klemet banshee Posted January 31, 2009 Report Share Posted January 31, 2009 (edited) i can get a KILLER deal on powervalve cylinders on there third bore .30 i think wat a dumbass he doesnt know his asshole from a hole in the ground lol but it doesnt come with the servos or other stuff so all you rz guys list what i need and let me know if these parts are hard to find Edited January 31, 2009 by klemet banshee Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted January 31, 2009 Report Share Posted January 31, 2009 so they are rz cylinders? i wouldnt fuck with them. not worth the hassle in my opinion. youre not gaining anything you couldnt get by just using your own cylinders. Quote Link to comment Share on other sites More sharing options...
4stroker Posted January 31, 2009 Report Share Posted January 31, 2009 so they are rz cylinders? i wouldnt fuck with them. not worth the hassle in my opinion. youre not gaining anything you couldnt get by just using your own cylinders. how do u figure that? wouldnt you like a nice broad power band with the peak power of a drag ported cylinder? having said that though, there is alot of fucking around with them. you need the complete RZ electrical system, including stator, flywheel, cdi, servo and controller. or you could just buy a zeeltronic cdi (www.zeeltronic.com), an R1/R6 exup servo (easy to find on ebay) and run your banshee stator and flywheel. you would then have a programmable ignition (comes with hand held programmer) and programmable pv controller. the zeeltronic set up would prob run you $300 and the servo another $100. you would have to get it wired yourself but its piss easy, comes with the diagrams and everything. so if ur gettin the cyls cheap and your mechanically inclined, it will work out really really good. what pipes have u got at the moment? you need to make a super flat pv cover so the left pipe clears. my toomeys fitted fine with this setup. oh yeah does it come with the head? banshee head wont fit. Quote Link to comment Share on other sites More sharing options...
FireHead Posted January 31, 2009 Report Share Posted January 31, 2009 ...........let me step up on my soap box here for a minute: With regard to a Banshee style engine, power valves can make sense if electronically controlled in a cylinder designed for them. On the other hand, the mechanical pressure responding valves found in a Cheetah, some Big Block Twisters, T-Rex's, etc., need a very specific set of conditions to work properly. Aftermarket cylinder block designs have progressed to a point with Banshee style engines that power valves don't make sense for most folks. If y'all are interested, I can dive deeper into this..... Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted January 31, 2009 Report Share Posted January 31, 2009 ...........let me step up on my soap box here for a minute: With regard to a Banshee style engine, power valves can make sense if electronically controlled in a cylinder designed for them. On the other hand, the mechanical pressure responding valves found in a Cheetah, some Big Block Twisters, T-Rex's, etc., need a very specific set of conditions to work properly. Aftermarket cylinder block designs have progressed to a point with Banshee style engines that power valves don't make sense for most folks. If y'all are interested, I can dive deeper into this..... please do. ive been contemplating a 421 cheetah set just for the ability to ride comfortably in all conditions. ive heard before the a pv cheetah has no benefit in a drag racing application but i dont understand how more low end torque wouldnt benefit in a race. please explain. Quote Link to comment Share on other sites More sharing options...
4stroker Posted January 31, 2009 Report Share Posted January 31, 2009 you can buy a conversion kit from the twostrokeshop.com that converts the cheetah pv's to electronic operation by the YPVS system (eg RZ or aftermarket such as zeeltronic) http://www.twostrokeshop.com/two_stroke_sh...ngines.htm#ypvs this would be the ultimate set up in my opinion. i made great improvements to my 4mm RZ's powerband by writing custom power valve and ignition curves for it with the zeeltronic. Quote Link to comment Share on other sites More sharing options...
