I have a few questions that the 'B' experts might be able to answer.
If you're still willing to listen to me... Don't know about you, but it
was pouring down rain on my house on Sunday, so I went back to sleep (having
been up till one helping Kim pack and waking up at 4:30 just out of spite).
Since then my cars have been telling me that if I'm going to spend any time
under an MG, it ought to be one of mine, Macintosh setup or no...
1. The workshop manual makes a big deal out of centering the transmission
front oil seal/ cover assy on the shaft.
Don't know about the transmission oil seal. Does that O/D box need one?
2. I have found a reference to someting called a vacume switch for an
overdrive. There was no indication as to what years it was installed,
where it is located, or what it does.
Q. What is it when was it used???
Beats me. The Big Healeys had a throttle sensor that controlled when the
O/D went in and out; for instance, if you were in top-gear O/D below a
certain RPM level and you stomped on the gas, the O/D would kick out and
you'd go back to direct drive (like an automatic kickdown). (To be brutally
frank, one of the reasons I sold the 'box was that I felt less and less
like doing all the details necessary to the conversion...)
3. I need to replace the rear engine seal (68 BGT)
Q. Any thing I should watch out for? any gotchas? do I need any parts other
than the rear seal, & the locking tabs for the flywheel?
There are two things that are called the rear main seal. One of them is a
ring that goes around the end of the crankshaft; the other is a piece of cork
that goes between the bottom of the rear main bearing and the top of the
oil pan.
To replace the ring, you need to remove the back plate of the engine,
press out the old seal, press in a new seal, and replace the back plate
of the engine. Removing the seal is a screwdriver job; pressing in
the new one is a hammer-and-block-of-wood job.
The bottom main seal is a strip of cork that is meant to take up the
slack between the bottom of the rear (and front) main bearing and the
oil pan. Basically, this allows for align-boring the bearings fairly
easily; you shave the parts of the bearing cap that go into the block,
then you hone the bearing area on an exact circle, then you make up
for the amount you shaved in Step 1 by fitting the cork strip.
In either case, it might be a Real Good Thing to have a conversion
gasket set on hand, as this has basically all the bottom-end gaskets
and seals you'll need. BPD sells them for about $16 or so.
4. There are no special tabs on the engine for hoist attachments (neat
feature on TR engines).
Yeah, the GTI's got 'em too. So does the Miata. I figured that what the
MG really needs is a big red arrow in the trunk with a sign on it saying
"HIT HERE TO RESTART FUEL PUMP."
Q. Where are recommended points to attach chain for lifting engine?
The Official Approved Factory Tool for this is a bent hunk of heavy sheet
metal with a hole the size of the valve cover retaining caps in the short
end of the L, and an oval suitable for hooking a hunk of chain through in
the long end.
What I've done is to remove the valve cover, place a suitable chain over
the studs sticking up from the head, put BIG washers on to take the load
against the chain, and tighten the nuts back down on top of it. Works
like a hose.
5. I'm getting tired of having wet carpets in the GT whenever it rains.
Q. Any ideas where the inside "rain" might be coming from? How to stop
it?
Brake pedal box, drain plugs in the top of the footbox, beading at the
fender seal, any number of places. Q: What's the difference between
getting your feet wet in a car with Lucas electricals and a car with
Bosch electricals? A: In a car with Lucas electricals, your feet will
get wet because it's a leaky old LBC that you're driving in the rain.
In a car with Bosch electricals, your feet will get wet because you have
to get out and push...
6. My B tends to overheat at idle when the ambient temp gets above approx
75F. I have 160F thermostat, correct timing, cleaned out cooling system,
and good hoses. It does not overheat sitting in traffic except on hot
days. I am ordering a new radiator cap since I loose coolent out the
overflow easily. The car is fitted with a 7 blade metal fan. I have
looked at the later ('72-74) 7 blade plastic fan. The pitch looks
greater on the plastic one and the blades look wider.
Q. Does the plastic fan draw more air than the metal one? If I decided to
try one, will the plastic fan interchange with the metal one with the
same fixings??
Yup. I've got the plastic fan from my '72 parts car in my '71. The main
advantage they have, in addition to being lighter and quieter, is that the
blades can't work out and go flying through bodywork (the car's or someone
else's). I saw a Big Healey shroud with a fan-blade-shaped hole in it a
few years ago. Not a pretty sight.
Hmmm. Do you have the right grade of radiator cap on that car? I'll check
mine, but I think a 14-pound cap is correct. If you have too low a pressure
rating, you'll spit coolant (see below) and there'll be less coolant to keep
the car running properly.
Also, of course, the actual proportion of antifreeze to water makes a big
difference in temperature dispersal. Try running more water than coolant
and see if that helps the car shed temperature more easily.
As a final point, is your fan installed the right way round?
7. My '68 BGT takes a thin wiper arm that was only fitted to part of the '68
year. The car now has universal arms on it.
Q. If I want to go back to MG wiper arms, would the later arm fit onto the
splines of the assembly?
Yes, they'll fit. Make sure you get them for a GT because the roadster in
some years had triple blades, which were much shorter than the blades on the
GTs. Find a junk GT and get the blades and arms from it.
Bonus question (requires knowledge of late TRs & Spits)
I would like to fit a coolent recovry bottle onto the BGT. There is loads
of room in front & to the side of the radiator for a bottle with a bottom
mount.
Seems to me that I have seen the mounting on a coolent recovery bottle of
either a TR6 or Spit. Could some one point me in the right direction?
You'd have a much easier time retrofitting from a later MGB, if they went
to a closed system. Remember that a coolant recovery system is just that,
a system, and it requires the right kind of valve to draw the coolant back
into the radiator when it condenses. The system in your car now (what I
have called the Onanistic approach to coolant pressure relief) has no
provision for getting the coolant to go back into the system. Of course,
if all you want to do is keep from spitting Prestone onto highway 17 on
hot days, buy a cool red bottle at an Army surplus store and hose-clamp
it to your radiator shroud.
--
"Do you ever wish you had a joystick with a big red button on it so
you could just nuke the person when you send a reply?" -- Kim
Scott Fisher/sfisher@wsl.pa.dec.com/DEC Western Software Labs/Palo Alto, CA
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