Effects of compression
Thread Starter
TECH Fanatic
Joined: Aug 2003
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From: Newport News, Va
Effects of compression What effects compression? Besides heads, gaskets, and pistons? Also, what if you have like 9:1 Pistons, but 10:1 heads? And Can someone elaborate on gasket info?
Sorry for all the questions, but I really dont understand compression factor
Thanks all for being helpful
Sorry for all the questions, but I really dont understand compression factor
Thanks all for being helpful
TECH Resident
Joined: Nov 2002
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From: Orlando
Pretty much a combination of all of the factors you list will affect the compression ratio (CR). If you use a thinner head gasket, you can effectively raise the CR because you are pulling the head closer to the block deck and taking away room in the compression chamber for the charge to fill. The less room, the higher the CR in a basic sense. You are better off trying to achive the CR you want with the heads than you are trying to change pistons in an LS1. If you have heads with larger CC's (i.e. the 6.0 heads), then the CR will lower because there is more room for the charge to fill up. Heads with smaller CC's (i.e. the 5.3 heads) will raise the compression. Get it? Also, milling stock heads can also raise the CR using essentially the same logic as swapping to a thinner head gasket.
Thread Starter
TECH Fanatic
Joined: Aug 2003
Posts: 1,049
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From: Newport News, Va
Oh, Thanks Alot that makes sense. I new about the smaller combustion chamber. The running thing is, today on our chemistry test, we had a qwuestion about pressure, when you decrease and increase the cylinder volume. It was pretty cool, But Thanks alot for the help!
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From: Atlanta, GA
Altering the combustion chamber also alters the squish of the cylinder. Believe it or not GM probably spent many millions to design an optimal combustion chamber, so when you decide to change the geometry, keep that in mind.
It is possible to lower compression (For boost for example) and induce more detonation than at stock compression by altering the squish.
I've seen it on a few different engine types (not ls1) by going to 9.5:1 from 10.5:1 they ended up using losing power with more boost. Reason the motor was less detonation prone in its original design than the methods (pistons/stacked gaskets,etc) than the original setup from the factory.
I'm sure it has some relevance to n/a but in the boosted world it is a very serious thing to consider.
It is possible to lower compression (For boost for example) and induce more detonation than at stock compression by altering the squish.
I've seen it on a few different engine types (not ls1) by going to 9.5:1 from 10.5:1 they ended up using losing power with more boost. Reason the motor was less detonation prone in its original design than the methods (pistons/stacked gaskets,etc) than the original setup from the factory.
I'm sure it has some relevance to n/a but in the boosted world it is a very serious thing to consider.
