Valve spring questions

281pony

Active Member
Aug 31, 2003
2,681
2
46
Oly, WA
i found out my valve springs arent rated very high (.525 max) on my heads i just got.

i have a custom cam, lifts .54x/.563. my questions are, how much tolerance on the springs do i need over that? i have heard you only need .030, and others have said .1?

what is the rule of thumb? would i be safe with a .600 lift valve spring? if so, what valve springs should i go with?

thanks
 
ok, thats where it gets confusing.

its a custom cam made for someone else that im getting, i dont have all the exact specs and im not so sure he does either. ill see if i can get the specs card from him then.
 
He should know who the custom came from - contact the designer, give 'em the cam specs, they can help you figure out springs. Alternatively, check online from folks like CompCams or Crower - look for similar peak lifts and durations at both .050" and .006" (the ramps should be similar then) -- whatever springs they recommend for that cam ought to work for yours.