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.

 

http://www.cometic.com/catalogs/harleydavidson.pdf

 

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.

 

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.

 

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.