft. Retorquing the head, even several times, is important, too. Because of the great expansion of the aluminium, I would torque the head cold.

The coefficient of expansion for aluminium is about 2 x 10 (-5) per degree Centigrade. So, for a head of about four inches in thickness, rising from about room temp to about 200F, the head will expand by (60degrees Centigrade times about four inches times 0.00002) about 50 thousandths of an inch. Since the cylinder head studs are 3/8-24, then each turn of the head nut yields about 40 thousandths of an inch. So, the expansion is about the same as one turn of the head nut!

While it is easy to skim the bottom of the head to within several thousandths of an inch, surfacing the top of the block is a real chore -- obviously, as you have to disassemble the engine!

If the gasket blew out between one and two, or between three and four, I would suggest laying a short piece (two inch)of twisted copper wire (use two individual strands from normal 16 gauge automotive stranded wire), held against the top of the block with a dab or two of silicone gasket sealant. Place the new head gasket on top of this, and the head on top of that.

With a boost of less than 10 psi, you shouldn't encounter any more problems.

John
EngineExhaust StudsI really enjoy reading your tech tips.
I would appreciate you telling me if it is alright to use new exhaust studs that have coarse threads on both ends. The original studs seem to have one side that is fine thread along with a larger nut for the exhaust flange. What do you suggest to make my new engine safe ?

Thank you
DAVE
Dave!

I am certain that you will encounter no problems using "coarse/coarse" studs. However, even NAPA sells "coarse/fine" studs (about two inches long). You know, the original nuts were brass, but we find that they loosen over time (although they're not supposed to bond with the steel). We now use "prevailing torque" nuts (we call them elliptical nuts because the thread is distorted on one side into an ellipse).

Moss sells the correct studs, too.

John
Engine76 MGB - Weber CarbsDear John,
You have helped me over the phone several times in the 15 years
I
have owned my 76 MGB. Congratsulations on becoming the technical advisor.
I have two questions. I hope to convert to the Weber carb and was
wondering
if you have any used or rebuilt around, and also how to size up or order
the
exhaust maniflod I will need to replace the combined manifold I now have,
and what sort of surgery is needed on the headpipe. I also need to
replace
my heater core as it has been leaking antifreeze for some time now and
fogging the windows. Is there a source for these besides Moss? An
internet
note from Chicago MG club decribed the preocedure (looks awful) and
mentioned a core replacement for around $100, considerably less than Moss'
quote. Currently I have the Stromberg setup and it has started running
very
rich after it warms up (and rough) and becomes impossible to restart
unless
it cools off completely, making me think that the choke is sticking, only
I'm not sure how to get at the choke. Take care, Hal
Dear Hal!

Your best bet is to purchase a new Weber, not a used one. However,
Weber has been on strike for a while now and the carbs are not easily found.
If you must purchase this unit, get the DGV32/36 progressive and not the
36/36 which is simply not suitable for the car.

For less than the price of a Weber you can get your original
Stromberg rebuilt. Several firms, including mine, perform that service.

Before changing the heater core, CHANGE the hose clamps and hoses
that attach the heater matrix to the heater control valve and the return
pipe. If these clamps get loose (common), then the coolant sprays directly
into the heater box giveing the impression that the core is faulty. They
are rarely, if EVER, bad. But, you live in a colder climate than do the
rest of us.

Changing the core is very difficult, true. There is a way to do it
fast, but it bends up the front of the heater box pretty fiercely.

Let me know!

John
EngineFitting Thrust Washerstips for fitting the thrust washers in a '79 MG Midget 1500CC engine??
Just HELP PLEASE

Mike
Mike

The workshop manual calls for about 0.010 clearance. This is wrong,
wrong, wrong. You want 0.002-0.003. Purchase oversize thrust washers and
surface them if necessary so that they fit allowing just that bit of end
float.

If the engine is ALL apart, then you should have the bottom end
align honed and the rear thrust washer relief cut away to accept TWO thrust
washers at the rear face of the rear main cap.

Contact me again if you want ALL the spiffy 1500 Midget rebuild
notes.

John
EngineMoss Oil SealJohn, I read your March, 2002 email answer to Dr. Simson regarding not using
the Moss seal and recommending that he "do the right thing" and have the
engine Align Bored and Honed.
I unfortunately have the original Moss oil seal installed which did not
work. Short of putting in the new kit or "doing the right thing" has anyone
figured out a method to make this old system work? Special materials or
modifications? I would be satisfied with the old quarter size oil puddle
that I had before the Moss seal was installed. Now it looks like the Exxon
Valdiz beached on my garage floor.
Thanks for any help.

Bill
Bill!

If that Moss seal is fitted EXACTLY correctly, if it is fitted with EXTREME
care, if your machine shop has experience in fitting them before, then it
can be successful. My personal experience is mixed -- that means that the
Moss seal has worked several times; and it has not worked several times. For
each time it has not worked it has cost me dearly!

The only way out is to disassemble the engine, remove the bearing pins, get
the bottom end align honed, the slinger align honed (to 0.007" larger than
the scroll thread on YOUR crank). The engine is build with metric
measurements.

The main bearing housing is 56.54mm which is 2.2177-2.2185". the groove on
the crank should be 58.75 -.03 -.07 or 2.313 (although 2.312 is more
commonly fine). Therefore, the housing bore is 59.00 +.05 -0.0 or 2.323 (use
2.3185).

This is a very frustrating type of problem. If I were you I would contact
Moss and ask for ALL of their technical updates and try, once more, to get
that seal to work.

I've been where you are. Good luck!

John
EngineFront Pulley in MGAJohn,

Thanks for your expert advice at this year’s MGA get together. I had the MGA with the loose front pulley. This pulley has been that way for nearly 25 years (and 30,000 miles). You stated we would not make it back here. My son and I safely made it back to Louisville. I will heed your advice (and immediately changed the seat backs around after your review). Again, this is very good for me, as I have had this car for many years and all I have is the manual.



Thanks for donating your time and expertise,



Steve


STEVE!



You're really fortunate that the wear has not progressed so much that the front pulley has come loose from the crank altogether.



The "correct" and profession fix here is to remove the engine, remove the crank, get it welded up and recut, and fit a new front pulley.



A simpler "correct" fix invovles using a new keyway, soldering it into the crank, which is difficult.



The dollar solution is to remove the front nut and then drill a 1/4" hole into the crank and pulley using the inside diameter of the pulley and outside diameter of the crank as the center for the hole. Drill in about 1/2", drive in a 1/4" pin, then refit the locktab and nut.



Doesn't that tickety tick from the pulley drive you nuts?



Hope this helps.



John



EngineMGB Engine ProblemHi John, I have a problem with my 71B that I cannot figure out. I have
switched out a motor from my parts car (79B) into my 71. The 71 was leaking
badly and was 15 years old. The new engine's #3 cylinder is dead. There is
fire to the plug as well as the other three. The engine fires right up and
seems to run good (except for the miss). After the engine reaches running
temperature (just above 'N") I am getting quite a bit of grey smoke from the
exhaust especially after coming to a stop and then taking off ( I expect
this is unburnt fuel from the #3 cylinder building up in the exhaust). I
have replaced valve seals, rebuilt the carb (a Weber DGV), installed new
plug wires, plugs, distributor cap and rotor. It is equipped with a new
Petronics Igniter electronic ignition module. I have checked the compression
and it seems to be good (#1 140lb, #2 145lb, #3 155lb and #4 165lb all plugs
out, reading taken after 6 revolutions (needle stopped climbing)). Any
ideas?
Thanks for your help!

Mark
Mark!

Very interesting. If the compression is good then the engine is OK,
unless the cam lobe(s) for #3 are just horrid. Watch the engine run with
the valve cover off. Are the #5 and #6 valves opening the same distance as
the other valves? If you can see a difference, it's too much.

You have spark at #3. it could be that the new plug got so washed
in gasoline at some point that it quit firing. It could be a bad plug.
change it for a new one, or swap it with #1.

You have to have compression, spark, and air/fuel. So, it could be
that there is an air leak at the 3/4 port between that aluminium manifold
and the head. While the engine is idling, spray carb cleaner around the
inlet manifold at the head. If there is a leak the engine speed will change
dramatically. It rises or falls depending on the severity of the leak and
the mixture of the carb.

Please let me know what it was when you find it.

John
EngineT-Type Engine ColoursJohn
If you have time to reply, I'd appreciate your advice.

I am at last reassembling the engine of my TF 1250 (well, about 1350 now, as it's 100 thou oversize!) and would like to paint it correctly. At present the block is yellow and the rest silver. I have the dark red paint for the block and head, and believe that the generator and starter should be black, but what about the bits and pieces? Alloy sump, timing chain cover, oil pump body/filter mount, fan and pulleys, inlet manifold, engine stabilizer assembly? Oh, and how about the gearbox?

Also,a couple of years ago I bought from you a front oil seal for the crankshaft, Moss # 120-750. It is narrower than the grooves in sump and cover but snug diametrically. Do you use a sealant on the o/d, and if so,what type? You told me which way round to fit it but I've now forgotten; does the spring go inside or out?

Thanks in advance. All the best,

Michael
Michael!

The engine is most certainly that dark red. We've used PPG DAR 2673H also PPG 50782Y. I shy away from the Moss spray paint because several drops on anti-freeze stain it indelibly. I wish I could tell you the paint we use right now, but I'm at home and the paint is at the shop! You can call any day during tech time and I'll go out and get the can to see for sure.

My understanding is that the dynamo and the starter motor are black. The sump is usually unpainted. The bell housing is usually unpainted. The aluminium timing chain cover is usually painted. Water pump and pulleys are engine color. Intake manifold is engine color. Exhaust manifold is just rust -- you can have it "jet hot coated" and that makes for a very, very nice appearance. They were aluminized originally, but that's hard to duplicate and it only last for so long.

That seal is narrower than the slot in the sump and timing cover, but with some silicone sealant (Dow Corning RTV clear) and a little attention to detail the seal will line up just fine.

John
EngineMGB Engine Mount Good evening,
I really enjoyed reading your tech tips on the North American MGB
Register web site. Would you have any advice with regard to replacing the
left front engine mount on a 1979 MGB? Mine's broken, and I can feel the
vibration of the engine against the steering column when I make right
turns (not good - hence I'm not driving it while I figure out what to do).
I'm trying to figure out if this is something I can do myself or if it's
something I need to find a shop to do for me. Any advice you have to
offer would be greatly appreciated.
Regards,
Kevin


Kevin!

There are two parts to the engine mounts: the rubber mount itself;
and, the engine bracket.

The rubber mount on the right side is easily changed; the engine
bracket on the right is easily changed.

The rubber mount on the left can be changed without removing the
steering pinion, but it's nearly impossible. The engine bracket on the left
is very difficult to change.

When installing new engine brackets, weld a gusset at the top corner
where the tear begins -- that will prevent the new bracket from tearing as
the old one.

Let me know what you've done!

John
EngineDiameter of PistonsJohn,
I am restoring a MGTF1500 with I bought here in Holland with a 1250 engine in it. I was lucky to find a 1500 motor here in the neighbourhood.
This motor has the following pistons L57 AEF119 TO SUIT +0,030 BORE , the diameter I meassured on one piston was 72.75 mm. This should be 72.763 mm.
Can you tell me which max. cylinderdiameter belongs to this pistendiam.

Regards
Ernst

Ernst!
About the XPAG: You know, all the basic measurements are metric. Hence the bore of 72mm and the stroke of 90mm yielding 1466 cc. However, since the engines were supplied in countries which used inches as the basic measurements, nearly all overbore and undersizes are in inch increments.

A 0.030" overbore is 0.762mm. That means that the piston should measure 72.762mm less the bore clearance of some 0.005" or 0.127mm or about 72.635mm. The difference between your measurement of your piston 72.75mm and my calculation of 72.635 (the calculated piston size for a 0.030" overbore) is 0.115mm or about 0.005 -- which could be errors in measurement or errors in piston to bore clearances.

The book gives a clearance at the thrust face of 0.0021-0.0024" (or 0.053-0.061mm). So, I would bore the block at 72.75mm + 0,57mm or 73.32mm.

But, in the end, go with the suggestion of your machine shop.

Do not miss the most important part of the machining -- and that is align boring or align honing of the block and sizing the rear slinger to run 0.007" or 0.178 larger than the scroll thread on the crankshaft. The main cap diameter should be 56.54mm.
There are many jobs for the machine shop: boring the cylinders; turning the crankshaft; fitting the cam bearings; etc.
One part of the machine work which is often forgotten is to machine the main journals -- where the main bearings are located. These three holes become distorted over time. The machine shop removes the pins which hold the bearings, then they skim a little metal from the main caps. Now the hole is no longer round. Then, they run a boring or honing bar inside the three main caps and bore or hone those holes round.

The same job should be performed on the rear slinger -- the device that keeps the oil from leaking past the rear main journal.


Hope some of this helps!

John
EngineSticky Oil Pump?Sir,

Thanks for the informative article on overdrive.

I have a 1980 MBG LE (#508817) that is fitted with overdrive. The OD worked intermittently when I 1st got the car (April 05), but now not at all. I have confirmed that the gearbox has enough oil. I have tested the electrical by placing my volt meter in line on the gearshift switch. It registers 12V when the ignition is ON, the gearshift switch is switched to "IN", and I slide the shifter into the 4TH gear position. 0V when the shiftger is out if 4TH.

Would this indicate that 3/4 switch and solinoid are ok?

Eliminating oil level and eletrical, would you suspect a sticky oil pump?

Thanks again,

Thomas
Thomas!

If you've tested the voltage at the Lucas female connector between the operational wire and the solenoid wire -- and it's hot when the switch is ON, then I'll agree that you've got power.

If you have power but no overdrive operation, then the solenoid itself -- or the oilpump are culprits.

You can remove the bottom cover, watch the oil pump, and turn the driveshaft by hand to see if the oil pump bobs up and down. If it's stuck down, remove it and clean the burrs off the piston.

Hope this helps.

John
EngineOil ConsumptionJohn

I saw a note in MGB driver that we (members of NAMBGR) can e-mail you and ask a question concering problems with their car.

I just went to the "triathlon" in VT last weekend and had some difficulty keeping oil in the engine. I drove approx 600 miles and used 8 quarts of oil. (not good).

Prior to this trip, I was having a high temperature situation to which I replaced the radiator , checked the water pump and removed the thermostat. we learned that the head gasket was leaking. (at this time I would use about 1 quart of oil every 400-500 miles). I had the head gasket replaced and the head reworked. (valves ground)

Max rpm was 3,000-3,500 during the trip.

If I kept the speed down below 3,000 rpm on the return trip & it seemed to reduce the oil usage.

there is no smoke from the exhaust, no leaking, compression is 125 in all cylinders, spark plugs are black a bit sooty but not fouled.

If you hold your hand approximately 2-3 inches from the exhaust you get small crystalized particles on you hand. (they do not smear like oil)

Can you assist in what might be the problem?

Gary
Gary!

Oil consumption is caused by leaking or by burning. If the engine is leaking it's obvious when you park -- there will be oil drips or puddles larger than a nickel or quarter sized drop that the "dry" ones leave. If it is not leaking then it MUST be burning.

The engine burns oil in three ways: the PCV system pressurizes and the oil control rings cannot scrape the oil off the walls. Check your PCV hoses to make CERTAIN that they are open and unrestricted.

The second way the oil is burned is when it's drawn between the valve stem and guide. This results in a lot of smoke at idle and on deceleration.

But the problem is always the rings -- and it's probably yours. One quart of oil spread out over a hundred miles doesn't leave a trail of blue!

Hone the cylinders and fit new rings!

John


EngineAbrath ExhaustHi John:

Forty years ago when I had an Austin Healy sprite I put an Abarth exhaust on
it. I loved the sound and those two little exhaust tips sticking out from
under the bumper. Is there anything similar on the market today that I
could put on my MG TD?

Thanks for your help,

Gene
Gene!

Gosh, we just had a twin piped TD in the shop -- but that unit was as old as the one you fitted 40 years ago!

I do not know anyone who makes such a creature -- although with some work and fabrication I'll be you could come up with something!

John

EngineOil and Oil Filter for StorageJohn,
Need recommendation for oil, (viscosity, type, etc.) for my 80' B and 52 TD. And oil filter for the B. I store them from late November to early spring.

Thanks,
Bob
Bob!

We use Castrol 20W/50 GTX for all engines, TC through MGB LE. Use 80/90 gear oil in the TD gearbox and that same GTX in the MGB gearbox. Use 80/90 hypoid gear oil in the diff on the TD and MGB -- and the same in the rack an pinion. I used to use engine oil (factory specification) for the carburetter dampers, but have now changed to that much heavier 80/90 gear oil.

Be sure to use some moth balls!

We have winter storage instructions available

John

EngineCompression on 1971 MGBJohn,

I just took compression readings on my 1971 MGB 1800V engine.
My readings show 110 PSI across all piston cylinders (engine warm). Absolutely no variance between cylinders.

My question:
I believe that 130 PSI is the proper compression pressure for my engine. Is 110 PSI acceptable compression or would you suggest replacing the piston rings.
Is it a requirement to take the engine out to replace the piston rings?

I am also planning on replacing the current head with a new one. Will a new cylinder head improve the compression pressure also?

Sincerely

Doug
Doug!

You have no need to fret! The imperative here is that the cylinders have consistent compression. That they do, so you're in great shape. The maximum variation suggested by most good engine tuners is 10%.

Now about the actual figure. There is a "static compression" calculated from the displacement and the size of the cylinder head. Say that's 8:1. Atmospheric pressure is about 15psi. So, 8 x 15 = 120 less the 15 we started with leaves a static compression of 105psi.

But, there are many more factors at play. First is the cam. The inlet valve doesn't close until 52 degrees AFTER Bottom Dead Center -- on the compression stroke, so if you were turning the engine over by hand, the piston would have traveled 52 degrees with the inlet valve open -- building up no compression! If the engine is stone cold, then not much heat will be generated, but if the engine is warm, the heat of the compressed air will be greater -- and it is the heat of the compressed air which pushes the compression to those figures higher than the "static compression."

Then there is the accuracy of the gauge you're using. If it's an old unit, purchased for little, it may not be very true. If it's new and expensive, the readings may be better. How many times did you spin the engine? Twice? Twelve times?

Doug, the CRITICAL function here is consistency! You have consistency. You have great compression.

Hope this helps!

John
EngineGold Seal Engines and Blue InteriorJohn-
I have several questions that you have probably seen before. I am
looking at purchasing a 1964 MGB "project" car that has been sitting
for 20 years. The advertisement says the body is in reasonable shape
and the engine is a factory "Gold-seal motor". The owner says he
bought the car a year ago from a restorer in Minnesota who was getting
out of the business who said he took the engine out of the car and
stored it safely away to prevent it from getting cannibalized in the
yard for other MG projects. The engine is painted gold and currently
out of the car.

I am somewhat skeptical of this story and I was wondering if you could
tell me anything about gold seal engines? Is there a way to identify
the engine by a serial number that could somehow be linked back to the
car? If it can be verified as a true gold seal replacement does the
lack of an original engine impact the value of the car? Before
installing the engine back in the car, could it be painted to look like
a factory original?

The other question I had concerns the interior. The car is iris blue
with medium/light blue leather seats with dark blue piping. Yet when I
attempt to research available interiors on these pull handle cars, I
only find that black and tan interiors were offered. Moss Motors
doesn’t list blue leather either as replacements. Can you comment?

I would appreciate any information you can provide.

Best regards,
Jim
Jim!

The factory offered "Goldseal" and "Silverseal" rebuilt components. Your Goldseal engine has an engine tag, no doubt with the prefix 48G. Give me the actual engine number and I can tell you more -- but the bottom line is "YES"there were Goldseal engines. You can certainly paint the engine the original maroon -- but you know, your "original" Goldseal engine would be a conversation piece at any MG event.

My Factory Parts Book -- AKD 3227 -- lists Seat and Seat Fittings: Seat Assembly - bucket - RH - Blue with Pale Blue piping. AKE 4492. The top and tonneau were also available in blue.

I believe I still have one copy of this AKD3227, an invaluable source of information for your 1964 pull handle (?) MGB. I'd be pleased to send it to you for $45, shipping included. It, coupled with Clausager's "Original MGB," makes up the basic documentation for the MGB. Plus, it has EVERY SINGLE part drawn and labeled. It is impossible to restore an early MGB without it. Yet, it is not a popular book. Mine is a reprint of the original.

Good luck!

John


EngineExhaust Manifold GasketJohn,

I am the proud, relatively new owner of a 1979 MGB roadster. Recently, I successfully replaced the clutch. Actually still in the re-assembly process.

My question relates to re-installation of the exhaust manifold. I found an orange colored rubbery material on portions of my old gasket. It looks like someone added some kind of gasket compound at the last installation. Is this ever done? I thought that the new metalic gasket was usually installed without additional sealants. Does such a sealer exist that will withstand the temps in that area of the engine? Is it appropriate to use such a material?

Most sincerely

Doug

Doug!

You've probably already worked through this....

the orange stuff was high temperature silicone gasket material. It was used around the #1 inlet port as the manifolds warp and this port lifts away from its seat. Best bet is to have the manifold resurfaced (on a long belt sander).

Let me know if you need any more assistance.

John
EngineRear Seal LeakOn my 75 B, with a LH overdrive, I am leaking major oil from the rear OD seal right behind the driveshaft flange. I don't have the opportunity to remove the engine and tranny from the car. So, as you can guess, I'm contacting you with the question: " can I replace the rear OD oil seal with the overdrive in the car from under the car?" Some folks mention needing an impact wrench, which I also don't have..

Anyway, thanks for reading, Hear you're a major MG guru.

Derek

Derek!

It is very odd for the rear seal to leak. Make sure that's the source! You can purchase oil dye from NAPA and use a black light to cause the dye to fluoresce -- making the source of the leak unmistakable. You'll have to clean off the gearbox, add the dye through the filler hole, run the car for a couple of miles, come back, jack it up and look with your black light.

If it is the rear seal, you need to drop the driveshaft, remove the rear nut, and withdraw the rear flange. Then you need to polish the seal surface on the flange and change the seal. You'll need a BIG screwdriver to pry out the seal. You will need an impact wrench (you can rent, beg, borrow, steal battery operated ones).

Get your diagnosis right before you start! All the oil leaking from the engine washes back onto the gearbox and it's not uncommon to misdiagnose an oil leak.

Hope this helps!

John
EngineEngine Swap, MidgetHi Folks,

This past weekend my midget crapped out in Ann Arbor-I live in Ohio 150 miles away. The mechanic (Larry at Illi's Auto Service in Ann Arbor called me today and told me the engine's seized and I'm looking at 2-3K for repair. That's what the car's worth but I've been thinking perhaps an engine swap may be cheaper. I've been terribly depressed all afternoon thinking about what I'm going to do. Can you offer me any suggestions?

Thanks Mike
Mike!

It's so very unusual to have an engine seize up during operation -- unless it's lacking coolant or oil. We have no rebuilt engines. Any "used" engine you purchase will be a pig in a poke. Any Midget 1500 engine or Spitfire 1500 engine will work. Two to three thousand for a rebuild is a low price.

Give me a call!

John
EngineValve TickingGreetings John--

I have a valve that continues to "tick" regardless of repeated adjustments ( it's actually the 1969 MGB engine's valve, not mine). I religiously follow the "sacred rule of 9." I'd appreciate any suggestions you might have. Is it likely that the contact face (rocker arm-valve stem) of the rocker arm needs to be "dressed?"

With highest regards--

David
David!

You can quickly identify that ticking valve by inserting a 0.010" feeler between the valve stem and rocker face as the engine is running. But if, after repeated adjustments, you must conclude that the camshaft and lifter are faulty (the ticking comes from an incorrect ramp closing speed). We can change a cam in our shop in a day, but it's quite a task. Remove the distributor drive gear, pushrods and lifters, front cover, gears and chain, radiator, sometime the oil cooler, and the cam will side out the front of the engine. Sometimes you have to lift the engine off the mounts to remove the front pulley. Call me if you need any more information!


John
EngineValve SealsHi,

I'm having some "burning issues" with my 1961 MGA.

Smoke on acceleration and idle, as well as start up.

Do you have a link as to how to install the Feltpro umbrella seals - without removing the head ?

Many thanks,



Duncan
Duncan,

You can change the valve seals without removing the cylinder head. Use Felpro SS70373 seals.

Loosen all the rockers completely, then rotate the engine, slipping each rocker off the pushrod when possible. Remove the #1 and the #8 rockers completely (withdraw the split pin). Position the rockers vertically so they cannot push down on the valve stem.

Use compressed air in the cylinders, or, failing that, feed a couple feet of cotton clothesline into the cylinder (piston down), then rotate the engine (by hand) until the rope is pushed up tightly against the valves.

Use a pair of screwdrivers, lever UNDER the rocker shaft, and DOWN on the valve spring cap. Lift away the collets, remove the cap, the springs, and the oil shroud. Do NOT replace the oil shroud or it will tear the umbrella seals to shreds within several revolutions.

Use lots of grease for installation.

Replace the collets in the same manner as removal.

This task is easier with two people -- but BE CAREFUL -- as the collets are very small and easily lost!

Hope this helps!

John
EngineMain Bearing SealsIt has been some time since we talked. You re-built a steering rack and front shocks for me sometime ago,both are doing well thank you.

I am installing the afore mentioned seals on the oil pan the 1969 MG Midget. As you can see there are several choices to make . Confusing to say the least. Not being a mechanic I have a couple of questions on the subject. Well,actually,a couple of dumb questions.

After soaking in oil would the seals need any further sealing other than Hylomar gasket seal at the point where the main and cap seals meet or would the Hylomar be compatible with the oil (I think not) to seal the entire cap "seal"?


Thanking you in advance.

John

John!

