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Re: Ring job on 78 B

To: BOB HILL <oldcars@newt.vallnet.com>, mgs List <mgs@autox.team.net>
Subject: Re: Ring job on 78 B
From: Jim <microdoc@apk.net>
Date: Mon, 25 Oct 1999 11:27:31 -0400
1000 miles on a quart of oil is really not bad. 500 or less per quart is.

I have a '74 MGB-GT that used to consume scads of oil, but never made smoke.
It ran great, but was never the most potent B around. Before the engine swap,
it had deteriorated to 1qt every 100 miles ( I repeat, 100 miles!). Because
the head was stuck, and I had a completely rebuilt spare engine, I only
exchanged them. Subsequently, we pulled the bottom end, and then were able to
extract the pistons. The rings were perfect! They were measured and examined
under a microscope to confirm it. (That's my profession.) I had to conclude
that the problem was in the valves. Coupla years later my son helped me shake
the head loose. The valves were covered with combustion residue and
by-products. I confirmed that our second choice suspect was the guilty one.
The oil was being taken in from leaking intake valve guides and burned, hence
no smoke.

There is always a good argument for precautionary repairs and replacements.
There is also not limit to how far one can go with this. Certainly, if you
pull an engine, do a thorough clutch job and change the rear engine, and front
transmission seals. But in your case, in spite of the mileage, do a valve job
first. It's a heck of a lot less work and much less expensive. You can also do
it in one weekend with a Haynes manual. There is little duplication of effort
to first do the valve job, followed by the rings (whole engine rebuild), if
indeed that is necessary. The valves will want to be worked anyway. This route
may also hold off the big costly work until you are ready for it financially.

I estimate from experience gleaned as long as 15 years  ago that a valve job
will run $500-$1000, and an engine rebuild $1000-$2000. Certainly some other
owners can give you a more accurate estimate.

Well, that is only my opinion. Good luck.

Jim


BOB HILL wrote:

> I am looking at a 78 MGB and interested in purchasing the car.  The car is
> a very nice driver with good paint, almost perfect interior, all
> electricals work great and no rust.  THe problem with the car is that the
> owner says it uses about a quart ot 2 quarts of oil every 1000 miles.
> While there is no noticable smoking, obviously this oil consumption is WAY
> high.  FIgured it would need rings and probably with 105k miles, might
> replace the main bearing as well.  THe question I have is does any one
> have a ball part figure of what this would cost (parts and labor)?  THe
> gentleman hinted that he woudl take $2000 cash for the car and it sounds
> like a good deal IF the engine repairs are not excessive.
>
> Also, if anyone know where there is a rubber bumpered MGB that is a nice
> driver, please let me know.  Prefer in the southeast but would travel for
> the right B.
>
> Thanks
>
> Bob


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