Best Valve springs for stock ls6
#1
Best Valve springs for stock ls6
I know this probably has been beat to death but wanted some real input from my fellow mechanic oriented performances based corvette brothers. I have a 03 z06 low miles 28k that I'm going to keep stock cam ect in with no plans for motor work ever. I'm going to swap out oem valve springs for preventative maintenance reasons as I don't want to risk a spring breaking. So I'm more leaning to the new blue ls6/ls2 valve spring as noted above my plans are to keep stock cam, but wanted some input if I should go pac 1218, comp ect. From what I'm reading the new updated gm ls6 spring is great with zero issues but I want to hear from you guys. I want to put a set in and not have to worry again for many many miles down the road.
Last edited by mainecobra; 09-29-2015 at 11:53 PM. Reason: I can't spell
#2
Melting Slicks
PAC 1218 would be by far the best choice for a stock replacement
LS6 valve spring specs:
seat pressure: 90 lbs @1.8"
open: 294 lbs @1.25"
rate: 370.9lbs/in
PAC 1218:
seat pressure: 130lbs @1.8"
open: 318 lbs@1.20 (302.3@1.25)
rate: 313.3lbs/in
The 1218 springs will be much better for longevity. They have a slight bump in pressures over stock, but a lower spring rate. The lower spring rate means the metal isn't going to fatigue as much because it results in less stress in the material. This also means that they will maintain their spring rate for more cycles.
The secret here is that the Trickflow TFS-16918-16 is the exact same spring as the PAC 1218, but a few bucks cheaper.
http://www.summitracing.com/parts/tf...FYVCaQod15YPsw
LS6 valve spring specs:
seat pressure: 90 lbs @1.8"
open: 294 lbs @1.25"
rate: 370.9lbs/in
PAC 1218:
seat pressure: 130lbs @1.8"
open: 318 lbs@1.20 (302.3@1.25)
rate: 313.3lbs/in
The 1218 springs will be much better for longevity. They have a slight bump in pressures over stock, but a lower spring rate. The lower spring rate means the metal isn't going to fatigue as much because it results in less stress in the material. This also means that they will maintain their spring rate for more cycles.
The secret here is that the Trickflow TFS-16918-16 is the exact same spring as the PAC 1218, but a few bucks cheaper.
http://www.summitracing.com/parts/tf...FYVCaQod15YPsw
Last edited by SaberD; 09-30-2015 at 11:21 AM.
#3
So you would run the pac 1218 over the new blue ls6 gm springs? I just wonder when u see c5 vettes and z06's with 150k plus miles wonder if they are running the oem springs or pac's / after markets. But if the pac 1218's are better than oem new ls6 springs and i dont have to worry about touching them for thousands of miles im going to use the pacs.
#5
Melting Slicks
The blue springs have the same specs as the old yellow springs. The PAC springs are endurance racing springs. They will far outlast the oem's.
I went with the PAC 1215's for my mostly stock LS1 that uses the stock cam and valvetrain geometry. Actually the same spring rate as the 1218's with less seat and open pressure to give a slight bump above the stock LS1 springs.
I'd also do the rocker trunion upgrade while you're in there to further increase durability.
I went with the PAC 1215's for my mostly stock LS1 that uses the stock cam and valvetrain geometry. Actually the same spring rate as the 1218's with less seat and open pressure to give a slight bump above the stock LS1 springs.
I'd also do the rocker trunion upgrade while you're in there to further increase durability.
#7
PAC 1218's it is then. I found a great deal on them also. And ill take your advice on the truunion upgrade also. And ill do retainers and keepers as well as new valve seals. Do it all while im in there
#10
Melting Slicks
There should be no reason to replace the retainers and keepers unless you lose them. I'm reusing mine with 135k on them.
#14
Wow thats alot of miles!!! Just goes to show how strong these motors are. What year is your car? Ive heard of 02-03 z06's valve springs breaking and ruining motors. There is a long list of cars on the forum that someone made to show some of the failures. After hearing and reading this my mind is going crazy that mine may break as well. I cant get it out of my head!!!!
#15
Racer
I have a 2000 base so its an ls1 not ls6. Not sure on the spring break problem but if you can afford it then it would be peace of mind and the 1218's are great springs.
#16
Melting Slicks
If I had an 02-03 LS6, I'd replace the springs the first day I bought the car. The valve springs are prone to failure. Not worth the potential risk. I think he is doing the right thing.
#17
Yea it was specifically for the 02-03 z06's not the ls1 motor. I just ordered the PAC 1218 springs. Just gives me peace of mind and one less thing to worry about.
#19
Le Mans Master
Spring breakage was primarily within a certain VIN# range. I don't remember the numbers in the original post but my car was okay with that. By the time I started reading those posts I was already much higher in mileage. Point is my '03 Z06 is currently at about 140,000 miles on the original springs and still runs like new. I've thought about changing the springs but if they were going to break it would have happened a long time ago. Maybe if I do some performance upgrades this winter. It's already got some bolt-ons making it faster than stock now.
#20
Spring breakage was primarily within a certain VIN# range. I don't remember the numbers in the original post but my car was okay with that. By the time I started reading those posts I was already much higher in mileage. Point is my '03 Z06 is currently at about 140,000 miles on the original springs and still runs like new. I've thought about changing the springs but if they were going to break it would have happened a long time ago. Maybe if I do some performance upgrades this winter. It's already got some bolt-ons making it faster than stock now.