Compression Vs. Quench?
09-01-2003, 06:59 AM
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Car: 1991 Firebird
Engine: 383 stroker
Transmission: T-56
Compression Vs. Quench?
Well I just found out that I can't use my SCE copper gaskets cause they need ring grooves and everything I have already is assembled, so I'm not going that route. So now I have to order another set but I'm already fight compression ratio as it is, but I don't wanna move too far away from the "optimum" .040 quench space. For some background, I'm putting together a 383 with 220cc port 64cc Pro Topline Iron heads with a 236/242 .539/.558 cam. Now here's the Fel Pro's and specs that I've been looking ok.
1004- .041 comp 4.190 bore--> 10.72:1 and .054 quench area
1014- .039 comp 4.200 bore--> 10.77:1 and .052 quench area
1034- .041 comp 4.200 bore--> 10.71:1 and .054 quench area
1044- .051 comp 4.200 bore--> 10:44:1 and .064 quench area
The quench areas that I've listed are from a .013 piston to deck height that I measured by taking a pushrod and laying it across the bore and using a feeler guage since I don't have a dial indicator and stand. So a question is now, if I were to go with the 1014 and run a .052 quench, I'll be up to 10.77:1. But if I go with the 1044, my compression with be down to 10:44:1, but my quench will be up to .064 which is not gonna help detonation. So I'm kinda torn between trying to bring the compression down a bit or try to keep the quench as tight as possible. Any opinions would be great.
Tom
1004- .041 comp 4.190 bore--> 10.72:1 and .054 quench area
1014- .039 comp 4.200 bore--> 10.77:1 and .052 quench area
1034- .041 comp 4.200 bore--> 10.71:1 and .054 quench area
1044- .051 comp 4.200 bore--> 10:44:1 and .064 quench area
The quench areas that I've listed are from a .013 piston to deck height that I measured by taking a pushrod and laying it across the bore and using a feeler guage since I don't have a dial indicator and stand. So a question is now, if I were to go with the 1014 and run a .052 quench, I'll be up to 10.77:1. But if I go with the 1044, my compression with be down to 10:44:1, but my quench will be up to .064 which is not gonna help detonation. So I'm kinda torn between trying to bring the compression down a bit or try to keep the quench as tight as possible. Any opinions would be great.
Tom
09-01-2003, 08:14 AM
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Car: 1987 Camaro Z-28
Engine: 6.3L Victor EFI
Transmission: Tremec TKO 600
Axle/Gears: Moser 9"/4.11 Trac-Lok
The 1014 is the way to go. I used that in mine & got about 10.6 with the piston .010" in the hole & 68cc chambers.
09-01-2003, 12:26 PM
#3
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I got a real good solution for you. GMPP head gaskets. They're composition style head gaskets so they're real easy to seal up (vs. a steel-shim gasket, for instance) but their compressed thickness is only .028" which will bring your quench distance down where you want it. Link below....
http://www.sdpc2000.com/cart.asp?act...id=576&pid=651
I used them in my current 383 when I was in the exact same situation as you. I'm running boost and making 450-500HP- no problems whatsoever.
http://www.sdpc2000.com/cart.asp?act...id=576&pid=651
I used them in my current 383 when I was in the exact same situation as you. I'm running boost and making 450-500HP- no problems whatsoever.
09-01-2003, 05:23 PM
#4
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Should have worked this out before you ordered the pistons or heads.
grind 4/5 cc's out of each combustion chamber.
Not that hard. The cr is a little too high for 92 octane gas.
Anything worth doing, is worth doing right.
grind 4/5 cc's out of each combustion chamber.
Not that hard. The cr is a little too high for 92 octane gas.
Anything worth doing, is worth doing right.
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