The modern corn gaskets provided with most kits won't break as they're impregnated with some sort of rubber or flexible plastic. Hence, no need to soak.

These gaskets are compressed dramatically and really don't need gasket goo, but if you do use some, I'd just use RTV silicone sealant (I prefer the clear variety).

When fitted, the gaskets will be incrementally longer than the slot into which they fit.

Draw the sump up evenly, back and forth, from the center to the ends.

Hope this helps!

John
EngineReplacement Valve CoverDear John,

I want to replace my stock 18V valve cover, (which has a breather tube that connects to the charcoal canister) for a polished cast aluminum valve cover which does not have a breather tube.
What are my options? Doesn't the breather tube act like a PCV vavle?????

Thanks,
TOM
Tom,

Note that the tube from your original valve cover, while it's about 1/2" in diameter, has only a 5/64" hole at the end. If you fit a 1/4" NPT pipe nipple to your new valve cover, solder a washer on the end - something - so that the final hole is the same size as the original (or you'll lean out your mixture).

John
EngineEngine ColorDear John,

What color was the engine block & cylinder head painted in 1979
MGB 18 V ?????
What color was the valve cover???

Mine is RED on the block and BLACK on the cover!
Thanks,
TOM
Tom,

Engine "red" is really primer. Engine was painted BLACK (DAR 9000 in PPG), as was the valve cover. I've attached my notes about the Stromberg. Hope this all helps.

John
EngineEngine SmokeHi John,
Talked to you last night about the PCV valve on the '68 Midget ( I have owned the car all of 3 days, its a surprise for my wife as her first car was a '67 back in '69) and how I thought it was causing the engine to burn oil. Again, after the car has run for about 5 to10 min. alot of blue smoke comes out the exhaust. I also notice when running down the road there is less smoke and a lot more when starting up from a stop.
I have checked the PCV and have found oil inside, spring looks ok, as does the diaphragm and plunger. With the engine running and the PCV opened up, if I push down on the diaphragm with my finger (closing the valve) the vacuum keeps the diaphragm pulled in (down). If I increase the idle the vacuum pulls the diaphragm down into the valve housing. However, when I clean out the oil and put the PCV back together it takes longer for the smoke to appear. The oil filler cap (plastic) is not plugged as I can suck or blow air through it. Ug! The separator (can) is not clogged as I can also blow air back through the hose. The hoses to and from the valve are not cracked, matter of fact they look new. I have also noticed when I put my finger over the port coming from the separator there is, I think, a strong vacuum and a small amount of air pressure coming out of the hose from the separator. You did mention compression rings. Can't find what the speck is (psi). Any help is greatly appreciated.
Thanks
Roger
Roger,

Another option here for a temporary fix -- is to leave the hose from the separator loose -- vent it to the ground -- and to plug up the PCV valve. Then drive it and see if it continues to smoke.

Smoking at idle and taking off is a tell tale sign of bad valve guides -- I don't think this is the problem, but try disconnecting the valve. In the end, it's probably the rings. You can check for compression and you can expect to find a consistent compression + or - 10%. I have no "real" or "proper" figures, as the compression indicated is a function of the gauge, the speed of the engine, the heat of the engine, and the valve lash.

Hope this helps!

John
EngineSnapped Timing ChainCan a snapped timing chain ever physically jam a crank shaft from rotating?

It is my last hope before I start pulling the engine
Pohs Eesteh!

If the chain has snapped, you usually have some free movement of the crank, maybe not 360, but some. The chain cannot snap by itself, and in the ONE case I've seen of a snapped chain in my 35 years in this trade, it happened at speed -- and the force of the engine carried the chain into and out of the timing cover -- it was a terrible mess.

Before you pull the engine, please give me a call so we can go over the possibilities.

John
EngineMGB SuperchargerHey John,



I have a quick question that I just can’t seem to figure out. Ever since I got the super charger installed (on the 76) I smell a fuel smell pretty strong on the driver’s side post acceleration (at speed 65 and above). Nothing at idle or general driving. Just when I put my foot down around 4000 RPM. I am also noticing that I am producing a decent amount of brown smoke out the pipe when this happens. Definitely not blue smoke and doesn’t smell like oil it legitimately smells like gas. Do I just have the carb setup bad? Could it be the original fuel pump is pushing too much fuel? Etc etc. be glad to try anything.




Thoughts?



Thanks in advance,



Josh
Josh,

That gasoline smell is often from the boot -- broken lines around the fuel tank. But, in your situation, the smell, accompanied by unburnt gasoline, means that the carb is overflowing at that point. Where do you have the carb vent routed? It should go to the charcoal canister -- but if there is none, then it should hang down near the bottom of the car. What have you found in the meantime?

John
EngineRocker PostsG'day John,


On dismantling the Head, I found 2 shims under the centre 2 Rocker Posts - are they necessary & if so why.
- I put a straight edge over the top of the head & its flat (I have had the bottom faced).

Cheers
David
David,

it is a mystery to me why the center two rocker stands have those shims. They were added, I believe, at the introduction of the 18V engine in 1972. We always replace them, but I haven't a clue why they're fitted. All the earlier cars seem to work just fine!

John
EngineXPAG Head StudsI have a 1954 Lotus Mark VI fitted with a 1466cc XPAG factory-racing-block, Laystall-Lucas aluminum head, and TC gearbox.

1. The head studs and nuts seem to be 10-1.5 mm. Can I chase the threads with 10-1.5 mm die and tap?

2. What torque would you recommend I use for the head nuts with my aluminum head?
(I'm using a .110" solid copper head gasket to drop its racing days compression of about 12:1 to a more
reasonable 9:1.)

3. Is it true that the XPAG (my engine) and the 1466 XPEG had different bore spacings?

Thank you,

Walter
Walter,


The studs are, in fact, 10mm x 1.5 so you can use a 10x1.5 tap and die to clean the threads on the studs and the nuts.

I would use a torque of 50#, then retorque to 50# when the engine is hot.

The bore spacings remain the same XPAG or XPEG, as the crankshafts are all the same.

Hope this helps.

John
EngineCrankshaft LocktabHi John,



How far need to go crankshaft pulley into the crankshaft? Right now the face of my pulley is 1/8” into the face of the front face of crankshaft shaft. I though the oil thrower it was installed wrong so I removed the front cover to verified the installation of the oil thrower, I verified the F stamped on oil thrower it was looking forward. The only change I did during the rebuilt was to removed the single wheelchain into double wheelchain following the installation instructions of the Haynes Manual. Also the locktab washer for the crankshaft, its supposed to have a notch or a tooth in the inside diameter of the washer. Thank you very much Jorge


Jorge,

The end of the crankshaft sits about 1/8" below the face of the front pulley -- so you have your crank assembled correctly. The lock tab is driven into the half moon detent on the face of the pulley, then folded over that 1 5/16" nut in the front. It is not necessary for the locktab to have a keyway cut into it. Some do, some don't.

Hope this helps!

John
EngineUmbrella Valve GuidesI have purchased your tech book and am putting it to good use rebuilding my TD from the frame up. I have the peter Edney video on rebuilding the XPAG and I see you advise umbrella valve seals too . Tell me is there a corresponding valve guide with a circular lip that engages the seal that is available as well? ( Boy I wish I lived closer ! )
Keith
Keith --

The umbrella seal will remain on the guide from friction -- if you're concerned, have your machine shop chuck up the guides and pin a groove in them.

If you need the Felpro seal number, call me at the shop during tech time -- I cannot locate that number here at the house.

John
EngineLarger BoreHi John,

What is your stand on the larger bore MGB engines? I'm considering this on my next rebuild coming up soon.

Many thanks,

Kevin
Kevin,

Power = torque x rpm. The torque is expensive, the rpm is your foot on the throttle.

You can increase torque by increasing displacement. The cylinder walls will hold at 0.160 over (that's the standard Lotus piston). Another CRITICAL factor is the condition of the cylinder head. Get Sean Brown to port, flow, and polish the head for you. Those two factors should increase your HP to the rear wheels from something around 60 to as much as 75.

Call me during tech time, or come to our "Tuning for Speed" class next weekend (see the info at www.eclecticmotorworks.com)

John
EngineBlue smoke out exhaustHi John,


Talked to you last night about the PCV valve on the '68 Midget and how I thought it was causing the engine to burn oil. Again, after the car has run for about 5 to10 min. alot of blue smoke comes out the exhaust. I also notice when running down the road there is less smoke and a lot more when starting up from a stop.

I have checked the PCV and have found oil inside, spring looks ok, as does the diaphragm and plunger. With the engine running and the PCV opened up, if I push down on the diaphragm with my finger (closing the valve) the vacuum keeps the diaphragm pulled in (down). If I increase the idle the vacuum pulls the diaphragm down into the valve housing. However, when I clean out the oil and put the PCV back together it takes longer for the smoke to appear. The oil filler cap (plastic) is not plugged as I can suck or blow air through it. Ug! The separator (can) is not clogged as I can also blow air back through the hose. The hoses to and from the valve are not cracked, matter of fact they look new. I have also noticed when I put my finger over the port coming from the separator there is, I think, a strong vacuum and a small amount of air pressure coming out of the hose from the separator. You did mention compression rings. Can't find what the speck is (psi). Any help is greatly appreciated.

Thanks

Roger
Roger,

Another option here for a temporary fix -- is to leave the hose from the separator loose -- vent it to the ground -- and to plug up the PCV valve. Then drive it and see if it continues to smoke.

Smoking at idle and taking off is a tell tale sign of bad valve guides -- I don't think this is the problem, but try disconnecting the valve. In the end, it's probably the rings. You can check for compression and you can expect to find a consistent compression + or - 10%. I have no "real" or "proper" figures, as the compression indicated is a function of the gauge, the speed of the engine, the heat of the engine, and the valve lash.

Hope this helps!

John
EngineCam TimingHello John,

I have a stock 1971 MGB that appears to have jumped a tooth on the timing chain. The engine will start and run but has a pretty bad shake in it (no knocks) and is down on power.

I was pulling away from a light when there was a "ba-bing" noise (sounded more like a spring breaking?) and the roughness shake was immediately apparent. I dove the car home and checked the timing. The timing light showed that it had retarded itself about 20 degrees (no marks on that side to be exact) so I put it back to 14 degrees by the light. The distributor wasn't loose and the dwell on the points was correct before and after whatever happened to move the timing.

My multiple questions are:

1. Have you ever heard of a double row chain jumping? (crude check of the slop in the timing chain shows about 12 degrees of slop without the motor running--assumption that the tensioner isn't pressurized when turning the engine with a ratchet,,,)

2. Is the crank pulley a solid steel piece or a harmonic balancer that may have slipped?

3. Is it easier to raise the engine up to get the crank pulley off or is it smarter to drop the steering rack?

4. Other people have speculated that something in the flywheel/clutch may have broken free, creating the imbalance to put the shake in the engine. (Shake is there at idle with no forward movement of the car)

Thanks in advance for any insight you can offer.

Best regards,

Jim
Jim,

In my nearly forty years of servicing MGs, I've yet to see a timing chain slip, so I doubt that is the problem. There is a method for checking cam timing:

Set the #1 inlet valve to 0.060" instead of the normal 0.015". Roll the engine over, by hand, slipping a piece of paper between the valve and the rocker. When the timing mark hits TDC, the rocker should "just" grab the paper. Don't forget to reset the clearance.

Check the compression.

If it IS a tooth off, the engine simply won't run well at all, if at all.

Let me know what you find!

John
EngineGasoline in the OilJohn,

Need to ask for you expert advise and opinion. I'm having a problem with the B.
I haven't really driven it since the trip to Michigan and went to start it this weekend and it is smoke very badly out of the exhaust but even worst oil seems to be coming from every imaginable area of the motor. I check the oil and it is extremely high, well over the full line. When running I have no oil pressure. Any thoughts other than what I already know...something very very bad seems to be happening? Your knowledge is valuable would love to know what you think.



Safety Fast,



Les
Les!

It seems to me that you've got gasoline in your oil -- hence the overfill, the low oil pressure, and the smoke. Do two things, Les: drain the gas/oil from the sump and refill it; disconnect your carb(s) from the charcoal canister and try to purge the gasoline vapors from the canister.

Give me a call, Les, and let me know how it's working out!

John
EngineHi John,


I have a question regarding oil changes for my 74 MGB. I live in Orillia Ontario and drive the car only about 200 miles a year. (for the time being until my 2 year old can come with me!) With this mileage in mind how often should I change the engine oil and filter?



Thanks for your help!



Sincerely,



Andrew

Andrew!

The rule is: change the oil just before storage. This prevents the acids in the oil from eating away at the bearing material. But, gosh, after only 200 miles a season, I'm sure that an annual oil change is probably excessive. But I'd do it every other or every third year if I were you.


John
EngineMGB Oil Change RuleHi John,


I have a question regarding oil changes for my 74 MGB. I live in Orillia Ontario and drive the car only about 200 miles a year. (for the time being until my 2 year old can come with me!) With this mileage in mind how often should I change the engine oil and filter?



Thanks for your help!



Sincerely,



Andrew

Andrew!

The rule is: change the oil just before storage. This prevents the acids in the oil from eating away at the bearing material. But, gosh, after only 200 miles a season, I'm sure that an annual oil change is probably excessive. But I'd do it every other or every third year if I were you.


John
EngineSearching for Supercharger for MGAJohn,

I am looking for a Judson supercharger for my 1961 MGA 1600 coupe. Can you help? Or point me in the right direction?

Thanks.

Jim
Jim!

The only reason you would choose the Judson over the new Moss one is because you want to add only period devices and accessories. The Moss blower is SO VERY MUCH better than the Judson -- hands down!

If you haven't already, contact Carl Heideman at Eclectic Motorworks in Holland, Michigan. He knows the name of the US expert on Judson units.


John
EngineModern Oil Lacking?Dear John


No doubt you are aware of the problem being talked about, that the formula for modern oil is lacking various ingredients considered essential for our older cars? I am the original owner 1974.5 MGB GT (my only car/regular driver), and I have just had a new engine installed in her; I'm particularly anxious not to ruin it! I have heard various suggestions - add STP; add something called "Compcam"; use "Red Line" synthetic oil.......what are your thoughts?

Whenever you have time, I'd be very interested to know your opinion, please?

Many thanks.


Ruth
Ruth!

You SURE want to have enough ZDDP in your oil at startup! Where to find it? Red Line has enough; Castrol makes a racing oil with enough; or you can call David Anton at APT (or contact them through APT-FAST.com) as he sells excellent cams and must have this stuff on the shelf.

I am still uncertain as to the veracity of the original complaints and if they are as dire as some state, what the proper plan of attack is. My Castrol rep tells me that their racing oil is good.

Hope this little bit helps.

John
EngineSuitable Replacement Valve Stem SealJohn,
Hi. I hope you had great holidays. I haven't sent you a question in a few years, but I sure would like to know what valve stem seals your shop uses when rebuilding MGB cylinder heads. I've heard the little o-rings that came w/ my rebuild kit aren't the way to go. Any recommendations with manufacturer and part number would be very helpful at this point in my project.

thanks in advance.

- Dan



Dan

We use Felpro SS 70373 which fit some sort of Chevy truck. They are
the perfect replacement for those little O rings, which, while better than
nothing, just don't do a very good job.

Be sure to have your machine shop open the bronze-silicone valve
guides (if you're using those) to 0.002 instead of 0.0005 or the valve stems
will gall.

Hope this helps!

John

EngineMGB Oil LeakI currently have three MGBs, a 1968, 1978 and a 1980. On two of the MGs I am having issues with dripping oil from the bottom of the overdrive. (The cover that hold the wire screen filter). I have replaced both of the screen filter/gaskets and I continue to get seepage through the small bolts that hold the bottom plate of the filter cover. ) have tried using Teflon tape with no success) I dare not over tighten the small machine bolts due to possibility of stripping out the threads. This dripping is causing my wife to give me grief about stains in the garage and on the driveways. Short of using a sealer what would be your guidance? Is there a particular sealer you may suggest or is there something I should be looking for or am doing something wrong? This is a common, passive leak. Some of the suppliers were, for a time, providing a low quality mesh screen (not the heavy gray gasket material laminated around the screen but a very light tan colored paper type of filter) -- and those are more prone to leak. You can reduce the leaking by surfacing the bottom plate with fine sandpaper so that it is flat to start. I use grease on the filter faces. You can use RTV silicone sealant on the threads of the bolts -- a liberal amount of sealant - which will ooze into the cavities and stop most of the leaks. You can use that same type of silicone sealant on the face of the gasket/filter, but use it sparingly, and in lieu of grease.

Another option is to purchase several large size trays, like pizza pans, and fill them with oil absorbent or kitty litter. This will pick up the oil before it hits the concrete in the garage. Dish detergent (Cascade) will work well to remove the existing stains from concrete.
EngineEngine Break InCould you please direct me to info about the break in of a newly rebuilt engine. I am having trouble finding any. There are a couple of things here. First, make sure you have added extra ZDDP into the oil. This will protect the cam during run in. Then, get oil pressure BEFORE you start up the engine -- FOR SURE! Remove the plugs and spin the engine until the oil pressure gauge blips. I always leave the valves very loose -- something around 0.020 to 0.030 during the run in process. Run it at 2-3000 rpm (whatever the cam mfg asks you to do) for about half an hour. Then re-torque the head and adjust the valves to 0.012 or 0.015, whichever the cam mfg asks for. Never walk away from the engine -- that's just asking for trouble!
EngineCam Duration, Lift, and Timinghello, I have a problem, what cam duration, lift and timing would work for my engine setup? The cam will be reground to my specs. The lifters are the later short lifters with tubular push rods.It is bored .060 over, with the dished pistons, the rods are lightened and polished with ARP hardware, everything is balanced and the flywheel has been lightened some (but I don't remember how much). It will be using a long center branch header with a 1 7/8" or 2" exhaust into a Supertrap. I have a pair of 40DCOE Webers for it. Any ideas on baseline jetting just to get it started? Also what is the minimum clearance between the cam and the rod bolts?The rods are not the angle cut early rods. Remember that the crossflow head does not flow better than the original cast iron head until you exceed about 5000 rpm -- after that, the crossflow is really the nuts. Therefore, it's not any better for "regular" driving. Purchase your cam for the rpm range you'll be driving the car. If you are going to be using the car on the street, then I wouldn't go much more than about 270 duration. You can ask for a little higher lift (original spec is 0.265 at the cam), but the more the lift, the shorter the life of the cam. Don't forget to use ZDDP ad an additive when you change the oil. If I can find the chart, I'll include the camshaft specification sheet today -- if I cannot find it, I'll try to send it along tomorrow.
EngineMGB Rear Oil Seal Leak Per our conversation this morning, appreciate if you could email the
information in regards to the 1971 MGB rear crank oil seal replacement and
the reason for the engine oil leak from the transmission housing (*behind
the oil sump cover).

Also, do you have a copy of the repair/shop manual on a PDF file that you
could email me?

Hope I could replace the rear crank oil seal without removing the crank
shaft. the engine No# 18GB-U-H-67858.
There are two reasons that the rear oil seal is leaking on your MGB engine.
The inside of the engine may be pressurized because the front tappet cover
ventilation hose is plugged; or the seal/crankshaft may be faulty.

If the seal is faulty, the crank may be faulty too. If the seal surface on
the crankshaft is grooved, repair it with a speedi-sleeve from Chicago
Rawhide -- CR 99350. Install the speedi-sleeve backwards to the
instructions.

To gain access to the seal you will have to remove the engine from the car.
Remove the clutch, remove the flywheel, and remove the rear engine bearing
plate. You will need a new gasket for the rear of the engine. You should fit a new clutch.
EngineMGB Valve GuideHope you can help me. I had the head rebuilt on my 69 MGB with harden valve seats. The engine ran fine for a few minutes then started skipping. I removed the valve cover only to find a valve stuck open. I removed the head and took it back to the machine shop. The machine shop is a reputable shop with an excellent reputation. He checked the head and polished the valve stems and checked the valve guides. I reinstalled the head and it worked perfect for about 5 miles then it started skipping again. I removed the valve cover only to find another valve stuck open. The valves are adjusted cold to the specification called out in the owner’s manual. I have removed the head again and plan to take it back to the machine shop. The oil was changed as part of the head work and the engine averaged around 60 PSI of oil pressure. I have been working with MGB’s for many years and have never had this problem. Have you every experienced this problem?

______________________________________

Thanks for your assistance. I spoke to the machine shop about the head and he told me that he had to replace all the exhaust valves because they were rubbing the guides. The new guides were the cast iron type with a smooth guide surface. He told me that he plans to cut ridges in the guides and taper the lower part of the guides (apparently they were flat on the bottom). The new guides were from Federal Mogul and appeared to be cut differently from previous guides for MGB according to the machine shop. He also plans to open the valve guides some and install the small o-ring on the valve stem. Hopefully this will correct my problem.
The problem you have is with the valve guide, not the valve. There are two types of valve guides: cast iron and manganese bronze, the latter type are a coppery color. The cast iron guides require half a thousandths clearance between the valve stem and the inside of the guide; the manganese bronze require four times that, or 0.002". The little O rings are not sufficient to control oil consumption, so with the manganese bronze valves especially, use FELPRO umbrella oil seals SS 70373. Your problem is not uncommon at all -- you only need to open up the valve guides some.

______________________________________

Do NOT use the small o rings! Use the FELPRO SS 70373 umbrella seals.
EngineBugeye Sprite EngineI have had my 1959 Bugeye Sprite since 2003 and have done nearly all my own repairs. This winter I am pulling the engine and transmission to install a ribcase in place of the smooth case. With the engine out (0.948 liter) I am inquiring what the cost may be to have the engine evaluated, cleaned, painted and all gaskets and seals replaced to prevent (preferably) oil leaks. As of present, the engine operates admirably, but I want to improve its reliability. This is not a racing car but a hobby car and reliability and economy is the goal. I have checked the compression and it is not significantly out of spec. The car does not burn oil. A separate cost to have rings replaced and the valves/seats improved would be appreciated.

The condition of an engine is a function of four factors: Compression; Condition of the camshaft; Oil Pressure; and Oil Consumption.

With the engine out of the car, the oil pressure cannot be determined. With the engine out of the car, oil consumption cannot be measured. The compression is easily checked. The condition of the cam only requires that the rocker assemble is removed from the head and a dial indicator used to check the cam lift.

The bugeye has several areas that can leak oil passively; several from which it can leak under pressure. The front seal was originally felt -- a rubber lip seal is the best to fit there. The valve cover gasket can leak easily -- but that's just a cork gasket replacement. The side covers can leak -- again, those are cork seals. The sump gasket never leaks unless it was installed incorrectly. The rear engine seal is a very different matter altogether.

The rear seal is a slinger -- a scroll thread on the crank that screws the oil back into the engine. To ensure this is working correctly, the engine must be completely disassembled, the bottom end of the engine align honed or align bored, and new bearings installed.

Offhand, a "complete engine" rebuild would be in the neighborhood of $4500.
EngineMGB Moss Oil Filter Adapter I have a Moss Spin-On Oil Filter Adapter that came installed on my 66 MGB
when I bought it. I'm having trouble with the hex bolt interfering with
the
top of the filter and jamming the filter into the hex bolt. Then, it's
very
difficult to remove the filter, and when you eventually do, the hex bolt
comes out with it. This problem is documented on the web at MGAGURU.com.

I'm trying to use a NAPA 1516 (Wix 51516).

Just wondering if you know of another filter element that works better
with
the Moss Adapter?
I am no fan of those spin on adaptors, that's for sure! The best
way to take care of this problem is to take the adaptor to a friend or shop
with a lathe and reduce the thickness of the nut. Our experience has been
that the nut holds the filter proud of the sealing surface and allows the
filter to leak!
EngineBearing WiggleSince 1980 I own (and sometimes drive...) several Morris Minor's, Austin A40's and MG Midget's; and never had a problem with front bearings, till recently, as my A40 developed (probably due to electrocemical corrosion in the metal after a very long idling period) a rumbling in the left front wheel bearing. I orded a new set of bearings (ball bearings, open on one side, you can take out the inner races) from a reputable source, put them in the car ("thrust" on the outer race facing to each other, not forgetting the distance piece), but now I have a more than noticeable backlash in the hub because there is no way to adjust the bearing's preload, like you have shown in the MGB's hub with the aid of adding/extracting shims.

Of course I do not want to waist your time, and I can only please you to give me a hint - I had believed from myself that I know everything on these A-series equipped cars, because I had done all thinkable work on them...but this time I am really out of ideas. Or should I simply install a new set again and say to myself the old ones were defective...but I like to know the reason! Here in Austria the people who worked on those cars (or at least owned one) are long gone, so there is nobody to ask...
It is not uncommon for the outer race to wiggle in the housing. The quick fix for that is to use a prick punch and make about 200 little dimples on the inner hub surface.

If the bearings do not fit closely enough together, then remove CAREFULLY some of the length from the distance tube. If you take off too much, you'll have to find a shim to make up the difference. This is a tedious method since you have to assemble, measure or feel, disassemble, shorten the piece, reassemble...... Use oil when you are setting it up -- grease it only when you are done.
EngineAnti Run On Valve The B was running fine when I drove to my friends house to have him help
me
install a Pertronix electronic ignition. When then decided to take the
distributor completely out and really give it a good cleaning. In the
process of removing the distributor we accidentally broke off the nipple
connection to the anti run-on valve. To be honest I am not certain the
electrical connections to the top of the anti-run on valve were connected
for many years so I was not too concerned that we had lost the nipple.
My
friend felt bad about breaking off the plastic nipple and he decided to
at
least correct the rather loose wires at the top. During this process of
getting good electrical connection he noted that the switch (noted in the
photograph at about 2:00) got extremely HOT so much so that he
disconnected
power to the switch (also in the photo).

