Trying to reduce compression on my Hemi. It has 12.5 to 1 TRW pistons, went assembling engine put a steel embossed gasket on first then a .040 dead soft copper gasket. Used high tack gasket sealer on all 4 sides and assembled it. Compression is now about 11 to 1 with a cranking pressure of 215 psi to high for iron heads I believe??? Been thinking of buying a set of MP aluminum heads and running the same head gasket setup with maybe .010 thicker steel or copper heads gasket combo. Don't really want to change pistons because might end up boring block to .60 over. The TRW's have .011 piston to wall clearance now, max p/w is .013 on these early 70's pistons. Maybe able to go .040 over but then a rebalance of engine is in order? Doubt I could get pistons the same weight, custom wrist pins to bring weight up to old piston weight? Little leery of using Cometic head gaskets because of block surface finish.
Haven't had any sealing issues with the copper steel head gasket combo. Just wondering/ want opinions whether the switch to aluminum heads will work ok.
Haven't had any sealing issues with the copper steel head gasket combo. Just wondering/ want opinions whether the switch to aluminum heads will work ok.