Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - pontiac 4x heads
View Single Post
  #19 (permalink)  
Old 01-05-2013, 09:59 AM
cobalt327's Avatar
cobalt327 cobalt327 is offline
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 616 Times in 565 Posts
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!!!
Reply With Quote