Originally Posted by escort frenzy
I've had this problem before with my mates just after it got set up. It would be fine up too about 5500rpm then it lost power (like a misfire). I found that it was the valve springs. We fitted a set of brand new ford valve springs and it was mint after that. Hope that helps.
i would like to back to original valve springs as the piper springs are softer due to less material.
But what about the springs becoming coil bound, that is what it says on the warning. what sort of cam was your mate using.
cheers,pete.