First off, let me say that I'm VERY displeased with this. CM sold me these springs, along with the rest of my valvetrain, so I'm doubly displeased with that.

Second, these springs had 5000 miles on them.




I was driving to CAM (Carolina Auto Masters) for a dyno tune on the setup. They're about 355 miles from my house. I got literally TWO blocks away from there, and was at a redlight. All of the sudden TAPTAPTAPTAPTAPTAP. I thought, oh ****, there goes a bearing. Nope. Valvespring just SNAPPED. I have it here in three pieces, no metal fell into the motor, but there was definite piston/valve contact. All on brand new, 5000 mile Lloyd Elliot heads, which he setup and assembled for me. I'll post up a FULL damage report and what CM is willing to do to help me out and fix this monday.


For those wondering, it was the #4 cylinder exhaust spring that broke.
7/16 studs, NSA pro-mags and guideplates
6400 rpm
.567/577 lift

On a side note: we pulled it to CAM, and tried several things to get it back drivable to no avail. Jeff at CAM is a STAND-UP guy and I'd recommend anyone doing anything F-body to see himf or tuning, or engine work www.carolinaautomasters.com

 

No offence, but before bad mouthing a company here, why not try to let them resolve the issue first?

 

I'm not bad-mouthing the company. No where did I say anything bad about them. Whether they make good on it or not is up to them, but the spring still broke for no good reason and left me stranded 350 miles from home. Dave was helpful on the phone friday night, and suggested I got a bad batch of springs. We're going to talk again monday.

 

Bad batch of springs ? Thats a new one. I have a cam kit coming from them. It should be arrive Monday or Tuesday. Guess I'll send the springs back for an exchange. I sure don't want to be stranded like you.

By the way the EX brand spring, did it say where they are made ?

 

Bad springs eh? I think I know the answer to this question already but im going to ask it anyways. Did you use clay to check your piston to valve clearance?

 

I am curious about your problem. Does it sound like TAP, TAP, TAP, tap, tap, tap, TAP, TAP, TAP, etc.?
I have been trying to figure out my problem with and I have 612 springs. I have under 500 miles since the install.
It gets REAL noticable from idle to reving it up.

 

Didnt need to. Checked the installed height and coil bind, no issues there. I'm not lifting enough for a piston to hit a valve.

T/A #4, no it doesnt say where they're made. They're white box springs, CM's house brand, though I am curious as to who makes the springs.

JeffK: The spring break was catasrophic. If you had a broken one, your car wouldnt run well if at all. It's louder then hell, like a hammer being hit against the valve cover HARD about 5 times a second.

Going to go over all the springs again before i pull the heads off with a feeler gauge to check for coil bind again, though I feel its redundant.

 

Gotcha. Mine sounds like a collapsed lifter, but a broken spring has been mentioned.

 

I know what a broken valve spring sounds like, not good I broke a Crane valve spring.

As for the CM 612's, I've had nothing but good luck with them. My springs have seen 6600 RPM on many occasions and are still going strong. I'm running an XE cam, 224/236, .537/.556. So, at least for this application they seem adequate.

 

How do you have your lifters lashed? The Comp Cams "R" lifters are really touchy.

 

I have heard that. I am about to loosen and retighten to find out what is going on. I am told the original adjustment is a 1/4 turn. All was great for 440 miles and all hell broke loose.

 

Hmmm... This is interesting. I have a set of 612s that I'm installing very soon. My lift isn't quite as high as yours, but still... I've tried to find out who makes the springs and have been unsuccessful. CM only says they've performed very well. They couldnt tell me of a failure, so this is the first I've heard.

 

Spinner,
Hmm...not good at all

What other springs would you recommend that fit the stock heads without machining?

 

well, what you need to realize is that any spring will have breakage as a possibility. it sucks that you got stuck w/one of the bad ones, but thats just the way it is. no way can ANY product be make 100% perfect. there will always be some bad ones. I have the 612 springs too, so thats what Im banking on. anways, dave at combo is a good guy and hopefully they'll help you out. and hopefully the damage isnt too bad. to start out with, Id do a cyl. leakdown test to make sure the piston doesnt have a hole punched in it or anything.
chris

 

talk about overreaction

"like, oh my god, 1 spring failed, so everyone should junk this entire brand of springs!"

thats like when one persons fbody breaks down, everyone else should sell theirs.

any high performance product if going to have occasional failures, its inevitable............no one makes a perfect product.

now if a large percentage of CM spring users were having the same prob, then youd have a point, but this is the first report ive seen, so looks like an isolated case. you just have bad luck.