dragon84

OK so if I were going to replace mine which is better? I know this is an opinion question that has been addressed several times before but the search function is much help.

I see a pretty good price difference from:

PAC 1518 for $356.00
Comp 918 for $169.00
Yellow GM LS6 replacement springs for $79.00

Any constructive feedback on these three options?

I'm planning on swapping them myself. I have never tried but it doesn't look all that hard.

Thanks for the input

Tom

pit-pony

My son's 2003 has about 10K on it now. We bought it with 5 this summer.

I would also like to have recommendation for preventative replacement.

Thanks

Its Bruce

I went with PAC 1218's because I'm not convinced that nitriding is the best thing for material toughness. Everything I've read about it leads me to believe the opposite. I'm sure many have used them with great success.

You have a PM.

UstaB-GS549

I went with the yellow GM springs. Got mine from Gene Culley as a set for about $60 two years ago.

I went with GM as Katech uses stock springs in their LS7 race motors. Do a search on Short-Throw and his engine build. It's in there somewhere.

The yellow springs are made by Mubea in Germany. The wire is not round, but rather elliptical in cross section. I suspect that there is a lot of hidden technology in these springs:

http://www.mubea.com/english/produkte_motor.html

Click on valve springs for more info.

pit-pony

Do you have the GM part number for the yellows?

Were the yellow not stock on the 2003?

MR Turco

I paid close to $200 for the PAC springs. Install was easy and straight forward. May want to check your prices.

UstaB-GS549

My late 2002 had yellow from factory.

P/N for all 16 is/was 12499224. Individually they are a lot more.

I used Crane tool and air hose. Installation was quick and easy.

NatB

I have followed the valve spring stories -I own a 2002 Z06 with 32K miles. Will likely swap out the springs soon as preventative maintenance.

I will either go with the GM yellow spring oem replacements or the PAC 1218's for my stock Z06 engine and cam.

Here's the thing- murphey's law sais anything that can will go wrong which combined with "if it ain't broke don't fix it" theory makes me a little concerned. After all- could replace perfectly good valve spring out of fear - with new ones that fail in 100 miles.

MTPZ06

PAC 1518's...and they can be found for around $200.

Last C5

4SFED Z

Get the PAC 1518's . Comp 918 if you dont have the funds.

You get what you pay for....

dragon84

Thanks for the input guys. The prices were the result of a very quick internet check. Bruce sent me a good price link for a little under $200.

I also agree with the murphy's law scenario... but I'm clocking a little over 70k miles on my car and just getting nervous. My luck I will buy the one faulty spring and it will break after I put it in haha.

Thanks again guys!

Tom

aquachuck1

Just a comment......suggest that you install the 2 spring(inner and outer) valve spring on your ZO6.....ZO6 do have a history of valve spring failure.....from experience I can tell you that the OEM yellow one on my ZO6 broke...valve into the cylinder....cracked the piston.....bent the rod...and cracked the cylinder sleeve.....and the actual cost for the repair was in the $10k range.....this all happened at 40mph on the way to work....as the mechanic said if you hade the dual spring you wouldnt have had all this damage........Chuck

Diceman9

I too lost a spring. Got it fixed at the stealership. Since then I worried about another one going. Maybe not as luck the second time..... destroying a piston or worse. So...... I had them all replaced. NOT WITH STOCK SPRINGS. I went with PSI springs. I can now sleep at night. I went with PSI because they had a lower spring rate than others... I figured that I didn't want to put too much more pressure on the rest of the valve train than neccessary. It really is designed all together. So your homework on the springs and you make the decision which will make you feel best.

These stock springs can go anytime.....not really a function of driving or timing. Just poor manufacuring.

pit-pony

Which is the inner & outer spring?

KrispyZ06

Any of you guys know what specifically was changed between yellow (GM) and non yellow (GM) valve springs?

PatternDayTrader

Anyone care to recommend a dual spring ? Imagine money was not an issue, and everything else was stock.

pql-lbc

This topic keeps popping up for discussion and is surely making me nervous. Any SoCal CF brethrens wanna give a brother a hand if I decide to swap out my stock valve springs? I have basic mechanical skills but have never attempted to play around with internal engine parts/components. LMK. I can compensate in beer or $$ if you would rather!

JD White

I swapped out my stock valvetrain earlier this summer with the newer Comp 918 springs which are now shotpeened and can be identified by their lighter shade of grey compared to the original design. Bought them from Summit, best price I could find. They have a slightly higher spring rate than stock and are supposedly good to 0.600" lift, others here will likely say less than 0.600".

Also installed Comp chromoly 7.4" pushrods with titanium retainers. A couple months later I went back and installed Yella Terra 1.8 shaft aluminum roller rockers.

Ultimately I now have a mild 220/224 duration 0.561/0.565 lift setup. I don't abuse my car but I do drive it as it was meant to be and haven't had any problems with this setup. I've done plenty of rev-limiter kisses trying to perfect my shift points for the strip as well.

The springs before the rockers did slightly reduce the cam's lope. After the rockers, the valvetrain also became noticeably quieter (trunion bearings), but not Cadillac quiet.

pit-pony

I too would like to get some dual springs ,if, no other mods are needed and remain safe. Otherwise I need advice what else to change.

BTW, how much time (cost) would a dealer charge to change the springs?

Do these work on an LS6?

Precision Race Components EHT .675" Dual Spring Kit

http://hinsonsupercars.com/p-1167-pr...pring-kit.aspx