Help with heads...Please!!!

[Erik the Awful]

Interesting. Summit's calculator says with the piston .020" in the hole, a 72cc head, and a .020" gasket it's over 10:1.

 

[Schurkey]

Interesting. Summit's calculator says with the piston .020" in the hole, a 72cc head, and a .020" gasket it's over 10:1.

4" bore, 3.48" stroke? I wouldn't have guessed.



There's a limited selection of .020 head gaskets, they may/may not fit the combustion chamber.

Most pistons won't be "only" .020 in the hole, unless you machine the decks a bunch. With cheap "rebuilder" pistons, you're more likely to be .040 in the hole, or worse.

Getting decent compression in the real world with 72--75 cc heads can be challenging. Most folks side-step a third of the problems by going to the 63--64 cc heads.