Head and compression questions???

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Originally posted by Fiat48
Closed chamber (109cc) would get you there.
You could angle mill the heads and get down to 110 cc roughly. But I don't advise that as it's permanent for the head. And your piston valve clearance will go down according to what you mill off the head.
Better way would be to change pistons. Get lighter pistons than you have now and it will just be a little overbalanced. That way you don't have to rebalance. And you don't mess up the heads.
But first you must find out how Speed pro is rating that compression chart by knowing:
How thick a head gasket are they figuring?
What deck clearance?
What bore size of head gasket?
These are all variables. You may be really at 8.25 to 1 with your deck, available head gasket.
Head milling chart: http://home.isoa.net/~mharrisj/mill.html
(Refering to the 2399f pistons)
Ok If we went to a closed chamber head wouldnt we run into problems with open chamber pistons. Piston to valve and piston to head clearance. i was looking at a set of 110cc heads.
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[Fiat48]

We determined with 0 deck you are already at 9.25 or close. You wanted 9.5. Isn't that close enough? If not, mill the heads.
1/4 point not worth the fight to get it.
Yes, closed chamber heads and these small dome open pistons would no doubt conflict.

[396_WAYS_TO_SPIT]

Ok thats whats I was looking for. I am thinking that we are running what we have.This is my buddy motor i am building for him thanks for the help Fiat48
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