Valve Spring

Reply Subscribe

Thread Tools

Search this Thread

Mar 16, 2004 | 12:38 AM

1979meangreen

Thread Starter

New User

Joined: Oct 2002

Posts: 17

Likes: 0

From: Chesapeake, VA

Valve Spring

I am in the process of rebuilding my 400 and am putting a larger cam in it. I have been told that 400 valve springs are weak. I already have a set of rebuilt heads vith stock valve spings. Should i run this or put stronger springs in it. I am planing on running a Edelbrock Performer-Plus cam shaft.
Cam Specifications:
* Advertised duration: 282 intake/292 exhaust
* Duration at .050: 204 intake/214 exhaust
* Gross valve lift: .484 in. intake/.510 in. exhaust
* Lobe separation: 112 degrees
* RPM range: Idle to 5,500

Mar 16, 2004 | 01:46 AM

Bill_Beyer

Posting Guru

Joined: Aug 2000

Posts: 2,416

Likes: 4

From: PacNW

Well I hate to shoot down another myth about the 400 but their valve springs are no better & no worse than any other springs FoMoCo put in their V8 engines.

However you still should replace the valve springs if you're going with that cam. IIRC Dave R. (BubbaF250) calculated the maximum lift you could run with stock springs on a post some time back and it came out to just under .500" before they went "solid" and you start bending pushrods. I'm sure E'brock recommends a specific spring for that cam. You might check on their website.

Mar 16, 2004 | 09:10 AM

beartracks

Lead Driver

Joined: Nov 2000

Posts: 6,623

Likes: 342

From: Albuquerque

Springs are cheap and easy to change. Just check the installed height. Bind should not be a problem but you might well see vavle float at higher rpm's.