My questions, which I am willing to call in if your would prefer, are:

1. What could be causing the valve switch to get so hot?

2. The anti run on valve is about $90.00 from Moss. Is this something
that
is really needed or just part of the 70s attempt to satisfy emissions
standards ? As I mentioned I really think the electrical connections were
not good before my recent activity.

3 The B now runs very rough, and is sluggish with frequent backfire
through
the carbs. Is this most likely a result form the Pertronix install, the
lack of connection to the Anti-run on valve, or possibly all or none with
other causes?

3.4 My next steps will be to isolate any vacuum leaks and the re-balance
the
carbs. Does the install of the Pertronix mandate a re-balance of the
carbs
in and of itself ? Do I need to wait until after I receive and install
the
new anti run-on equipment before doing the carb balance?
The anti run on valve wiring is HOT only when the key is OFF --
unless the two in-line fuses beneath the fusebox have been connected
crisr-cross (slate with brown / brown with slate). The switch is grounded
ONLY when you have oil pressure -- unless the oil pressure switch is the
normally closed type (as used on oil pressure lights).

Set your timing at 32 BTDC maximum with the vacuum disconnected.

The anti run-on valve is not critical -- sometimes you can make a
fix by heating a 3/16" section of copper tube (or 1/8") and pushing it
into
the hole that was once the nipple. Allow it to cool. Then replace the
hose. connected or not it will not cause the car to run poorly.
Engine1969 MGB Spin On Oil FilterWe met briefly at MG2008 this past summer and during the rolling tech session you suggested I change my oil filter from the inverted Tecalemit cannister to a spin-on type. I seem to recall that the benefit for converting would be faster time to reach proper oil pressure. Right now, when I start the car, the pressure hangs low for 5-6 seconds, then goes up to normal (60-75lbs) at 1000 RPM idle.

I have a 1969 MGB and in looking at the various catalogs, I'm somewhat confused as they don't mention a provision for an oil cooler (which I have on the car). The Moss catalog lists P/N: 460-910 as the filter head and my question is.....will this have a connection for the oil cooler hose? I'm probably making this more complicated than need be, but just want to be sure.

Also, is this type of job doable for a relative novice such as myself?
The oil filter setup you have is the worst one. You would be better off going to a scrap yard and finding one. If you can find one on EBay it will be better quality than the one from Moss. However, if there is not one on EBay, the one from Moss would be better quality than the one you have.
EngineSmog SystemI purchased a 1974 1/2 MGBGT ALL ORIGINAL AND IT WAS NOT RUNNING TOO WELL BUT WAS RUNNING. I DECIEDED AFTER TRYING TO TUNE IT THAT I WOULD HAVE A VALVE JOB DONE. OF COURSE I TOOK OFF ALL THE EMISSION CONTROLS IN THE PROCESS AND SINCE ALL THE ORIGINAL HOSES WERE CRACKED AND SPLIT I DECIDED TO LEAVE THEM OFF FOR THE TIME BEING. I LEFT THE ANTI RUNON VALVE ON HOWERVER

I GOT MY HEAD BACK AND INSTALLED IT AND ADJUSTED THE VALVE TAPPET CLEARANCE AND PUT THE SU HIF4 CARBS BACK ON.

I STARTED THE ENGINE AND AFTER ABOUT 30 SECONDS I SHUTS OFF AND IT SEEMS TO BE FOR LACK OF FUEL BUT IVE TRIED EVERYTHING I CAN AND IT STILL SHUTS OFF MAYBE YOU HAVE THE ANSWER

PROBLEM NUMBER TWO IS THE WARNING HORN GOES OF UNDER THE DASH I TH INK IT MAY BE THE SEATBELT ALARM . HOW DO I JUMPER THIS OUT. BRYSON LESLEY SAID U HAVE A QUICK FIX.



The seat belt warning buzzer is the easier of these two problems. Remove the column covers, and pull the purplish wire from the exposed spade terminal on the side or bottom of the key switch. Now the buzzer will be silent.

The smog system is composed of the air pump, the injector rail, and the gulp valve. Block the injector holes with 7/16-20 Allen set screws -- it looks good like that. Remove the gulp valve and bracket. Remove the 90 degree fitting in the center of the intake manifold -- tap that 1/4" NPT and fit an Allen pipe plug -- then it looks finished and won't leak air.

The ELC or Evaporative Loss Control system is helpful to keep in place. I believe this may also be the source of your problems. Let's use the charcoal canister as the starting point. There are three lines at the top of the canister. One loops to a steel line that goes back to the gas tank. Make sure the line is free into the tank -- blow through it and you should feel air/fuel escaping through the filler neck. One runs over to the HIF carbs, to the float bowls. Make sure that line is clear. One fits to the valve cover. Make sure that line is not cracked.

During engine operation, fresh air enters the tube below the anti run-on valve, travels through that valve and into the bottom of the canister. It is drawn out of the canister and into the engine, then out of the engine and into the carburetters (from the front tappet inspection cover hose). In this way, the charcoal within the canister is continually being washed with fresh air and the unburned hydrocarbons (gasoline) is purged from the charcoal. If the canister plugs up then the engine places a vacuum in the gasoline tank and in the float bowls and the car will quit running. That's just what the anti run-on valve does when you turn the key off.

The anti run-on valve is HOT when the key is off and is grounded only when there's oil pressure -- that's in those two to ten seconds after you turn the car off. So the valve only works for a couple of seconds. You can hear is CLICK off after you've turned the key off and the engine quits running. When the valve operates, it blocks the free flow of air and the canister begins to evacuate. Further, by the valve's operation, manifold vacuum is routed to the canister which creates a tremendous depression. That vacuum is transferred over to the carbs, on top of the gasoline in the float bowl. Now the vacuum created inside the carb at the jet is not enough to draw gasoline from the float bowl and the engine stops dead.

I suspect this may be occurring to your car right now -- not properly -- but from incorrectly connected hoses or a plugged canister.

EngineNew Motor Oil As you know, several reports have appeared recently in British car publications (e.g., MGCars.org.uk) stating that reformulations of commonly used motor oils are resulting in very serious damage to our British engines.

Please let me have your thoughts about his issue, and your recommendations on how I and other MG owners may deal with this problem.
I have spoken with a rep from Castrol; I have Googled "ZDDP engine oil;" and I am reading as much as I can, as quickly as I can. I do believe that I'll include my thoughts on the matter in my next UML mailer. Right now, it would appear that this compound is critical at new engine break-in (hence the special grease provided by the cam manufacturers), and less important as the engine ages.

The company rep from Castrol told me "not to worry," but that didn't set my mind at ease.
More information follows.
EngineSnaped Timing ChainCan a snapped timing chain ever physically jam a crank shaft from rotating?

It is my last hope before I start pulling the engine.
If the chain has snapped, you usually have some free movement of the crank, maybe not 360, but some. The chain cannot snap by itself, and in the ONE case I've seen of a snapped chain in my 35 years in this trade, it happened at speed -- and the force of the engine carried the chain into and out of the timing cover -- it was a terrible mess.

Before you pull the engine, please give me a call so we can go over the possibilities.
EngineChanging Valve GuidesIn the Bentley Manual it states that you can replace the valve guides by driving them down into the combustion side of the head. After 30 some years of these parts being in the head. Just how easily is it to remove these guides with a drift without damaging the head? Would a hydraulic press work better?There are two reasons why I would like to remove the guides myself. First I live on the Outer Banks of North Carolina where there are no machine shops. The nearest machine shop is around 70 miles one way. The second is the price given to me. $350 and I supply the guides. I should have added a third reason. Which is the workmanship down here isn't the greatest. If you want something done right you need to do it yourself. Which leads to a good self education in the skill trades. Why people down here except the poor workmanship I do no! t understand. I did take an engine I am planning to rebuild to one of the best (I am told by our club) machine shop up in Virginia Beach, Va for cleaning, cam bearing replacement and to have the crank reground. That was March 7, 2007. As of today I am still waiting for it to be done. I have never done any cylinder head work myself -- I've always sent it off to our machine shop. The machining is a critical process, as you well know from the descriptions you've given. We do not have the machinery to rework the cylinder heads ourselves. I would suggest that you find a good shop for this work -- so I'll make a pitch for our services. We (with our machine shop) can completely rework a cylinder head for an MGB for about $550. Whoa! That's $200 more than your local shop charges. Here's why: the head is baked (not boiled in caustic soda) and then shot peened to remove all the external scale and carbon; the guides are pressed out; the new silicone-bronze guides are pressed in and reamed; new seats are installed on the exhaust (hardened, to prevent valve recession); the head is crack checked (that's probably just after the cleaning!); the head is surfaced; and there is a triple angle cut placed on the valve seat -- plus there are umbrella oil seals installed to prevent the oil from leaking down the guides. This is a common and frequent repair for us. For an additional $300, the shop will port and polish the head to give you more power. The workmanship is excellent and we're only a UPS shipment away.

If you are doing this job yourself, you might consider not even changing the valve guides but simply installing the Felpro Seals SS 70373. If you do install new silicone-bronze guides, be sure to have them opened to 0.002" (instead of 0.0005" as the workshop manual suggests). New valves are not necessary and sodium valves, stainless valves, etc are simply not worth the extra money. It's those hardened seats which make all the difference!

I would use a press and a shouldered mandrel to remove the guides -- but I would not be concerned about the time they've been in place -- that shouldn't make a difference.
EngineMG T-type Manifold ColorI have a question that I thought that you could help me with. The T Type exhaust manifold
that we generally have aluminized, getting that white color, what was the coating originally?
Why was it there? Many british cars did not have a coating.
When asked about the "original" color on the manifolds, I usually reply "rust!" But, you're right, the original T type manifolds were aluminized. We've found that Jet Hot Coating is a really excellent method of protecting the manifold -- and making it look really great. There are a variety of colors from black to silver to purple. You can Google them and get an address. We just got some back for a Jag XKE which were originally porcelainized. This jet hot coating looks SO much better and will last far, far longer!
EngineMGB GT Exhaust UpgradeI am looking for advice on which exhaust system to
replace the Moss SS system I have on my 67BGT. I am
experiencing gobs of back pressure from my present
system(it can knock down walls at three feet from
the exhaust tip).
It has been suggested that replacing with a bigger
bore I will enjoy better acceleration and power.
Which of the systems do you think best and where do
you recommend I shop?
Ansa, Monza, Peco??
You won't easily believe what I have to say here, but Carl Heideman's numerous dynamometer pulls bear this out: "Big Bore" exhausts make nary a difference in power.

But, for looks, for sound, and for durability, the ANSA!

For power: a good tune-up; electronic ignition (2 hp); MSD ignition (as much as 2hp); port and polish on the head (as much as 10 hp); the Moss blower (30 hp). These all are about $100/hp.
EngineEngine InstallationI am currently having my engine rebuilt by Kent Prather, stage 2 to 3. I am very excited to get it back soon he is almost done. Any suggestion you may have upon install would be greatly appreciated. Kent will put the engine on the dyno and then it should be ready to go.
Make sure that Kent uses grease on both sides of the cork sump gasket. You will have to remove that sump to insert the engine into the car, unless the body is off and the toeboard is out. Grease on both sides allows the sump to fall away easily once the bolts are removed without damaging the gasket. I know! I had the sump off this one twice!
EngineMGB Sidecover GasketI've recently (within the last two year) completed a 99.9% restoration, and dont like the way my front tappet cover is affixed. Since purchasing the car in '92, I have had multiple oil leaks, yet after rebuilding the engine only the front tappet cover has leaked more than other spots.

I replaced the origonal front cover with a more planer unit purchased from Motorhead (Fairfax, VA) and used excessive amounts of RTV...but I'm afraid if I hit that breather hose, I'll knock the cover loose.

Do you sell a unitary tappet cover replacement for both covers?
Funny your email should arrive right now. We ALWAYS change the side cover gaskets when the engine is out of the car. The trick here is to use a THIN cork gasket -- made for the MGA. Those thick cork or thick rubber gaskets are simply not suitable for the front cover. We get our gaskets from Moss or Engle. We use a bit of clear silicone RTV sealant on both sides of the gasket. On a 77 MGB, you can do the job in place without removing the manifold (although with some difficulty!).
EngineEngine Break-InI saw your pictures of the engine break-in and was wondering how you kept the engine on top of the table – without it roaming all over? I noticed the vice grips towards the front of the oil filter and was thinking maybe you had some mounting system to clamp on to. It would seem that the engine would want to jump around but it doesn't -- it just sits there. Oh, I suppose if you let it run for a while it could, possible, move around -- but just idling it doesn't move at all. If you were going to run an engine on a bench as this for 15 minutes or an hour you could simply strap it down. But, really, I don't think you'll have a problem. I know, it's counter-intuitive.
EngineMain BearingI am rebuilding a 52 TD engine and my machine shop is needing the main bearing housing bore size and what tolerance is allowed . This is for the actual main cap and block casting. The housing diameter is 56.54mm or 2.2177-2.2185".

But the IMPORTANT information is the slinger info -- as that will be what keeps the engine from discharging copious quantities of oil into the bell housing:

Groove on crankshaft: 58.75 -.03 -.07 mm or 2.313 (figure 2.312")
Housing bore 59.00 +.05 -0 or 2.323 (use 2.3185).
EngineTD Valve Angle am rebuilding a 52 TD head with new steelite valves and standard guides and competition springs. My question is I have read a couple different oppinons about valve angle . Should it be kept at the 30 degree angle or cut to the 45 degree angle or what is your best opinnon. Thanks again for your help .

I would keep the 30 degree valve face but make sure your machine shop gives it a triple cut to allow the gasses to sweep around the valve seat with less restriction. But, for the record, I don't do our own valve jobs -- we send them out. We've had any number of heads -- XPAG / XPEG -- ported and polished. I've never asked my machine shop about changing the face. But, offhand, to get a 45 degree face, you'd end up cutting away some of the outside diameter or you'd have to reduce the valve margin -- neither one of them a good idea.
Engine'79 Midget Manifold NutsMy current issue is this... I am in the process of removing the intake manifold on my 1979 Midget. I can't seem to get at those lower manifold nuts. Precisely what wrench can I use to get them loose? Do I need a specialized tool?

All I can suggest is blood, toil, sweat, and, perhaps, some tears! Use an open end 9/16" wrench and move those nuts 1/16 of a turn at a time -- whatever -- until they come loose. Be sure to chase the threads of the stud and nut, and use plenty of grease when you reassemble so that the job goes quickly in the other direction. I assume you've removed the carburetter and the heat shield, as those will certainly slow you down. Let me know how it's worked out!
EngineMG Oil LeakI have a minor problem that I'm hoping you can help me with. My MG, like most tends to "mark her territory" as most MG's do. my problem compared to most is minor in that she only drips from 2 places, the bottom drain plug on the tranny and the drain plug on the rear end. Since these plugs have no shoulders on them do you have a suggestion for stopping the leaks? The only thing I can thgink of is plumber's pipe dope. Don't be too hasty. Follow me through on this. The engine leaks everywhere: from the valve cover filler, the valve cover, the side covers, the front seal, the front engine bearing plate, the rear seal...... About the only place it doesn't leak is the drain plug. What??? They why is the oil on the plug? The oil moves down and back, from gravity and the force of the wind, and ends up dangling from the drain plugs.

Here is a method to find the REAL leaks. Buy the NAPA oil dye which has a Balkamp part number. Pour this into the oil. Use a black light and watch for the leaks. If it's just some slow, passive leaks, you'll have to run the car for a number of miles and then examine it. You'll find the real leaks above the drain plug.

However, the drain plug uses a copper washer (6K638). The drain in the gearbox is a taper pipe thread. The gearbox plug you can silicone or use some Teflon pipe tape on.
EngineMGB Valve LiftYou've answered every question I have about diagnosing problems in my MGB's engine, save one. As I understand it, one of the things I need to check out is the valve lift. I'm not sure how to go about this. Can you clarify this?
The cam lift, on a normal MGB camshaft, is about 1/4". This is amplified through the rocker arm ratio (about 1 1/2 to 1) for a total valve lift of about 3/8". The cam guys will tell you that 0.010" wear on a lobe is too great. That works out to 0.014" at the valve. You cannot even begin to see such a slight difference. BUT, if you can see that one valve is opening less than the others, then the lobe is terribly worn. If the valve is an inlet, you will be underpowered at speed; if the valve is an exhaust, you'll burn the valve (and head) soon. It is VERY uncommon to see any difference in the lift simply by watching them bob up and down, with the valve cover off, at a very low idle -- but IF you can see a difference, it's cam time.
Engine'74 Midget Engine ColorCan you tell me, or tell me where I can find, what the correct engine
color is for my '74 Midget (1275). I seem to be able to find body
colors, but not engine color.
Black. PPG DAR9000. Black. Gloss, semi-gloss, flat? Well, not flat.
Gloss sure looks nice on the valve cover. The earlier engines (prior to
about 1972) were red, a deep maroon red, but the later engines were BLACK!
EngineEngine BearingI have an 1800 3 main engine on which the pilot
bearing spun in the crank. I do not know if the
bearing absorbed the wear or the crank shaft.
What is the diameter of each supposed to be?
I have ordered a replacement bearing from the
usual suspects but I am concerned that it may
be a loose fit in the crank.
You can hold the new spigot bush in place with Locktite. You can scar the inside of the hole with a prick punch and then use Locktite. The bushing should be oilite which is constructed of powdered brass and oil, pressed into shape. Therefore, it's not possible to sweat solder on the outside. Well, that said, you can tin the outside but then you'll have to soak the bushing in hot oil for an hour or so to ensure that it is fully lubricated.
EngineHot Valve Adjustment A little background:, I've owned a 76-TR6 since March (my first British car) and I've been improving the carbs, ignition, etc. over the past few months.

I love working on this car!

I read the 6-Pack forum and everything else I can get my ears and hands on. I especially like your You Tube videos! (my next toy will be an MG)!

Here is the question: Last month I adjusted the valves. The general consensus on the 6Pack forum was to adjust the valves cold. I believe the Haynes Manual also says to adjust cold. After reviewing your video about adjusting valves (where you mention to do it hot), I am still wondering which is best. I know we are talking about a very small difference here, but I am, by trade, a structural engineer and somewhat anal. So I would like to know which is best.

My car is stock, as far as I know, so there is no aftermarket cam in it.

Your thoughts?
The valve lash changes by about 0.001" between stone cold and really hot. Personally, I do not believe that it makes any difference if the valves are set at 0.010" or at 0.012" or at 0.015" as long as they are all set the same. The thickness of a human hair or two cannot affect the valve operation very much! From my viewpoint, the important thing is that the valve lash is the same when the engine is running -- hence my advice to adjust the valves when they're hot.

When adjusting a six cylinder, I watch the first six valves and adjust the rear six. When that's done, I watch the rear six and adjust the front six. Watching the movement of all twelve valves is too much for me! If you watched the YouTube video about adjusting the valves on a TF, which I believe I do in about five minutes, then adjusting the valves in your TR6 shouldn't take more than about eight!
EngineMGB Engine In An MGA
EngineEngine Ticking Now I have an issue for which I could use some direct wisdom.

Here's my problem: I have a '62 MGA MkII with an intermittent, loud
ticking sound that occurs most noticeably at idle, after the car has
warmed up, and seems to disappear at driving RPMs. It's not a 100%
steady ticking, but rather "skips a beat" every now and again. To
start, valve clearances are all as should be, .015 when hot, and
compression is good: 1=180, 2=160, 3=160, 4=160. A timing light shows a
steady 20 degrees BTDC at idle.

At first it was difficult to determine the origination, but I was pretty
sure it was coming from the front of the block. After perusing the Q&A
database, I suspected it might have been a bad pushrod, but further
investigation (using a .010 feeler between the rocker and valve stem
while the car was idling) seemed to rule this out, as there was no
difference in the sound.

Next, using a mechanics stethoscope, I poked around the block and then
ended up by the water pump (having recently installed a new radiator, I
was a little worried something didn't get flushed out before I installed
it and was now living in the water pump). Then I landed on the timing
chain cover and BINGO, there it was. In retrospect, that is pretty much
exactly what it sounds like: a moving chain flapping against something.

So, while I probably seem to have tracked it down, I'm still left with a
few quandaries before I rip out the radiator. First of all, does this
seem likely, for the chain to get loose enough to contact the cover?
And would this suggest the tensioner is kaput? Should I just plan on
replacing the chain and tensioner? And though this is relatively
painless, is there anything else you think it might possibly be? I saw
somewhere else in the database some mention of piston slap, which had
similar symptoms (louder at idle, disappearing at higher RPMs), and
sounds much more dire.
You could take the fan belt off to make sure that its not the water pump or
generator, but it sounds like its the timing chain. There is no substitute
to calling the shop for help. John has his technical hour from 1-2 EST
Monday - Friday.
EngineLow Oil PressureAs a relatively new owner of a 1957 MGA 1500, I’ve found some conflicting information on the subject of oil pressure and was hoping you could help clarify it. It seems that most people I’ve spoken with have recently rebuilt engines so they aren’t necessarily a realistic reference for one that’s got a lot of years behind it. While I’m sure it’s inevitable that I will need to have it rebuilt, I would like to drive the car for at least this season, if possible, if for no other reason than to recharge my enthusiasm after far too many surprises while trying to make the car reasonably roadworthy (but still not much to look at).

I am using Castrol GTX 20W/50 oil with a Fram filter (Moss spin-on conversion). My dual gauge is new, which I hope means it is reasonably accurate. On startup, the oil pressure is around 65 psi. The oil pressure stays reasonably high for some time after the coolant temperature has reached a normal level (180 deg. thermostat), but by the time I’ve run it for maybe a half hour, it is down to around 20 psi or slightly below at 1000 rpm idle and at 40 psi or slightly below at 2500 rpm. I haven’t had it out in temperatures above about 70 deg. so far, so I’m imagining things getting worse as summer gets here. I’m not sure at what point the alarm bells should be going off in my head though. In the original workshop manual, they say the oil pressure should not be less than 10 psi at idle and it should not be below 30 psi at “road speed”. Most of the comments I’ve seen on the internet seem to suggest it should never be lower than 50 psi at 3000 rpm, however, so I don’t know who to listen to.

I’ve had some people tell me it should be fine for a few thousand more miles and some suggestions that adding an oil cooler would help. I’m planning to make a 600 mile round-trip in July to attend GT-33, my first NAMGAR event, but I may reconsider driving it if there’s an imminent catastrophic failure of some kind. Even though roadside breakdowns make for some great fireside stories, I’d rather avoid them and be a boring conversationalist.
Your bearings are bad. Do not drive your car until they get changed. You need to change the 4 rods, center main, and oil pump. All of which can be done from under the car. There is no substitute to calling the shop for help. John has his technical hour from 1-2 EST Monday - Friday.
EngineT Type Engine BearingI have a YB, with a TF Goldstar replacement engine that need building.
My crank is turned to .10 under, and I need rod and main bearings. What kind do you recommend?
Also, there is a set of Vendervell rod bearings in the size I need with a buy it now of 89.00 dollars. Are these good bearings, fair price?
There is a crummy supply of bearings. Vendervell is the best you can get.
EngineT Type Engine ThreadsAfter many years I'm getting ready to assemble my friend's 1954 TF. I'd like to mount the engine on my engine stand. I tried some new BSF 5/16-22 bolts and they didn't quite seem to fit. The one that I tried, with lubricant, went in with just a little more resistance than expected. I didn't turn it in very far, but as far as it went the threads were slightly distorted. So, my question is: Are the proper bolts BSF 5/16-22 and do I need to buy such a tap and chase the threads or is it something else?
I am not quite sure where you want to mount it, but the engine is all metric. I believes you are looking for a 8 X 1.00 Metric.
EngineMG T Series Spin On Oil Filter A bit of discussion on our forum regarding your MGA - No Oil Pressure
video on youtube...

Are the spin on filter adaptors for the T series (moss/grunau) similar to
the MGA spin on? Its been mentioned that the T series bypass valves are
not part of the adaptor, but in the oil pump? Couple people are wondering
if they should have their adaptors machined or changed or tossed? (I
myself enjoy the taste of 20-50 oil as I unscrew bolts and slip my grip on
the stock cannister).
The MGA/MGB spin on adaptors which take the place of the original,
wonderful felt element filters do NOT have the bypass valve in them.
Therefore, once the filter plugs or slows the movement of oil, the only
indication is a lack of oil pressure on the gauge. In my nearly 40 years of
working with MGs, I cannot remember ever seeing a plugged filter.

The XPAGs with the vertical filter have an oil pressure relief valve
between the block and the pump. The XPAGs and XPEGs with the horizontal
filters have an oil pressure relief valve located in the pump housing. I've
seen very few spin on adaptors for T series, but my feeling is that the OP
relief valve works in either case.

The later TD and TF horizontal filters are not so difficult to
change and get lined up -- but the filter on the MGAs and early MGBs -67
have TWO housings which must be seated. Unseated, it's possible to dump the
full four quarts on the floor within about 30 seconds -- I know!
EngineRemoving a Broken StudI was preparing to adjust my valves by loosening and then retorquing the head nuts to 50lbs as you tought in class. Using my cheapo Harbor Freight torque wrench I snapped the stud almost flush - there is about 1/8 inch of the stud still visible.

I could try to enlist a friend to bring welding gear to my garage and try to weld the nut back onto the stud.

Would another option be to just remove the head assuming the head itself isnt threaded? If I removed the head I should be able to remove the stud just using some pliers. Is removing the head as simple as just removing all the nuts and pulling it off or am I going to be creating other complications? Would I need to replace the head gasket? Any other parts?
If some of the stud is visible, then welding to it is certainly acceptable. Another option is to drill it (start with a 1/8" bit) and then eventually thread it with a tap, then fit a bolt and jam nut and unscrew it. Another option is to drill it with a pilot, then use a reverse drill which will eventually grab it and unscrew it.

If you do remove the head, it's not so bad of a job (and you can clean the combustion chambers). You WILL need a new head gasket at least.

