would anyone know the actual compression ratio of the 67 442. head cc and piston to deck height. olds must have used a thin steel head gasket ? not what they claimed but one measured on tear down. thanks for the help on the LSA cam post. thanks for your help on here too.

 

Designed for 10.5 and used the steel shim. Reality would vary from design per individual engine.

 

As-cast Olds heads run anywhere from 2-4 cc larger than the advertised blueprint chamber volumes. The blueprint number for a 1967 C head casting is 80cc. You'll typically measure 82-84 cc on a head that hasn't been touched. Unfortunately, you have no way of knowing if the car has had a valve job in the last half century, so all bets are off. The original head gaskets are 0.017" compressed height steel shim. The common blue FelPro head gaskets run about 0.040" compressed, so you lose some CR with them.

 

i can see and measure head gasket sticking out it's over .030 . do you know about how much the stock piston is in the hole ?

 

Deck clearance on an untouched "E" block is about .025" or so providing a total quench with the steel shim head gasket of approx .042" or so (correct me if wrong Joe or Joe).

 

ok thanks. going with what was posted here, split the heads at 82 cc, [ between 80-84] stock compression is 10.05, now with the .040 gasket i could be at 9.60. wondering way there was no pinging, plus the stock curve distributor and stock camshaft on a 114 LSA. makes sense. thinking 9.75 compression would be max on 91 octane on a rebuilt ?