I agree, but the won't. No such thing as partial liability, so accepting responsibility would involve paying for all parts, labor and engine refresh. I would definately ask them for a "good will gesture". This would get them off the liability hook, and the op would have a new cam and lifters he could use, or sell.

 

I have an engineer friend who has access to a metalurgy lab who may be able to tell us what happend. He will be back on Tues and is picking up the cam. Once he has the workup on the cam done I will post what they say. They may be able to tell us everything, or nothing, we will see. I can tell you this, I spoke to three different people at Comp at different times and they have the SBC design flaw story down pat. I can tell you that I am a college grad, 67 years old, been around the block more than once, and when a company tries to put STUPID on me, I am done with that company. Because of BS I now have to strip down the entire engine, examine it with a fine tooth comb just to satisfy me what went wrong. I must say that this is not a cheap proceedure, but I do not want to do it again, so I say this to comp cams if you know anything please speak up. When talking to Isky, I was told they use only american cores! The motor has a new set of AFR heads, new 4340 crank and rods, and has run for about 10,000 miles with this setup. I have $12,000 in this engine and for a $300 part to break for no reason other than a defective core/chinese core is criminal....Buy American!!!! "AGAIN, WHY SHOULD A CAM JUST BREAK" that's the answer I am looking for. Thanks for letting me rave.....

 

I sent Comp a link to this thread.

 

comp makes the cheapest parts they can period,there is plenty of documented spring failures using their springs.patriot was making their springs and then comp decided mexico could make a cheaper spring and a lot of people using behive springs found they were failing,causing engine failures just a few years ago.having chinese cores would not surprise me for comp,they used to have a good reputation and I had a cam for my big block years ago that was fine but now with the bean counters and greed their quality sucks and I would never use their products ever! i have never had a failure with quality american made parts.

 

Comp Cams spends a ton of money on marketing, unfortunately their products are generally not of great quality. Crane Cams which went under last year had a better reputation with the real racers and engine builders. Unfortunately, they had good parts but were poor business people.

 

Rebuilt my first 327 44 years ago, lost count how many since then. Have never seen a cam snap like that. The analysis of the break will be interesting. I am a bit surprised Comp would not want the cam back to run their own tests. Will not take many failures like this before comp can hang their shingle beside Cranes.

 

We have taken the motor apart and cannot find a mark, scratch anywhere, the cam just broke and there dosn't seem to be any damage I can find, other than the cam bearings, this is very confusing and now I am now parinoid on what to buy. Pulling an engine then striping it is not a easy/cheap task. I do not want to put it back together until I know what went wrong.

I would be happy to let Comp run the tests after I get the results back from the lab here. The lab here runs tests on jet engines and have every piece of equipment available for running metalurgy tests. I sincerly doubt if Comp has the expertise these people do.

 

I only saw one oem cam break before and that was on a Ford 390 FE truck engine.

What is the plan? To get the exact duplicate cam in another brand?

 

No, Right now I am leaning towards a 4/7 swap cam from Isky. The grind I have decided on is a 236/236 duration, 600 lift, and a LSA of 112. I will have the cam ground straight up. I need to vist with crower and Isky one more time, as I want to learn a little more about ramp styles if there is such a thing. The more I try to learn about cams, ramps, etc, the more I want to know....

 

Why are you all so quick to assume that since one cam breaks all of their other cams will definitely break as well? This is the first time I've ever seen a cam break like this, and I've been into engines since I was a very small child. Most likely, this is just one cam that made it through their QC.

 

Probably always be a % of failures from any mfr. More made more youll hear about.

 

I dont think thats the case. The problem is, they did not stand behind their product. A big problem for me.

 

I have only seen 1 snap like that. It was a 355 blower motor that had a gear drive. The motor hic-cupped and I assume the lack of timing chain contributed.

 

I have been around motors for a long time and I have never seen a cam break on its on own, always another reason like a broken valve or something. That's why I am going through my engine to see if it can be something else, like springs other than what I ordered, and I can't really think springs that are too stiff for the cam might break it????? Am I grasping at straws??

Probably always be a % of failures from any mfr. More made more youll hear about.

The problem is that I have not heard of many cams breaking on thier own. It will be nice to receive the information fom the metallurgy lab, then I will know. If it was a bad core, then i will try another company, if it was something else, then what broke it. The likleyhood is I will never know as the manufacture will never say anything, and so far I have found nothing wrong with any engine parts in the engine.

 

If it were a cast iron core, and excessive spring pressures were found, I could buy into a cam snapping like that. But a billet core? I am not buying it either. My bet is faulty core. What scares me now is that there is a core shortage, and all manufactures are scrambling to find them.

 

I beleive that the cam is a cast iron. It is comp cam # 304 -HR CS 304H-R10 (244/244 duration @ 50, 600 lift, 110 LSA)

When I ordered the heads from AFR I gave them the cam specs and that I had 1.6 rockers. When I talked to the salesman he said that the springs were good to 630 lift. The springs have red paint on them. The springs I purchased from comp for the edelbrock heads were 950-16

 

Small base circle?
I would put the springs in the spotlight now. Check open and closed pressures at their installed height.
I have seen cast iron cams snap with alot of spring pressure.

 

 

It is not a small base cam, My AFR salesman will be talking to the engineering dept on Tue., I have no idea what will come of that. I am not a mechanical engineer who builds heads, but my question was what if they put in the wrong sized springs, would that make any difference. When I purchased the heads soon after installing them the motor started breaking rocker studs. My salesman talked to the tech guys at AFR and they suggested going to the larger studs, which I did. I put 40,000 miles on the previous heads with the same cam and 3/8 studs with no problems. AFR sent me the heads with 3/8 studs. 4,000 miles after installing the new heads I have broken 2 studs, and a cam it just makes one wonder, likley a conicendence, I have no idea. If the metallurgists come back with a stress fracture then the heads become suspect. There is not a scratch or dent on the cam so that rules out after 40,000 miles the possibilty of a rod end hitting the cam. Can breaking rocker studs and a cam have any relashionship, is it even possible that the wrong springs can cause to two different problems. These are the questions that need answers before I am putting the engine back together and running it. I just want to say, I am not pointing fingers here at anyone, AFR or Comp, I will do that once the metallurgy test show something conclusive. Pulling and striping an engine is no fun, and to not know why these problems started appearing is perplexing at the least. I was hoping that someone on this forum might have the knowledge of this happening to others and may shine some light my direction.

 

Snapping studs and the cam is symptomatic of excessive spring pressure. Easy enough to check. Measure the installed height of the spring.
Take it to someone with a spring tester and document the installed height pressure (closed) and subtract the lift to find the open pressure.