Let me know how you repaired this!

Some of the new studs are not very strong at all -- and some of the inferior wrenches are terribly inaccurate.
EngineEngine Identification TagsA mechanic friend recently inherited a 1967 MGB-GT that he is
rehabilitating. He would appreciate information that would help him locate
all the identification tags in the engine compartment or replace the missing ones.
There is a tag on the engine: 18GB U H ...... between the second
and third spark plugs. There is a tag to the right of the radiator on the
right inner fender, screwed in place with the VIN eg GHD 3L ....... There
is a tag welded to the body on the left side of the rad (opposite of the VIN

tag) with the body number eg MGB......... Once you have the VIN, you can
write to British Motor Heritage at Gaydon in England and purchase a copy of
the production information.
EngineFixing MGB Compression About six months ago I bought a 79 B and drove it back from WI to LA. The engine has about 3k on an rebuild. It has a 45 DCOE and had the small foam air cleaner which I found had totally disintegrated. My first thought was to run a compression check and found pressures in 1 and 4 to be 110 & 100 respectively. Cylinders 3 & 4 are 130. The previous owner threw in a pair of SU with K & N's, needless to they are going on as soon as this is resolved. It looks to me that a set of rings maybe in order. What are you thoughts?
I would start with the head. You need to find where it is leaking, start by torquing the head and adjusting the valves. Please call during my tech hour so I can explain what to do.
EngineMGB Engine RestorationI have a ’71 MGB with 18GK engine that was put away in a shed for about 25 years. The engine was overhauled to some degree sometime before it was parked in the shed. No special preparation for storage, other than draining the cooling system, appears to have been done. The owner had considered restoring it himself and did replace rotors, pads, drums, shoes, wheel cylinders, clutch cylinders, and a few sundry parts before deciding to let the project go to the highest bidder …….. namely me.



The engine had not been run for 25 years, so I did a compression check and found #4 cylinder near 0 psi. I decided that it would be best to pull the engine/transmission and thoroughly examine the internals since it was likely parked for 25 years with old, dirty oil in the crankcase. I found the cam and crank in very good condition, but the bearings show what I believe is deterioration from acids in the old oil (flaky, spotty, blotchy appearance).



My main concern at this time is whether I should rebore the block since the piston skirt to cylinder wall clearance is about .004 inch. I think the spec is more like .001 to .002 inch. Is that correct? Do I need to have the cylinders bored out and install new pistons? I’ll probably never drive the car more than a few thousand miles a year, if that much.



The low compression on #4 cylinder was due to a rusty exhaust valve and seat. The exhaust valves in particular show wear from the valve seats. Is it best to have hardened seats and stellite exhaust valves put in now or would a simple regrind be sufficient for a car that will only be driven a couple thousand miles a year?



In the end, I still want a dependable engine, so I’m not afraid to invest what’s necessary. What’s the best way to go here?

All engine work is expensive, so my approach is to make the engine run first, take it on a long drive and then rate the engine by these four considerations: compression; oil pressure; oil consumption; camshaft condition. Had you started it up, you probably would have found that it ran well. You then could have changed the bearings and redone the cylinder head. But all's not lost!

I'm assuming you have the engine pretty well apart. You will want to cut the ridge and hone the cylinder walls, first with long stones to ensure parallel surfaces, then with a glaze breaker to achieve a 60 degree crosshatch. The clearance you find is just fine. You will want to fit new rings and all new bearings, along with an oil pump rebuild kit.

When you send the head out for a recondition, be sure to have it crack checked, surfaced, hardened seats installed on the exhaust valves, new guides installed, and umbrella seals fitted. Spend the extra $500-$600 and have it ported and polished to achieve a little more power (about $100/horsepower).

My tech book has a step by step instruction for rebuilding the engine -- you might find that helpful.

If you have further questions, please call during tech time. Good luck with your project!
EngineMGB Rear SealGot a quick question. I am now rebuilding a '68 MGB whose engine had been rebuilt several years ago and has good compression. It leaks oil from the rear of the engine - leaves a spot about 5" in diameter each time I park it after driving. Sounds like a rear main seal. But here's what's strange. I put the car up on ramps, had it idling while I lay underneath, and watched for oil dripping and never saw anything! Waited about 10 minutes with engine idling. So, appears not to leak while running but only after shutdown.

Any ideas? Like to avoid removing the engine if not required.
If the engine is leaking from the rear seal, it is doing so for one of two reasons: 1) the engine is pressurizing and oil is blowing out wherever it can (including the rear seal); or 2) the seal and/or crank is faulty. If 1), then the engine won't leak idling because the internal pressure is not great enough. If 2), then while it is leaking, the oil is being flung onto the inside surface of the bell housing and won't drool down for a while (after the car is shut down).

So, I would check the front tappet inspection breather hose. Remove it from the Smith's PCV valve and blow into it to make sure that you can move air through the hose and front cover and then have it escape from the filler cap. Second, I would make sure that the Smith's PCV valve is clean. If all that's OK, then the sad truth is that you'll have to work with the engine. Until then, keep a large pizza pan in the garage filled with oil dry or kitty litter -- and make sure to keep adding oil!
EngineNon-Original ExhaustMy '79 Midget has an old performance header (four welded once stainless pipes) which is still in good condition. A flange was made up to connect the balance of the exhaust system which slipped over the header...very poorly! It leaks badly and needs to be replaced. I find exhaust systems available through Moss or VB but only with a flange for the 1500. Can you suggest anyplace to or anyone to resolve the problem. I was going to try to weld a piece onto the conventional pipe after removing the flange but have been unable to find anything locally which will fit the header and the pipe. I hate to bother you with this but YOU ARE THE GUY WITH THE ANSWERS. We have an exhaust shop right down the street. When we get into a jam -- non original parts -- we take the MGs there. The one fellow on site does a wonderful job. You probably have a shop like that near you.
EngineMGB Screaming NoiseOur MGB motor (USA MGBLE 03-1979) is producing a very high screaming noise.

It seems the crankshaft is causing this noise. If we turn the shaft by hand the noise is also being produced.



We've made a 1 minute video. Is it possible to indicate the cause of this noise by listening to the video noise.

Please be aware that on the background there is an additional noise of a shipping motor to be avoid.

The case is the high screaming noise.

The video is to be seen by clicking on the following link:



http://nl.youtube.com/watch?v=--XX4PZgpdQ



Can you give us an idea what causes the screaming sound?

Appreciate your cooperation in this.
Your video was very helpful! It was a wonderful idea to use this medium so I could listen. I will encourage others to use You Tube the same way you have.

If the gearbox was in gear and not turning, then I would suggest that the problem is that the spigot bushing or pilot bushing has a burr, a lip, or is distorted so that the bushing grabs the first motion shaft of the gearbox. This is very common on a rebuild and occurs only when the clutch is depressed (engine turning, gearbox not turning), and when it is cold. Now there are two crankshaft bushings, one very much longer than the other. You have not said that you have rebuilt the engine, but it looks very fresh and the engine ID tag is missing. Did you change the spigot bushing? To repair this problem, you will need to remove the engine and sand the inside diameter of the bushing -- perhaps put just a wipe of grease in it for lubrication.
EngineMG T Type Manifold Hardware and Jet CoatHaving removed the carbs I decided this would be an excellent time to have my
exhaust manifold "Jet-Hot" coated to reduce engine compartment temp.
(Discovered a really nastie looking weld hiding on my exhaust manifold....ground it
down re-welded & bead blasted it...)
I was wondering if you have (or know of a source) were I could obtain new
stainless steel studs and brass nuts for :
Manifolds to engine block / Carbs to Intake manifold / Exhaust manifold to exhaust.
I am a little Leary about obtaining the proper threads from the boyz @ my local NAPA
store for these!
Remember that those threads are 8x1.00metric in the cylinder head; and 10x1.50metric on the bottom of the manifold. I have not used stainless in these applications. Have you tried McMaster's in Chicago? We have changed from using brass nuts to using "prevailing torque" nuts -- especially on the bottom of the manifold. These are easily available.

Be sure you have the manifold "Jet Hot Coated" and not simply "Jet Coated" -- we've just ground off the "jet coating" to smooth the manifold for the "jet hot coating." I expect you're using the firm in Pennsylvania -- if you're dealing with someone else, call me for the 800 number for the firm I'm using.
EngineMGTF Cylinder BoreI am restoring a MGTF1500 with I bought here in Holland with a 1250 engine in it. You gave me the name of Gregg Purvis on the beginning of this year. Gregg did find one engine in parts and that looks good, but it was expensive with the transportcosts to Holland.
I was lucky to find a 1500 motor here in the neighbourhood.
This motor has the following pistons L57 AEF119 TO SUIT +0,030 BORE , the diameter I meassured on one piston was 72.75 mm. This should be 72.763 mm.
Can you tell me which max. cylinderdiameter belongs to this pistendiam.
About the XPEG: You know, all the basic measurements are metric. Hence the bore of 72mm and the stroke of 90mm yielding 1466 cc. However, since the engines were supplied in countries which used inches as the basic measurements, nearly all overbore and undersizes are in inch increments.

A 0.030" overbore is 0.762mm. That means that the piston should measure 72.762mm less the bore clearance of some 0.005" or 0.127mm or about 72.635mm. The difference between your measurement of your piston 72.75mm and my calculation of 72.635 (the calculated piston size for a 0.030" overbore) is 0.115mm or about 0.005 -- which could be errors in measurement or errors in piston to bore clearances.

The book gives a clearance at the thrust face of 0.0021-0.0024" (or 0.053-0.061mm). So, I would bore the block at 72.75mm + 0,057mm or 73.32 72,807 mm. (I think this was a little fault the red will be the bore.)

But, in the end, go with the suggestion of your machine shop.

Do not miss the most important part of the machining -- and that is align boring or align honing of the block and sizing the rear slinger to run 0.007" or 0.178 larger than the scroll thread on the crankshaft. The main cap diameter should be 56.54mm.
EngineBroken Head Stud I screwed up!

I was preparing to adjust my valves by loosening and then
retorquing the head nuts to 50lbs as you tought in class. Using my
cheapo Harbor Freight torque wrench I snapped the stud almost flush -
there is about 1/8 inch of the stud still visible.

I could try to enlist a friend to bring welding gear to my
garage and try to weld the nut back onto the stud.

Would another option be to just remove the head assuming the
head itself isnt threaded? If I removed the head I should be able to
remove the stud just using some pliers. Is removing the head as simple
as just removing all the nuts and pulling it off or am I going to be
creating other complications? Would I need to replace the head gasket?
Any other parts?
If some of the stud is visible, then welding to it is certainly acceptable. Another option is to drill it (start with a 1/8" bit) and then eventually thread it with a tap, then fit a bolt and jam nut and unscrew it. Another option is to drill it with a pilot, then use a reverse drill which will eventually grab it and unscrew it.

If you do remove the head, it's not so bad of a job (and you can clean the combustion chambers). You WILL need a new head gasket at least.

Let me know how you repaired this!

Some of the new studs are not very strong at all -- and some of the inferior wrenches are terribly inaccurate.
EngineValve LiftHi, your YouTube videos are fantastic! You've answered every question I have about diagnosing problems in my MGB's engine, save one. As I understand it, one of the things I need to check out is the valve lift. I'm not sure how to go about this. Can you clarify this? The cam lift, on a normal MGB camshaft, is about 1/4". This is amplified through the rocker arm ratio (about 1 1/2 to 1) for a total valve lift of about 3/8". The cam guys will tell you that 0.010" wear on a lobe is too great. That works out to 0.014" at the valve. You cannot even begin to see such a slight difference. BUT, if you can see that one valve is opening less than the others, then the lobe is terribly worn. If the valve is an inlet, you will be underpowered at speed; if the valve is an exhaust, you'll burn the valve (and head) soon. It is VERY uncommon to see any difference in the lift simply by watching them bob up and down, with the valve cover off, at a very low idle -- but IF you can see a difference, it's cam time.
EngineLower Manifold NutsMy current issue is this... I am in the process of removing the intake manifold on my 1979 Midget. I can't seem to get at those lower manifold nuts. Precisely what wrench can I use to get them loose? Do I need a specialized tool? All I can suggest is blood, toil, sweat, and, perhaps, some tears! Use an open end 9/16" wrench and move those nuts 1/16 of a turn at a time -- whatever -- until they come loose. Be sure to chase the threads of the stud and nut, and use plenty of grease when you reassemble so that the job goes quickly in the other direction. I assume you've removed the carburetter and the heat shield, as those will certainly slow you down.
EnginePinion Oil Seal I need to replace my pinion oil seal on my tube axle. I am concerned
about having to use special tools as per workshop manual.
I do have standard torque wrenches. Do you recommend this operation?
If not, I am not sure who could do this here in the Milwaukee area.
This is a difficult task to do at home as you need a "special tool"
and the drive flange can be very difficult to remove.
Basically, you're going to remove the front flange of the differential, pry
out the seal, fit a new seal, and refit the flange. The flange is
sometimes stuck, stuck fast -- so you need to tap it forward with your
hammer, turning it slightly between each tap so nothing is bent or stressed.
When the flange comes off, you will want to polish the contact surface with
some fine grit paper (600 or so).

The old seal comes out with a pry bar or with a long, heavy
screwdriver. The new one is inserted and tapped into place with a hammer --
carefully!

Now comes the part that needs finesse. Reinstall the flange, fit
the nut, then begin to tighten the nut, constantly feeling the restriction
to movement of the front flange. You are searching for a pre-load, or
resistance to turn, of about one foot pound. The "feel" is a very slight
tightening. The problem here is that the flange rotates independently of
the crown wheel by as little as 1/8" on its circumference -- and you must
gauge the preload in that distance! Further, you should not use an air
impact to turn the nut as there is little control. You should use a long
1/2" breaker bar. But, you have to keep the flange from turning, so you'll
have to make up a tool that you can bolt to the front flange. I've used a
3/4" piece of rod, about two feet long, with two 5/16" holes on one end.
Run two 5/16" bolts through those holes, fix them tightly with nuts, and use
that, passed through the 5/16" holes in the diff flange to keep the flange
from turning. You could bolt this tool to the front flange, but then you
wouldn't be able to feel the preload. Tighten, feel; tighten, feel;
tighten,feel. Eventually you'll begin to draw the two taper bearings close
together and achieve this very slight resistance to turn.

I'd be pleased to review this with you on the phone. Of course, it
would make a good addition to our YouTube videos.

BTW, don't forget to refill the diff with oil!
EngineMGB 3 Main EngineI decided to put a 3 main MGB engine into my 1960 MGA. The MGA's 1600 engine is bored 0.40 over and has liners, and I was scared to eyebrow the block to enable use of a modern flowed cylinder head on the engine to get more power.

I've never worked on a 3 main MGB engine before. I bought a used shortblock for $100. When I got home with it and cleaned up the tops of the pistons, they look eerily like factory pistons! They are stamped MOWOG in the middle, with "Front" on the front side. They have a "3" stamped on the far side. Does this mean that these are 0.30 oversize? Does this mean that they are the original pistons and the block hasn't been bored out yet (which I find hard to believe)?
The pistons were originally sized at 3.160 inches. That number, stamped on the top (and stamped on the top of the block sometimes -- if you look carefully) is the number of ten thousandths oversize. The number is sometimes inside a rhombus. The blocks were bored and hone then measured. The pistons were spun and measured. The bores were not all the same size -- nor were the pistons. This marking allowed the factory to get the best fit. It is meaningless today.

The MGB block will work just fine for you. Consider using Pete Alberta's rear main seal -- it's very expensive, to be sure, but it is a positive seal. Otherwise, ensure that your machine shop align bores the main caps.
EngineMGB Exhaust I am looking for advice on which exhaust system to
replace the Moss SS system I have on my 67BGT. I am
experiencing gobs of back pressure from my present
system(it can knock down walls at three feet from
the exhaust tip).
It has been suggested that replacing with a bigger
bore I will enjoy better acceleration and power.
Which of the systems do you think best and where do
you recommend I shop?
Ansa, Monza, Peco??
You won't easily believe what I have to say
here, but Carl
Heideman's numerous dynamometer pulls bear this
out: "Big Bore"
exhausts make nary a difference in power.

But, for looks, for sound, and for
durability, the ANSA!

For power: a good tune-up; electronic
ignition (2 hp); MSD
ignition (as much as 2hp); port and polish on the
head (as much as
10 hp); the Moss blower (30 hp). These all are
about $100/hp.
EngineJudson Supercharger I am looking for a Judson supercharger for my 1961 MGA 1600 coupe. Can you help? Or point me in the right direction? Thanks. The only reason you would choose the Judson over the new Moss one is because you want to add only period devices and accessories. The Moss blower is SO VERY MUCH better than the Judson -- hands down!

If you haven't already, contact Carl Heideman at Eclectic Motorworks in Holland, Michigan. He knows the name of the US expert on Judson units.
EngineAdding ZDDP to OilYou won't know me, but I've seen you at various MG gatherings over the years! One day I'd love to get out to Michigan!

No doubt you are aware of the problem being talked about, that the formula for modern oil is lacking various ingredients considered essential for our older cars? I am the original owner 1974.5 MGB GT (my only car/regular driver), and I have just had a new engine installed in her; I'm particularly anxious not to ruin it! I have heard various suggestions - add STP; add something called "Compcam"; use "Red Line" synthetic oil.......what are your thoughts?

Whenever you have time, I'd be very interested to know your opinion, please? Many thanks.
You SURE want to have enough ZDDP in your oil at startup! Where to find it? Red Line has enough; Castrol makes a racing oil with enough; or you can call David Anton at APT (or contact them through APT-FAST.com) as he sells excellent cams and must have this stuff on the shelf.

I am still uncertain as to the veracity of the original complaints and if they are as dire as some state, what the proper plan of attack is. My Castrol rep tells me that their racing oil is good.
EngineValve Stem Seals Hi. I hope you had great holidays. I haven't sent you a question in a few
years, but I sure would like to know what valve stem seals your shop uses
when rebuilding
MGB cylinder heads. I've heard the little o-rings that came w/ my rebuild
kit aren't the way to go. Any recommendations with manufacturer and part
number would
be very helpful at this point in my project.
We use Felpro SS 70373 which fit some sort of Chevy truck. They are
the perfect replacement for those little O rings, which, while better than
nothing, just don't do a very good job.

Be sure to have your machine shop open the bronze-silicone valve
guides (if you're using those) to 0.002 instead of 0.0005 or the valve stems
will gall.
FuelFuelThe springs for the throttle stop screw on the SU carbs on the 74 where can i get them? On the MGB the car has sat for ten years it now has a new fuel pump the car will run but looks like it's burning coa,much of the emissions styff if gone along with air filter,which would be the best anb cheepest way to go? ps the engine doesn"t sound bad no oil smoke and no rattles also no cat on this car. Thank you for your help. Woody Woody, You can purchase the carburetter adjuster screw springs (AUC 2451) from MossMotors.com or from JoeCurto.com. If I were you, I'd find a set of original air filters as those have the greatest cross section of filtering surface and use inexpensive paper filter elements. If you want to send me a digital picture of the engine bay -- several shots from several angles, I can tell you if the emission control system has been disconnected properly -- for if it has been improperly removed or plugged it may make the engine smoke. Catalytic converters were not fitted until after 1975. Hope this helps a bit. John
FuelFuelMr. Twist, I have a 1980 MGB and that has had HS-4's installed for many years. I recently purchased a Zenith Stromberg 175 CD-2 with the long-term thought of returning the car to it's original configuration somewhere down the road. This particular carb was removed from a 1977 MGB. I noticed that the idle air regulator is not installed on the carb and that the port has been sealed with some sort of epoxy-like material. My first thought was to simply clean out the port and install a new regulator, but then I got to wondering why it was removed in the first place. I also noticed that the Haynes repair manual says "if installed" when it refers to that piece. Question - should I clean out the port and install a new regulator or is it better to leave it removed and the carb sealed? Thank you, Bob Finley Bob, First of all, I'd leave the HS-4s on the MGB. If you do the math, the twin 1 1/2" throats offer half again the cross sectional area of the single 175 Stromberg (the 175 stands for 1.75 inches). Further, the air flow is much more direct into the cylinders and doesn't have to turn those dramatic 90 degree corners as it does in the Stromberg manifold. Then, too, the exhaust is plumbed out of the engine in a double Y manifold (if you're using the factory exhaust manifold) instead of doing about a 180 degree turn as it does on the Stromberg manifold. I LOVE the twin SU carbs! The idle air regulator is for mixing a little more air to the mixture -- added beyond the gasoline metering needle. This is necessary to meet idle air emissions. In practice, I usually shut that valve all the way down when I'm tuning a Stromberg for performance (We have no emission regulations in Michigan for our MGs). If your goal is to return the car to factory specification, then you WILL want the idle air control as it was fitted to all Federal, California, and Canadian spec MGBs. There are plenty of Strombergs available at swap meets and on eBay, so your time is probably better spent doing something other than clearing the JB weld out of the air holes in that existing carb. Hope this helps. John
FuelFuelHello John, Thank you sir for your online support. I've watched your YouTube videos & more other info but my question remains. My 1966 Volvo 122s has twin su carbs but came w. different needles HZ rear & KD front. Carbs are marked different & slightly different in appearance also. Rear marked AUD 8108 on oil damper cap & AUD 8103 on front one. Float bowl lid marked AUC 94F (rear)& 33F (front). Seems to run best w. rear totally lean on bottom mix nut up, & 1 1/2 turn down on front mix nut. Is this ok? waiting on unisyn & new fuel pump (moved uphill) to recalibrate them. Thank you in advance for your advice. Sincerely, Andrew Lee San Clemente California Andrew, I do not know the specifics for your Volvo but I can tell you this -- it is ESSENTIAL that the carbs are matched and that they do the same thing as the other, at the same time. I would suggest that you contact JoeCurto.com as he has the most extensive SU inventory in the USA, plus he knows your carburetters intimately. He can offer you the parts you need (needles, dampers,....) to make the carbs match. Remember that a good tune up requires that all four systems are in top notch condition -- emissions, engine, ignition, and finally fuel. Hope this helps a bit. John
FuelFuel PumpHi John! I'm experiencing a problem with my Sprite. It will occasionally act like it's run out of fuel, stall out and not restart. The Fuel filter is dry and when I disconnect the fuel line from the carb and turn over the engine I get nothing. I've eventually been able to get it restarted after waiting a while and using starting fluid! But this has happened multiple times. I've never heard of a mechanical fuel pump acting in this manor. Your thoughts?'d forgotten that there is a mechanical pump on your engine. Most of the cars we see have an electric pump at the back. It appears that the mechanical pump is losing its prime -- that's from air entering the system between the tank and the pump. Loosen and retighten all the fittings. My experience with mechanical pumps is that they work -- or not.
FuelCaruburetor Linkage Hi John, I just wanted to say thank you for your great videos. I'm the proud owner of a 58 MGA project, which I've had for the last 10 years or so. My car had been in storage for a while, so I'm nursing her back to health. Anyway, I noticed that fuel was pouring out the back of the rear carb, so I decided to rebuild the carbs and in doing some research found your videos. After watching your video I realized that my car's throttle arm has been in the wrong position since I've owned the vehicle and as a result I've likely never been able to open the throttle fully. I really really want to thank you for that video and I'm really excited to get the carbs back on the car so I can take her for a spin with the throttle arm in the correct position! I have one small question, my choke linkage did appear to be connected correctly, however there is a considerable amount of slop in the arms which connect to the jets. Is this normal or should I replace the levers? Thanks again and keep the videos coming!!Several notes about the choke assembly... The choke cable should be held to the inside rear bolt of the pedal assembly (the ring that fits around the pedal draught excluder) by a small clip. The choke levers have 5/16” holes but a 3/16” clevis pin. This allows the levers to be moved up some distance without dropping the jet. This is designed so that the fast idle cam can begin to work before the mixture is enriched. With the 90 degree connector pin disconnected (or at least the clamping nuts run to their extremes) pull up both arms until they lever against the jets. Don’t let the jets begin to move. Then, position the clamping nuts so that both arms begin to drop the jets simultaneously. Now, pull the levers about half that distance and tighten the cable stop holding the inner choke cable. Remember to twirl the inner cable several turns so that the choke knob on the dash is loaded anti clockwise – so it more easily locks into position when the choke cable is withdrawn from the dash. Ensure that the jets have dropped as far as they can when the cable is at its full extension. When the engine is idling, pull the choke cable out until the engine is running at it’s fastest. You’ll find that the idle will increase, and then once the jets begin to drop that the idle will fall back down. Select the position where it’s running the fastest and then set the fast idle screw so that the engine rpm is 1600-1800. It’s not uncommon for the bracket that holds the choke cable sheath to be mispositioned. Use a pair of pliers to angle this bracket and position it so that the inner cable is able to draw the arms up with as little bias on the cable as possible. Obviously this must be done before locking the inner cable with the cable stop. It is possible to solder in a new inner cable to the original choke cable. This is (in my humble opinion) far superior to the new cables which rarely lock well. Hope this helps!
FuelAutochokeNo, I have not found a video on rebuilding the Zenith-Stomberg 175 carburetor. I also rebuilt the choke like the video suggested but with the car at normal operating temperature the coolant hardly moves the spring compared to when I boil it in water. What is going on?Ensure that you are running a 195F thermostat. Ensure that the water flow from the head is not restricted -- and that the return line is open as well. I have found restricted lines in the past. Remember, too, that when you open the bi-metal spring to the atmosphere, the temp falls considerably, hence the rotation will seem a lot less than it does when boiling.
FuelRough EngineDear University Motors,

I have a 1978 MGB roadster with a believed-accurate 84,000 miles on it, and have just returned from an uneventful 500 mile round trip to a British car show in the Smokies. Day before yesterday I had it out, and it started to smoke heavily from the tailpipe (and I mean a lot of smoke), going about 55 mph in 4th. It soon started missing, and wouldn't idle at all. Coming home, it was running so roughly up a hill that I didn't think I would make it home, smoking all the way. The car had the cylinder head off a couple of years ago, new valve guides, seats, and machine work, and has been modified with a '71 twin SU/exhaust-intake set up, and no smog gear. I also had the points replaced with an Ignitor electronic system last month. Any suggestions when I attempt to drive it to Greg, my mechanic, later this week?

