DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    valve spring pressure
Go
New
Find
Notify
Tools
Reply
  
valve spring pressure
 Login/Join
 
DRR Trophy
posted
I just bought a new set of valve springs for my big block chevy with a flat tappet cam. These springs have 425 pounds pressure when open. Most of the springs I have run has been around 375 pounds when open. What do you guys think, will the flat tappet cam stand this much pressure with out wiping out a lobe?
 
Posts: 36 | Location: corona, ca | Registered: October 13, 2009Reply With QuoteReport This Post
DRR Trophy
posted Hide Post
I think you should use the valve springs the manufacturer of the cam recommends and sells. Then you should pray you don't wipe the cam out.
 
Posts: 32 | Location: U.S.A. | Registered: September 24, 2015Reply With QuoteReport This Post
DRR Trophy
posted Hide Post
Come on guys, surely I can get more than one reply. I'd like to hear from some one who actually runs a flat tappet cam.
 
Posts: 36 | Location: corona, ca | Registered: October 13, 2009Reply With QuoteReport This Post
DRR Top Comp
Picture of wideopen231
posted Hide Post
only one reply because its dead on. With flat tappet cam you need to run very close to manufacture suggestions,add zinc additive to oil if it does not have it and most don't now days. Flat tappets work fine when used as designed with loads used during design.

Look at specified springs and go from there.50 lbs open does not sound like much but its about 14% increase over your normal spring.




America home of free. Brought to you by 2nd amendment.
 
Posts: 4246 | Location: Greensboro NC | Registered: May 24, 2011Reply With QuoteReport This Post
DRR Pro
Picture of rusty
posted Hide Post
its been long enough my memory is failing me,but here is a thought i tink we ran 425 on ours,but,i also remember wiping lobes on startup.lol not a good thing.we would leave the inner springs out use the best lube we could get and breakin on low pressure and then put inners back in.you didnt list cam specs but less pressure may be safer.can shims be removed?


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

 
Posts: 1422 | Location: texas | Registered: February 17, 2006Reply With QuoteReport This Post
DRR Trophy
posted Hide Post
I always on start-up remove the inner spring and run the motor for about 20 minutes and then re install the inner springs. The springs are 425 pounds set up at 1.94. I am thinking about setting them up at about 1.99 or maybe 2.00. I wonder how that would effect the open pressure?
 
Posts: 36 | Location: corona, ca | Registered: October 13, 2009Reply With QuoteReport This Post
DRR Pro
posted Hide Post
The real question is, what did the cam manufacturer recommend for spring pressure. They know the cam material and what it will take.


Fellow racer and servant of the Lord of Lords
John 14:6
"Creekside Racing Ministry"
MFI system, ProCharger Non-intercooled [6.02 @ 229 or 3.91/660' soft tune and killing power above 6K rpm]
Ron Clevenger
 
Posts: 1006 | Location: Visalia, Calif. 93292 | Registered: November 23, 2000Reply With QuoteReport This Post



  Powered by Social Strata  
 

DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    valve spring pressure

© DragRaceResults.com 2024