what is a Powervalve engine?

[dizasterzrfun69]

I hear about powervalved tri-z's and everyone makes them sound like they are bad a**. So what does it mean if it is "powervalved"? Can you do this to other engines like 250r's?



Kevin

[nouseforaname90]

No. Yammi made some dirtbikes that were powervalved, which is basically just a variable exhaust port that makes your bike have more power throughout the RPM range. And you can switch the whole engine or just the head from these dirtbike engines onto your Tri-Z. There are no PV'ed heads that fit onto a 250R.

[Dammit!]

There are no PV'ed heads that fit onto a 250R.

Yes there is. Red Rider did it (http://hometown.aol.com/flys4pnuts/index.html). More complicated than the Z swap though.

Easiest way on a 250R is to buy an aftermarket top end. ESR and LRD both make powervalved top ends for them. Big money though. $1500 and up for a complete kit.

[nouseforaname90]

Oh. Well then I guess I should have said there is no easy or cheap way to PV a 250R.