RANDALL!

I'll put my money on a hole in one of the pistons! I'm certain that Greg will do a compression test first off -- and then let you know. He'll probably find that three cylinders have excellent compression, but one of them has none. With luck, you won't need any more work on the cylinder head (lapping the valves is ALWAYS a good idea, any time the head is removed). And with luck, the cylinder bores won't be scratched or grooved, and you can simply fit a new set of STD low compression pistons.

Let me know what Greg finds!
Fuel45 DCOE CarbCould set me on the correct path, for modifying the 71MGB Engine.
So that it could handle the 45 DCOE Carb...

Steven P. Keese

STEVEN!

For the sidedraught 45 DCOE to work well it is imperative that the compression is nearly equal in all cylinders -- closer than the 10% variation often given for ensuring proper operation.

The distributor must be purely mechanical -- giving you a maximum advance of 35 degrees, yet idling at about 20 BTDC.

The engine must run HOT -- use a 195 degree thermostat.

Still, expect a momentary stall when you make a full throttle acceleration from stop -- this is the nature of the beast.

These sidedraughts are for racing -- they are not for tooling around town. I believe you'll find the SU carburettor a much better carb for all round use!
fuelFuel Enricher Choke, Changing Carb I am the fellow who called you yesterday at around noon from North Carolina... kindly gave me your home number and I wasn't able to get to the MG to take the fuel enricher "choke" off last night. I'm going to try it this weekend and will call you back next week if I can't find the problem. I was a litttle embarrassed yesterday, I didn't feel like I had all the facts in order when we talked and I want to jot down a few notes that will be benenficial and get the most out of your few minutes on the phone. I have the MG restoration book that guides you through "detoxing" the emission control system. I believe you are referenced in that book. I will go throught that step-by-step, then re-evaluate and if I can't figure this problem out I will recontact you.

If you answer this E-mail, I would like to ask if you have heard anything about putting on the MGB carbs on these Midgets? Where might I find info on that?

Thanks

Bob Hollingsworth

BOB!

As I remember, you have a 1977-1979 Midget with an automatic choke on the Zenith Stromberg. Remove that choke assy (three copper colored, slotted screws) and check the mixture. If you cannot lean the carburettor with the choke removed, then the needle and/or jet may be the problem (or the float height). If the carburettor does run well, then the problem must be the automatic choke.

The Home delivery Midget 1500s used twin HS4 carbs. You'll need the factory manifold which you can purchase most easily from British sources.

Good luck! Call back!
FuelElectronic Fuel PumpWho makes this Electric Fuel-Pump??

the only Labels are:

* Made in Canada
* Warning, must use a filter, or will null the warranty
* (+) (-)

I took it off a 71MGB(That reside, in my Backyard), the Carb on the 71 was a 45 DCOE.. I installed just the Electric Fuel-Pump, on my Daughters 77MGB, with out the carb(45DCOE).

Now Fuel is dumping out of the bottom of the carb(StromZ)..

Does it need a Regulator / is the needle valve stuck???

Steven P. Keese

STEVE!

I do not know the manufacturer -- perhaps for Tire Canada? In any event, it should work just fine UNLESS it develops more than THREE PSI. You can rap the Stromberg with the wooden handle of your hammer to try to get the shutoff valve to close (needle and seat); you can measure the psi of the pump; you can purchase a factory, SU fuel pump (but that wouldn't take care of the sticky needle and seat, if that IS the problem). A regulator can reduce the line pressure to two psi.
FuelGas TankJohn,

Am interested in new or rebuilt 1971 gas tank. Mine has some leaks. What is cost to repair?

Carter Brown

Carter!

Almost any attempt to repair the MGB gasoline tank is futile. There is a design flaw which allows dirt to sit on the very front edge of the tank -- which, in turn, holds moisture, and that rusts through. The best solution is to purchase a new tank and coat the top of the new tank with tar before fitting it. The tank is about $200; the installation time is 2-3 hours, depending on the difficulty in removing the old one. So, at my shop, the price to install a new tank would be about $340 to $400. If you attempt this job yourself, be EXTREMELY CAUTIOUS as the tank is a terrible bomb, just waiting for ignition!!
FuelCarburettor LeakHello there,

I recently purchased a 1978 MGB that has a minor problem, the carburetter (a Zenith 175 CD) has a leak on the side (the leak is not huge, but there's oil and fuel around the area), the ex-owner of the car pointed this out to me and told me that the broken piece is no longer sold. I received a catalog from Victoria British and they sell every piece of the carburetter except that one 🙁 problem is that the engine shakes a lot, the smell of fuel not being burnt properly is really bad and the car of course hesitates when accelerated. I suppose that air is getting inside of the carburator through here. Can you guys help? Please let me know if this is something that can be repaired.

Thanks in advance,

Alexis

ALEXIS!

If you want us to rebuild the carburettor, we can do that. If you want to order the piece you need, you must describe it better, or simply give me a call between 1-2pm EST Mon - Fri, and I can see if we can find a rebuilt piece to send.

The shaking is caused my misfiring -- probably a difference in the mixture between 1/2 and 3/4 -- probably a vacuum leak along the manifold to head gasket, but perhaps somewhere else.

Tell me where you're writing from, perhaps there's a shop I know that I could refer. OR, come here yourself with the carb, and I'll rebuild it as you watch!
FuelAdjusting CarbsJohn,

I just wanted to tell you how valuable the 'adjusting your carbs' part of your seminar was this past Feb. You may not remember, but you demonstrated adjusting the carbs on a GT. The car was running very rough with the #1 and 2 cylinders not firing. The problem was no fuel from the front carb.

This past weekend, I took my TC on an extended drive with the rebuilt carbs. The car ran fine for an hour or so, then began missing out. After a couple of stabs at points, etc., I discovered that the #3 and 4 cylinders were not firing. I took the air chamber off of the rear carb suspecting that the piston was sticking. When I did, the jet needle fell out!

I repositioned it, tightened the set screw, and reassembled. The car runs like a champ!

Thanks for an excellent confidence building experience.

Mike

Mike!

Thanks for the kind note. Hope those carbs continue to operate correctly!
FuelClicking I have a 1974 MGB which has a constant clicking when I turn on the ignition, and all during driving. I was told that this could be a faulty fuel pump. Could you please advise if this is a possibility. And if so, what is the estimated cost to bring my car to your shop.

My wife and I visited your shop last year and found your staff to be very helpful.

Thank you.

Russ Hess

RUSS!

The factory SU fuel pump clicks only when it moves the fuel required by the carbs -- perhaps once every ten or twenty seconds. If your MGB has a factory fuel pump, then the problem is that the pump is faulty, or there is a leak on the inlet side of the pump. If your MGB has an aftermarket pump, then you may have to suffer the rattling until you get another pump. Sometimes the noise can be greatly reduced by mounting the offensive pump on rubber insulation. If you do have an aftermarket pump and you brought the car to my shop and wanted a factory pump installed, the cost could be about $150.

Hope this helps!
FuelSmog Pumps, BackfiringJohn,

I have a '79 MGB that has an affinity for destroying smog pumps. The previous owners went through 2 or 3 before I got it. For me it has destroyed two of the Moss Motors replacement pumps (modified Nissan devices) over the course of about 2000 miles. The gulp valves and check valves fail as well. Have you any advice in this area?

I have one idea, but I don't know if it makes sense. When I accelerate from a stop and the engine's cold it backfires(?) in the engine compartment. It's not a like a gunshot out the tailpipe, more like a loud poof, I think through the carb. The thing is, if it's in the intake system, why would it affect the smog pump in the exhaust side?

I don't notice this explosive poofing so much when it's warmed up. Only when it's first catching at startup and, as I said, when I'm accelerating from a stop, cold.

I suspect that my automatic choke needs some tweaking. I've read your procedure and will perform it when I get a chance. After boiling my thermal mass do I need to put something on the spring to stave off rust?

Thanks for any advice you can give,

Tony Campbell
San Diego, CA

Tony!

The spitting, coughing, hiccuping, you experience when the engine is cold is a result of a lean mixture or retarded timing. Check the timing first! Set the timing at 15 degrees before top dead center at 1500 rpm, vacuum disconnected. Then, make certain that you connect the vacuum advance line directly to the intake manifold (NOT through the TCSA switch on the master cylinder box). This will ensure proper timing for good running. Then adjust the mixture. Use your Stromberg adjusting tool. Lift the air piston with the tool (angle it dramatically and lift). The engine rpm should INCREASE about 50 rpm and then fall off. If the rpm falls immediately, the mixture is too lean; if the rpm rises and rises, well over 50 rpm as the air piston is lifted, the mixture is too rich. Turn the tool clockwise to pull the needle up into the air piston; hence out of the jet, making the mixture richer.

I am unable to tell you that this coughing/spitting is causing a problem with the air pump -- but, eliminating it cannot do anything but help!
FuelHD-8 CarbsMr. Twist,

I am one of the technical advisers for the Philadelphia MG Club and currently have a problem that I suspect not too many, if anyone, has ever run into. I spoke to Mr. Joe Curto last week about the situation and he could not help me by thought that possibly you could. If you cannot help me directly, maybe you could suggest a direction for me to go. The problem is as follows.

I have a couple of HD-8's from a Mk10 Jaguar that I am planning on using on my MGC and E-Type Jaguar. Due to possible concerns with bonnett clearance, I had the Mk-10 carb dash pots cut to the same heigth as the E-Type dash pots. About 0.250". All of the remaining critcal issues regarding these carbs seems to be identical as the E-Type carbs after having comparing them with a friends carbs. I thought(?) that I had inspected all three carbs sufficiently before having them cut to screw in the cap and damper only to find that one dashpot only has one thread left in it. I suspect that this is a Whitworth thread but am not sure. The cap and damper measure about 0.687" in diameter and have around 26TPI. I believe that the dashpots on all SU's, and maybe Zeinths, use the same thread and cannot believe that I am the first to have this problem. Someone has to know, and have, the proper tap for these dash pots to cut another one or two treads for me. I was going to send Burlen Fuel Systems an E-Mail about this but cannot find a web page or E-Mail address for them. I know that they are havingnew carbs manufacutered as some other may and therefore the tap has to be avaible. I am willing to pay someone to do this but need to know who and were. I do not really want to buy a tap for three - five carbs.

I would appreciate any advise or suggestions that you may have

Thank You

Fred Wright

FRED!

I've got a catalogue from SU at the shop -- they're owned by DANA, the US automotive corporation! Try them as SU, as SU/BUTEC. Call me tomorrow, 1-2pm EST and I'll give you their website as it's printed on the back of the catalogue!

Also, try Robert Clark, of Clark and Clark Specialities. Robert had some octagonal dampers made up with an MG logo -- and HE found out what the threads were (from SU, I believe). He sent me a note some time ago with the thread form -- but you're right -- it's a Whitworth form. I've included him in the cc line. Perhaps he can help!
FuelRich Needles John, I am looking for a set of rich needles for my 1.5" SU's. I ported and polished the head on my xpeg engine, and now seem to be running a bit lean above about 2000rpm. Haven't had any luck with MOSS or Abingdon Spares. Do you have any leads I might follow to find these needles?

Scott McAllister
Cleveland, Tn.

SCOTT!

Joe Curto has nearly ALL the SU parts. Try him! His e-mail address is joecurto@aol.com.
FuelZenith Stromberg Carb Air Cleaner I recently attempted to put a k&n filter on my zenith CD carb. The car was running fine before I put this filter on. It works fine when I replace the old filter apparatus back on the car. The car has just been completely restored ( including engine rebuild). When the k&n filter is in place the idle is rough and there are lots of flat spots on acceleration. I advanced the timing (that helped a bit) but there is still hesitation on acceleration. I also adjusted the mixture up and down and nothing seems to help. I cant figure if the car is getting too much air or too little or what. Have you ever had someone successfully install a k&n on a zenith. Can it be done.

Thanks
Mick

MICK!

The simple truth is that the Zenith Stromberg carb works ONLY with the factory air cleaner. I had to have a guy sleep overnight at my house once while I was discovering this truth!! Another time, a fellow from Texas sent me a case of Lone Star beer in an old suitcase for the simple suggestion to refit the factory air cleaner.

When the engine is run without the air cleaner, too much air gets under the piston and pushes it up too high -- thus leaning out the mixture. I know a different needle would do the trick, but WHAT needle I have no idea. So, I always fit the factory air cleaner.

Why not call the place you ordered the air cleaner from and ask THEM??
FuelWeber Carb I have a 1977 MGB with a Weber carb. The car runs, very rough, very rich, and backfires on occasion. The timing is correct accoring to the timing light and staic timing. Th choke is manual and operational.

I can not "lean" the carb out (maybe I don't know how). Could you help me? I have attended your technical seminars and have used the experience to do a full restoration on my 61 MGA.

Thanks,

Ed. Sherman

ED!

I should have you speak with the guy whose letter I just answered -- he figured the answer to his running problems was a WEBER!! Your Weber has a screw, just like your lawn mower carb, for adjusting the mixture at idle. It's often on an angle pointing towards the passenger. Screwing it in and out changes the idle smoothness dramatically -- I just did one this morning!

Is the air cleaner free from grit?
FuelStarving for FuelDear Mr. TWIST,

I have "recently" acquired a 79 MG MIDGET , about two years ago . Since my ownership of the car unfortunately , I have only put about 100 miles on it. When I purchased the MG, it had just finished a complete engine and transmission rebuild, with paper work and receipts to prove. On my way home after just purchasing the car I ran into a little difficulty keeping the engine running on the open road "highway". The MG runs fine around town as long as I don't get my "foot" into it. If I try to accelerate to rapidly than the MG starves for gas. The electric fuel pump does run extensively to try to keep up with the demand for gas.... I'm sure this won't help the longevity "life" of the pump . After pushing in the clutch and taking it out of gear and coasting for a few seconds it recovers and I can continue on my way.

Since this glorious drive home I have taken it to a mech. that works primarily on European cars. I have had It in and out of the mech's shop since that first day . The mech has rebuilt the carburetor with a kit from Victoria British , adding new dampening oil , new rings , gaskets , ect. what ever comes in the kit I have no idea . I took the vehicle home , assuming that the problem was fixed , well to my surprise It ran a little better but still had a problem accelerating fast and getting over 50 - 55 miles an hour. I took it back to the mech. , for further diagnosis .

Well more parts and labor involved , the mech. installed all new fuel lines , a fuel filter and a new fuel pump, 3.5 to 9 lbs of pressure on the pump. Once again I took the car home and encountered the same problem . I of course took the car back to the mech. .... and after further test he assured me that the carburetor was built properly and the lines were all correct , as well as the fuel pressure was proper. We even took a drive In the car together with a fuel pressure gage hooked-up to make sure that the carburetor was getting all the gas that it should. Well extremely discouraged I took the car home and parked it for quite some time now. Still starting it occasionally to let the engine idle and run for a while to ensure that it stays clean and free of "inner garbage".

I have recently spoken to another individual that insist that the car must have a venting problem... and that the carburetor isn't "drawing" the gas like it should . As well this individual has suggested to ditch the carburetor and get a Weber. I would rather try and find out what exactly is wrong, before dropping around $650.00 into a new Weber , and intake to find that this doesn't fix the problem either .

Well that's about it , if you have any ideas or suggestions what so ever " please , please ", email me back, or drop a letter on your site how ever you might contact me . Any help is greatly appreciated. By the way great web site , I have just found it and it has lots of information , and possibly if the "problem can't be solved ..... I might think about making a long road trip from TEXAS with the car on a trailer just to get it to your shop.

Thanks
Thomas "no-gas" Dimase
79' MG MIDGET

THOMAS!

There are two easy answers -- try these and then get back in touch.

#1 -- make certain that the original air cleaner is on the car. It simply will not run well with some chromed up, aftermarket thing.

#2 -- and this is probably the problem -- DISCONNECT the charcoal canister from the carburetter -- the line exists either ABOVE the fuel entry -- or on the front side of the carb. These canisters get plugged up and place a vacuum above the gasoline in the float bowl -- which leans out the mixture at higher speeds.
FuelFuel Problem John, let me describe a strange occurrence that is happening with the above car. I am in the process of restoring this car and I am having a fuel problem which started a few months ago while I had the engine out and it was a warm day the fuel would push out through the open fuel line in the engine compartment, On removal of the gas cap which resulted in a strong sucking sound out of the fill pipe but by leaving the cap off this process stops. Now I have everything back in place last weekend I tried to turn the engine over what happened was that the fuel pump ticked over as normal then slowed down but kept running resulting in the fuel running through the carburetor and then into the first emissions canister and spilling out into the engine compartment. I have now purchased a new canister but not fitted it yet as I believe that they must be something wrong with the fuel breather system.

Could you please advise as soon as possible or give me a quick note and I could call you during your lunchtime tech advise sessions, I am hoping you will be able to get back to me as soon as possible as I am getting itchy to get this out on the road.

Talk to you soon thanks again

Steve Plimmer

STEVE!

I believe you have two problems. The first one is a plugged ELC system; the second is a problem with the needle and seat in the carb (or reversed fuel and ELC lines).

There is a charcoal canister fitted to the MGB from 1970 through 1980. All the air entering the tank (to replace gasoline drawn out by the pump) and all air/fuel leaving the tank (expansion from heat) must pass through the canister. The charcoal adsorbs the fuel vapor, which is, in turn, drawn through the engine and into the carb when the engine is running. The problem you describe is a classic case of a plugged line from the tank to the canister, or most unusually, a plugged canister.

The second problem is either (simply) reversed fuel and ELC (evaporative loss control) lines. The ELC line enters the carb at the topmost, the fuel enters at the bottommost (I only assume you have a late model, Stromberged MGB). Otherwise, you have leaky or sticky floats or needles/seats in the carb (if you had HIF carbs, this wouldn't surprise me).

There is never a need to buy a new canister, as the old one is easily dis-assembled, and the charcoal can be placed on a sheet of metal (a cookie sheet when the wife isn't home) and "activated" by exposure to the sun all day.

Hope this helps
FuelVokes Air CleanerI am looking for a Vokes air cleaner assembly for a 55 TF 1500. Do you have one or know where I might find one? Thanks

HOWARD! I would suggest that you try the "shotgun" approach and write EVERYONE whose name you can find who deal in MG parts -- private and businesses. I have been successful in finding parts in this way. Additionally, try the website www.mgcars.org.uk to place your wanted advert.

You can try Abingdon Spares in Walpole NH; Mick Conde who trades as Keystone Classic Cars in Jeannette, PA.

Good luck!
FuelFuel Hose Boots Is there a supplier for the rubber boots that fit over the end of the fuel system hoses? moss and victoria british only sell them with the hoses
thanks

DAN! Contact Joe Curto in New York. Joe sells all things SU. Hope this
helps!
FuelHigh IdleJohn,
This letter hails from Chesnee, S.C. The garden spot of South Carolina of which Gramling S.C. is one of our run down suburbs. Bill Sapp argues otherwise but his attitude is typical of people who live in such areas. I have a '79 B (its from Gramling) in my garage that does not want to idle
down once the engine gets up to operating temperature. It has a single Stromberg. The air pump is missing and the vacuum advance has been disabled. The throttle has been backed off all the way and the kick down device for the cold idle is disengaging once the engine warms up. The
timing is set at 15 degrees and holds steady with a timing light. I have checked for vacuum leaks and have not found one. Any ideas of what to do with this thing other than get rid of it? I also have a question concerning TD's. Do they have a rear oil seal or is the crank grooved?
Thank you for your time and expertise. Larry Diaz

The high idle you are experiencing with the Stromberg is the fault of the throttle disc. It is being held open by the throttle cable or throttle screw adjustment; or, the overrun valve is so weak (and you have the car so well tuned) that the vacuum is pulling that valve open. Perhaps this Stromberg article at the end of this message may help.

The XPAG/XPEG engines have a scroll thread at the rear of the crank that screws (well, it's supposed to) the oil back into the sump. It is ESSENTIAL during the rebuild that the bottom end of the engine be ALIGN HONED or ALIGN BORED. This ensures that the saddles and the rear slinger are concentric. I do have all the specific technical information in my technical book.
FuelTesting Fuel Pump, Gas Tank Rust I purchased a 1979 MGB Tourer this fall. Negative earth ground. This is
my first MG project. The car was difficult to start due to lack of fuel
when I purchased it. The car appears to have most of the original fuel
lines which I am in the process of replacing along with auto body repair,
etc. I have removed the fuel pump and would like to know if there is a
way for me to test the pump at home or if I would be better off boxing it
up and sending to you to get checked out. What does a new fuel pump cost
versus a rebuild?

I've removed the gas tank and repainted the exterior. No rusted through
spots. There is some rust on the interior. Any suggestions for
"stabilizing" the interior gas tank rust short of replacing the fuel
tank?

Thank you,
Russ Holder

RUSS! A good idea to change the fuel hoses! The original lines fail, not
with pinholes, but splitting along their length, gushing gasoline
EVERYWHERE. They are very, very dangerous! Modern American fuel line,
reinforced with webbing (the regular kind of fuel line) is a perfect
substitute.
The main reason the fuel pump quits working is because of a loss of power
or earth. Use your 12v test light to ensure that the WHITE wire attached
to the pump is HOT, ignition ON; and that the body of the pump is EARTH.
Easiest way: connect the test light to the WHITE wire and push the prick
end against the metal solenoid body of the pump. The light should
illuminate. Loss of power is most often the "impact switch" located behind
the dash above your left knee (it pops and disconnects when the car has
been hit, jarred, or shocked); loss of earth is most often the
disconnection of the large ring of BLACK earth wires behind the licence
plate bracket.
There is no way to clean or protect the gasoline tank other than removing
it from the vehicle. And, at that point, spend the money and fit a new
one! Fitting a "see-through" gasoline filter in place of the metal can is
a good solution to monitoring a dirty tank.

Hope this helps!
FuelRebuilding Fuel PumpI AM LOOKING FOR A MAJOR REBUILD KIT (ALL SEALS AND DIAPHRAGM) FOR AN SU
FUEL PUMP ON A 73 MGB ROADSTER. THE BODY IS IN GOOD SHAPE.

THANKS FOR ANY HELP.

PETER

Peter! Let me warn you that 10% of fuel pump rebuilds fail. Therefore,
for the $50 or so that you'll spend on the parts, the price of the new pump
(about $100), makes the $50 extra that you've spent a good insurance
policy. The $50 that you've saved won't mean much if you find yourself
sitting by the side of the road. This is just my experience -- you may be
fortunate to be in the 90% group!
FuelMixturejohn, the mixture was too rich which flooded the carb and woudn't let it
run
or restart. I guess it shut off instead off getting the cat red hot,
better
then a fire, I drove the car up and down the driveway. It seems fine and
mixture seems right as you explained in your article and haynes manual.
Another aspect of the mgb I have learned, with your help. Its hard to
work on
something when you haven't seen it done. Now I can teach someone else.
I'll
take it to a friend to check the co next week.


thanks again for your help and patience. It must be hard to talk to
hobbiests
that are not mechanics. but I worked in auto parts in my youth

thanks again

larry strassman

Larry!

I'm so pleased that the car is running better. Stay in touch!
FuelProblems With Air FilterJOHN LARRY AGAIN, SINCE I SPOKE TO YOU LAST CAR STARTS FINE AND IDLES
NICELY,
RAISING PISTON AND IT SEEMS RIGHT . DROVE UP AND DOWN DRIVEWAY SEEMED
FINE,
W/O AIR FILTER. WITH AIR FILTER WON' T MOVE VERY FAST 0-60 IN ABOUT A
HOUR.
FILTER DOESN'T LOOK DIRTY WIFE SAYS CAR STINKS MORE THEN SHE REMEMBERS.
SMOKE
OUT OF TAILPIPE CLEAR AT IDLE , BLACK ON REVING. STILL TO RICH, TO LEAN
NEED
CO METER? ANY THOUGHTS WOULD BE APPRECIATED

Larry! The air cleaner richens the mixture -- so it MUST be on when you
adjust the carb. How to lift the piston? Unscrew the damper, angle it off
to the side, and lift. It will grab the side of the dashpot and allow the
piston to rise.
Remember, when the carb is adjusted correctly the rpm will increase about
50 when the piston begins to be lifted, then fall off. Use that 1/8" allen
wrench down the middle of the piston to change the mixture. Clockwise is
rich. Make the initial turns, one turn at a time; then by halves; then by
quarters. The car MUST be HOT (Normal on the temp gauge) and you MUST have
half a tank of good gasoline.
You are having such a time with this! Are you absolutely CERTAIN that the
plugs are clean and gapped to 0.035", that the timing is set at 15 BTDC at
1500 vacuum disconnected, that you have no manifold air leaks?
FuelBuying Rebuilt Stromberg CarbHello!

I have a 1979 M.G. midget with a Stromberg 150CD-4T carburetor,
Stromberg #C3962. I am looking to buy a rebuilt one. Please email me
information about availability and cost.

Thank you very much.

Gary Sonnenberg

GARY!

Please read over the two articles, attached, to give you some ideas
before you take the plunge and purchase a rebuilt carb. On the other hand,
you can send yours to me and I'll rebuild it for about $300. Turnaround
right now is probably three weeks. In another two weeks the turnaround will
be two weeks. BUT, you can probably find the problem by working with the
articles attached -- and/or calling me during my technical hour 1-2pm EST
Monday - Friday at 616 682 0800.

