BB Chevy Rebuild Books

[Duke W.]

Re: BB Chevy Rebuild Books

The only way to reduce CR without removing the pistons to reduce dome volume or replacing them with pistons with less dome is more gasket thickness. My recommendation for SHP big blocks is no more than 10.25 true, so double .040" gaskets will do it.

Double shim gaskets were used on SHP SBs in the early sixties. I don't know of any cases where double composition gaskets have been used, but it will probably be okay.

Maybe Clem can comment. He's tried just about everything at one time.

Duke

[Joel F.]

Re: BB Chevy Rebuild Books

John,

Cometic makes a 0.078 multi-layered steel gasket off the shelf, and can do a custom gasket up to .12

Joel

[John M.]

Re: BB Chevy Rebuild Books

Thank you Joe and Duke,
If I enter the 0.078" into the calculator I get 10.3 for the smaller volume chamber. I think my next move is to make accurate measurements of everything and if it comes out to 10.3 I'll go with the 0.078" (if you guys agree)
John

[John M.]

Re: BB Chevy Rebuild Books

Thanks Joel and Duke,
I went to the Cometic website but could not find the 0.078 one you mentioned. Do you have a part number for it?Thanks,
John

[Duke W.]

Re: BB Chevy Rebuild Books

A single .078" gasket sounds good. You can do a little chamber grinding to knock the highest ones down to 10.25.

Duke