Well just wanted to update everyone. I had 987s and an XER cam and for some reason I was getting what appeared like valve float above 6200. It turns out that I have a (couple) of bent valves...cant really say how many because they are still being cleaned. I had noticed some small eyebrows on the pistons from my old shortblock but because they were so small and the runners held cleaning solvent it never crossed my mind that the valves were bent. I am going under the assumption that the springs are good but were going to check the pressures to make sure. The bent valves may have caused the power to fall off above 6200. Please reply with any comments.
Phillip

 

I had the same issues with 987's last year. In my case it wasn't so much the spring pressure that was down, it was the fact that the vendor that did my heads used very big and heavy valves, which in turn, bumped up the needed spring pressure to keep float down.

I have since switched to some GTP heads from thunder racing, and am using 987 springs with them and all my float issues went away.

 

what are the symptoms of valve float. I have 987s and rev to 6800-6900 rpms every once in a while. Seems to stop pulling at 6500. Think I may start shifting at 6500 for longevity.

Greg

 

With that cam, you do not need to shift that high. That is not a really agressive cam. Where did it peak on the dyno?

 

I have 10K miles on my 987s with my TR224/224 112LSA cam and have never seemed to have any problems with valve float.....

I usually hold my shift till 6500RPM so I can come in strong on the torque/hp curves in the next gear....

max HP @ 6000RPM
max Torque @ 5000RPM

 

Phill, thanks for updating us, maybe there was p to v contact with you xer custom cam and heads milled to 11.75, maybe just a little flycut some new valves and youll be off to the races again