I have a question regarding the advertised compression ratio for the standard pass car 455 engine. If my memory serves me correctly it advertised as a 10 to1. Has anyone ever checked this to verify? I am planning to do a camshaft swap (probably a KB 118 or something on those lines) for my 62,000 mile '70 Wildcat convertible in the future and I do not want to have detonation issues and I want to be able to run pump gas.I was wondering if I replaced the factory steel shim head gaskets with say a Fel-Pro blue where would the motor be compression wise.i'm sure the cam would help bleed off some cylinder pressure also.But the priorty here is pump gas,with my '70 Skylark 455 being 12.5 to 1 it severely limits how much I drive the car and I want to be able to enjoy the 'Cat without turning the factory cast pistons into dust.Thanks in advance.
I think the actual compression was closer to 9.5 to 1 or so....I had a stock 70 455 engine I put a gsca 220/230 into and it ran just fine on regular gas for many years... later Tim
Tim is right on, about 9.5 comp. Going to the fel pro's will lower your compression by 1/2 point. There are other things that can be done to heads enabling you to run reg.pump gas without detonation. Randy
If that's the case with the motor being 9.5 to1 then I should probably try to find a set of steel shim head gaskets if I remove the heads and leave it there as apposed to dropping it to 9 to1 with the Fel Pro's.
I've also heard the figure of 9.2 (from John Osborne). Get the steel shim gaskets if you can. Most of the time, used ones can be cleaned up and reused.
