sothpaw2

I started a thread over in the Z06 section related to this--

one poster indicated that he'd heard of failures on '04 LS6 engines but no one else.

Anybody here heard of this happening?

I am debating changing the springs in my new-to-me '02 just because it is an '02 and there have been failures in '02's and early (up until Dec. 2002). Would prefer just using '04 springs but only if they are really failure-free. The comp 26918 spring is a one that I have used my LT1 with hardened pushrods, but I am not sure I want to pay a pro to do spings and pushrods, now this is pricy.

Thanks

Cobra4B

FYI the springs in the '02-'04 cars are the same and commonly refered to as "yellows" because, well, they're yellow.

The stock '01 springs are blue and thus refered to as "blues". There have been failures in all years I'm sure, but it's most known in certain '02s.

The most logical explanation is an isolated bad batch of springs. However, my buddies '03 broke springs on 2 seperate occasions w/ his only mods being a blackwing intake and borla catback.

The dealer only replaced the one damages spring, then when the second one went, he got fed up and traded it on a C6.

For reference here are the stock springs from my '01 Z06 w/ 65k on them, they looked perfect.


Here are the "yellows" I replaced them with b/c I am keeping my stock cam.


I made the swap b/c I track the car and it sees lots of extended high rpm use. I had to pull the valve covers to get my LT headers out so it just made sense.

So... the '04 springs you'd buy are the same as the ones in there now, just you'd hope the quality control is in place to ensure they aren't "bad".

Many will say put "good" springs in like a comp 918, but the increased seat pressure will put more load on the valve-train, timing chain, and eat up some horsepower.

HTH,
Brian

UVETTYA

Just passing on what I've heard... some say revving the engine over 2500 rpm before the oil temp is 160 F or greater is hard on valve springs.

sothpaw2

The '01's have a lower lift cam profile, right? I thought the spring was the same '01-'03 and a new part # in '04.

When was your buddy's car made? Thus far I have confirmed spring failures (from asking the above question around here) in any cars made in Calandar year 2002. That is a big batch.

Did your buddy drop a valve and blow the motor the 2nd time or was it as simple as spring replacement? It seems most of the spring failures do not drop a valve, but maybe that is just luck that they were not at high rpm on the track at the time.

Cobra4B

When cold the springs are more brittle. My general rule is no WOT and nothing over 3000 rpms until the oil temp on the DIC is 150.

No... '01's are specific as pictured above and '02-'04s are the exact same spring. Yes, the '01 cam is a slightly lower lift.

Not sure

Both times the valve stayed up.

Like I said the '02-'04 all have hte same design... you could replace w/ a comp 918 but you'll have more seat pressure. You could replace w/ a new set of yellows.

Or... just sack up and get a cam

sothpaw2

I think no WOT / rev over 3000 rpm is a good idea for any/all engines. You don't have the lubrication on a cold engine, most engine wear occurs during warm-up.

'02-'04 same design == Bad news for me. Don't like the idea of "hope they fixed the quality problem".

Are the yellows the same as LS2 springs currenty in production as well?

vettenuts

I have seen failures reported, and from memory the 02's seemed to be prominent. Not sure on vendors either, my new set of "yellows" that I plan to rebuild my stock LS1 heads with are Made in Germany.

Cobra4B

^ Yep mine too... got the from fred beans all in one box. Each was in it's own plastic bag w/ a blue sticker on the spring, which was of course removed.

ZeeOSix

I tried to get a handle on this issue with a poll on the other board. Not many responses, but you can see there are more 02 failures.

Someone might want to do the same poll on this board since there seems to much more activity here.

http://z06vette.com/forums/showthread.php?t=99618

sothpaw2

One response for an '01 and one for an '04. Those really muddy the waters.

If the '04's are not any more reliable, just newer and less miles so less failures have shown up as yet, then that forces us to go to an aftermarket spring. I would like one with very similar seat pressure--within 10%, so I don't have to change any other parts.

ZeeOSix

I just read somewhere on this board that the Comp 918s spring pressure was just slightly above the stock LS6 springs. It might have been within 10% ... would have to go digging for the thread. A few guys thought that Comp 918s were the perfect replacement springs.

Here ya go ... post #13. Guess they are more than 10% stiffer than the stock springs ... but not horrible.
http://forums.corvetteforum.com/show...light=comp+918

Cobra4B

^ You are way overblowing the "issue" the intardweb tends to seriously overblow things b/c we're a large group of enthusiasts. Yes, some springs have failed... but so have some new allmighty LS7's. When playing w/ a fairly high lift cam (LS6 at the time was the most agressive factory mass produced cam ever) things can happen.

The "yellows' are not flawed... I for one am not worried at all and just put a set in my car. However I still have an '01 cam.

vettenuts

Comp 915's are the closest, less stiff than the 918's.

TYSON1997

The extra seat pressure of after market springs is a good thing. There will not be any lost horsepower because of stiffer springs! think about it yeah you have to compress the spring, but what happens when the spring decompresses all the energy that was used to compress them is now exerted to "spin" your camshaft. And as far as durability I have not seen a cam wear out since roller lifters were invented. I bet a million people have replaced cam, lifters etc.. out of high ,mileage cars and they look brand new when you pull them out. Only diffrence is your power curve will not drop as soon and your motor will peak at a higher rpm due to less valve float. go with aftermarket springs such as comp 918 or a double spring "if your scared of breaking springs" for extra safety.

ZeeOSix

So how many guys have had aftermarket valve springs that have failed? I haven't heard of any on the chat boards.

Guess if I had the choice between OEM and high performance aftermarket springs, I'd take the aftermarket ones.

Cobra4B

W/ a stock cam there is no valve float at all... I fully agree that springs should be replaced w/ an aftermarket cam.

Putting comp 918's on an otherwise stock motor will eat up about 5 ponies... this comes from DRM and LGM.

Cobra4B

Are you serious? They fail all the time... but people don't cry about quality b/c everyone blames the higer lift cam.

sothpaw2

I had my Comp. cam springs fail, and yes, they were for a .566" lift cam with 1.6 rockers. But Comp. didn't recommend them for that application, my cylinder head "specialist" who comes very well recommended here put them in.

My impression of Comp. is that they think performance first. I don't think anybody goes to them for higher quality. It's accepted that with a high-hp modded car you will have to do more maintance.

I want a high quality spring, meaning one that will last a long, long time in this (stock LS6) application. The key is the to avoid metal fatigue of the spring steel, and that can be done with proper design and manufacturing quality.

torchredfrc

I had a set of aftermarket Manley springs fail recently. Switched to 918's and have been happy since. Valve did not touch piston as far as I can tell. I do have an aftermarked MTI (Houston) C2 cam .576/.576 224/224 112 LSA. Gotta pay to play; Good luck finding your replacement springs. For your purposes, I think I would stick to the yellow LS2 springs.

vettenuts

And surface treatments such as nitriding or shot peening. The PSI springs I am running are nitrided, but are still a beehive design.