Ooh, bummer, sorry to hear about it. I would have to say, get on those
bearings right away. When my old motor started thunking, it only took a few
hundred miles to turn into a jackhammer. I don't know if it was cause or
effect, but when I opened it up, the #2 main cap was broken through. You
don't want to get to that point, since it ups the ante from bearings to tear
down and line boring.
I have also heard that the main bearings are the weakest link in the motor.
On this occasion the guys at British Motorsport thought maybe 50K was all
you could expect.
On the tranny issue, I bet you could get an exchange OD for 1/2 to 1/3 the
cost of the Datsun 5-speed kit, from what I've heard. The OD was $800 from
Vicky B last I saw (several years ago). If you want to cobble the 5-speed
yourself from a junkyard tranny it would be cheaper of course. But which
would get you back on the road quicker?
I recall an extended discussion of the relative merits of these approaches
several months ago. I don't think it was settled conclusively <g>...
on 8/12/01 1:21 PM, Larry Colen at lrcar@red4est.com wrote:
> I've got about 24,000 miles on the motor for my MGB, but about 1800 of
> those are on racetracks, which may accelerate the wear a little bit.
> I've noticed that the oil pressure that used to be really solid (75+)
> when the motor was fresh has dropped way down to about 35 when cruising
> and relatively cool, down as low as 12 when hot and idling.
>
> Sometimes under load, she seems to be making a deep thunking noise
> that is engine speed dependent, and she seems to get hot and lose
> power on protracted up hill stretches like driving over hwy 17.
>
> I have noticed that fresh oil seems to help. At the track the
> temperature guage would nearly max out which is why yesterday I
> managed to "Tom Sawyer" Max (thanks Max!) into installing my new
> radiator while I did other things to get the car back on the road
> after it's paintjob.
>
> Is there anything besides bearings that this is likely to be caused
> by? The wear seems rather premature to me, but then I know that a lot
> of racers will change bearing after only a few hundred miles of
> driving, rather than 1,800 miles of track and 22,000 miles of street.
>
> I don't have the money for doing so, but....
> I've heard good things about substituting the MG tranny with a Datsun
> tranny. I was getting all ready to do that when I found myself out of
> work a while back and never got back on track.
>
> What's the cost of that conversion? The O/D on my tranny died, and
> they are too expensive to wrestle with. Alternatively, I have what I
> expect may be a rebuildable O/D that I may be willing to swap for a
> good 4 synchro tranny.
>
> I'm pretty happy with my $200 20/20 paint job. There are inded flaws,
> she won't be winning any carshows, but it's a lot better than before:
>
> http://www.red4est.com/jasmine/beforepaint/
> http://www.red4est.com/jasmine/afterpaint/
>
> Larry
--
Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the red one with the silver bootlid.
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