I am wondering if anyone, besides me, has had any problems with premature lobe wear with Cam Motion cams? My first one back in 2005 had one lobe going bad in 30,000 miles. Too much time has elapsed to remember whether it was an intake or exhaust lobe. My second one has gone 43,000 miles, and several lobes are showing considerable wear, especially #8 exhaust lobe. VERY disappointed. I was happy with the performance of both cams, but not durability. I'm going to post this here and in Gen IV......

 

No. Nobody at any company would do anything about a cam worn out 18 years ago. As for the newer one, they could offer me FOUR new cams, and it wont cover my *** busting. Shrapnel in my engine is also for sh... I have a new cam coming from Tony Mamo@Mamo Motorsports, via Comp. Tony is a GREAT guy to work with......

 

You can't hold something against a company that happened almost 2 decades ago. Too much water under the bridge.
Cam Motion has a very good rep nowadays, better than Comp. remember their "flakey" cams a few years back? It was more widespread than anything Cam Motion ever did.
Let it go....

 

His complaint is too late but I can understand still being upset due to down time, labor, and costs involved. Plus one cam could be considered some kind of lemon but two is like just bad luck or poor quality. Wouldn't use that company again to avoid a third failure. There's other good cam companies.

 

In my experience, limited though it is, about 90% of the time, a cam wipeout is due to inadequate valve springs combined with too much RPM, resulting in loss of valve control at the instant the valves hit the seats at closing, or spring harmonics. Using the bare minimum that the cam mfr "specs" for a given cam, is about the surest way to guarantee short component life. That is, cam mfrs will usually tell you the least amount of spring to use, butt don't tell you that if you go with that, you better check things often, because its lifetime will be limited.

There aren't all that many sources of cam cores (the piece of metal that cam grinders buy in bulk). MANY mfrs usually use the same supplier. In that sense, the quality of the metal, is outside of the control of the cam grinder, except to the extent that if they test it and it's inadequate or inconsistent, then they should change core suppliers. Many of them change suppliers anyway over time as new alloys or other features are introduced, or delivery times change, or any number of other factors. Even if the cam core in this case was inferior in some way, CM may well have moved on from that supplier already anyway, for reasons other than quality. I'd think, CM being a "reputable" cam grinder, that if they knew they'd had a core quality problem around when your cam was made, they'd be willing to soften the blow to you somehow; most everybody in that business is that way.

I know it SUCKS when parts fail and tear up other things, butt don't be so quick to blame the vendor. Especially not if the springs are the least bit questionable in any way.

I'm pretty sure Tony doesn't make cam cores, or even grind them. AFAIK he provides the lobe specs he wants to someone who turns them into hardware. Who is that? Do you know their physical product is any "better"? The one thing buying from someone like Tony gives you, besides his knowledge of what works best with his own stuff, is an extra layer of protection, if things go wrong; butt it's not likely that the odds of things going wrong, will be much different.

 

Well, I understand what you're saying. BUT, if the springs were inadequate on the first cam, why was only one lobe worn? All 16 springs (VERY pricey 26921 Comp springs) were set up with the same installed height. No valve seals showed any interference, so there's that. On this latest cam, only a few lobes were worn, with #8 exhaust the worst. Both the old cam and the most recent one were only .600" lift, relatively tame by most built LS standards. Lastly, most (99+%) of this engines life saw rpm under 2,200 (70mph), and 200°-205° oil temps. I'm 70 years old, and don't run the living guts out of my engine like I did when I was 25 or 30! Plus, the guy at PAC told me that, as far as the springs are concerned, theres a huge difference in spring life between a .600" lift cam, and a .650" lift cam. He told me my 1905 duals (165lbs seat, 425lbs@max lift) could go 75,000+ miles at .600" lift, where a .650" lift cam would probably need the springs replaced at 25,000-30,000 miles, maybe sooner, depending on use. So, in my opinion, I believe the lobes are of questionable hardness. I still have a few contacts left in the toolroom that I worked in for 41 years. So one thing I can, and will do, is take the cam to the shop and check it on our Rockwell hardness checker. I'll report back with my findings, and post a few pics of the cam.......

 

Production tolerances; probably in the heads somewhere. Maybe in the spring setup.

It might be that other 1% that contains the answer. Only takes acoupla times buzzing it past the point where the valve train is stable, to DESTROY stuff. Only takes a little bit of destruction ONCE, to set up an eventual failure. A small chip, minor spalling on a lobe, a flat spot on a lifter roller, doesn't heal itself. Does nothing but grow. Unfortunately it can be tough to pin down what exploded first when looking at a pile of shrapnel.

Definitely do that. It'd be worth knowing, even if it's a dead end. More knowledge and facts are always better. Pay particular attention to any difference between lobes that survived and those that didn't. If they're different, ... well, you may be on to something. If they're all the same, ... well, the cam wasn't at fault, and it was something else. Be honest with yourself; don't hide from the truth, make excuses, beat yourself up, blame the aliens, get mad at your builder, or whatever. Let the data tell you the story.

Keep us posted on what you come up with.

 

Honestly there are so many variable that could impact durability besides the cam hardness or lobe profiles. Proper valvetrain geometry, rocker arm deflection, pushrod stiffness, valve float, spring bind, spring height pre-load, spring pressures, spring resonance, lifter preload, oil viscosity, oil pressure, metal debris in the oil, etc. etc.

Let us know what you find out on the hardness.

