Z06_BluByU

I was reading lingenfelters book last night and he cited that he recommends replacing the valve springs in any motor that has been overreved where the valves have floated because in essance the springs have overheated.. this didnt make sense to me? what do you guys think? I have an old trans-am that I floated the valves in years ago and never replaced the springs.. it seems fine.. :confused:

ZylaRace

Recommended, yes. Do you have to, no. It will still run, but it won't run as stong as it would w/ good springs.
Like said, float = very quickly overheated spring = weaker spring = prone to float at lower RPM's,... and it starts all over again.
L98 will float fairly easy. Some have seen springs so weak as to allow opening them w/ little more than hand pressure.

fullboogie

Seems like whether the spring actually overheats or not, they're inadequate for your needs. Replace them.

96GS#007

:iagree:

Z06_BluByU

I floated them in my Big Block Pontiac Drag car... I missed a shift and had my rev limited set wrong.. I normally dont rev it to 6500 RPM... they were adequate for my needs.. I only floated them for maybe 1 second or so.. that little bit of time ruins the springs that quickly huh.. what makes them overheat?

ZylaRace

Compression.
Normal valve operation generates heat. Increasing the compression rate (higher RPM) generates higher heat.
Just because you floated them, doesn't mean they need replacement. Repeated floating will lead to their downfall.
You could pull a spring or two and measure the pressure. If they are not up to par, they overheated.

Z06_BluByU

if I pull a spring how do I test its seat pressure?

JCAIRE2

http://www.streetrodstuff.com/Products/533/



These are more accurate, or you could use one of these:

http://www.enjoythedrive.com/content/?id=9401

Remove a spring and take it to a machine shop. They should definately have one if they are a good machine shop.

:cheers:


[Modified by JCAIRE2, 8:42 PM 2/4/2004]

96GS#007

You really need to test more than one. I just had my heads done and the springs on there were less than a year old. 6 were bad (one had lost 35# of open seat pressure!) while the others were good. Had we just checked one spring, there's a possiblity I'd have never known. FWIW...

dizwiz24

How do you know if you floated a valve?

Does the valve hit the piston..? Do you hear a tapping noise? and then does your pushrod get bent....

(confused)....

I remember one time going for 5th and getting 3rd at 120+ MPH. I had the clutch back in in a split second. I did the math....8000 RPM or something like that. No probs ever since and the car runs N/A 12.9's hotcam/ported heads/E. Wright chip LT-1....

Z06_BluByU

I bent all the pushrods REALLY bad./. like made them all banana shaped.. :cuss

silver & red CE

For the cost of a set of new springs, I would replace them. A dropped valve will cost you $$$, springs are ~$50-~$100, cheap insurence.

Eric