Fast Forward!
FuelWeber CarbsI just came across your web site and must say that I am impressed.
Some very good reading there! I have a quick question for you, and that
is:
My 1973 MGB SU carbs are in desperate need of an overhaul. Is
it worth it in time and hassle, and performance, to go with Webber
Carbs? I've been thinking about it for a while.
Any input would be welcome.
Thanks;
Jonathan Shaffner

JONATHAN!

I hope I've not written too late. Throw away that order for the
Weber carb! Work with/repair the HIF carbs -- you'll be more pleased --
I'll be more pleased.

The SUs are wonderful carbs -- but after a time parts need to be
replaced! So, in yours, it is the floats, the needles and seats, the jets,
the needles, but MOST OF ALL, the small O rings that make up the rotary
chokes. Once these begin to leak, all efforts to tune the car -- and later,
all attempts to drive the car, are wrought with frustration.

You can do this work yourself -- it's not difficult -- OR, you can
send them to me. The turnaround time right now is about three weeks. In
another month, it'll be down to two weeks.

If Kimber has wanted Webers on MGs, he would have make a deal with
Mussolini in the 30's.

SAFETY FAST!
FuelFuel PumpHello John!

I have a question about the fuel pump in my '66 Midget (10CC).

Over the years, I have experienced hesitation, loss of power, and other
assorted power ills that we, on occasion, have talked about. I never
could
find an electrical problem and always suspected my fuel system. Now, my
fuel
pump isn;'t working (pumping). I have rebuild this pump twice in the last
6
years. I am ready to replace it completely rather than rebuilding again.

My question: I the various cataloges, British Victoria, Moss, etc., the
fuel
pumps are listed as Negative or Positive. I'm assuming Negative means
negative ground, and Positive, as positive ground. My car is wired as
Negative ground, yet the pictures they show of the positive fuel pump
isn't
the one I have, and the picture of the one I have is listed as Positive.
What do I need to do - if anything - when replacing the pump being sure
the
polarity is correct?

Hopefully I can get the machine back on the road this summer.

Best wishes,

Mark V'Soske

MARK!

A couple of notes: rebuilding an electric fuel pump is an exercise
in futility. Rarely does the rebuild work well -- and when you're stalled
on US 23 in heavy traffic, you probably wish that you'd purchased a new one!

The fuel pumps have points, just like the distributor. To keep the
points from burning up, a condenser was fitted, just like the distributor.
Lately (past ten years), a new and improved method of keeping the points
from sparking has been introduced -- fitting of a diode instead of a
condenser. This "new and improved" method works well, BUT you MUST observe
battery polarity! If the car is wire negative earth, then the pump MUST be
negative earth. If the car is still POSITIVE earth, the pump MUST be
positive. A mismatch caused a nearly dead short through the diode -- it
will glow RED HOT and melt the top of the pump. So these pumps are new, but
maybe not "improved."

Buy the negative earth pump for your car.

Say hello to John Alexander when you see him!

SAFETY FAST!
FuelGasHi,

I cannot find lead additive in my area for my '73
and '77 MGB.

I tried all the regular auto parts stores in my area.

Do you have lead additive for sale??

Please advise. Many thanks.

Tom Lawrence

TOM! No need to waste your money on mystery cans. Simply use 89 octane.
Some day, you will burn out your exhaust valves -- usually number three
exhaust. At that time be certain to have installed: hardened seats;
bronze-silicone guides; umbrella seals. The 1977 was designed to run on
unleaded; the 1973 will run just fine too! My wife's 1973 MGB/GT has used
89 octane for the past fifteen years.

FAST FORWARD!
FuelFuel PumpThanks for the tips on bleeding the brakes and locating the line that
blows a fuse.

Took the fuel line off at the front T and pumped out two bottles of
Coke. But the fuel pump still works continuously. Have run the '68B
roadster for only a few minutes at a time from the street (where I keep
it covered so that the lack of plates will not be noticed) to the
driveway 10' away where I can work on it. Might the problem go away
when I get it registered and can run it around the beltway? If that
doesn't work, I'll take off the fuel line at the pump and pump out gas.

Got a used folding frame for the top (I have the stowaway frame). The
seller gave me a 1" flat, countersunk bolt. Now I know the thread but
the seller said that each side takes two different lengths of bolts. If
so, what lengths?

I may need seat belts, the ones without the take-up creel. Would you
have a set of good used or new ones? If so, how much?

Thanks again.

Jerry Stilkind

JERRY! If the fuel pump is an original, SU pump, then it will shut off
once the pressure in the fuel line reaches about 2-3psi. If the pump does
NOT shut off, but continues chattering away, then: you're out of gas;
you've got a leak in the inlet line (which would result in tiny bubbles in
the gasoline pumping into the Coke bottle); you've got a failure in one of
the one way valves in the pump (cannot remember when that was a problem).
Some aftermarket pumps hum and hum and hum!!
You are correct, however -- if you drive the car, sometimes (should I say
"rarely?") the problem will go away.

Those bolts holding the top frame on the car are 1/4-28 flathead phillips.
We used to have a source for them, but now purchase them from Moss.

I would simply purchase new seat belts -- three point fixed -- unless you're
really keen on the original BMC "Magnetic" belts. For those, contact Jeff at
Motorhead; look at www.mgcars.org.uk; and/or advertise directly in some of
the MG club publications -- the Washington DC Centre is right there -- and
they have many, many members with many, many MGs. Someone has what you
want!

Call me during my tech hour any day, Jerry, I enjoy speaking with you.
FuelGas Tank VentingDear Mr. Twist:
I own 3 MGBs: a 1965; a 1970 (GT); and a 1975. The 65 and 70 have had
their original gas tanks replaced, and the 75 still retains its factory
installed tank. Every summer I encounter a situation that has been a real
puzzle. On hot days, gasoline in the fuel tank backs up the filler
connection, pushes out the vented cap and spills all over the back bumper.
I've talked with several people in an effort to find out what is going on.
Everyone has theories on why it happens, but the only working solution is
"don't fill up the tanks when the weather is warm, or going to be warm."
Only recently has it occurred to me that the 75 (with the original tank
still in place) doesn't suffer from the overspilling. Additionally, I
reread, more carefully, several of my MG books and came across the statement
that factory installed gas tanks have some sort of "buffer" inside to absorb
expansion that gasoline undergoes when the ambient temperature gets very
warm. Apparently, the after-market replacement tanks do not contain this
"expansion" buffer, and this is why such tanks overflow when the gasoline
inside expands. What do you think?
Sincely yours.
Kevin J. Holland

Kevin!

Gas tanks, from the T series through the 1969 MGB were vented
directly to the atmosphere. In this "old fashioned" method, gasoline
expansion pushed air/fuel mixture out of the vent hole in the cap to the
air; conversely, as the gasoline was used, air would enter the tank to
replace the gasoline, through that same vent.

In 1970 (through 1980), an improved system was installed. These
tanks have an internal expansion chamber, AND, the cars were fitted with an
expansion tank at the right rear of the boot. Now, any expansion of the
gasoline forces the air/fuel mixture from the tank to the expansion tank,
and from there through the charcoal adsorption canister (rear of the RH side
of the underbonnet), and from there into the atmosphere. The activated
charcoal captures most of the fuel vapor. When the engine is running,
fresh air is drawn through the charcoal adsorption canister and vented into
the carburetters, thereby purging the charcoal canister of the fumes.

The problem with this new and improved system is twofold. First, if
the lines in the boot crack open (which they ALL are doing in the 1977 -
1980 MGBs), then the fuel vapor fills the boot and makes its way into the
cockpit, nauseating the occupants! Secondly, if the line from the expansion
tank to the charcoal canister becomes plugged, then the tank bulges from the
pressure (the fuel cap will eventually vent excess pressure), but the tank
will implode from lack of air to replace the gasoline used. I've seen new
gas tanks sucked up flat from this problem!

Whether the aftermarket tanks contain this internal expansion
cavity, I do not know. But if connected to the proper fittings, expansion
of the gasoline should not be a problem. Factory tanks carry an "NRP"
prefix on the part number.
FuelGas Smell HELLO JOHN,,,IVE HEARD NOTHING BUT GOOD ABOUT YOU,,AND I HOPE TO GET TO
PERSONALLY MEET YOU SOME DAY,,THE PROBLEM I HAVE IS A FAINT GAS SMELL WHEN
DRIVING MY CAR(77MGB),,IVE CHECKED UNDER THE CAR,,,UNDER THE
HOOD,,,CANNISTER,,,ETC,,,NO LUCK,,,AS FAR AS SEEING ANY LEAKS,,,AGAIN,,ITS
FAINT,,,BUT WHEN DRIVING,,EVEN WITH THE TOP DOWN,,YOU CAN SMELL IT...ANY
IDEAS???THANKS ,,,VINCE,ROCHESTER NY

Vince!

The late model MGBs 1977 - 1980, used a type of non-reinforced hose
in the fuel system that is DANGEROUS on the pressure side and aggravating on
the ELC (Evaporative Loss Control) side. In the former, this fuel line is
used between the tank and pump, pump and line, line and filter, filter and
rollover valve, and rollover valve and carb. Lots of line to change TODAY!!
PLUS, the rollover valves are now all leaking (some SAFETY device) and
should be plumbed out of the system.
In the latter, the non-reinforced line connects the fuel tank to the fuel
evap canister in the boot (right side), the evap canister to the line, the
line to the charcoal canister. The lines in the boot are the ones that have
split. You are getting the smell from there!
Fuel77 MGB John
I have a 77 MGB with a Zenith carb. Here in Georgia we are getting serious
about emissions on even older cars. I feel I will have to clean up this
car
by getting a catalitic converter and changing the carb. What is the most
cost effective and technically effective way to do this. I have heard
using
two HSU carbs or using one big HSU carb that bolts to the existing
manfold.
Can you give me some guidance before I have something done.

Thanks

Tom Jostworth
Atlanta, Ga.

TOM!

Your 1977 MGB was originally fitted with a Zenith Stromberg 175CD
carburetter, a catalytic converter, an ELC system, and a smog pump. If you
will have to meet emissions regulations, you'd better not stray from the
original carb, but instead rework your original system to original specs.
The car will run just fine with the original equipment!

You can, for instance, send that carb to me for a rebuild -- we
charge about $300 for a complete rebuild. You can purchase a new carb from
Moss or Victoria. I can also supply the converter (used) and the complete
air pump assembly if you are really serious about doing this correctly.

If you are interested in making the car run really well, then a
conversion to dual SUs is just the nuts! I would not, however, use a Marina
manifold (dual front exhaust and single carb) as the carb will sit on an
angle, and screw up the float height. Neither would I substitute a 1 3/4 SU
for the 1 3/4 Stromberg.

Hope this makes sense.
Fuel1952 MGTD Hello, I am looking for a breather plug for the valve cover to my 52'
MGTD as I have replaced the air filters with chrome after market air
cleaners. Please let me know if you have this in stock, as well as an
800 number and parts catalog.

Thanks, Doug

DOUG!

We do not sell parts by mail order. I would fashion something
attractive and simply block off that port. You DO have a 3/4" ID pipe that
hangs from the left side of the engine. That should give you pretty good
ventilation in nearly all situations. On the other hand, consider using a
1/2" piece of black fuel hose and routing that to one of the carbs. Use an
expanded 1/2" OD screen door spring inside the 1/2" fuel line to keep it
from collapsing when you make that tight 90 degree turn!SAFETY FAST!
FuelZenith- Stromberg Throttle Response I acquired '79B (Arizona car - NO RUST but sorely neglected). Because it
had no rust I decided to spend some money on it and I have done a lot of
work to get it back into original condition (in some cases maybe better
than original). I tend to lean toward originality (I even like the
backfire on deceleration). I have replaced the entire interior, dash,
windscreen, front end rebuild, clutch assembly, all new chrome fittings,
new top, had it professionally repainted to original Russet Brown while
I had all the lights and chrome off (wish it were BRG like my '74 E-type
I bought new and let slip away- no kicking necessary -- I've already
kicked myself enough), etc. etc.. The intent was to end up with a nice
stock car. I don't mind spending whatever it takes to get it running to
match the way it looks. It was running fine (idle was rough but
tolerable) when I acquired it and gradually went down hill. Till it
finally got to the point that down hill was about all it would do.


Carb was so rich the heat from the catalytic converter melted the
plastic knob on the damper. I replaced the damper and the EGR and Gulp
valve as a precaution thinking the diaphragms might fail from the
effects of the heat and leave me stranded. And while I was doing that I
went ahead and replaced the PCV valve. The pump seems to be fine. The
diaphragm in the carb is ok. All of this took place before I found your
web site.
Enough background.

Now, when I release the throttle between shifts, the rpm will
momentarily increase then about a second later drop off to an idle. A
second is really a long time when you approach a traffic light and let
off the accelerator and the car continues at speed for that second
before decelerating. The carb is still rich and I am waiting on an
adjustment tool to correct this. I don't know if it is going to solve
the problem. I've been told this was normal. If so, isn't this a little
rough on the clutch? not to mention dangerous in a sudden situation when
you need to stop quickly? Have you ever run across this before? Any
suggestions would be appreciated. I am not very familiar with MG having
only had this on about a year but am not a stranger to auto mechanics.

I have read your article on detoxing and on those damn Zenith-Stromberg
carbs. I have also ordered your technical manual.
Do you recommend detox? Is the result really worth the effort? I would
prefer smooth running and idle over originality in this case, but if
good idle and smooth running can be obtained with originality that would
preferable. We do not have emission testing in this part of the state
but any knowledgeable mechanic would miss the pump and fittings -
especially on a later year car.

Thanks for your time. I wish I lived closer to your location and could
just drop this off to have it tuned up.


Ed Dudley

ED!

The problem you describe is caused by problems in the emission
control system. If you remove the smog system, and do it correctly, then
all these problems will disappear (except the richness). Let me try to
explain what is happening.

When you de-celerate, the manifold depression (vacuum) rises
dramatically, as the engine wants to suck in as much air as it can. The
sensing tube connected to the gulp valve transfers this vacuum to the valve,
which then opens. The air pump blows fresh air, under pressure, into the
exhaust manifold. Now there is supposed to be a restrictor in the line from
the pump to the gulp valve -- this is often missing. That hose is about
1/2" diameter, but the restrictor has a hole which is only about 1/8"
diameter! Because your car is running rich, this extra air improves
combustion and the car runs better (faster).
Additionally, there is an "overrun" valve in the throttle disc. The
manifold depression causes this to open, which slows deceleration (and lets
more of the over-rich mixture into the intake manifold). The pop pop
popping from the exhaust is the unburned gasoline igniting as at passes
beyond the catalytic converter (if you have one).

What to do? First, get the mixture back to "normal." Ensure there
is a restrictor in the hose from the pump to the valve. If the spring
tension on the overrun valve is too weak, change the throttle disc.

OR: Remove all that stuff, solder up the valve, and the car will
run GREAT!

You make mention of a PCV valve. There is no PCV valve in the
system. I wonder who has added what, or what it is you are describing.

Hope this offers some slight assistance.

FAST FORWARD!
John H Twist
FuelMixtureThanks for the info. The PCV mentioned was actually EGR (opps). I plan
to follow your suggestions.
I've adjusted the mixture and the difference in performance is already astounding. Once I get it to decelerate properly it will be really nice.
Thanks again. Ed Dudley
FuelFUEL TANK SENDING UNIT hello.. just a quick question please.. what is the OHM reading for a 1978
MGB FUEL TANK sending unit.. both the EMPTY and FULL settings..

also, where might i send my original gauges to get the fronts of them
redone.. ? i would prefer to have my gauge faces white with black letters
/
numbers


John "BARNEY" Bauernhuber

BARNEY!

I believe the range is from about 50 to 200 ohms, something like
that -- but I forgot to test a unit today at work. If you want, call me at
the shop during my technical hour 1-2pm EST Monday - Friday, and I'll pull
one from stock and check it as you wait. Try me at 616 682 0800. BUT!!
Don't try me Tuesday or Wednesday. I'll be home doing necessary paperwork!

SAFETY FAST!
John Twist, Service Manager
Fuel"Online" and Zenith Carbs 1) I recently bought an '80 MGBLE , which has a rough idle. A thread on
the
MG Car Enthusiasts site refers to an article by John Twist "Those Damned
Zenith-Strombergs' which was recomended as a tuning guide. I wonder how I
might get a copy.
2) I tried to find same on your "online" section, but could not open that
page. Perhaps a problem exists with that site.
Thanks for helping!
Bill Cole

Now available by emailing me directly, or purchasing my technical book. Thanks. John
FuelChoke Hi John,

My name is Larry, I just received a LE MGB - mfg. 6/79, with 21K miles,
from a
friend, who was the original owner. Basically, he just retired and
passed along his
"toy" to me. As a result I am on a very steep learning curve on MG
repairs.

After reading your article " Those Damned Zenith Strombergs" and see
your reference concerning a manual choke conversion. it appear that this
information is just what I need.

Basically, I dealing with what you call running rich. There is quite of
bit of carbon coming
out of the exhaust and new plug have a thin carbon dusting after running
the engine for a
few minutes. Another observation is that I need to keep the engine
running 1500 rpm
or it will die. Once it does, it appears to want to " cool down" before
I can get it started
again.

Anyway, I am curious to know your recommendations. It has been
recommended, as
thought process.
1. Get the automatic choke working, temporary solution. Do you have any
detailed
instructions? I have a hayes manual and Leyton.
2. Consider installing a manual choke, slightly longer term view.
3. Consider installing Weber DGV carburetor, longer view. but should
keep the old
Zenith 175 CD2, in case I need to switch back for some
"inspections". In this case
there appears to be three varieties - electric chokes, water chokes
and manual. The
recommendation is to install a manual.

Any comments are greatly appreciated.

Regards,

Larry

Newbe to MGBs

Larry!

Keep the original carburetter. The cost of a manual choke or a
complete carb replacement exceeds a rebuild of your carb. I've enclosed
more information about those Strombergs -- perhaps something here will be
helpful.

Disconnect the choke from the carb (three slotted, copper colored
screws). Run the engine. Is it still so rich?
If the carb seems OK (or at least is adjustable) with the choke
disconnected, then the choke or the mating flange is the problem. If the
carb continues to run rich (and is not adjustable) with the choke
disconnected, then the problem is the float height, jet, or needle (or a
combination).

Hope this little bit helps.

FAST FORWARD!
John H Twist
Fuelrunning too richJohn, Thank you for setting me straight on leaning my TD. I called you during tech hour earlier this month about black smoke, fouled plugs, and 8 mpg. You gave me 4 suggestions; The 1st was to disconnect the chokes. When I did this the front carb choke slammed closed. The rod connecting the levers was about 1/4 inch short, thus leaving the choke partially operating. I should have called you 3 sets of plugs ago, to say nothing of 1200 miles at 8 mpg. Things are very smooth now and I am getting 22 mpg. Should I try any gas additive to help clean out the mess I may have created in the combustion chambers or manifold?

Thanks again
Bob ellis

Bob!

I think a high speed run will clean the plugs better than any can of magic. Make certain you're using the correct plugs! Very often the head has been exchanged and the plug that SHOULD fit the car is wrong. Measure the depth of the threads in the cylinder head for an "L" plug (1/2") or an "N" plug (3/4"). Use an L-86 or L-87 or an N-5.


John
Fuelmanual chokeplease send info on zenith carb choke, i just bought a 1980 le with an underhood fire, an am wondering what to do? someone told me to put a manual choke on this one and use it, i also have older su carbs i could possiby fix or buy a weber.any thoughts about which is best for the least amount of money? the car has only 30k miles on it.


thanks

Ron!

If you are concerned with originality, then you should rebuild the Stromberg and refit it. If you are looking for the least expensive option, you should rebuild the Stromberg. If you want "retro" power, then the SUs are in your future -- those twin 1 1/2" carbs draught half again as much air/fuel as the Stromberg. The Weber is clean and fast, but you'll need an exhaust manifold -- and the headers the vendors sell with the Weber are noisy, they leak, and they are headaches.

If you brought your MGB to my shop, I'd urge you to rebuild the Stromberg. If you can't rebuild it yourself, send it to me! Prices are on my website.

SAFETY FAST!
John H Twist
University Motors Ltd
6490 Fulton Street East
Ada, Michigan 49301
FuelRebuilding original carb - remove cat. converter john if i rebuild the original carb shold i leave the cat. converter on or remove, i plan on removing all smog stuff thanks, ronald

Ron!

If you are concerned with originality, then you should rebuild the Stromberg and refit it. If you are looking for the least expensive option, you should rebuild the Stromberg. If you want "retro" power, then the SUs are in your future -- those twin 1 1/2" carbs draught half again as much air/fuel as the Stromberg. The Weber is clean and fast, but you'll need an exhaust manifold -- and the headers the vendors sell with the Weber are noisy, they leak, and they are headaches.

If you brought your MGB to my shop, I'd urge you to rebuild the Stromberg. If you can't rebuild it yourself, send it to me! Prices are on my website.

SAFETY FAST!
John H Twist
Fuel1970 MGB Hi John,

First, let me say that I recently checked your tech tips page out and it
is very, very nice. Thanks for all of the information. I have two
questions for you. And here they are:

I have a stock 1970 MGB with dual S.U. HS4 carbs. This car is so
difficult to start in cold weather. When I pull out the choke, I don't
feel the accelerator being pulled away from my foot like I thought I did
when I ran another set of S.U.s on my 1976 B. I thought the first 1/3
should be a fast idle-like movement.? Second, even when it is warm, if I
pull out the choke the whole way out, the engine doesn't 'load up' like I
thought it would. It idles the same with the choke in as it does the whole
way out. Does this mean that the choke/fast idle mechanism isn't working at
all on these carbs? Any suggestions on what I should do or with what might
be happening there? What should I look for?

BILL!

Have your associate (Kim?) pull the choke while you watch the carbs.
The jets should drop AT LEAST 1/4" from the bottom of the jet bearing. If
they don't, then you'll have to lubricate the linkages. Secondly, the idle
SHOULD increase. This is more difficult since it's so hard to reach the
fast idle screws (on the bottom of the linkages). Remove the air cleaners
and have your associate HOLD the choke cable so that the engine runs as fast
as it will. Adjust the fast idle screws so that each carb is drawing the
same amount of air AND the engine is idling at about 1800 rpm.
FuelMGB Fuel Pump and FuseJohn!
I installed an inline fuse on the white wire to the fuel pump on my 1980 MGB, I need to know what size fuse to install. Thanks for your time and help.

Richard O'Connor
King, NC

Richard!

I just measured the coil in the fuel pump to find it has 3 ohms. So, when the points close and full current runs through the coil, it's drawing just over 4 amps (3ohms x 4amps = 12 volts). I would fit a 5 amp fuse here -- but since the initial draw might be a surge, be prepared to change that to a ten amp fuse. You are trying to avoid burned wiring from a dead short, so a 10 amp fuse should protect you very well. I'm interested to know if the five amp fuse works -- perhaps you can write back and tell me!

John

FAST FORWARD!
John H Twist
University Motors Ltd
6490 Fulton Street East
Ada, Michigan 49301
Phone: (616) 682 0800
Fax: (616) 682 0801
www.universitymotorsltd.com
John

Thank you for the your time to calculate the amperage of a su fuel pump. I tried a five amp fuse and it works fine. I haven't driven the car I detailing it for show. The car sat 20 years and has less than 400 miles on it. So when I bought it I had to go through the carburetor. Actually I had the local MG mechanic show me.

I put the carburetor on the car and proceeded to run the back the needle adjustment out too far and had to take it apart and fix it. I did everything you mentioned in the article you send me, "Those damn Zenith Strombergs". Now in some circles I am not considered right up stairs, but I kind of like these carburetors. My problem is the car runs rich when the choke is on, black smoke out the tail pipe and back fires. How can I fix this?

Thanks again for your help. I have wanted one of these cars since I was 13 and sat in a MG Midget in a dealership in East Liverpool, Ohio. Now at 46 I am glad I bought this one.


Richard O'Connnor


Richard!

There is a fellow in East Liverpool with whom I used to buy and sell parts -- Bob Beck. He and Janet lived on Allison Street; he had T type MGs. Wonder if he's still around those parts?

Hope all's well with your fuel pump!

John

FAST FORWARD!
John H Twist
University Motors Ltd
6490 Fulton Street East
Ada, Michigan 49301
Phone: (616) 682 0800
Fax: (616) 682 0801
www.universitymotorsltd.com






Fuel1972 MGB/GT Vapor Recovery System Failure John,
1972 MGB/GT
Can't find an answer anywhere. Fuel is pouring out of the vapor recovery
charcoal canister through the overflow onto the ground. Where do I start
to
eliminate this obvious vapor recovery system failure?
Appreciate the help.
Ed

Ed!

Your HIF carbs are overflowing -- that gasoline is pouring into the
charcoal canister and from there into the engine and onto the ground. What
to do?

Change the oil and filter.

Remove the charcoal canister and let the charcoal pellets ventilate.
Activate them by lighting them with your propane torch and turning them, as
they burn, until they simply won't burn by themselves anymore. Do this
AFTER! most of the gasoline has evaporated.

Change the fuel pump to a factory model if you have an aftermarket
pump on the car. You cannot exceed 3psi!!!

Remove the carbs, replace the needle and seats with the Viton tipped
valves. The new "Grose Valves" on the market do NOT fit the HIFs, no matter
what the advertisements say!
Joe Curto sells the Viton tipped valves.

Hope this helps!

John
FuelFump Pump & Tachometer Are Talking to each other...Howdy from the Nickel City!

Just got back in the "British car thing" again with a '72 Midget after selling my '74 Midget back in 1993. I guess the call of an empty garage was too much to handle.

