Does anyone know if supertech dual valve springs need to be shimmed to rev over 9000 rpm???

 

nevermind, figured it out

 

What did you figure out? I wouldn't think so unless you had a custom cam with some ridiculous lift.

 

they dont need to be, but some do. stock springs have around 63 lbs of pressure whereas the supertech dual springs have about 93-95. I have a customer that was floating valves at 35 psi at 9000 rpm and once hs himmed them his problems went away

 

on many engines that i have built for various manufacturer's that would run between 15 & 17k, we would set-up the springs ~0.020" -0.025" before coil bind.

this helps ensure / minimize the likely hood of of VTP contact during upshift/downshift over revs.

just be certain of the spring pressure when setting the springs up that way.

 

that's some exceptional info right there!

 

What kind of engines?

 

2.65L v8 engines that ran in the CART series

cosworth, toyota & honda

 

How do you deal with the harmonics at that crazy rev?

 

Don't forget to use the special thin valve stem seals with these springs cause you'll have a big problem if you use the stock seals.

 

For a Beehive race spring, ti valves, lock and retainers thats all fine and dandy but thats crazy for a production spring anything closer than .070 to coil bind and you are asking to break them. I've pushed them close to .04-.05 but that was a triple spring with dual isolators. 600 seat 1300 open pressure, we had to run 5/8 pushrods. i've actually snapped the nose off of a jessel Fully optioned j2k rocker

 

i used what b/r sent me. i thought they was the stocker's. i have no problems

 

The stockers supposedly get chewed up by the inner spring and needless to say you're looking at a headache. I can't imagine Buschur sending you something that wouldn't work. You should be fine.