valve float

[zlssefi]

I have a 602 with brand new gm valve springs in it. I have a feeling i got a bad batch. The engine floats the valves at about 6 grand. Is this normal on the newer crates? i know on my old 602 i could turn 62 to 64 before i had any problems...

[brad hibbard]

It may very well be low on spring pressure but the 602 springs run pretty decent so I would suspect a set of lifters that are not happy with where they are adjusted.

try less preload---with the higher factory oil pressure that the 602 runs they may be pumping up at high RPM----we never recommend 0 lash and never ever run clearence lash but if you are running a 1/2 turn try backing it down a bit

this NOT a recomendation for 604's ----we have found the 604 to be happy around 3/4 turn of preload

you can also try closing down your plug gap-----if there is any weakness in your ignition that is causing this "float" condition a tighter plug gap will band-aid it and the RPM will come up but if that fixes the problem ----you should examine the ignition for break down---(usually coil or wires)

hope that helps
Brad
www.race-1.com

[zlssefi]

Hi brad thanks for the reply. I have a new set of sbi springs coming. They are legal 80 pound springs and the track I run allows them. I will change them and re set the valve lash as well as check the plug gaps. .045 is standard gap correct? Also, ive done my valves before, but do you have a cheat sheet on how to do the valve adjustment? i like having that infront of me when im doing the valves.

Thanks!

[JJ128]

http://race-1.com/faq-2/#valve

Lots of good info on there.