L-92 70cc chamb -28 dish pistons What head gasket?
03-09-2007, 10:40 AM
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L-92 70cc chamb -28 dish pistons What head gasket? I was wondering if anyone ran into this. I have 70cc chambers and -28cc dished diamond pistons and was wondering which head gasket to stay at 8.5 to 9.0. I was on the Diamond site and they say I would be at 8.4 but they don't say what gasket thickness. I know GM' s are .060 and Cometic makes .051 but do I really need copper? I will be running 15-20psi. I just hear copper is hard to seal.What are your guys thoughts?
03-10-2007, 10:16 PM
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Originally Posted by phildo
I was wondering if anyone ran into this. I have 70cc chambers and -28cc dished diamond pistons and was wondering which head gasket to stay at 8.5 to 9.0. I was on the Diamond site and they say I would be at 8.4 but they don't say what gasket thickness. I know GM' s are .060 and Cometic makes .051 but do I really need copper? I will be running 15-20psi. I just hear copper is hard to seal.What are your guys thoughts?
Mine is 8.80:1
L92 70cc 9.230" deck
+0.006" out of the hole
4.00" 1.125ch 16cc Piston
6.300" rod 6.622 stroke crank
4.060" X 0.051" Cometic gasket
Frank
03-12-2007, 05:06 PM
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Originally Posted by phildo
Sorry it is a 4.00" stroke,4.00" bore with 6.125 rods.
With a 28cc 9.240" deck +0.010 out of the hole you would be 8.72:1 with the 4.060 X 0.051 gasket. Perfect!
Frank
Last edited by StingrayCrazy; 03-14-2007 at 04:09 PM.
03-12-2007, 11:18 PM
#5
4" stroke
4" bore
.051" gasket
70cc heads
-28cc pistons
equals 8:6:1
.060" gasket would equal 8:5:1
Cometics are not copper, although they do make them. There standard gasket is MLS, like the GM's. If you don't mind the thicker gasket, the GM's are the way to go. If you HAVE to thin them out, the cometics come in almost any thickness.
4" bore
.051" gasket
70cc heads
-28cc pistons
equals 8:6:1
.060" gasket would equal 8:5:1
Cometics are not copper, although they do make them. There standard gasket is MLS, like the GM's. If you don't mind the thicker gasket, the GM's are the way to go. If you HAVE to thin them out, the cometics come in almost any thickness.