I would have to disagree. Most any part with complicated geometry or manufacturing processes will have a weak point, or more commonly referred to as a stress concentration.

For example: when the balance weights are welded onto a driveshaft, the material properties at the point of the weld are changed such that a stress concentartion is created. This is why a split/twisted driveshaft is commonly broken directly along the weld. A design flaw? I don't think so. This added stress is just part of the design that must be dealt with accordingly.

I'm sure COMP was well aware of the stress concentration they were creating due to the geometry in the spring design. IMO the cause of failure was more than likely a bad heat treatment. When you get into high performance parts the heat treatment process can get complicated. If you screw up the heat treatment, the spring can have a significantly lower yield strength (i.e. weaker material) and be much more proned to failure.

 

If you design a product that has a high rate of identical failures with the intended use, what else would you call that other than a design flaw?

Rich

 

Nice to see you post again Joe. The 987s I was using with your small cam, 222/226, developed valve float right after peak HP (6k). Graph fell like a rock after the 6k. Now with the 918s it still peaks at 6k but only loses about 15 hp by 6400rpm. If the 918s are not the way to go, what would you recommend? Hopefully you'll come back once in a while if your not to busy.

 

Man, these were part of my recipe for the valve train. What ones now? Have not gotten valve springs and retainers yet but that is the last pieces I need for a cam swap.

 

Could be a spring problem OR possibly valve train geometry problem. If the geometry isnt just right the tips of the rocker arms will put a side load on the spring AND valve guide causing most of the pressure to be concentrated onto that one part of the spring. Then, you have a breakage at the weak point. In this case its where the spring gets flat. Just think of it as a piece of metal bending. What happens to a piece of flat metal that you bend back and forth alot, it breaks. Just my opinion but what is that worth. LOL

 

People broke them with stock rockers on LS1's so those weren't a result if improper geometry.

 

I am F'ing noided out now. I have seen way too much evidence. I wonder if Lloyd will take my springs back, being they have not been used yet. I would rather go with the PAC ones now.

 

Apparently factory stock hemis are blowing them out too.

 

Bad News: Took off my drive side valve cover and did some looking around. First glance, everything looked ok. Second glance, still fine. 3rd glance and I caught it, the rearmost spring looked to still be in place, however I can see a full crack in the location everyone else is showing.. The broken part of the spring is still seated in place however. I found at least two more broken on on the driver side by feel, and can feel the crack with my fingernail and just barely see it..

Good News: None of the broken springs look to have separated or fallen into the engine (at least on the drivers side. haven't looked at the passenger side yet)

Even better news: That we have a fantastic bulletin board like camaroz28.com to bring to light issues such as these.. Sure it stinks that these parts are breaking, but I bet there are a few of us that were lucky enough to save our motors based on the heads up others have provided here.

Once I have the springs out, I'll think I'll see if I can have our metallurgist and materials failure lab take a look at them as a side project, or at least see if they may let me use some of the equipment to make an educated guess as to what's going on.. (no promises here it's a long shot)

Some history: motor was rebuilt this winter, and I currently have about 1500 miles on it now. Was running great, no problems to speak of other than some slight ticking which I took to the Comp R lifters and pro mags... If I didn't read the posts here I would have never looked so closely at the valve springs and probably would be rebuilding again shortly...


I'll try to have some pics up later..


Lastly, one question: What is Comp Cams stance on this?

 

Do you know the batch # by any chance?

 

As a general rule, no performance parts manufacturer will take responsbility for anything other than their part. The logic is that they don't control the use, installation, conditions, etc. So, if you lose an engine due to a failed part, you can forget collecting for anything other than a (hopefully) non-defective replacement for the broken part. The rest is your responsibility. This makes sense, generally. And I sure that Comp has no legal responsibility for anything other than the springs themselves. In fact, here's what their warranty says:

COMP Cams® warrants that all of the products are free from defects in material and workmanship, and against excessive wear for a period of twelve months from date of purchase. This limtied warranty shall apply for a period of one year from the date of purchase and shall cover only the original purchaser. This warranty is valid on camshafts only where new lifters and proper valve springs are used, such as those found in COMP Cams Kits. COMP Cams obligation under this warranty is limited to the repair of replacement of the product.

But it looks like they should have known of this problem a long time ago and have done nothing to notify customers or change the product to eliminate the defect. If, when this has shaken out, they don't help people who have had major damage resulting from these springs failing I will never buy from them again.

Rich

 

IHMO you are assuming that every well designed part will always function just as it was designed to. The design may look good on CAE and the testing may prove the design valid, but when it comes time to make the part those calculation all go out the window if the part isn't made to print. Like I mentioned above, heat treatment will make a very large difference on the strength of a material. A pour surface finish can lead to stress concentrations in extreme case, but I don't think that applies here.

Odds are when COMP changed suppliers (which was likely to cut costs), the new supplier wasn't able to make springs to the print, thus making faulty parts. What likely happened is when COMP discovered the imcompetence of the cheaper supplier, they switched back to PAC.

 

Have they switched back? Not trying to start an argument, but how did you learn this? Is it only the Mexican sourced springs that are a problem? Whether this a design flaw or a major QC issue, Comp needs to investigate and come clean. Saying nothing has been proven time and again to be a PR nightmare.

Anyone called Comp recently? What did they say?

Rich

 

If you design a product that works fine when built according to the design, and then the material used is changed intentionally or unintentionally, causing it to fail, then I'd call that a manufacturing or a management flaw, depending on if the change was accidental or intentional. A "design flaw" says that the designer did his job wrong. In a case such as is being hypothesized, the designer did his job correctly.

Comp has made poor management decisions regarding springs before, so it's not a great leap to imagine that something similar has happened here:
http://www.lxforums.com/board/showpo...6&postcount=76

 

yes, mobleman, batch # please if you've got it. I'd like to add it to the list...