Id avoid the swirl style squish bands...Heres why.

Some of the intent of a squish band is to get the fuel air mixture towards the center of the head- the combustion pocket. Squish clearances that are too big trap good fuel air mixture and its not sent to the combustion pocket where it can be put to good use- COMBUSTION and power.

Now if we have a head that is swirling the mixture that is in the squish band, my thoughts are that the mixture that is farting around swirling and jiving around isnt where it needs to be. In the combustion pocket.

 

I have seen two different styles. One had about 6 big grooves in it. The pockets are large and are at a very steep angle. A steep angle in relation to lines drawn radially out from the center of the chamber. I think they would reduce the efficiency of the squish band just like Backcountry stated. The other style is a lot of little angles. I saw an LT250 head that was supposed to have been done by Trinity that was like that. The grooves looked to be at about a 30 degree or less angle. This second design would not cause as much of a swirl. I think it also would not disrupt the squish effect as much either.

I guess the main question I have is what is better about a swirl? Based on what I have read, a wide swish band with a deep dome gives better low end with a loss of top end due to high squish band velocity causing high turbulence at high RPM. Possibly the swirl would lower turbulence at high RPM allowing the use of a wider squish band resulting in better low end without the loss of top end. I'd like to hear the benefits from someone doing it as well as numbers to back up that it really works.

 

The CORRECT combustion chamber design can and wil lmake a huge difference in power and engine over-rev.

I am not allowed to advertise on the forum but if you want to talk heads please contact me.

Kelsey

 

torqueline head with 23.5cc dome and orings. its nice having something different than everyone else and its better.

 

something else about my head that i was wondering if other aftermarket heads are the same. when i put a plug in it the gap is pointed in the perfect direction for burning unlike my stock head.

 

So all plugs are indexed the same? I can rotate the domes in my Pro Design head then tighten it down so the gap faces the intake.
ERIC

 

i can only put my dome in one way

 

chuck1221
ProDesign does make the heads for PT (Duncan). It comes down to what you want engraved on top, "Cool Head" or "Power Head"

 

Spinks250R hit it dead on when he said not to waste your money. I have the Trinity Pro-series head on one banshee, and racecut stock on the other. There is no power difference. No noticeable temp difference. The only difference is in my checkbook. Check out these numbers (for banshee):
Head-$330
New orings-$20
New domes-$40 each
If you are rebuilding your engine you still need a topend gasket set-$35

Racecut on stock head-$140 <--cheaper at other shops and single cylinders are half as much
topend gasket set with stock style head gasket-$35

Plus, I hate trying to line up a bunch of orings!!!

I have had good luck with stock head being recut on my polaris, 250r, banshee, blaster, yz490, and other bikes.