fastrthnu Posted January 31, 2009 Report Share Posted January 31, 2009 I think powervalves arent going to do a whole lot for drag bikes, but if you have a decent mild drag bike used for some general riding, they would be worth it. any trail bike or tight turn quad is going to benifit alot from it, ecause you gain alot more power in lower rpms, because the valve is in the exaust port and cuts off alot of flow/energy to bounce back into the cylinder that normally would not be "on the pipe yet" where the motor makes its power from. since they open all the way wot there is no restriction. I have rockets on my PV cylinders and make better bottom end torque than std mx ported cyls with pt mids and all the other crap, but still have all the high end I need. I also dont have that hard pipe come on. the electronics are a bit of a pain in the ass, and can be a bit of money, but if you can get those cyls for next to nothing it might pay off. I see rz parts on ebay quite often. For aany hill, dune, drag quad its prob not worth the aggrivation, but Id recommend it for any other typical uses. think of it this way, a stock banshee motor makes what about 36hp give or take, Im pretty sure the stock rz motors where between 60-80hp depending on where they were made, stock stroke, unported, ect. Quote Link to comment Share on other sites More sharing options...
RollinRhino Posted February 1, 2009 Report Share Posted February 1, 2009 Powervalves aren't worth the hassle. On my dirt bikes they cause more trouble than they are worth. Especially in light of the fact that I run in the upper rev range anyway and they are only useful if I was trail riding them. Just port out what you have especially if you are going to be drag racing it. Quote Link to comment Share on other sites More sharing options...
klemet banshee Posted February 1, 2009 Author Report Share Posted February 1, 2009 okay one at a time lol idk if it comes with the head ill ask im not dragging i heard it was good for trails cylinders are already ported i really want to try something new (love projects) and can anyone give me a good price i could sell these for if i dont use them (just the cylinders) Quote Link to comment Share on other sites More sharing options...
FireHead Posted February 1, 2009 Report Share Posted February 1, 2009 please do. ive been contemplating a 421 cheetah set just for the ability to ride comfortably in all conditions. ive heard before the a pv cheetah has no benefit in a drag racing application but i dont understand how more low end torque wouldnt benefit in a race. please explain. As I eluded to previously, the modern cylinder designs move enough air at a velocity that would require a very widley varying power vavle that moves more quickly than a mechanical valve can support. This type of application would need a sufficiently complex electronic command of the valve that it gets to the point that is outside of the commercial viability of the Banshee aftermarket. With that said, the RZ valve design is superior to most others available to us, but is most often mounted on a cylinder setup with an antiquaited port design. The Cheetah cyliders are good, but have also been surpassed with regard to their design. Some older Twister cylinders and all T-Rex cylinders suffer from the same issues. :geek: Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted February 1, 2009 Report Share Posted February 1, 2009 As I eluded to previously, the modern cylinder designs move enough air at a velocity that would require a very widley varying power vavle that moves more quickly than a mechanical valve can support. This type of application would need a sufficiently complex electronic command of the valve that it gets to the point that is outside of the commercial viability of the Banshee aftermarket. With that said, the RZ valve design is superior to most others available to us, but is most often mounted on a cylinder setup with an antiquaited port design. The Cheetah cyliders are good, but have also been surpassed with regard to their design. Some older Twister cylinders and all T-Rex cylinders suffer from the same issues. :geek: was that in english??? ive heard before the a pv cheetah has no benefit in a drag racing application but i dont understand how more low end torque wouldnt benefit in a race. more low end torque will most def benefit in a race due to the fact you can pull taller gearing or more tire off the line. im not sure how the cheetah pv system reacts in drag situations. i wonder if going from idle to full throttle instantly negates the benefit you would see from having powervalves. mark?? Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted February 1, 2009 Report Share Posted February 1, 2009 was that in english??? more low end torque will most def benefit in a race due to the fact you can pull taller gearing or more tire off the line. im not sure how the cheetah pv system reacts in drag situations. i wonder if going from idle to full throttle instantly negates the benefit you would see from having powervalves. mark?? that makes sense. i read in a post a while ago that drag racers often block off the power valve. i also keep hearing about problems with the power valves. what type of problems? sticking maybe? Quote Link to comment Share on other sites More sharing options...
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