I am thinking of purchasing a 10.25 high compression piston, .390 lift cam and aluminum valve springs from Alba. I already have a White Brothers E-Series. What do you guys think?

 

I am thinking about the same mods. That or putting a 350X motor in a 250X that's my dream quad!

 

With a compression rate of over 10: to 1 won't you have to use high test fuel?

Dunno, just heard that somewhere, I'm not a motorhead, I'm a computer ****.....

 

10.25 is pushing the border for race gas. If you use those parts use a very competent builder and some titanium valve springs. I lost $2500 to a built engine from a bad builder and sued him and court and won but he claimed bankruptcy so i never saw a penny. But the reason was this The piston was a 12.5:1 Arais and i had a full race cam, the clerances with the valves open were minimal and they had to grind away some of the piston to leave room for the valve, Apparently this didnt even help after about 30 minutes i suppose the heat increase from misignition of 92 octane decreased the clearances and we had a valve piston collision, I had valve pieces blow out of the exhaust and back through the new flatslide. Not pretty for new port and polish and $1800 in parts. Just picture whats left of the guy who jumps on a live grenade in the army movies, then picture the engine. GET THE POINT.