Busted a Valve Spring

[ChevyIIMan]

Ok heres the deal these springs have 40,000 miles on them, they have always been run on the same head, and always matched with the same Cam.

Comp Cam 274XE and Comp Springs 981

I was on my way home from Amarillo, TX headed for St. Louis, MO and around Stroud, OK somewhere on the highway I busted the valve spring cause when I let off the gas to stop at a gas station it just died and wouldent idle. Thats when I found the #7 ex valve was in 3 pieces.





Now these have seen maybe 150 passes at the strip, cruise RPM's from 2400-3500, and never reved over 5800 RPM.... So what happen? they were checked for correct install height and coil bind at time of install. So just a bad spring? Luckilly it was a clean break in both spots and as you can see the valve didnt drop. Could have driven almost 100 miles with it busted.

Should I replace them with the same comp sorings or a similar spec spring from another mfg?

[Steve68]

Go with the new beehive springs, there supposed to be better!!!

[68BNUT]

I think Adam camaroboy69 just did this on his camaro you might ask him what he did. He had some springs break I think.

[graycamaro]

Does your car set for any lenght of time. Because if it does there is always atleast one valve open and when the valve is open ther is preasure on the spring and if it sets for any length of time the spring will relax which usually reults in it breaking when you start to drive the vehical again. I work in a machine shop and have seen this same situation countless times.

As for as fixing it I would suggest testing the rest of the springs and replace any that measure outside of 10 percent at installed height. So if it has 120lbs at installed height (valve closed) then all springs should measure within 12lbs of 120.

Hope this helps James

[andrewb70]

I had a set of comp 918s in my LS6. Two springs broke after only about 1000 miles. They replaced them , but in my opinion they should have never broken.

Andrew

[graycamaro]

andrewb70 did the engine set maybe not even the car but just the engine while the car was being finished with the valves adjusted because if it did then you could have the same problem I spoke of above.

[ChevyIIMan]

Yes the car sat for close to 8 months getting exhaust, Overdrive transmission, ect... and usually sits every winter for long periods. I guess there is something to say about firing the car up every so often and letting it run huh?

Something had to have gone wrong cause last year after I had a valve job done and new guides I began to lose power. Lost almost 100hp @ the rear wheels. And it was slower then ever days before the spring broke. Possible that I have more springs that are "relaxed" as you said. I ordered another set of Springs and im going to swap them all out.

[CAMAROBOY69]

I think Adam camaroboy69 just did this on his camaro you might ask him what he did. He had some springs break I think.

Very Close.
I actually broke a push rod and a couple rocker arms. All I did was replaced them and and was all set. Car runs perfect again.
The only thing I did wrong was drive for 2 hours after they broke which heated up a couple valve guides. Still no big deal at all.
If you stopped right away and shut the car off you will be fine. Get a new spring and you will be all set.
Spring might have broke from improper rocker arm adjustment. Seems to be very common for people lately. Just keep in mind that sometimes things like this just happen. Defective parts.

[ChevyIIMan]

Yeah I figured as much. I proably drove upto 80 miles maybe more on it... who knows I went from one gas stop where the car ran fine to another where it wouldent idle about 120miles away.

[CAMAROBOY69]

You will be fine. Just replace the spring. Everythign still looks nice and oiled. When my push rod broke it caused the lifter to pop up just enough to block the oil valley and it dried my head up. Yours still looks in great shape. No sweat. You will be back :3gears: in no time.

[WELTERRACER]

I had a spring on my DART PRO 1 heads break...

Do you think the 30,000 miles on them and constant 7200rpm blasts had anything to do with it..

High performance parts dont last forever..

[graycamaro]

chevyIIman That is probably your problem then if it has set for that long and normally sits. We normally recomend that you start the engine every couple weeks depending on the kind of springs you may be able to go longer or ned to do it more often.

If you put your car in storage in the winter and can't actually start it just bumb the engine over every couple weeks that way it will have a diffrent valve spring compressed and the other one can come back up. The other allternative is to back the rockers off and readjust the valves when you go to drive it again.

Usually the more spring preasure your running the more often you need to turn the engine over.

James

[ChevyIIMan]

Well I did a spring swap today on just that one. Compression tested fine and she fired right up. I cant wait to drive her now.

[ChevyIIMan]

Well I drove her yesterday and she runs fine but still reads lean on the a/f guage. Any ideas? Could I have fouled the plug having no exhaust valve? Is it possible that a weak exh spring could have been showing me a false rich setting and now that its fixed its reading right?

[CAMAROBOY69]

Yeah you could have easily fouled the plug.

[ChevyIIMan]

Wouldent a fouled plug create a rich reading though?