If the power valve works anything like the ones on a multi-cylinder sled engine, it won't add top end power. It gives more low end power by mechanically lowering the exhaust port at lower RPM's. It would be an interesting addition, though.

 

DaveB;
You are failing to see the true advantage of an exhaust valve to an engine builder. With an exhaust valve; one can raise the exhaust port much higher without sacrificing bottom end. Higher exhaust opening = higher revs. Higher revs = more power. The exhaust valve will keep the taller exhaust port looking like a smaller port at partial throttle opening. The best of both worlds! Woohoooooooooooo!

 

Just got back from Little Sahara,Ok.There were a number of people giving me the thumbs up after a couple of passes on the drag strip.A couple of guy's stopped me just to make sure it was indeed a Polaris.Had a blast.If any one on here was there give me a shout.

 

Who and when is this power valve suppose to be public ?

 

Last week, when I was out at the shop, there were around a dozen cylinders sitting in the shop. One was installed on an HPD race chassis. Yes, these things put out 85hp. A really smooth operating custom designed valve. My new HPD shocks scream faster, faster, but with a couple of not so intentional off trail experiences last weekend, I don't think I'll be making any more hp additions. Treebark hanging on the jersey kinda makes the girlfriend angry.....gotta buy some more flowers.

Ken

 

[img]i/expressions/face-icon-small-happy.gif[/img] Ken, you forgot to mention the one big important thing to anyone wanting to run the big HP cylinder. Mike at HPD told me that you will have to buy a different pipe and reed cage and it seems something else as well as the cylinder to get that power gain. He said total package will be about $2000.00. I dont know about anyone else, but that is too much for me. I'll just take my race mod and put it on alcohol, then buy a good used trail bike. Anyone elase have an opinion on that price?? Bubba

 

[img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img] Hey Bob, I rode a full race mod 416cc on alcohol at little sahara, and it was outpulling my buddy's 310cc Honda 250r, even on the top end. I also weighed in about 125 pounds heavier total(i am 200lbs and he is a buck forty five) Now if you ever rode a light switch powerband 310cc all out drag motor, WHEW!!! The polaris just made monster torque and power. That 85hp will be crank power Im sure. I bet Ken's machine might just surprise you. HEY KEN! you never answered me on another post as to whether or not that was your machine in the ATV sport magazine. If it was, I wrote them a nasty letter telling them to get their figures corrected and stop trying to dyno a race clutch setup at such a low rpm. You would have been proud of you fellow Polarian!!!

 

Bob;
Nobody mentioned rear wheel h.p. here. The fact is that an auto tranny cannot be properly dynoed on an inertia dyno. All HPD's h.p. claims are taken at the crank. You can subtract 15-20% power to get a round about rear wheel h.p. figure. There are a couple of 760 Pami Raptors at the sand drags and several at Glamis, and not one has come close to beating me yet. While the Raptors are wheelying and bangin gears; I'm already through the whoops with my auto. No missed gears, always in the right gear and no loss of rpm's in between gears.
Don't get me wrong; I had an eye on a Raptor the first year, but seen too many failures with them at the dunes. This scared me off. There's guys at Glamis with nitrous Raptors and they still can't beat me. It's not just the h.p. that wins a race. It also is decided by driver skill, torque and the added benefit of the auto tranny. This is why many of the Banshee draggers are switching to lock out clutches and override trannies. I wish we lived closer as I love a good race. May the best man win!

 

If you guys race, someone should record it and post it on a website so we can all watch!

 

Ouch! $2000 for the cylinder, pipe and reeds? I think this will be another move like the HPD race chasis. Not many people are going to be able to afford it. Why spend $13,000 on the race chasis, when you can get a Cannondale Blaze for about $3000 less? The same thing with the new power valved cylinder. If you are starting from the bottom up, I could see the advantage in it. But if you already have the motor built, that's a heck of a lot of money to dump into a machine that all ready has a mint put into it. It ain't worth it (at least to me). Darryl must be following the old saying: "Speed is a question of money, how fast can you afford to go?" Plus, you would probably have to run race gas too. At $5+ a gallon, that could get slightly expensive really quick.