[nick22100]

So I bought a 306(302 bored .030 over) from a friend of a friend. Bad idea. Along with problems with valve seating which I have had professionally fixed the pistons are sticking .007 above the deck surface at top dead centre. It has 1.94 int. and 1.6 exh. Valves also. They are flat top pistons with 4 valve reliefs equalling 2.00 cc. It's my understanding the combustion chambers are 64cc or bigger then stock.

My question is, is .007 above the deck a lot? Will I be running a really high CR? I definatley do not want to be running 110 octane. This is a street car.

Thanks for the help!

 

[BuckeyeDemon]

just put a thicker head gasket on it. i think mine are out more than yours.

 

[rex1965]

You need to check the valve to piston clearance also, as the 1.94 and 1.60 are bigger that stock, so the valve reliefs may not be far enough out on the pistons, if you have to cut some new reliefs, this will also lower the compression ratio a small amount. Good Luck.

 

[Mustangfreak196]

Definitely check your ptv clearance. .007 in the real world is not a lot. That's about the combined thickness of two sheets of paper. Just use a little thicker head gasket if you are worries about it.

 

[cindys_sn95]

this is actually a good thing. use a felpro 1152 head gasket. it is .045 compressed thickness giving you .038 quench. perfect! and with the 64 cc head you should be right at 9 to 1.:bigthumbsup

 

[kenash]

Yes, .007 is not a worry, as long as, you compensate for it in the manner that has been posted. Your alternative is to mill the .002. Also know, if you care, these changes affect your CR.
My pistons are above deck .005, but, was considered in building the overall package. If you look closely, you'll see it protruding...