Help with compression ratio
Thread Starter
Racer
Joined: Aug 2008
Posts: 457
Likes: 2
Help with compression ratio
Hi,I'm in the process of changing my cylinder heads.Right now I have on the Lt1 heads and I'm putting on AFR 210CC HEADS.I have a 1994 396stroker with a big solid roller cam.When I built my motor I had the lt1 heads all done up and i have custom JE piston with 11.1 compression ratio.When I put on the AFR heads with the LT4 intake what will happen to my compression ratio.The AFR heads are 64cc. thanks jeff
Le Mans Master
Joined: Aug 2000
Posts: 8,838
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From: Australia
Assuming the stock LT1 heads are 54cc , you are going to drop a heap of compression; down to approx 9.7:1
Going to need the heads milled down to reduce chamber size if you want to maintain CR.
http://www.wallaceracing.com/cr_test2.php
Going to need the heads milled down to reduce chamber size if you want to maintain CR.
http://www.wallaceracing.com/cr_test2.php
Team Owner
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Race Director
Joined: Jan 2005
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From: Slidell Louisiana
For normal aspirated engines (if every thing else remains the same he will lose some horsepower)
However, increaing the static compression ratio can help tame a big hairy cam . So if he has a big cam it may end up with worse manners on the street.
For the original poster there are lots of good engine calculators that will let you know where you are at and predict where you will end up.
MIke
However, increaing the static compression ratio can help tame a big hairy cam . So if he has a big cam it may end up with worse manners on the street.
For the original poster there are lots of good engine calculators that will let you know where you are at and predict where you will end up.
MIke
Last edited by aboatguy; Jul 26, 2009 at 12:01 PM.
