I just dynoed my car at around 5900 6000 rpm valve float shows up. What could be the cause??? I was told dirty fuel filter most probable, also weak pushrod, weak injector unlikely. Any opinions appreciated.

 

If you still have stock valve springs, that is usually it. My car does it occassionally on the dyno around the same RPM.

 

If you are willing to do it, this might be the perfect excuse to redo the entire valve train. You can get some beehive springs and some LS7 rockers. Cam and even heads of you like. You could lighten the entire valve train and push your peak hp closer to your redline.

Or you could just focus on the valve float. I wouldn't think much of it unless I race and have a heavily modified car. It doesn't look like you're modified too much. It might not be worth it to even invest in fixing the problem until it's time to redo the whole valve train.

 

A set of Z06 valve springs is $55, swap them out as that is likely the source.

 

LS7 rocekrs are the same as every other GEN3/4 rocker with the exception of the LS7 and L92 heads use offset exhaust rocekrs.

 

Actually the LS7 rockers will not work on the LS1 at all, the LS7 exhausts will wipe way off center and the geometry is wrong. I wouldn't use them at all, stick with the stockers.

 

Good to know. The point is that if you replace a part, don't just fix your problem; get a part that is truly superior. You don't want to buy a part that might get replaced one day when you upgrade. You want the best part now.

 

Stock rockers with the Harlan Sharp mod are more than Enough for the Average Ls1techie, only real Upgrade would be a set of shaft mounts from T&D, Jessel, Comp.

Valve float comes from the spring not being able to properly control the movement of the valve/ or not having spring pressure to close the valve quickly enough.

Beehives are a great spring for low lift cams, for anything over .600 lift i would recommend a dual spring, i would happily sacrifice 1-2hp for the added safety of having the internal spring keep the valve away form the piston in case of a spring failure.

In an all out race application a beehive is better suited because the harmonics are kept to a minimum; but at the same time a race engine is meticulously maintained and inspected and is not required to go 30k miles before the springs are changed.

 

Waiting for something to brake is never the proper way to deal with things. Would you wait until you spun a rod bearing to change the oil, or not put fuel in the car until it shuts off? By not fixing the issue he slamming the valve against the seat potentially damaging it and could possibly break the head of the valve costing him a new short block, possibly a long block.

Spend the $350 for a set of TSP platinums/Prc golds/ comp 921's/ AFR 1019's or whatever and if you decide to change the cam thats one less step you'll have to worry about.

 

What I mean is that if this only happens at 5900 or 6000 RPM, then he can just avoid those RPMs until he can upgrade to have the best end result. I'm no expert, but I would think that it wouldn't break if you didn't hit those RPMs.

 

I plan on getting a 231/237 cam kit with dual springs in a few months so that should take of it..Thanks for the opinions guys.