62cc J Head Chamber

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OLFOOL

OLFOOL
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I have a set of J heads with 68cc chambers, I need 62cc to reach the 10.4:1 compression I need. I already have a set of Cometic head gaskets .060" which I will use. Has anyone milled them that far?
 
I have a set of J heads with 68cc chambers, I need 62cc to reach the 10.4:1 compression I need. I already have a set of Cometic head gaskets .060" which I will use. Has anyone milled them that far?
Talk to your machine shop. They will do the milling and know how far they need to go to get there. (with or without your head gasket you want to use)
 
I have a set of J heads with 68cc chambers, I need 62cc to reach the 10.4:1 compression I need. I already have a set of Cometic head gaskets .060" which I will use. Has anyone milled them that far?
Mine are 60cc
Why the .06 gasket?
 
I have a set of J heads with 68cc chambers, I need 62cc to reach the 10.4:1 compression I need. I already have a set of Cometic head gaskets .060" which I will use. Has anyone milled them that far?

that’s about 30 thou…no sweat.. but why the thick gaskets
 
What's the reasoning to get 10.4 comp? Big cam with pump gas? No reason to mill a lot and cause intake mounting issues when thinner gaskets are available.
 
I have a set of J heads with 68cc chambers, I need 62cc to reach the 10.4:1 compression I need. I already have a set of Cometic head gaskets .060" which I will use. Has anyone milled them that far?
I paid $140 for an 0.005" cut on both heads a few months back. You will need a few passes to get them down to 62cc.
Serco in Capalaba will probably make you a thin set of cometics for less than the machining costs.
But a cheaper thin composite gasket will probably do the job for much less.
Hell you might even be able to pop the rivets on the 0.060" gaskets and take some layers out to get down around 0.028" thick.
 
I have a set of J heads with 68cc chambers, I need 62cc to reach the 10.4:1 compression I need. I already have a set of Cometic head gaskets .060" which I will use. Has anyone milled them that far?

Yes. Mine are at 60 cc
 
My J heads cc'd at 72, if I remember right. They are ported out, with oversize valves. Does that mean I can go from the blue Fel Pro PermaT, to a thinner gasket, and make more power? Asking for a friend...
 
Shops that charge per pass suck balls.
Talk about nickle and diming someone...
A lot of shops here charge like that - up to 0.015" is X $$, between 0.015" - 0.030" X $$ and so forth.
One place quoted me $220, I figured they didn't need the work...
 
I have a set of J heads with 68cc chambers, I need 62cc to reach the 10.4:1 compression I need. I already have a set of Cometic head gaskets .060" which I will use. Has anyone milled them that far?

Sooooooo about .030 to get to where you want to be. Then, I'd mill the intake side of the head for another batch of money. If it were me, I'd sell the gaskets and get thinner ones and be done.
 
A lot of shops here charge like that - up to 0.015" is X $$, between 0.015" - 0.030" X $$ and so forth.
One place quoted me $220, I figured they didn't need the work...
The set up is once... all it is after that on a run of the mill 'pun intended ' machine...is turning the dial before the next pass...or even easier selecting the amount/program.
Can find a number of things to do while it runs back n forth.
 
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