choosing cc size?
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
This all depends on the rest of your set up, such as piston type, flat top, dished, dome,, etc. Factory dished will have approx 9.5 with 64 cc, flat tops will be higher, approx 10.2. With 72 cc and dished about 8.5 and flat tops about 9.2. Again these are approx. Head gasket thickness and bore size will allo chage this numer. Do a search here on the forum and you will find the formula to be a little more exact.
For a street engine able to live on pump gas stay under 10.0 compression, with the aluminum heads. I have a 383, dished pistons, Trick Flow 195 / 64 cc heads and I have a calculated 9.7 compression ratio using a composite head gadket .039 compressed thickness. I can run 89 octane without any problems. Haven't tried 87 yet. The more total timing you run, will give you performance but can limit your gas choices Best of luck
For a street engine able to live on pump gas stay under 10.0 compression, with the aluminum heads. I have a 383, dished pistons, Trick Flow 195 / 64 cc heads and I have a calculated 9.7 compression ratio using a composite head gadket .039 compressed thickness. I can run 89 octane without any problems. Haven't tried 87 yet. The more total timing you run, will give you performance but can limit your gas choices Best of luck
