.020 out of hole piston/ gm head gaskets = .033 quench
10-10-2013, 01:06 PM
#1
.020 out of hole piston/ gm head gaskets = .033 quench There's 2 ways to reach quench
Thinner head gasket such as .040 cometic head gasket, .007 piston out of the hole = .033 quench
.020 piston out of hole, .053 gm head gasket = .033 quench
My question is does it matter which way you go to achieve it? Cost wise the 2nd way is more expensive since you need to deck the block to reach .020 out of hole..
But is there a performance difference, side effects of doing it the 2nd way?
Thinner head gasket such as .040 cometic head gasket, .007 piston out of the hole = .033 quench
.020 piston out of hole, .053 gm head gasket = .033 quench
My question is does it matter which way you go to achieve it? Cost wise the 2nd way is more expensive since you need to deck the block to reach .020 out of hole..
But is there a performance difference, side effects of doing it the 2nd way?
10-10-2013, 03:54 PM
#3
There's 2 ways to reach quench
Thinner head gasket such as .040 cometic head gasket, .007 piston out of the hole = .033 quench
.020 piston out of hole, .053 gm head gasket = .033 quench
My question is does it matter which way you go to achieve it? Cost wise the 2nd way is more expensive since you need to deck the block to reach .020 out of hole..
But is there a performance difference, side effects of doing it the 2nd way?
Thinner head gasket such as .040 cometic head gasket, .007 piston out of the hole = .033 quench
.020 piston out of hole, .053 gm head gasket = .033 quench
My question is does it matter which way you go to achieve it? Cost wise the 2nd way is more expensive since you need to deck the block to reach .020 out of hole..
But is there a performance difference, side effects of doing it the 2nd way?
if it is, I suggest not going tighter then .030" quench or you risk kissing the head with the piston... in this case I would run the factory gasket, or a .060" cometic
10-10-2013, 06:18 PM
#6
My engine guy knew I was using ls9 head gaskets for the build.
Now that I think of it .020 seems high compared to others that's why I figured I'd ask and see what others thought
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10-10-2013, 07:15 PM
#9
Even stock from the factory, the tolerances can vary.
I have seen from .001 to .025. stock and hi-po builds.
The key question is how did you mesure this?
I find TDC. Then once its at its highest point, push down on one side of the piston and measure the other side with a dial caliper. Then vise versa the other side of the piston. Take the 2 numbers and add them, then divide by 2. This will give you the avg. and ballpark.
The most crucial thing is that you are simulating the rocking motion of the piston in the bore.
How did you come to the conclusion that you were .020 out of the hole? Is this after measuring both sides of the piston?
10-10-2013, 07:49 PM
#11
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I may be wrong, if so someone correct me, but for a turbo motor I thought one would want more quench then less. For an all motor car, less quench in the area you are running it, is good.
10-10-2013, 08:26 PM
#13
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You should be fine, you could run a bigger bore LS9 gasket. I think they are .055 thick. Mine are out of the hole about .010 to .012.
Oops, sorry you are running the LS9's
Oops, sorry you are running the LS9's
Last edited by 96lt4c4; 10-10-2013 at 08:32 PM.
10-11-2013, 03:55 PM
#15
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Not sure about the LS1 but My LM7's factory pistons were out of the hole .015" so when I bought aftermarket slugs n They were flush with the blocks deck I was a little surprised.
