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Old 01-05-2013, 11:14 AM
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Originally Posted by cobalt327 View Post
Cutting the deck is all well and good, but you do not depend on cutting the deck for raising the compression as much as the deck is cut to obtain a good quench figure. That the compression may be raised is secondary to that. Get a clue.

Surely you must realize that the quench distance should be about 0.040". That is done regardless of compression ratio. The chamber volume and dish/dome volume is where the compression ratio is 'made'- NOT the head gasket thickness or deck height, except as a secondary effect to getting the quench right. Get a clue.

A Pontiac 455 can make well over 450 HP on 9.5:1 CR. 450 HP can be done w/9:1. This is NOT a SBC!!! Cutting a Pontiac head 0.060" most certainly WILL do something, AFA compression ratio is concerned. Get a clue.

One more time: The lower compression ratios of the '70s were NOT related to mileage- it was done for emissions. If mileage was a concern, they'd have used different cam timing and a different piston design. And higher compression can potentially get better mileage than lower.

Get a clue!!!
Heres your clue head gasket is .041 quench solved. Zero decking the block will give you more cr increase than cutting the heads. You do realize with 4x heads its going to be a pass. Car engine and did not come with pop ups or flat tops pistons.

My 455 ho had more than 9.5:1 from the factory it did not make 450 hp. Heads were also much better. A big cam big exhuast and good intake and carb got it to about 340 at the wheels and some tuning and tweaking got it a little higher but no dyno on that it was a small gain. I was told by several ppl this was actually pretty good for stock long block.
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