Valve spring questions

281pony

Active Member

Aug 31, 2003

2,681

2

46

Oly, WA

Oct 24, 2004

#1

• Oct 24, 2004

• #1

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

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

Oct 24, 2004

#2

• Oct 24, 2004

• #2

I'd follow the cam manufacturer's advice on the spring selection.

 

Rick 91GT

Mustang Master

Nov 29, 1999

9,692

95

99

PA

Oct 24, 2004

#3

• Oct 24, 2004

• #3

I'm with Mike, what kind of seat and open pressures does the cam company suggest for your cam....go with that.

 

281pony

Active Member

Aug 31, 2003

2,681

2

46

Oly, WA

Oct 24, 2004

#4

• Oct 24, 2004

• #4

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.

 

Michael Yount

Mustang Master

Apr 10, 2002

9,039

6

79

Charlotte, NC

Oct 24, 2004

#5

• Oct 24, 2004

• #5

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.