Head Gaskets for Performance and Squish
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Road Master
Joined: Apr 2011
Posts: 772
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From: Corpus Christi, TX
Head Gaskets for Performance and Squish
So I'm planning a 107" build, and looking over my old engine-building notes, I recalled the whole quench/squish situation. (In the small-block Chevy world, we always called it "quench", but it's the same principle.)
The way I always set this was by measuring the deck height above the piston, then finding a suitable compressed-thickness gasket to get the correct squish.
So what are some good sources for different thicknesses of gaskets that will work with a 3.938" bore? I prefer copper, but am willing to take other suggestions.
The way I always set this was by measuring the deck height above the piston, then finding a suitable compressed-thickness gasket to get the correct squish.
So what are some good sources for different thicknesses of gaskets that will work with a 3.938" bore? I prefer copper, but am willing to take other suggestions.
Road Warrior
Joined: Dec 2008
Posts: 1,733
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From: Linden, NC
Road Warrior
Joined: Nov 2007
Posts: 1,984
Likes: 7
Axtell 107 cylinders.
My head guy milled the stock heads 0.060. Smoothed the edges around the bathtub.
Flattop forged pistons.
Installed per Axtell instructions which 3 years ago included a Evo base gasket. That or the piston would be too high.
0.030 Cometic Multi layer.
Zero deck heigh.
Squish is the gasket.
My head guy milled the stock heads 0.060. Smoothed the edges around the bathtub.
Flattop forged pistons.
Installed per Axtell instructions which 3 years ago included a Evo base gasket. That or the piston would be too high.
0.030 Cometic Multi layer.
Zero deck heigh.
Squish is the gasket.
Last edited by Old Gunny; Jun 6, 2011 at 01:13 PM.
HDF Community Team
Joined: Jun 2006
Posts: 12,776
Likes: 2,607
From: san antonio
Cometic is the best but there aren't that many different thickness. You should be OK with a .030" head gasket; stock Harley pistons are usually down in the hole .003"-.005". I do believe Cometic makes a .027" thick gasket as well.
BigBoyz makes copper but IIRC, only .030" thick.
BigBoyz makes copper but IIRC, only .030" thick.
Ultimate HDF Member
Joined: Feb 2007
Posts: 7,663
Likes: 7
From: Northeast Ohio
I have found that most , if not always the pistons are down in the hole by .009 in the newer bikes using stock pistons. If you are using pistons that have the pin set a bit lower to achieve zero deck height then settinh quensh is very easy. CP makes such pistons for the 107" builds. If using such pistons that are down in the hole, Headquarters has a .018 thick gasket that with the .009 will give you quench in the acceptable level.
If you achieve zero deck height, then the Cometic .030 works fine.
If you achieve zero deck height, then the Cometic .030 works fine.
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