350 rear main bearing cap issue

[Chuck R.]

The machine shop FIANALLY started work on my 350 today and left me a message stating that he had found a problem around my rear main bearing cap and wanted me to see it first hand.

Needless to say, I was thinking all kinds of happy thoughts on the way over.

A portion of the lip on the cap it'self that holds the pan seal in place was broken out about 3/4 of an inch long.

Two questions:

1) How critical is the missing portion of the lip for total sealing against the oil pan?

2) If I find another bearing cap, will I have to have it line bored to the block or will it be a match out of the gates if it's the same style cap?

I'm actually entertaining thoughts of building it back up with brass.

Any thoughts?

Chuck

[Joe L.]

Re: 350 rear main bearing cap issue

Chuck----

If by "lip" you are referring to one of the "rails" on either side of the pan seal surface, I don't think that will be a problem, at all. If a significant part of the pan sealing surface is gone with it, that's another matter.

In any event, in either case you should be able to repair the area by brazing, silver solder, Muggy-Weld or, even, JB Weld. There's no particular strength requirement here and the repaired surface need not be precision-machined.

SERVICE rear main caps for small block Chevrolets have not been available from GM in years. So, that means that if you were to replace the cap you'd have to go used or aftermarket-new. In either case, the cap would have to be machined to register properly in the block and the engine would have to be align-honed (or, align-bored). For the problem you have as I understand it, I really don't think that you need to go to this effort and expense.

[Chuck R.]

Re: 350 rear main bearing cap issue

Well Joe that's a load off my mind.

I'll braze it up, dress it up and kiss it off!

Mr. L. the Mr. T. of Vettes

Thanks Joe,

Chuck