Warriorxcr thats on a rear wheel dyno, and I've seen high compression piped,and cammed 450Rs making over 50HP. Hey a lot of people doubt Mickey but the guy tells how it is. He also said it's a different kind of power then the big three quads are making, the 446 Warrior engine is making it's power around 7000 RPM were the 450 quads are making that power with pipes around 10,000 RPM, so that saying the warrior is still no MXer, it is still a trail quad at heart, those other bikes will still win in a top speed race. And everyone who still doubts a 2 valve engine needs to look further into it, here is your example, 2006 Chevy Corvette, 6.0L 2 valve pushrod V8 motor, 405HP, Ford Mustang Cobra, 4.6L dual overhead cam 4 valve supercharged V8 390HP, alright the chevy has the displacement but, big BUT, the ford is supercharged and has 16 more valves, tons more technology, and still makes 15HP less, put a supercharger on the Vette, with the avarage gain of 40% more HP and you end up with 567HP.
Also Suzuki has used the old atiquated 2 valve aircooled GS motor in drag racing for years, and to this day, still one of the fastest platforms in which to build upon. Just a small example, so doubt the 2 valve motor. Everthing is taylored to it's spicific use, and has a pupose.
