MOUNTAIN SERIES BILLET HEADS = EASY POWER

[Speed Shop Inc.]

A great bolt on for your machine is our ProCool heads. The stock chamber has as anti detonation style dome, I call it anti-horsepower. By going to hemi style pocket and increasing the squish velocity you it's instant power. Our low Altitude head makes more power with slightly less compression even. And the Mountain series has a higher compression ratio so you benefit from the extra compression as well. Basically you get back a lot of what you lost as you go up in altitude. 91 octane premium pump gas is what we test with. You will notice a lot more low and mid range torque and grunt. And of course added peak horsepower as well. If you only do the head you don't need a fuel controller either. Along with a muffler is fine too. But a pipe and head combo require a fuel controller.


*** We also redesigned our head cover this year so that it uses o rings to seal the head bolts instead of using messy silicone. This way you don't have to mess with silicone to seal it. Much cleaner and nicer when you are installing the billet head kits on the AXYS.

 

[mountainhorse]

How much has the squish been "enhanced"... and what effect does your squish configuration have on the anti-deto effect in the chamber.

These "hemi" designs on 2 stroke heads often have problems meeting EPA regs... which is something that you don't have to worry about here.



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[Speed Shop Inc.]

Basically Polaris went away from the radius in the pocket and made it more like bath tube style and then having the spark plug protruding to aid in anti deto for bad gas basically. With good 91 octane the radius in the pocket works the best. And then I have simply played with different squishband widths and steps to see what it likes best. I'm not just jacking the compression to the moon, that isn't the case. This wider and tighter squishband with a relatively lower compression ratio to what you would use on a narrower squishband, worked out very well. It is very forgiving not to deto, and makes great power gains. Different motors like different designs. The cat for example prefers a narrower squishband. This is dome design that Me and Jim from Dynotech came up with years ago. And the Polaris motor just really likes it.

 

[icr]

What gains did you see on the dyno? Do you have a link to those runs for dtr customers?