O.K. here is the problem - when the ignition key is moved to the "on position" but not to "start" you can hear the very slow clicking of the electrical fuel pump (looks like an original Lucas unit to me) but at the same time the Tach needle jumps to the same beat on each fuel pump click.
Very strange. The car is from the West Coast and I am slowly replacing all of the rubber gaskets and rubber items as I move around the outside of the car. I expect to work my way under the dashboard later next week. Anything to check as to why both electrical units are dancing together?

Mike Pelone

Mike!

The 1972 Midgets began with 105501, so your Midget must be between that number and 123730 (beginning of 1973). You should have an alternator. Follow me through on this: the tach takes its pulse as the current passes from the key switch to the hot side of the coil. The key switch is BROWN on the HOT side, and WHITE on the IGN ON side. There are three WHITE wires. One goes to the tach and from there to the coil. One goes to the ignition warning light. The last goes to the fuel pump and the fusebox. It must be that the fuel pump has been incorrectly wired to/through the ignition coil circuit -- and that results in the pulse you see when the pump operates.

At least that's what I can figure out on a hot Saturday night sitting at my computer!

John
FuelRebuilt CarbsDear John:

You recently rebuild my carbs. They were off of a 1974 MGB, chrome bumper.
The air pump, air manifold and related tubing have been removed - I'm the guy that had the screw fall OUT of the engine. The evaporative loss system has been left intact.

I followed your instructions - I believe - and installed the carbs. I have two problems that may or may not be related.

First, the at rest idle drifts. This was also a problem before the rebuild. I believe now that it started when the air pump and manifold were removed. If I set the idle between 800 - 900 RPM, it will (sometimes) drop to 500 - 600 RPM when I come to a stoplight.

Second, the car is running hot. I've had the car for six years now and only once did the running temp rise above N. That was a faultily thermostat, so I tried a new thermostat, no luck. Now the only was to stop the temp from continuing to rise is to turn on the heater. This happens whatever the outside temperature; I could be in traffic in 90 degrees, or just idling in the shade at 70 degrees. The only other things that help is travailing over 60 MPH.

Any help or direction you could give me would greatly appreciated.
Thanks

Butch Parilo
Fuel1969 MGC/GT Fuel Problem
Hi. I have owned a 1969 MGC-GT since 1984. I lived overseas for several
years so
it got limited use for a long time and since coming back I've had a fuel
problem
so I just haven't driven it for fear of it catching on fire.

I'll explain the problem and hope you can offer some suggestions as to
what the
problem is. What happens is that when I turn on the ignition, fuel pours
out of
an overflow pipe at the carburetor and runs down the side of engine. I had
Gross
jets in it (since the mid 80's) so I replaced them with new standard
needle
valve jets thinking that the float valve was not shutting off the fuel to
the
carbs but it still made no difference.

I have a friend who's a mechanic and he told me the pressure from my fuel
pump
may be too high and that's what's causing it. He suggested possibly an
in-line
fuel regulator. I took an old regulator he had and used it just to test it
out
(I really don't want a jerry-rigged set-up) and it appeared to solve the
problem. However, I struggled to get it to balance between shutting the
fuel
down enough to keep it from pouring out yet still feed fuel to run the
engine.

Q: Do you think I am dealing with a faulty fuel pump?

Q: I replaced the stock fuel pump back in the 80's with an electronic one
because the factory unit went out. If it is the fuel pump, do you have a
replacement and how much would it cost (how do I order one)?

If you think it may be something else please let me know. Any advice you
can
provide would be appreciated.

Also, I am missing the "C" in MGC-GT on the rear hatch.

Q: Do you have any of those or know where can I get one?

Finally, I am considering selling the car once I get the fuel problem
fixed
because I just don't seem to have the time for it that I used to. I bought
it
with 34K original miles (it apparently had sat for a long time based on
the
rotor corrosion) and have dumped a lot of money into it mechanically over
the
years. I fully restored it in 1992 replacing the rusted out rocker panels
and
lower rear quarters with metal panels, detailed the engine cmpt.,
repainted the
wire wheels, etc.. a class "A" job. It has new carpet and it has always
ran
great except for this fuel overflow problem. The only thing really left to
restore is the original leather seats which are very tattered. It is BRG
in
color. It now has 42K miles original.
Q: Do you have an idea of what it's value may be (ballpark) and what the
best
way to sell it would be since MG's are a pretty specialized market?

Q: Would there be any opportunities to sell it through your organization?

I live in Richmond, KY which is just south of Lexington off I75. Thanks
for your
help and advice.

Regards,

Dave
Dave!

The factory fuel pump is always the best one -- it delivers plenty
of fuel (flow) but maintains a low pressure (max 3 lbs). The standard
needle and seats (especially the Vitron tipped ones) can handle that three
pounds pressure with no difficulty.

You'll want to tie in with the American MGC Register; also look
through Hemmings Motor News, British Car Magazine, as well as Classic MG
Magazine and a recent copy of Moss Motoring. These will help you decide
where, between $10,000 and $14,000 (or so), you'll want to price your car.

Find ALL the MG club sites from www.mgcars.org.uk

Hope this helps!

John
Fuel1979 MGB - fitting dual carbsJohn,
It was just as you thought the voltage stabiliser. It had gotten moved out
of
level when I was working under the dash before the problem started. I have
a79 B I'm thinking about installing SU carburettors,I currently have a
downdraft Weber. I have two sets of SU's AUD326R ,405R that need rebuilt .
Which of these would be suitable for my application and is it difficult to
install with nothing to compare too?
(such as hoses and linkage)

Thanks For Your Help
Randy
Randy!

You can probably find another MG owner not too far away and use his
MG as a guide for your installation. I prefer the HS carbs (float bowls on
the side) rather than the HIF (float bowls on the bottom), but either are
OK. I also prefer the vented HS carbs (a vent between the suction chamber
and the throttle disc, at 45 degrees, to the front of the front and to the
rear of the rear), so that you can hook up the emission controls more
easily.


John
FuelFuel Pump Wiring


My problem is while driving along at hiway speeds on the freeway in California, I ran over a 4x4 piece of lumber laying across the road. I ran over the 4x4 with my left front tire and it made a loud bang as it hit the underside of the car. The car took the bump rather well considering, but about 2 miles down the road the car started to act like it was running out of gas. I pulled off of the freeway and off to the side of a road where I had plenty of room to check out the car safely. I notice that the fuel pump was not ticking and I was not getting gas into the carb. My trusty test light showed that I was not getting power to the fuel pump. I have by-passed the roll over switch because it had been leaking previously. My question is, there a fuse that I can't find that allows power to the fuel pump? I would like suggestions as where to look before I start taking wiring looms apart to see where the white wire from the fuel pump eventually ends up. My MGB is a 1980 LE by the way. Any information that you may render would surely be appreciated. I've searched your manual and couldn't find this information anywhere. Thanks in advance for any help you can give. Bob


I was transferring files tonight when I came upon yours. You have, no doubt, found that the "impact switch" which lies above your left knee had "popped." Usually, simply depressing that switch (or is it pulling it up?) will reset it. What did you find?

John

FuelMore power to 79 MGB in CarbsHey, John!

I'm looking for wisdom to help me with my '79 MGB roadster. It's stock, but I have fond memories of the power and relative simplicity of my '63 'B ("Rodney the Batmobile" - long story).

I have a set of SU HIF carbs from a '72 B (probably need overhaul), and a free-flow exhaust header. Would like to detox, swap out Zenith and associated exhaust/catatonic converter and hopefully get closer to that '63 performance. =o)

Any and all articles helpful in this quest would be vastly appreciated. Also paid for.

Thanks!!
-Chris
Chris!

With proper tuning, you can make that single Stromberg pretty snappy. If that route does not make the car as fast and reliable as you wish, then the dual carb conversion is a good route. A couple of comments.

Use the factory exhaust manifold rather than the header. All headers are noisy, all headers leak, all headers are headaches. Rebuild the HIF's before you use them. The existing distributor will be OK -- but if the distributor is from an unknown origin, make certain that it matches the carbs.

John
Fuelthrottle open?John,

I'm helping the kid next door with his 77 MGB. As soon as the engine starts, it goes to full throttle. We installed a carb kit with all new gaskets, O rings, and a new diaphragm, but the rams still do not respond to the linkage. The butterfly valve opens and closed correctly. How can the engine over rev. when this valve is closed? Piston and damper also seem to be working. I have a 76 Spitfire with a similar crab, but it has never acted like this. I would appreciate any help.

Ray
Ray!

The throttle must still be open! OR, the spring loaded deceleration valve in the butterfly must be weak or jammed open. Unscrew both adjuster nuts for the throttle cable. Make certain the throttle disc closes ALL the way! Make sure the automatic choke is tight and not causing the throttle to jam open. If all else fails, remove the carb to check that spring loaded valve -- but I'll bet it's something easier. Let me know what you found!

John

FuelCarb Rebuild Kit John,

Because I have those crazy British SU Carburettors, no one seems to have
the
rebuild kit or replacement needles. Can you help me out on this?

Here are the numbers:

AUD2277 Tag # FZX1122F

AUD2277 Tag # FZX1122R

Needles: ADN

My online Moss rep said he has tried all of the usual places, but no one
has
them. He recommended I contact a UK company (???)

Can you help me?

Thanks!

Gabe
Well, the guy I use for the odd SU (is that redundant?) is Joe Curto --
Try the phone -- 718 762 7878
FuelCarb Running Rich JOHN,
JOHN, I HAVE ONE QUESTION WHEN ADJUSTING THE
VALVES DO YOU JUST TIGHTEN DOWN TILL THERE IS A LITTLE RESISTANCE ON THE
FEELER GAUGE AND ALSO DO YOU PUSH DOWN ON THE SET SCREW WHILE ADJUSTING,
WHAT
IS THE BEST WAY? I AM GOING TO GO THROUGH AND CHECK THE VALVE CLEARANCE
NEXT.

THANKS,
KARL
Karl!

Follow me through on this:

Run the engine until it's nice and hot; leave the plugs in; remove
the valve cover; you'll notice that two valves are open (down). Adjust the
opposite two valves. What? Imagine a centre line between #4 and #5 valves;
a line of symmetry; an imaginary mirror. The opposite of #1 is #8, the
opposite of #3 is #6. As soon as you've adjusted the valves to 0.010" --
which drags slightly on the feeler, then bump the engine over half a turn
and two other valves will open -- adjust the opposite valves. The number of
the valve open added to the number of the valve to be adjusted always equals
nine. Continue until you're done, then go through and check them quickly.

Hope this has helped!

John

FuelFuel in 71BGreetings John,
I've just purchased my wife a 1971 MG for her birthday. Now it's been
quite
a few years since she had hers and leaded fuel was the norm. What is the
proper procedure for fuel in these cars? Unleaded only, Unleaded with and
additive? High test, If an additive, how much for how many gallons.

Thank-you
Tom
Tom!

I would try the midgrade first -- something like 89 octane. If that
allows the engine to ping / spark knock / diesel, then I would try the high
grade. You cannot purchase leaded gasoline, and even those substitutes
don't really do the job. Just fill it up at the pump. Someday you'll have
to do a valve job -- then you can install hardened seats and better valve
guides -- but until then, just enjoy the drive!

John
FuelTank FuelJohn
Do I have to remove the fuel tank of my B/GT to replace the tank fuel
level sending unit?
Thank you for your consideration.
Roger
Roger!

It is NOT necessary to remove the tank -- but this is a job best
attempted when the tank is very low on fuel! Follow these notes: Jack the
car up on the RH side, so the gasoline flows to the LH (driver's) side. Use
a blunt chisel and tap the three pronged ring anti-clockwise until it falls
away from the small cams on the tank. Fit a NEW seal (ARA 1501) and a NEW
ring (ARA 1502). Fit the seal first, covered in grease; fit the new sending
unit second, front and back surface covered in grease (where it will contact
the sealing ring and the rubber seal), then fit the ring, tapping it slowly
and carefully clockwise until it wants to turn no more. In my shop this is
a half hour job.

John

FuelSU CarbsJohn Twist.
I have a set of HS4 carbs on my mgb powered mga. They have the plastic one piece float i.e.. no metal tab to bend to set the float / fuel level. I am not having any problems with fuel but with emission test's at idle. I feel that I may be getting too much fuel. How can I check/adjust this situation Can you help.
Thankyou.
Roger
Roger!

Ensure that the float height, the distance between the top of the float and the bottom of the float bowl lid, is 1/8 - 3/16", when you hold the assembly upside down. Change the float height by fitting thin washers under the needle and seats.

Hope this helps!

John

FuelHow many amps does a SU fuel pump pullI installed an inline fuse on the white wire to the fuel pump on my 1980 MGB, I need to know what size fuse to install. Thanks for your time and help.

Richard O'Connor
King, NC
Richard!

I just measured the coil in the fuel pump to find it has 3 ohms. So, when the points close and full current runs through the coil, it's drawing just over 4 amps (3ohms x 4amps = 12 volts). I would fit a 5 amp fuse here -- but since the initial draw might be a surge, be prepared to change that to a ten amp fuse. You are trying to avoid burned wiring from a dead short, so a 10 amp fuse should protect you very well. I'm interested to know if the five amp fuse works -- perhaps you can write back and tell me!

John

FuelMGB Z-S CarbMr. Twist-- I would appreciate your thoughts on a problem I'm having with the Zenith- Stromberg carburetor on my 1980 MGB with 10,000 miles. This carb was rebuilt 3 years ago by a very experienced foreign car mechanic. Since then, I have made idle adjustments using your article on these carbs in the Moss catalog as a guide, and always make sure there is adequate oil in the dashpot. The car runs beautifully once it is fully warmed up. The problem I have is cold starting. It must be cranked 3-4 times after sitting overnight before it catches. Then it idles high (1800 rpm), and there is a "popping" sound through the exhaust pipe. This problem only happens when the car sits overnight. After the first start of the day, it starts fine the rest of the day even if it sits for hours. The next morning it is again difficult to start, and the exhaust popping is present. This started last year. Once the engine reaches proper operating temperature, it smoothes out, the idle drops to 900 rpm, and it runs better than it ever has with plenty of power. I assume the problem is with the coolant controlled automatic choke, but don't know how to approach the problem. I want to keep this car completely original, but perhaps I should convert to a manual choke. Do you have any suggestions?
Thank you, Ed
Ed!

I understand (and applaud) your desire to keep your car original. You WILL be able to make it start easily but you probably won't be able to get rid of all the popping as long as the air pump is on the engine and is connected properly.

You are correct: The problem lies in the choke. You have two options -- repair it yourself using my instructions -- or -- send me the automatic choke and I'll fix it.

This is what I would do first: Loosen the 1/2" headed bolt that fastens the water jacket to the heat mass. Then, disconnect the two hoses from the water jacket and plug them with 7/16" bolts. Remove the bolt the rest of the way and CAREFULLY lever the water jacket away from the heat mass. Then, remove the three screws that hold the heat mass to the auto choke.

Remove the heat mass and carefully remove the black plastic insulator. Now you can work with the auto choke and calibrate the heat mass.

Copiously oil the inside of the autochoke, and exercise it -- hold the throttle wide open and move the little lever which engages the bi-metal strip of the heat mass from its 3:00 position to the 12:00 position -- about twenty times.

Place the heat mass in a pan of water and bring it to a boil. Pick the heat mass from the boiling water and inspect the alignment of the bi-metal strip -- well, really the rectangle -- and the line scribed in the circumference of the heat mass. That line is usually ill-defined or worse, completely obliterated. Cut a new line with your hacksaw wherever the rectangle is positioned.

Now reassemble the unit, taking GREAT care to match the finger of the choke with the rectangle of the bi-metal strip. Position all three lines (the boss on the auto choke body, the raised line on the black plastic insulator, and the line you just made with the hacksaw), in line.

Be certain to adjust the carburetter needle with the Stromberg tool in the same manner you would adjust an SU carburetter.

Questions? Write back or call during tech time!

John
FuelSU Carbs Hello John,
My 73 MGB spent the last several years in a barn - it is in good shape
and cranks - However the forward SU had a family of mice in the
aircleaner. (Back carb is perfect ) I cannot get the suction piston out
even though I have been soaking it in carb cleaner for several weeks.
Can it be fixed - are there any tricks to geting it loose? Exchange?
Thanks ,
Bill
Bill!

One trick is the heat, then quench the assembly -- that works
excellently, especially with metals of different compositions (which is not
the case here). Hold the suction chamber with pliers, heat it with your
propane torch for several minutes -- ALWAYS turning the suction chamber so
no one place becomes hotter than another -- then PLUNGE it into a pail of
COLD water. The shock should separate the two easily.

Hope this helps!

John
FuelMGTD Mark II John,

At some time in the past, the original air intake manifold and air cleaner
canister from my Mark II (12086 TD/C 11593) were removed and lost.
Chrome air cleaners with paper filters were installed.
I want to return it to the original condition.

Will the original air intake manifold from another (not Mark II) fit the
larger 1.5-inch Mark II SU's?

Was the air cleaner canister on Mark II the same as on other XPAG
engines? Will it fit?

Thank you and best regards, Steve
Steve!

The 1 1/4" air manifold and oil bath air cleaner are too small to
fit the TD Mark II. You'll have to find the original pieces -- but they're
out there! Watch eBay! I remember seeing one in New Zealand or somewhere
for just a couple hundred dollars.

John




fuelManual Choke ConversionHi John,
I would like to hear more on the subject of Manual Choke Conversion for my 1980 MGB. I have been having a bit of problems with my auto-choke and would like to see about getting a Manual put on. I live on Maui, so, of course, I don't have cold mornings starts to worry about.

I wrote you some time ago about a manual choke conversion and you set me straight and it works very well here on Maui. Now I have another question to ask you on my MGB.
Just recently, as I am driving on the very few straight-aways of an island, at between 55-60 mph, my car begins to start cutting out and I look in my rear view mirror and see smoke coming from the exhaust. (This happens more frequently as time goes by.) I adjusted the valves and haven't seen much difference. I did a compression check and the #1 cylinder is at 155, #2 is at 145, #3 is at 60 (!) and the #4 is at 155. Can I assume that I have a bad valve? or.......what is your recommendation?

Thank you for any info you can give me.

Aloha

The problem was a cracked head on the #2 piston. (I don't understand the dip in compression on the #3.) However, I totally went throught the engine, bored and replaced the pistons and replaced the head with an aluminum head. Also found that the Zenith carb was pretty worn down and reluctantly, I replaced it with a weber. The car now has never ran so good and I'm getting around 7 miles per gallon more.
Larry!
The manual chokes are available from various merchants and come with fitting instructions. If you want to do the job "properly" then follow the instructions in my Stromberg article.

You have probably already had the cylinder head repaired. I wonder if that made the smoking better or worse? Was it just a burned valve or a hole in the piston? Let me know!

John



FuelNew CarbsHi John,

I am having problems getting my '80 MGB LE to run with a new set of daul SU HS4 carbs that I bought for it. When I try to start it, it runs for a couple seconds, then sputters and dies. The fuel pump is new, and I checked to make sure I am getting good fuel flow. The fuel filter is also new and the fuel is clean. The carbs are definately getting enough fuel, as the inside past the air piston are soaked. Could my problem still be fuel, or could it be ignition related? I have also installed new points and a new condenser. Could the firing order be wrong?

Cheers,
Dave
DAVE!

You probably discovered that it was your evaporative canister placing a vacuum on the gasoline in the float bowls. How did you solve the problem?

John
FuelReach Lower BoltJohn,

I am in the process of removing the carb from my 79
midget (manual choke) to send to you for overhaul. i
am having difficulty reaching the lower nut/bolt that
attaches to the engine. any suggestions on the best
way to approach this? your help is greatly
appreciated.

jay
Jay!

A thin wrench (1/2"), and move as much as possible out of the way to
gain access to this nut. You WILL eventually get it removed -- so what
about the refitting?

Chase the thread on the manifold stud to ensure that the NEW
5/16"-24 nut spins on without difficulty!

John



FuelCarb TuningJohn, thanks for assisting the MG enthusiasts. I have 3 MGB's, one is a beautiful 1973 dark tulip GT.

I bought the car a little over a year ago and was told that the SU carbs (and engine) were rebuilt. The engine (and carbs) run fantastic except at idle. It either idles smoothly at 1500 to 2000 rpm (too high) or drops to 1000 rpm and idles very rough and wants to stall. Can you "tune" or adjust these carbs without going through a complete rebuild?

Also, there is a gearbox noise similar to what I would call a bad "throw out bearing" when the car is in neutral and the clutch is engaged. (A bad throw out bearing is noisy when the clutch is disengaged, right??). Someone told me that it was a bad bearing in the rear of the engine. Does that sound correct?

Thanks.

Respectfully,
Mike
Mike!

Black Tulip? Not many of those. The next year they lightened the colour and called it Aconite.

Two problems, one or either of them are causing the problem. Carburetters: The spring loaded over-run valve in the throttle disc is weak and is opening too soon. Simply solder them shut.

Or, the rotary choke is causing a problem. I just answered the same problem earlier so I'm sending you that letter rather than repeat the instructions.

John
FuelFuel Starvation You have answered many questions regarding MGBs and what appears to be
fuel
starvation. I have a 69 MGB and have done a lot of what you have
suggested; new points, conderser, rotor, dist. cap., plug wires, fuel
pump,
fuel lines, etc. What is interesting in my case is that the car seems to
run fine if the rear end is either jacked up or on ramps or going up a
hill
in reverse. The problems seem to occur most frequently when going up a
hill, and to somewhat of a lesser degree on level ground. I did one other
check and that was to run the car on a level surface from a separate gas
can and it seemed to run fine. One of your replys indicated "boiling" of
gas above the gear box. Do you have any further suggestions to you
previous suggestions to others regarding fuel starvation. Also, in the
fuel tank is there any type of strainer that can get blocked that would
limit the amount of fuel or is it just completely open where the fuel is
drawn from.

Thanks - Bob
Bob!

This is an unusual problem, indeed! I think it would be best to
look at the float bowls again -- and while the lids are off, place the fuel
line into a can or bottle and turn on the key. The pump should deliver one
pint per minute (a LOT of gasoline!). If there is a supply problem, then
work backwards -- but I wonder about the pickup tube in the tank, which is
impossible to inspect.

Look in the bottom of the float bowls to ensure they are free from
silt or varnish.

Let me know what you find!

John
FuelRuns Only on Full ChokeHello John!

Thanks in advance for any help you can offer.

I have a 1979 MGB Roadster with approximately 124,000 miles on the original motor. I acquired the car after it had been sitting for 8 years in a garage in fairly poor condition. It is equipped with the original Stromberg carburettor (I know, I know, Webbers are cheap but they're on strike right now and I hate to pay the inflated price while availability is poor). For the driving I do the Stromberg performs adequately and there is no immediate reason to change.
The cast iron head was replaced about 3,000 miles ago with a complete, new, bolt-on head. The rings and cylinder walls appear to be very good for the miles on the motor. All emissions equipment has been removed. The timing is right on the nose, and the condition of the plugs and wires appears to be perfect and delivering a strong spark.

The car has always run well and smoothly. The head was replaced because I purchased the car in fairly poor condition and while running it for evaluation had major overheating problems due to fans that didn't work properly and a radiator that was nearly completely clogged. The head had many cracks that showed up during magnafluxing and was replaced. There are no overheating issues remaining. Oil pressure is good (60-70lbs) at speed for an original motor. The car does not appear to be burning excessive oil, and, for once, I have a british car that doesn't leak much, either!

At present, the car seems to be always starved for gas. The condition came on fairly slowly. I noticed that as I drove the car it felt like it was being held back by dragging brake shoes or a poorly adjusted emergency brake, but when I richened the mixture with the choke it broke away and ran smoothly and powerfully like it should. It starts a bit hard but idles fairly well, but when a demand is placed on the engine it shows all of the signs of a very lean mixture by hesitating, backfiring and stalling while at speed or bringing the rpms up while stopped. The only way to operate the car is at almost full choke all of the time.

The carburettor has been completely rebuilt and appears to be within reasonable spec for a carb 25 years old. The floats are good, and the needle, jet, diaphragm and all gaskets have been replaced. The water choke was replaced with a manual choke during the refurbishing three years ago. The carb has been set using the proper adjusting tool. Damper oil is properly installed.

The fuel filter is correct and new. The fuel pump is delivering 4+ lbs of fuel pressure at all loads. The fuel lines are in good condition and do not appear to be clogged. A smoke test on the motor does not reveal any obvious vacuum leaks. A clamp applied to the brake vacuum assist line causes no change in performance.

At idle I am getting between 3 and 5% CO through the exhaust as I adjust the carb, within reasonable spec. At about 35% (yikes!) it runs smoothly because it seems to be getting the fuel it needs. At idle at about 4% I am pulling about 18 inches of vacuum, but when I attempt to accelerate the motor the vacuum drops to 8 inches. Spraying starter fluid directly into the empty air cleaner casing brings the car to a smooth run at any rpm and brings the vacuum level right back to 18 inches until the fluid is burned and the motor returns to delivered fuel.

The only area I haven't gone to that offers a strong possibility is the head gasket. Even though I see nothing externally, perhaps there is a failure in one or more of the barriers between the cylinders? I was meticulous in prepping the block for the new gasket when I replaced the head but who knows? Maybe flooding the engine with extra fuel provides so much combustion that any breach is overcome?

I'm running out of things to check, and I'm almost out of hair to pull out. Before I start really tearing things apart, I thought I would ask your sage advice.Any insight is welcomed!

Thanks!

Steve
Steve!

Offhand, I'd say you were trying to run the car without the air cleaner completely fitted, as it runs very, very lean without the restrictions offered by that unit. But if that's not the problem:

Check compression -- consistent within 10%
Valve lash at 0,013" HOT
Thermostat brings car to temp in 3 minutes at 195F
Champion RN9YC (415) plugs at 0,035"
Timing: Original distributor? Fitted with an aftermarket trigger (optical or Hall's effect)? Then time at 15 BTDC at 1500 rpm, vacuum disconnected.
Aftermarket distributor; non-original distributor? Who knows? This is a CRITICAL point of the tune-up!
The condition of the mechanical and vacuum advance is very important, too.

