Valve spring options
Thread Starter
Instructor
Joined: Jun 2008
Posts: 220
Likes: 0
From: Somers Point New Jersey
Valve spring options
What springs do you guys use with your H/C cars? I have my heads being done right now and we would like to use at LEAST a 400lb. spring. Now, My spring pocket will most likely need to be machined larger and the springs may be taller also. So I was wondering what path you guys have taken with your more serious cams??
Last edited by Targa98; Aug 20, 2008 at 12:00 AM.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
PRC or Patriot Gold Extreme's good to .660 lift seem to be the most popular. PAC's and Comp Cams 921's are popular as well. You need to pick out your cam and get your springs so the guys at the head shop can set them up properly. The springs should get set up differently for different cams based on your true valve lift.
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
I was running Comp 921's but recently changed to the new PAC 1521's to handle the lift on the new cam. The 1521's are good for .700 lift. 
I think these are undoubtedly the best springs out there now.
I think these are undoubtedly the best springs out there now.
Last edited by WKMCD; Aug 20, 2008 at 12:30 PM.
Thread Starter
Instructor
Joined: Jun 2008
Posts: 220
Likes: 0
From: Somers Point New Jersey
I was looking at the 921's. I definitely prefer Comp products. But I wanted to go a little more high perf. I will be seeing over 7000 rpm so I want to be safe. Is anyone here built N/A seeing 7-8,000 rpm? Curious what valvetrain options you went with.
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
Better than 921's = PAC 1521's for a drop in spring. They are nitrited and will last longer than the 921's.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
The other thing to watch with a larger diameter spring is contact with the rocker by the retainer. You may need an offset to bring the retainer down but not sure if that will buy enough clearance.
When you say 400#, at what lift are you looking for that value? The PSI 1511ML's are good springs with a stiffness of 384 lb/in.
When you say 400#, at what lift are you looking for that value? The PSI 1511ML's are good springs with a stiffness of 384 lb/in.