 

"If all the lobes are the same, the cam wasn't at fault".....Too much of a blanket statement. If all the lobes come in under 50 RC (too soft), the cam is definitely at fault! As for the first failure being due to production tolerances or spring set up, those heads were AFR 225 heads, with springs set up personally by Tony Mamo. They ran Comp 26921 springs, some of the best available in 2006, and still damn good springs. The second set of heads were done by Thomson Automotive, now Lingenfelter. When you have 2 different cams by the same company go bad, you start wondering. In both cases, engines were done by renowned head builders and engine builders, so it may be more than coincidence. Then again, maybe not. Bottom line is I merely ASKED if anyone else had experienced issues with cams from CM, that's all.....

 

The most recent was TWO MONTHS AGO......

 

OK fine.

Look up "logical fallacies". One of them is, argumentum ad auctoritatem. https://en.wikipedia.org/wiki/Argument_from_authority

Which of course is NOT to say, auctoritatem in this case, is falsum. (Yes I know Latin; please do not argue that; no I am not nor have I ever been Catholic)

Do the due diligence. However painful it might be. JUST DO IT.

You're ABSOLUTELY RIGHT.

That's what I just said. If ALL of them are soft, or too hard, which is also a defect ... imagine a cam made of glass, ... then there's an issue. If OTOH the one(s) that failed are DIFFERENT from the others, then, the cam could be at fault. No way to know for certain without KNOWING. Get the data, then you'll have something to go forward with.

Gather the data. Don't get all defensive with your panties in a wad. Since you have the measuring eqpt, MEASURE, then go from there, and quit arguing abuncha "it ain't my fault" CRAP.

OK fine. In 2006, maybe people that were doing what you did back then, were willing to assume some certain amount of risk. It's NOT 2006 anymore. The whole risk/reward curve has MOVED. Maybe what you did in 2006 was the best that could be done back than; maybe it wasn't "perfect" or "permanent". Maybe it's time to MOVE ON. Iunno, just sayin.

 

Yup I'm with you on that and since it's the trend to post the same in multiple places I'm in on that.

If you had a Cam that fell apart recently, then mentioning the one from 18 years ago is a moot point honestly. Literally had no positive added point to the matter than showing you recollect it because of boredom or just that salty over it. It adds zero anything to the problem here other than makes you out to be that prissy.

I've had several problems with Cams over the years from several manufacturers. Some were poorly spec'd, others were re-grinds with improper hardness. For the latter the guy who sold me them and told me to pretty much **** up a rope when I hardness tested them myself ended up with a terminal medical condition. The Lord works his ways..

 

And what Lifters were being used on said cam Failure?

As for COMP, They do the most advertising which is why you see them alot. As for the Soft Cams they sold, They Choose to Cheap out and use a core that wasn't meant for the application.

As was mentioned, there are only a handful of companies making cam cores.

 

LS7 lifters were used. 14 of the 16 lifters looked fine. Only 2 that looked rough were on the 2 worst lobes. On several other rough looking lobes, the lifters were fine. However, this thread has done nothing to answer my question, and has turned into a force field defense of CM! That is NOT the purpose of my thread. I'm simply asking for anyone who has had issues with CM cams to please post their experiences. How many of you guys here have actually run a CM cam in an LS engine? "Logical fallacies??" WIKIPEDIA??? Really?? I'll stop posting here, with the exception of cam pics, and hardness results. Hardness results may take a week or so.....

 

Guys, here's my pics from an hour ago. First 2 are of #8 Exhaust, the worst one by far.....





Interestingly, my first CM cammed engine had the one worn lobe at the rear of the cam. It wasn't the last lobe, but it was one of the last 3 or 4 lobes. Too long ago to remember which one. Also, BOTH engines used trays, which may, or may not, play a part. At 400lbs over the nose, they're seeing spring pressure around 100lbs over stock design. No lifters have ever turned, but have they oscillated due to spring pressure causing some small amount of flex in trays? IDK, don't have an answer. Here are the rest of the pics. 5 lobes (31.25%) show distress, with #8 the worst, by far.














Until I hardness test, I'm done posting. I just hope the hardness test isn't skewed by possible work hardening. May be a week or so before I have hardness results, as shop I worked at is a 65 mile round trip away, and I'll have to, uh, "sneak" the cam in for the testing.....

 

Yeah there's A BUNCH that are smoked, including "one of the last 3 or 4", as you described for the previous cam (which is kinda suspicious all on its own)... hardness #s should be interesting. Post em when you get em.

 

What is suspicious??

 

Possibly the same lobe going bad on 2 cams

 

Mike (OP)

I bet some of your springs were very low on pressure due to how old they were.

No matter who makes the cam if you dont have enough seat and open pressure you will get lifter bounce and chatter and its like an impact hammer on the lobes damaging the lifter wheel and the cam lobes slowly over time

You need to keep the lifter glued to the cam lobes at all times....too much pressure is waaaay better than not enough

Send me your original springs and I can measure them and confirm whether I feel that may have been the issue

Bet you I find some that are down at least 30 lbs on the seat....how many miles were on them?

Quite alot from what I remember!

I share this on the public forum versus an email or private message as its a good lesson to those reading this who may not be doing enough spring maintenance which is a must with aftermarket performance cams.

Performance engines require two things for long life....more frequent oil changes and spring replacements at much lower intervals than OEM stock engines. Cam aggressiveness, spring quality, and how you drive the car dictate how soon you need to change out the springs.

That might be 5000 miles for some and 30,000 miles for others with milder applications but going longer than that starts to get dicey and can effect reliability regarding cam lobes and roller lifters.

If I recall you had well over 30K on that build but I might be wrong

-Tony

 

There you go! Straight from Tony.