Fuel: 1 pint of fuel per minute

Call me!

John
FuelSpring and NeedleHello john .
1. I am in the midst of rebuilding a 1974 m.G. midget and I have two things that I would like some sage words cast my way about. Question 1; After reassembling the carbs and re installing them , what should I set the heights of the needle jets for initial set up. I know that for my "B" the jets start point is dead level with the machined flat area where the slide sits at idle. Is it the same for the 1275 midget?

2. Question 2; After reassembling the front suspension that had been apart a year and a half and re fitting the drive line, the car still sits as though it has no drive line in it. I removed one of the front coils to see if the assy. was binding but it can be moved up to full bump and down again quite easily . Any suggestions?

Peter!
1. The shoulder of the needle should be flush with the machined bottom of the air piston. Ensure that the little scribed line on the barrel which holds the spring loaded needle is pointed towards the engine, towards the air vent holes in the air piston.

2. It might be that the spring has not seated at the top. The spring will seat within a couple hundred yards on your first test drive with a giant "sproing" noise! Too, the springs might be too stiff. I know there's been a terrible quality control problem with both the coil and leaf springs coming from England. Good luck!
John
FuelLeaking FuelDear John,
1. Ten years ago you did extensive work on my TD (I think the car was in your shop for several months in 1994). It has run very well since then. Thank you again for the fine work your shop did.
I have run into a problem that I have not been able to solve and wondered if you might have a suggestion for me. About a month ago I noticed that fuel was leaking from the fuel pump. It seemed to be coming from the seam between the pump body and the magnet housing. I removed the pump and inspected it. The pump fuel filter had considerable debris in it so I cleaned that. I ordered a new gasket and new filter and replaced those. I think I followed properly the instructions in the workshop manual about reassembling the pump body and magnet housing. After reassembly, the pump seems to work fine and the car runs well. However, after the car has sat for an hour or so in the garage, I notice that there is a little seapage of fuel on the bottom edge of the seam between pump body and magnet housing.
Can you give me any suggestions?

2. Thanks very much, John. It was the gasket between the intermediate housing and the diaphragm that I replaced, but I'll take a closer look at the other.

I may need to turn to Tom Ball in Akron. Have you a phone number for him?

I've also seen a listing in the Sacred Octagon for "Britsh Car Part Restoration Company." Do you have any experience with them?

Thanks very much.
Alex Ross
Alex,
1. I think you're on the right track here, and I'll bet that the surfaces are slightly warped, making a seal very difficult -- or, worse, there is a problem with the diaphragm. You know, there is that gasket between the two parts of the pump housing -- between the two aluminium pieces. There is also a gasket between the intermediate housing and the fuel pump diaphragm. Did you change both of those? You might try to dress the surfaces with some 180 grit paper on a REALLY flat surface. Tom Ball, in Akron, Ohio, offers rebuilt pumps, if you cannot get yours straightened out -- and his have an improved valving.
2. Lawrie Rhoads is a great guy -- he's been rebuilding pumps, horns, &c for years and years. I don't have Tom's number handy, but I'll bet he's in the phone book.

Hope this helps!

John

Fuel62 MGAJohn,
I hope this finds you in good health and prosperity. I have been fighting a problem with my ’62 MGA MKII. Its an original California that has never been restored and is absolutely rust free! My problem is with the fuel sending unit. I cannot get the present unit to seal properly and it constantly leaks fuel when the level is above the unit. I replaced the existing unit and was able to stop fuel leak completely but that sending unit was faulty (I took it apart and found the wire broken at the post). OK, enough history. I need a good used or NOS fuel sending unit to purchase and I have found the Moss replacements to be poor quality. If you have the ability to help me it would be greatly appreciated. I look forward to hearing from you. Cheers!



Jim!

Get your original unit rebuilt! We can do that work -- it's pretty expensive (two hours x $75/hour for about $150) but you get back a unit that WORKS, works correctly, and keeps the needle on the dash from jerking wildly. You can do it too -- but it's tricky!

Use a CORK gasket ONLY on that unit, and seal it with some Form a Gasket #2 (gooey stuff that is impervious to gasoline).

John




FuelCarb Problem in 1976 Midget I have a 1976 MG Midget with a Stromberg 150 CD Carburetor.

I am having a problem with the idle. Do you have any suggestions on how to "adjust" the carb to keep it running smooth?

Thanks for your time and energies. I love your web site.



GLENN
Glenn!

Air leaks -- that's your problem I'll bet. Find the air leaks by spraying carb cleaner (or starting fluid) between the head and manifold, manifold and carb, manifold fittings, etc while the enigne is idling. If there are leaks the engine will speed or stall -- you'll know you've found something!

On the other hand, screws the air bleed all the way down (the brass slotted screw on the RH side of the carb) and back the overrun valve all the way closed (the pyramid shaped device on the RH side of the carb in line with the throttle shaft) back that screw off until it jams.

Let me know what you find!

John

FuelLeaking Jet to Float Bowl ConnectionHi John;

A couple years ago I rebuilt the HS4 carburettors on my Spitfire 1500
engine. About a month ago I found both jets leaking where the jet screws
into the float bowl. I found that the rubberwasher had turned to mush,
probably due to fuel additives, and replace the rubber washer with viton
rubber washers. After a couple days I found again that I have gas leaking
from the connection between the float bowl and the jet. I gave the nuts a
bit more of a turn but they are still leaking. Any suggestions as to what
I may have done wrong?

Also, I am getting gas coming out of the top of the float bowl, right
around the float bowl cover, when I rev up the engine. The carurettors
were rebuilt a couple years ago with a genuine SU rebuild kit, including
replacing the float needle valves. Could it be that the float height is
not correct? These are non-adjustable plastic floats.

Thanks in advance for your time and your comments.

Sincerely,

Mark

Mark!

Some of these rubber parts fail prematurely. I do not know enough
about rubber products to tell you which ones are best. I've always gone to
Viton when there was a question. It is nigh impossible to change those in
place, at least on MGs. Stacked, from the outside in are: the nut; the
brass washer; the O ring.

Gasoline leaking from the top of the float is a result of the needle
and seat not closing -- that could be dirt in the fuel. But, a shaking
engine will stir up the gasoline enough to cause it to splash out.

The distance between the bottom of the float bowl lid and the top of
the float should be 1/8- 3/16".

Hope some of this helps.

John

Fuel1980 MGB fuel cut off valve Sir, I am very much so hoping you can help me. I am having a problem with a 1980 MGB. The fuel cut off valve (between the fuel filter and carb.) is leaking all over the place. I am thinking this is more of a safety hazard than a safety feature. I cannot find this part at VICTORIA BRITISH, nor at MOSS MOTORS. I was wondering if you could help me to find this part, or inform me on the safety of bypassing it.

Any advice you can give would definitely be appreciated.
Thank you,

Lee
Lee!

This "rollover" valve is designed to block the flow of fuel should the car turn upside down with a driver incapacitated or unable to switch off the ignition. It seemed like a good idea at the time -- but since they ALL leak, it really isn't much of a safety device!

You have two options: The easiest is to simply plumb through it. I remove them altogether -- three Phillips screws at the base. The other option is to drill through the device, push through a length of 5/16" steel line, and connect the hoses as though it was a working unit (you would do this ONLY if you wanted an "original" look to your firewall.). You can find these valves on eBay, but let me tell you that ALL of them leak -- so what's the point in purchasing another faulty unit.

The other danger, under the bonnet of your 1980 MGB is the unfused circuit to the TCSA switch and/or the overdrive circuit. While unrelated to the fuel danger above, this one, when the wire shorts (and it will short someday!), it burns the wiring loom from the ignition switch, across the back of the dash, and down to the gearbox. A very horrid, very expensive repair -- and COMPLETELY avoidable! If you have overdrive, then fuse the circuit. If you do not have overdrive, then simply disconnect the circuit.

This wire is WHITE or WHITE/BROWN and is within the gearbox loom or separate (depending on the year). It connects to the junction of the main loom and rear loom, right there at the rear of the right front inner fender. It is plugged into the WHITE wires (one comes from the impact switch, one goes to the fuel pump, and this one I'm discussing goes to the gearbox). Simply pull this wire from the four-way Lucas female connector and tie it back with a wire tie. If you haven't already, then move the vacuum from the manifold directly to the distributor -- rather than using the TCSA valve on the brake master cylinder box.

Hope this is all helpful!

John
FuelNecessity is the mother of invention.Hi John,

First off, just wanted you to know that your technical book has already paid for itself by keeping me from making a mistake with the distributor on my mgb. It really is a good manual -- thanks for putting it together.

I've got a couple of quick questions. My MGB-GT is basically a 1974, but the previous owner kludged it together. As a result, not everything was there when I bought it, and somethings just don't match up with any picture, manual, etc. So, here's a couple of real dummy questions that would be easy to answer if I had another MG to look at.

Question #1: Each of the SU carbs has a vacuum port connection near the throttle plate. The previous owner connected the distributor vacuum line to the port on the rear carb and plugged the port on the front carb. I'm not sure this is correct. I would guess that both ports should be plugged and that the vacuum line should be routed to the intake manifold itself. Your thoughts??

Question #2: The overflow outlet on fuel bowls on both carbs weren't connected to anything when I got the car. From the pictures/drawings I've seen, it looks like the car came from the factory with lines running downward from the overflow outlet. Unfortunately, none of the drawings show where they go. Do they just run downward so that any overflow drops to the ground, or do they really go somewhere?

Thanks in advance for your help. You are very gracious in offering this service.

--Mark

PS: Funny fix - I didn't want to spend $19.95 for the rubber gasket that holds the heater tubes to the heater box, so I went to home depot thinking, "Surely, there is something here that will cost less that I can use". I wound up buying a pack of scouring pads -- the green ones that are about 5/16 inch thick. I cut 5 of them to size, cut out the two holes for the heater pipes, and pasted them to the heater in a stack by using the left over window trim adhesive I had. Then, I coated them all with the adhesive, let it set and wound up with a perfect gasket for less than $3.00.

Then I got thinking about heater tubes (missing from the car when purchased). Back to Home Depot where I purchased a $1.97 P-trap extension in the plumbing section, which was cut in half. It fits the heater box perfectly and is the perfect complement to the scouring pad gasket.

Next step -- adapting the flexible hose from my wife's portable vacuum cleaner (when she's not looking) to go between the heater tubes and the demisters.

Mark!

Necessity is the mother of invention. You should write to Home Depot -- they might use your experience in an ad!! Then we'd get some free advertising for our MGs!

In 1974 the engine design was heavily influenced by emission control concerns. The distributor should be a 20 degree advance (on a limiting finger on the mechanical advance, deep inside the unit). If so, then the timing should be set at 15 BTDC at 1500 vacuum disconnected. Once timed, the vacuum should be connected to the intake manifold. If, on the other hand, the distributor is an earlier variety (about a 10 degree advance), then the timing should be about 20 degrees at idle, vacuum disconnected, and then connected to a tit on the carb (usually the rear carb). With any distributor, the maximum advance cannot exceed 32 degrees at 4000, vacuum disconnected.

The 1974 came equipped with a charcoal canister to provide Evaporative Loss Control (ELC) to the gas tank and the carb float bowls. If that's gone, then simply allow the vents from the float bowls to dump down the side of the engine.

Call if you have more questions!

John



FuelMidget Zenith Carb LeakingHello John,

I have a 75 MG that is leaking fuel into the air cleaner box. I have heard these carbs are problematic.

Thanks!

Richard

Richard!

There are two reasons the air cleaner is filling with gasoline: the needle and seat in the carb float bowl is stuck open; or, the vent line from the carb to the charcoal canister is plugged.

Try this first: Remove the vent line from the carb to the charcoal canister from the carb. Have you associate spin the car over. Does gasoline pour from the brass vent pipe? If it does, then the carb has to come off and the float bowl has to come off and the needle and seat has to be changed.

But, if by removing this line the car now runs well, then blow out the lines and clean out the charcoal canister.



John
FuelFuel SmellHi John,

My trip back to Toronto was great, 75-80 mph and rain all the way. All went well until I blew off the resonator 2 hours out of Toronto. I removed it and stowed the resonator in the trunk, it seems the unit bottomed out on something, as there was a deep scrape on the bottom. That must have cracked the weld, and then it was just a matter of time.

There is one condition with the car that I forgot to mention when at the seminar and one which excists from time to time, perhaps you can shed some light on it.
There is a raw fuel smell that I can only detect from the drivers seat following hard accleration. The fuel tank dosen't leak and there is no fuel leak from the carb or any fuel lines. In an attempt to diagnose the problem I have run the float bowl overflow line into a plastic bottle to catch overflow fuel and in the hope that the problem is due to a float related issue. The odor is not as bad but it is still there. Any thoughts?
Tomorrow the car is going in for a leak down test as the "new" engine is using copious amounts of oil.

Anyway, so goes the supercharger saga.
Cheers,

Jon
Jon!

The fuel smell is either from the tank or from the carb. If it's the tank, then there is a problem (crack or tear) in an evap hose from the tank to the canister mounted on the RH inner fender.

If it's the carb -- well -- install a new or second fuel filter to get the particulates from the fuel. You could change the needle and seat on that HIF carb using the Viton tipped style instead of the steel tip (but I really don't know which style is in there now.).

BTW! Make CERTAIN that you double check the three bolts holding the idler pulley plate. These have cracked in numerous blower applications.



John
FuelDowndraft WeberJohn,

I have a question I hope you can answer. Or direct my attention to your website.

The 1980 MGB I bought had the Stromberg carb replaced with a Weber downdraft. It seems that my fuel consumption is high and my exhaust is a bit gassy smelling. I get about 14 MPG. Isn’t that a bit low?

Can you suggest if it is low what I might do?

Thanks in advance.

Eric
Eric!

Most carb problems are really ignition problems. Try this:

Time your MGB at 32 BTDC at about 4500 rpm, vacuum disconnected. Then, ensure that the vacuum is attached to the MANIFOLD vacuum port (highest on deceleration and idle).

Do you have the 32/36 progressive, the 32/36, or the way too large 36/36?

John
FuelVentingJohn,

I recently cleaned the HIF4 carbs and replaced the floats and needle and seats because I had flooding issues after changing the fuel filter and allowing some crud from the old rubber fuel lines to contaminate the float system. I cursed the HIFs because I had to remove them but now think they're a pretty smart carburetor. The fuel lines are all new, as are all the intake gaskets, shaft seals etc. There are no vacuum or air leaks.

I'm careful to do one change at a time to prevent muddling things up.

The car is a very clean no-winters car that had two mature owners before me and was very well maintained by professional mechanics. I'm the first owner to work on it but I have a long background in auto mechanics.

After making sure the carbs were working properly and carefully adjusted, I set out last weekend to remove the air pump and such. I plugged the air rail holes, plugged the small line that went to the gulp valve (3/16"-1/4") and plugged the angled 5/8" T for the gulp valve in the middle of the intake manifold. I left the small hose that runs to the other side by the canister to (the anti-run-on valve?) I think that's what it is with the two wires on top sitting right in front of the canister.

The car runs great! No flat spots, pulls at all rpm ranges much better than a car with 125K on it should. (head has 20K) I'm sure when I freshen-up the motor next year or the following, I'll have a bit more power but it runs fine. I have 2-1/2" K&Ns with APT CNC'd stub stacks and a stock-size Falcon stainless steel exhaust. I'm running what I think are original size needles in un-worn jets. I don't feel the need to go up to the next needle size but I'm not sure about that. I don't know if I'm missing any additional power due to carb leaning. It feels OK and I have a very smooth idle.

What I'm really not sure about and why I'm emailing you is did I do a complete and accurate de-smogging on this car? Like I said I still have the vacuum hose from the manifold to the run-on valve. (The vacuum advance line is of course still functioning as well, and the car has a Crane electronic ignition.) Also, would it be wise to plug off the carb vacuums for the side crankcase vent and run the vent instead to the 5/8" L fitting on the manifold? Should there be a PCV valve somewhere in the system? What if I switch to an aluminum valve cover? Should it be vented or not? I see that Victoria British has these that vent but all others use a venting cap. My car still has the stock steel cover with the rear vent connected to the canister.

I look forward to receiving your insight and suggestions about my particular set-up on my MGB.

Dan
Dan!

I read through your email and am pretty sure you've done it correctly.

We use 7/16-20 socket set screws in the cylinder head so that it looks attractive. We use a 1/4 NPT socket screw in the intake manifold to look good and to ensure there are no leaks. We remove the gulp valve and replace the fitting with both copper washers. BUT -- leave everything else the same!

Check your timing at 32 BTDC at 4500 rpm vacuum disconnected. If you want to change needles, use the ABD needles -- I've found them the best.

If you want to aluminium valve cover, use a 1/4" pipe nipple for ventilation, but RESTRICT the opening to 5/64 (look at your existing valve cover).

I do think you're home free!

John
FuelCarb OverflowJohn, thanks again for supporting the hobby. I have 1973 MGB GT (Black Tulip) that I took out of storage yesterday. It always goes into storage with a full tank and plenty of Stabil. It started up fine and I let it run for 20 minutes before I took it out on the road. As I pulled on the highway, I noticed that under medium or hard throttle, it would bog down, but under light throttle it was OK. About three miles into my ride, it died and would not restart. I called a tow truck and waited. 30 minutes later, it started but only ran about 100 feet before dying again. Had it towed back home (northern Michigan). I've had the car for 3 or 4 years. I replaced the fuel filter when I bought it. The fuel pump "looks" reasonably new, recognizing that doesn't mean much. Am I on the right track?
Thanks John.
John!

First, don't let the car warm up like that again. Simply start it and drive it -- just like a real car.

My guess is that the carbs are overflowing. Disconnect the line that runs from the front of the front carb, through a steel line, to the back of the back carb, and then to the charcoal adsorption canister. Disconnect the line at each carb. Turn on the key. Does fuel pour from either air vent on the carb?

Next, disconnect the fuel line from the carb. Place it into a can or bottle. Turn on the key. The pump should deliver one pint per minute.

Then, give me a call at tech time!

John
FuelPCV SystemHi John and cheers from Canada.

I don't have a local MG specialist close to me and hope you can answer a question. On my 74 1/2 MGB the crankcase breather pipe that normally goes to the carbs (HIF) has been disconnected and vented to the air, presumably to keep oil etc. out of the carbs. However the breather pipe that connects the carbs is now open to the air and is sucking air (ie. the crankcase hose has simply been disconnected from the Y fitting.) The car seems to be running OK. Should the open connection connecting the carbs be closed up. I could simply reconnect the crankcase hose but could oil be a problem? Or could I leave the crankcase hose as it is and block the opening in the connection between the carbs? Or just leave things as they are? I am wondering if any of this is a potential problem. The plugs look OK (Does the breather hose enter the carbs on the air side or engine side of the butterfly valve. If the latter could this cause a problem with the valves or maybe this is compensated for by excessively rich adjustment at the carbs? Anyway hope you can enlighten me. Thanks and cheers.

Gord
Gord!

It is important to have the PCV system connect up correctly. This system keeps the inside of the engine clean of water vapors and harmful, acidic blowby.

The system is simple: Fresh air enters the black tube hanging from the anti run-on valve. It passes through the valve and into the bottom of the charcoal adsorption canister. It passes through the charcoal, purging the gasoline fumes from the charcoal, then into the engine. From the engine, the air is pulled through the oil separator on the side of the front tappet inspection cover, and then into the carbs, where it is combusted.

The gasoline tank is connected to this system. As the fuel expands, the air/fuel mixture on top of the gasoline is vented through the canister, trapping the unburned hydrocarbons. Then, when gasoline is pulled from the tank by the pump, the air drawn into the tank must pass through the charcoal canister. Prior to 1970 the tanks were vented directly to the atmosphere.

The carbs are connected to this system, too. The float bowls need atmospheric pressure on top of the gasoline to push the fuel into the jet. But, when the car is turned off and the underbonnet temperatures increase, the fuel in the carbs expands and pushes air/fuel mixture out -- that is also trapped by the canister.

The anti run-on valve is also designed to keep air/fuel mixtures from entering the atmosphere by shutting the engine down positively. When the valve operates, it closes the fresh air vent and the draft created at the carbs pulls the air out of the charcoal canister. This places a vacuum on top of the gasoline in the float bowls which may kill the engine. But, just to make certain the shut-off is really positive, manifold vacuum is connected to the charcoal canister (at the anti run-on valve) which REALLY creates a vacuum in the float bowls and the engine shuts off NOW!

I would reconnect your PCV system and re-adjust the carbs (which are probably enrichened too much right now).

John
FuelFuel Filter1ST. I PURCHASED A NEW FUEL FILTER THIS DAY 7/05/06 NO INSTRUCTIONS CAME ON HOW TO PROPERLY INSTALL IT. ON THE ONE END THERE IS THE WORD "IN" NO ARROWS JUST THE WORD "IN." NOW DOES THAT MEAN THAT END GETS CONNECTED TO THE FUEL LINE THAT GOES TO THE GAS TANK OR THE LINE GOING TO THE CARBURATOR? 2ND. AFTER I INSTALLED THE NEW FUEL FILTER I ASLO INSTALLED A NEW BATTERY, WHEN I STARTED IT UP IT WAS IDLELING PRETTY ROUGH FOR A FEW MINUTES THEN STALLED OUT. I TOOK THE COVER OFF MY SINGLE CARBURATOR AND SPRAYED SOME CLEANER IN THE CHAMBER, MOUNTED THE THE COVER BACK ON IT AND IT HASN'T STARTED BACK UP SINCE, IT WANTS TO BUT IT WON'T STAY RUNNING. IT SOUNDS LIKE IT IS BEING CHOKED, WHAT IS WRONG? THANK YOU!

GINO
Gino!

The fuel filter should be connected so that the gasoline comes up the pipe, IN the filter, and out to the carb.

The rotational alignment of the piston and the rubber diaphragm is critical. Take the top of the carb back off, look at the edge of the diaphragm -- you'll see a little nub -- that goes at 9:00 (as you're facing the carb).

Change the plugs (use Champion RN9YC - #415) and it'll start right back up. It's NEVER a good idea to leave the car idling for any length of time.

Hope this little bit helps.

John
FuelDashpot OilWould you please advise me as to the best fluid to use in the dashpots? I hear everything from 20w oil to marvel oil.
Please advise.
Thanks, Randy

Randy!

Besides what you've found, I've seen 3 in 1 oil, transmission fluid, brake fluid, and antifreeze!

I have been using 90 weight gear oil. Actually, it's 80/90 hypoid gear oil. WHAT? AM I NUTS? Follow me through on this.

The mixture must richen at acceleration. It is the resistance to movement that keeps the venturi small and effects the enrichening. Even the newest original SU is 32 years old. The brass damper piston has been running against the inside of the steel dashpot tube all this time -- some wear has occurred. The heavier oil accounts for that wear. What about the "new" SU carbs? The ones I've seen have a mismatch between the OD of the brass piston and the ID of the dashpot -- hence the necessity of heavier oil.

Try it out!

John
FuelAdjusting the MixtureJohn,
I have a 1977 MGB. I recently replaced the o-ring on the needle holder in the piston. It wasn't holding oil. My question is on adjusting with the moss tool. Should the carb vent hose be connected? Also, do you screw the course idle nut and the brass fine idle screw all the way closed when adjusting the needle or lifting the piston (air cleaner on) to check for lean or richness? I have the Damn ZS Carb article that you sent me, but it doesn't say where to position the idle nut and screw. Thanks for your help,
Don
Don,

I always close down the air bleed -- that's the coarse and fine adjustment on the right side (facing the carb) of the carb. That adjustment is used to meet idle emission specs, and since there are no emission specs to meet in all but a handful of counties, the bleed has no use.

Start with the needle a bit rich -- screw the adjuster tool all the way clockwise and then back it off a turn. As the engine warms up, continually rev it to keep it from fouling the plugs. Once the auto choke has come completely off, then lift the piston to make the final adjustments. Oh, yes, absolutely have the vent tube from the from tappet inspection cover attached to the right rear of the carb!

Push a small screwdriver down the throat of the carb, under the piston, then turn the shank so that the blade lifts the air piston. As you begin to lift the piston, judge the change in rpm. If the engine revs higher and higher the farther you lift the piston, then the adjustment is too RICH -- turn the tool anti-clockwise to lean it out. If the engine stumbles and falls as you barely begin to lift the piston, then the adjustment is too LEAN -- turn the tool clockwise to enrichen it. The "perfect" position allows the engine to continue to run at the same rpm or just barely, incrementally, allows the rpm to rise just as you lift the piston 1/16 to 1/8 of an inch.

Remember that the car WILL NOT RUN without the air cleaner -- so any high speed idle testing, any road testing, MUST be with the original, factory air cleaner.

Once you're on the road and want to test the mixture, simply unscrew the damper assy, push it to one side which will jam up the valve, and lift slightly. Listen for the resulting change in rpm.

Hope this helps!

John
FuelBest Carburetors?Dear John,
I want to replace my worn out Zenith-Stromberg for a downdraft Weber 2 bbl. ( cost with intake manifold & electric choke is less than $ 600. Do I need to replace the stock exhaust manifold for a pre- 1975 one? If so where can I find one? Moss & Victoria do not stock this part.
Would I be better off to have you rebuild the Z-S carb???
Thanks,
TOM
Tom,

A rebuilt Stromberg will cost you $300-$400 -- much less than the Weber -- PLUS, it will perform well at low speed. Another option is to fit twin HS4 or HIF4 SU carburetters. The rebuilt Stromberg is certainly the way to go. We do rebuild the Strombergs, but isn't the prospect of your business that I'm giving you this advice -- the more original you can stay, the nicer the car remains.

John
FuelChoke ConversionJohn,
Has anyone ever