Re: AMA Supermoto Categories (chriscap)
I appreciate your skepticism!
I just did some tricks to my CRF250 with Motorcycle performance in Madison.
The JE 13.5:1 Piston kit was around $150
The original quote for the Head was about 250 including flow bench work and a fancy multi-angle valve job. I had to pay more as I needed 4 new valves (Damn CRF250's
, 40 bucks each)
I've been looking at the Vortex unit which lists for about $400
That leaves some $ left over for a couple hours of dyno time
I am also assuming assembly can be done at home.
A supermoto engine has many of the same characteristics of a good road racing engine, nice midrange with a respectable hit at the top of the rpm range. But more importantly A sharp engine tuner (Not your average mechanic) can develop what you are asking for. A good tuner will not build a grenade because it's just not good for business.
Also, a good tuner doesn't typically advertise because they are very busy.
In my opinion, a grenade is the result of the following:
> Extreme duty cams that beat the valvetrain to death
> An engine that makes peak power ONLY in the highest part of the rpm range
> Big bore kits with heavy pistons which over-stress the connecting rod
> Sloppy assembly and maintenance
really good grenades use all of these techniques at the same time!