I am wondering WHEN is a good time to put in HD valve springs, and are they REALLY nessessary???

I currently am running A1/A2 cams with RWR 11:5 piston ,with Decked head, and twist my engine to the sky!! and have never had "valve float". I have taken the head off several times, and never seen any "smiley faces" in the piston.

I know that the DS has ALOT more seat pressure than the Rappy,and I would even bet even more than a Rappy with HD valve springs. I also realize that rappy's have 5 smaller valves, Which means less moving wieght per spring.

I am aslo curious as to how much HP the HD springs rob from your engine,and if they hold your engine back from reaching Peak HP at a higher RPM??? I have a set of HD springs in a box,and was just wondering if I should spend the time putting them in, I probably will ,but I always wonder why some guys spend $$$ on shim under bucket,and HD valve springs when it does'nt seem the DS needs them.

My bike runs damn good, but am I causing myself loss of top-end power by staying with stock valves springs? doesnt feel like it.



Bigger.

 

bump....

 

I can tell you from experience, from a guy that has floated his valves (about 1/2 second worth) WITH the dual rates performance springs, and subsequently it caused microfractures on the springs. I didn't realize the damage to the springs, and on the next ride I had a complete failure of all the springs as they shattered in multiple places. The result was the valve spring shims left thier buckets, got chewed up by the cams, and the bits & pieces traveled down to the transmission and broke 3 gears - all that damage in about 3 seconds. I not only recommend performance valve springs to keep the valves from floating, but highly recommend shim underbucket valve springs just incase the springs fail the shims are much less likely to come loose from thier buckets.

In my opinion, you're playing with fire by using the stock valve springs with performance cams.

 

ANybody else ever have a Failure like Marky??? or even heard about one like his??

This is the kind of feed back I was looking for, but Marky is the only failure I have ever heard of.







BIgger.

 

I had the valves make 4 smiles on my piston with stock springs.. I have not checked it since the new springs. I did not get the under bucket. I don't rev past 10,000.

 

BIGGER, I CAN SEND A COUPLE OF PISTON THAT WILL SHOW YOU WHY YOU NEED HD VALVE SPRINGS!!ALSO BEWARE RW HAD SOME PROBLEMS WITH INTAKE VALVE STEMS BREAKING OFF JUST BELOW RETAINER,THIS WAS'T FAULT OF SPRING PREASURE BUT BAD VALVE.I KNOWN PERSONALY OF 4 ENGINES THAT HAD THIS PROBLEM.SHIM-UNDER BUCKET IS THE WAY TO GO!!!

 

Bump -

 

Up until recently i have had no shim under buckets or hd springs on my bikes. Because with proper installation your valves will stay where they were meant to be anyway's and i have seen just as many valves kiss pistons with shim under buckets too. I truley belive its preferance not necesity!!! Yes i ran my 760 for most of its life with out shim under buckets and she did just fine[img]i/expressions/face-icon-small-shocked.gif[/img][img]i/expressions/face-icon-small-confused.gif[/img][img]i/expressions/face-icon-small-tongue.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img]

 

What was the highest you revved? Did you have any HD springs in your 760?

 

I guess, maybe I have been lucky, but that would contradict the rest of my whole life, so........

I guess I do alot of things that probably would be consider'd "lucky"


So does anyone know how much HP the HD valve springs rob from a stage 2 engine??






Bigger.