Oversized case bearings
 

I started checking clearances on my new racing engine and to my surprise the main bearings seem to have about 0.010" of clearance. I remiked the crank and it was within spec. Measured the case to find out it has been oversized (62.250mm).

I guess the guy that sold me the case forgot to mention this detail. So now I am in a quandry. I have searched the forum and Henry wrote the oversize bearings are no longer available even at the exhorbinate price.

I have another case (call it case B), but I have a lot of machine work in this case A and case B doesn't have piston squirters. I do not know how straight the mains are in case B.

During my search I came accross cgarr's post about using steel sleeves on the through bolts to help stabilise the case. I like that idea. It would require the cases to be machined on the centerline and the mains rebored, this time back to 62mm. the intermediate shaft and main seal bores would also need to be remachined. A lot of work but I would have a better bottom end for it.

All that being said now to the reason for the post.

Does a 2.2 street engine have the same problem with oval main caps as the 2.7 engines. What is the probability that case B will need to be machined?

Any new information on the oversize bearings fom Porsche? I should mention the number 8 bearing is overbored also.

What would you do?

brgs
 

Neil, I may have a new set of O/S mains with std. crank dimensions for a 2.7 case, I can check on monday

Mike Bruns

Thanks Mike that would open up an option. This is a 3R case so the 2.7 would work.

Just bought a set of .25 oversize main bearings at Carlsen Porsche in Palo Alto, CA. They had them in stock, great guys.

eastbay,

How much were they?

I think they were ~ $650-$700