compression questions????
04-06-2007, 06:10 PM
#1
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compression questions????
ok im kinda new to the tuning and im learning as i go... im about to go turbo soon and i know that are cars cant handle to much boost on the stock block (to be safe for an everyday driver) well i heard a rumor that if you double up the gaskets on the head it will lift the the head up another millimeter thus changing the compression and if you lower the compression then youll be able to do more boost???? so is this true and if it is true, is it safe? all coments are accepted!!!
04-06-2007, 06:37 PM
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right i know you can do that... but like i said i had heard this and i was wondering is it true you can do it and is it safe????
i mean all your doing is adding another gasket and then tighten it down real good and technically you shouldnt have any problems??? right????
i mean all your doing is adding another gasket and then tighten it down real good and technically you shouldnt have any problems??? right????
04-08-2007, 12:22 AM
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The Myth of head lifting explained...
Here's when you may want to have a thicker head gasket...
-1--When you mill the head, you technically shorten it a little bit. Therefore increasing compression slightly. A thicker gasket will offset the head thickness slightly so things remain close to stock.
-2--In some occasions, over-sized pistons will require a slightly thicker head gasket. This isn't common though, because most aftermarket pistons put in cars are lower compression anyway.
Reasons NOT to install a head gasket spacer, or a thicker gasket.
-1--More than one gasket increases your seal points. Chances of a leaking/blown head gasket are increased.
-2--You can sometimes INCREASE your chances of detonation. In regards to the tC, I think this will happen. We don't have the best fuel pressure. When you raise the head a little but, you alter quench (see below for description). Lowering quench increases detontation.
-3--Chamber geometry. When you increase the combustion area, you change the chamber geometry. This can also result in detonation making you're care more prone to knock and short term life.
Quench is basically the fuel spread in your combustion chamber. Higher fuel pressures will better "quench" the combustion chamber resulting in a cleaner burn, with less detonation.
When you change chamber geometry, you also alter the tune a little bit. The result is a slight change in igntion timing, along with a couple other variables.
NOTE: Some cars to benefit from bumping the head height with a thicker gasket or spacer. The tC is not one of them.
Hopefully that helps! On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
Here's when you may want to have a thicker head gasket...
-1--When you mill the head, you technically shorten it a little bit. Therefore increasing compression slightly. A thicker gasket will offset the head thickness slightly so things remain close to stock.
-2--In some occasions, over-sized pistons will require a slightly thicker head gasket. This isn't common though, because most aftermarket pistons put in cars are lower compression anyway.
Reasons NOT to install a head gasket spacer, or a thicker gasket.
-1--More than one gasket increases your seal points. Chances of a leaking/blown head gasket are increased.
-2--You can sometimes INCREASE your chances of detonation. In regards to the tC, I think this will happen. We don't have the best fuel pressure. When you raise the head a little but, you alter quench (see below for description). Lowering quench increases detontation.
-3--Chamber geometry. When you increase the combustion area, you change the chamber geometry. This can also result in detonation making you're care more prone to knock and short term life.
Quench is basically the fuel spread in your combustion chamber. Higher fuel pressures will better "quench" the combustion chamber resulting in a cleaner burn, with less detonation.
When you change chamber geometry, you also alter the tune a little bit. The result is a slight change in igntion timing, along with a couple other variables.
NOTE: Some cars to benefit from bumping the head height with a thicker gasket or spacer. The tC is not one of them.
Hopefully that helps! On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
04-09-2007, 01:12 PM
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Originally Posted by Joe_Dezod
The Myth of head lifting explained...
Here's when you may want to have a thicker head gasket...
-1--When you mill the head, you technically shorten it a little bit. Therefore increasing compression slightly. A thicker gasket will offset the head thickness slightly so things remain close to stock.
-2--In some occasions, over-sized pistons will require a slightly thicker head gasket. This isn't common though, because most aftermarket pistons put in cars are lower compression anyway.
Reasons NOT to install a head gasket spacer, or a thicker gasket.
-1--More than one gasket increases your seal points. Chances of a leaking/blown head gasket are increased.
-2--You can sometimes INCREASE your chances of detonation. In regards to the tC, I think this will happen. We don't have the best fuel pressure. When you raise the head a little but, you alter quench (see below for description). Lowering quench increases detontation.
-3--Chamber geometry. When you increase the combustion area, you change the chamber geometry. This can also result in detonation making you're care more prone to knock and short term life.
Quench is basically the fuel spread in your combustion chamber. Higher fuel pressures will better "quench" the combustion chamber resulting in a cleaner burn, with less detonation.
When you change chamber geometry, you also alter the tune a little bit. The result is a slight change in igntion timing, along with a couple other variables.
NOTE: Some cars to benefit from bumping the head height with a thicker gasket or spacer. The tC is not one of them.
Hopefully that helps! On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
Here's when you may want to have a thicker head gasket...
-1--When you mill the head, you technically shorten it a little bit. Therefore increasing compression slightly. A thicker gasket will offset the head thickness slightly so things remain close to stock.
-2--In some occasions, over-sized pistons will require a slightly thicker head gasket. This isn't common though, because most aftermarket pistons put in cars are lower compression anyway.
Reasons NOT to install a head gasket spacer, or a thicker gasket.
-1--More than one gasket increases your seal points. Chances of a leaking/blown head gasket are increased.
