Replacing valve springs

[dgoetz]

I keep seeing on other web site forums that people are breaking valve springs and some are replacing them before they break. I have a 04 C5 ZO6 with 21K that i only autocross but i do hit the rev limiter once in a while. Do I need to think about replacing my Springs? And if so with what brand and model with the stk cam shaft?

[froggy47]

Originally Posted by dgoetz

I keep seeing on other web site forums that people are breaking valve springs and some are replacing them before they break. I have a 04 C5 ZO6 with 21K that i only autocross but i do hit the rev limiter once in a while. Do I need to think about replacing my Springs? And if so with what brand and model with the stk cam shaft?

I have an 04 with 40k mi hit the limiter once in a while, still on stock springs.

I believe the 04 LS6 (maybe 03?) got "better" springs.

FWIW

OTOH you won't hurt anything if you swap them out.

:)

[Junkman]

I've not read or heard about this being an issue with the C5. I wouldn't mess with them unless it was necessary, and then I would only use OEM equipment to replace them with. As much as I pedal smash my Vette, I haven't had one issue at 131,000 miles on mine.

[JBsZ06]

I'd also suggest staying with the stock valve springs.

The aftermarket ones are not designed to last way over 100k miles like the stock OEM design.

After market valve springs often used with aftermarket cams often require replacement every 20k miles.

Its a pain in the @ss that I don't recommend to anyone unless they are going with an aftermarket cam...and then I'd recommend dual valve springs only because when and if the aftermarket valve springs break...the second spring holds the valve up.

Hitting the rev limiter going up in the gears is not a problem...going down in the gears and over revving is not so good.

[Junkman]

Good points JB.

[dgoetz]

Is there a difference between the 04 valve springs and the previous ones?

[froggy47]

Originally Posted by dgoetz

Is there a difference between the 04 valve springs and the previous ones?

See post # 2 and google "ls6 valve spring change".

You will get a few hundred thousand hits.

Read a few.

My conclusion is summed up pretty much in the post quoted below.

Quote:


I know first hand after 2 broken springs that G.M. changed to the new part # (Now known as the ls2 spring) in late 03.. I have not had another problem since the change..

My research seems to point to this conclusion: The original springs were ok in the 385 hp 01 z06 with the smaller cam, but seemed to be problematic when they increased the 02 cam size. GM introduced the new spring in mid to late 03. I have followed this problem for obvious reasons, and I am lucky I didn't drop a valve. I have never heard of a stock 01 z06 break a spring at low load nor have I ever heard of a 04 z06 break a spring under the same conditions. I can look up the part #'s from my records if you like
End quote.



:)

[Randyman49]

This does happen. November 2011 I was driving my 2003 stock Z06with 80k in traffic about 45 mph and #1 intake spring broke, dropping the valve into the piston, then the valve broke and lodged sideways in the seat. Bottom line block was salvagable and head was not. Required a total over haul. All maintenance was done in its life time. as I said This does happen. Suffice it to say I am not a happy camper over this. Forced into a $8500 overhaul for the lack of decent valve springs from the factory. Have always been a chevy guy and always will be, which stings just a bit more.

[froggy47]

Hmmm,

Thanks for the post, first hand info is best. Was the car tracked/autoxed?

Mine is at 45k miles & does both.

:)