Ok, my question is, what in the heck are powervalves like they have on the 87 and up LT250R's? I knw that they are faster and have more power, but what in the heck are they? How do they work and why didn't Honda ever try to put them on the 250R' after Suzuki put them on their race bikes? Also, if I can find a Zilla engine and a LT250 rolling chassis, would there be much work tryng to mate the two together and would it be worth it in the handling department and trying to get the power to the ground?

 

power valves control the size of the exhaust ports to increase low-end throttle response while still allowing for greater exhaust port areas when the valve opens to boost the mid and top-end power.

 

that is how most newer generation powervalves work, however the LT250r and LT500r powervalves did not change the exhaust port size and timing. it's a variable volume expansion chamber valve that changes the harmonics of the pipe. it consists of a rotating cylinder with an opening, it closes a cavity in the front part of the engine cases at higher RPM... that RPM is adjustable to dial in the performance the rider likes. as for putting a 500 in a 250, it's been done, i've seen them for sale... that's about all i know on that.

 

look in the project quads forum for info regarding the 500>250 swap... it's basically the same thing that I had to do to get the Rm engine in.