-2--You can sometimes INCREASE your chances of detonation. In regards to the tC, I think this will happen. We don't have the best fuel pressure. When you raise the head a little but, you alter quench (see below for description). Lowering quench increases detontation.
-3--Chamber geometry. When you increase the combustion area, you change the chamber geometry. This can also result in detonation making you're care more prone to knock and short term life.
Quench is basically the fuel spread in your combustion chamber. Higher fuel pressures will better "quench" the combustion chamber resulting in a cleaner burn, with less detonation.
When you change chamber geometry, you also alter the tune a little bit. The result is a slight change in igntion timing, along with a couple other variables.
NOTE: Some cars to benefit from bumping the head height with a thicker gasket or spacer. The tC is not one of them.
Hopefully that helps! On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
finally .... thanks for the answer..... like i had said before i heard something but i wanted facts and details!!!! you deff answered my question and you had facts to back it up!!!!!
04-09-2007, 02:27 PM
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If you want to lower compression you can add a thicker cometic gasket to try to decrease knock levels but it is questionable and not worth the trouble to do for the reasons explained above. The proper way is to change the pistons which obviously you would want to change the rods as well.
04-09-2007, 05:31 PM
#11
Originally Posted by Joe_Dezod
The Myth of head lifting explained...
Here's when you may want to have a thicker head gasket...
-1--When you mill the head, you technically shorten it a little bit. Therefore increasing compression slightly. A thicker gasket will offset the head thickness slightly so things remain close to stock.
-2--In some occasions, over-sized pistons will require a slightly thicker head gasket. This isn't common though, because most aftermarket pistons put in cars are lower compression anyway.
Reasons NOT to install a head gasket spacer, or a thicker gasket.
-1--More than one gasket increases your seal points. Chances of a leaking/blown head gasket are increased.
-2--You can sometimes INCREASE your chances of detonation. In regards to the tC, I think this will happen. We don't have the best fuel pressure. When you raise the head a little but, you alter quench (see below for description). Lowering quench increases detontation.
-3--Chamber geometry. When you increase the combustion area, you change the chamber geometry. This can also result in detonation making you're care more prone to knock and short term life.
Quench is basically the fuel spread in your combustion chamber. Higher fuel pressures will better "quench" the combustion chamber resulting in a cleaner burn, with less detonation.
When you change chamber geometry, you also alter the tune a little bit. The result is a slight change in igntion timing, along with a couple other variables.
NOTE: Some cars to benefit from bumping the head height with a thicker gasket or spacer. The tC is not one of them.
Hopefully that helps! On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
Here's when you may want to have a thicker head gasket...
-1--When you mill the head, you technically shorten it a little bit. Therefore increasing compression slightly. A thicker gasket will offset the head thickness slightly so things remain close to stock.
-2--In some occasions, over-sized pistons will require a slightly thicker head gasket. This isn't common though, because most aftermarket pistons put in cars are lower compression anyway.
Reasons NOT to install a head gasket spacer, or a thicker gasket.
-1--More than one gasket increases your seal points. Chances of a leaking/blown head gasket are increased.
-2--You can sometimes INCREASE your chances of detonation. In regards to the tC, I think this will happen. We don't have the best fuel pressure. When you raise the head a little but, you alter quench (see below for description). Lowering quench increases detontation.
-3--Chamber geometry. When you increase the combustion area, you change the chamber geometry. This can also result in detonation making you're care more prone to knock and short term life.
Quench is basically the fuel spread in your combustion chamber. Higher fuel pressures will better "quench" the combustion chamber resulting in a cleaner burn, with less detonation.
When you change chamber geometry, you also alter the tune a little bit. The result is a slight change in igntion timing, along with a couple other variables.
NOTE: Some cars to benefit from bumping the head height with a thicker gasket or spacer. The tC is not one of them.
Hopefully that helps! On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
04-10-2007, 01:57 AM
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just to be on the same note, i know running a thinner head gasket is often used in some SBChevy's to get hp....
i assume that to be a bad idea for a tC since a thicker one is as well?
i assume that to be a bad idea for a tC since a thicker one is as well?
04-10-2007, 06:45 PM
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Originally Posted by Joe_Dezod
On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
Good luck!
04-14-2007, 09:46 PM
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Originally Posted by AcrimoniousBear
Originally Posted by Joe_Dezod
On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
Good luck!
04-15-2007, 01:50 AM
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Originally Posted by Whocares05050
Originally Posted by AcrimoniousBear
Originally Posted by Joe_Dezod
On another note, here's a tip on detonation. The tC has somewhat poor fuel delivery. Throwing in a good pump and fuel pressure regulator with higher fuel pressure will atomize the fuel better within the combustion chamber. Better atomized fuel not only makes more power, but with less chance of detonation.
Good luck!
Good luck!
...I'll explain;
A fuel pump can maintain a certain AFR (your example of 14psi on the stock pump works perfect). I'm not disagreeing with you about the pump keeping up. The issue at hand is detonation. Sure the pump can keep up but what about the fuel pressure? Poor pressure results in detonation due to the fuel particles not atomizing properly. High pressure fuel systems with the same AFR will work better than with the original. Less detonation is always best.
Whocars, please do not take that as a personal attack because I'm definately not out to do that. I WILL believe you when you say you can run 14psi on the stock pump. On that note though, a better fuel system with higher fuel pressure will still run better, and with more reliability.
Hope that helps guys!