Valve Spring Question

Reply Subscribe

Thread Tools

Search this Thread

Mar 27, 2011 | 09:16 PM

redbird555

Thread Starter

Drifting

Joined: Nov 2009

Posts: 1,385

Likes: 102

Valve Spring Question

Hi guys I'm doing an ls6 swap into my car however the heads I will be using dont have the sodium filled valves instead they use the standard solid ones. My concern is that with the heavier valves the springs wont be able to take it and I'll end up with valve float (someone correct me if 'm wrong here) so I'm looking for a good set of springs that wont break the bank as its a small cam and I'd like them to last meaning I dont want to have to pull the heads off in 25-30k to check the springs to see if they've lost pressure.
Thanks Dan

Mar 28, 2011 | 05:30 AM

vettenuts

Team Owner

Joined: Mar 1999

Posts: 22,025

Likes: 192

From: At the beach in little Rhody

You likely need to go with more spring then the LS6 springs, something like either PAC 1218 or PSI 1511ML based on the assumption that you have an aftermarket cam. Unfortunately, with the more aggressive ramp rates and higher lift of aftermarket cams you should really check the springs. It comes with the territory if you start modifying the car. If you are using the LS6 cam, the PSI 1511ML would be my first choice.

Mar 28, 2011 | 06:28 AM

ZZ06

Drifting

Joined: Sep 2007

Posts: 1,643

Likes: 50

From: Goldsboro NC

You said small cam. It would help to know the cam specs. Stock LS6 cam? As in the 01LS6 cam rated 211/204 duration .525 .525 lift 116lsa or 02+LS6 cam rated at 218/204 duration .551 .555lift 117.5lsa.......OR is it a different cam altogether. If that LS6 swap is the 01(which im guessing it is since it doesnt have the sodium filled valves) AND the cam is stock, you dont need to worry about the springs. AGAIN all being stock 01LS6 swap.

Mar 28, 2011 | 08:17 AM

AU N EGL

Team Owner

Joined: Sep 2003

Posts: 43,084

Likes: 33

From: Raleigh / Rolesville NC

and keep your RPMs down to 6000-6200
any time your in the 6200 to 6500+ rpm range the lighter valves are needed to prevent valve float.

Stronger springs do not always help at higher RPMs and may even hurt performance

lightest and strongest valve train is one of the best things you can do for performance. But that does come at a big cost too.

Good Luck

Mar 28, 2011 | 09:37 AM

redbird555

Thread Starter

Drifting

Joined: Nov 2009

Posts: 1,385

Likes: 102

Sorry guys I thought I thought I put in there that it is the stock ls6 cam for an 02-04 car, so it is a little bigger than the 01. The ls6 has a redline of 6600 rpm which is what I'll be spinning it to however I couldnt find a set of heads with the sodium filled valves so I was forced to get a set with the solid ones, and from what I hear the ls6 springs are almost maxed out with the light valve train anyway so if I'll be spinning it to the stock redline with the slightly heavier valves I'll need a slightly stiffer spring to counter the heavier valve weight and prevent valve float no?

Mar 28, 2011 | 12:12 PM

vettenuts

Team Owner

Joined: Mar 1999

Posts: 22,025

Likes: 192

From: At the beach in little Rhody

Quote:

Originally Posted by redbird555

I would agree. The PSI 1511ML would be a good spring for this application.

Mar 28, 2011 | 12:45 PM

redbird555

Thread Starter

Drifting

Joined: Nov 2009

Posts: 1,385

Likes: 102

Thanks I have it narrowed down to those or the PAC 1218 do I have to worry about installed height with these or should they be a bolt on and go application?

Mar 28, 2011 | 05:34 PM

vettenuts

Team Owner

Joined: Mar 1999

Posts: 22,025

Likes: 192

From: At the beach in little Rhody

I like to measure and set the seat value around 135#. As I recall the numbers, the PSI's will set up a little lighter on seat at 1.800" but are stiffer than the 1218's. However, my stock heads set up lower than 1.800". I usually set up a spreadsheet and use that to set up the valve train to keep track of installed height and seat values.