I'm wondering if anyone, besides me, has had any issues or problems with premature lobe wear on their Cam Motion cams? My first one, back in 2005, went 30,000 miles before one lobe showed serious wear. Too many years have elapsed to remember whether it was an intake or exhaust. The second has 43,000 miles on it, and several lobes show significant wear, especially #8 exhaust.......

 

Damn. Hate you're going through this. I'm running two of their cams now and have nothing but good luck with them. The one in my Vette has 50K miles on it. .620 lift on both sides. The one in my truck has over 100K on it. Maybe a little over .600 lift on that one. Both engines use BTR Platinum dual springs and stock rocker arms (no trunnion upgrade). I ordered their mid level (I think they offer three) of steel on both cams. Also use Mob 1 Euro spec 10w40 as it has higher zn and phosphorous levels vs their other oils. Knocking on wood....no trouble so far.

I did have a Comp Cam go bad in an LS3. It used one of their more aggressive lobe series (LSL). That's what led me to Cam Motion.

 

Thank you, OM. Your post is one of the very few that have exactly the answers I was looking for Assuming you meant 0w-40 M1, which is what I also use. I appreciate your input on any subject here. IDK if it's CM failures, or? But AFR heads on older cam were set up by Tony Mamo using expensive Comp 26921 springs. Engine built by Wheel to Wheel Powertrain/Kurt Urban/Billy Briggs. Was a great company. Second set of heads, OEM LS7, plus engine, both built by Thomson Automotive, now Lingenfelter. OEM LS7 heads redone by AHP in 2020, with second new CM cam. OEM LS7 heads currently being redone by Tony Mamo. GREAT guy to work with. So many guys on Tech think I'm attacking CM. Im not trying to attack anyone. What I am trying to do is find out what the Hell happened!! I'm going to post pics of the cam later today, and take the cam to the toolroom that I worked in for 41 years, because we have a Rockwell hardness tester. I'll post those results when I can "sneak" the cam into the shop and test it!!

 

Yeah, 0w40. Been up since 4:30 am. Hasn't gotten any better. Might go back to bed...

 

Man, do I hear you on that! Sleep quality sucks as Ive gotten older. Check out these pics, taken an hour ago.....

#8 Exhaust, worst of all...

Another view of #8...

5 of 16 lobes (31.25%) showed some distress, with #8 the worst. Here's the rest of the pics.....











So, here it is....WAAAAHH!!

 

That's pretty damn ugly. Some of the others don't look exactly pristine either.

 

What lifters were you using? How was the preload set?

 

I have a 2012 Grand Sport M6 28k odometer. I went with a Cam Motion LS3 TITAN 2 on the 8620 steel core type last November. Old_Motorhead and a few other forum members highly recommended Cam Motion to me and they claim have renown cam lobes that are easy on the valve train. I also have GM LS7 lifters, BTR dual platinum springs, CHE trunnions , hardened push rods. I also use Pennzoil ULTRA Platinum 5W30.
about 1,000 miles on the cam so far, but runs strong throughout the RPM range and very quiet under the hood. The 8620 steel core was only an extra $115.00 so i went for it even though my Vette is street only.

 

8620 is a nickel chrome moly steel alloy, and is a very good steel. I have also been told Cam Motion lobes are easier on the valvetrain than some other makes are. Been told this by more than one highly regarded engine builder, one of whom is Kurt Urban. That's why I've used them. I'm not blaming CM, but I'm not saying they're not the problem, either. Honestly, just trying to find out what the Hell happened, not trying to point fingers.

 

LS7 lifters, about .080" preload. There are more bad lobes than bad lifters. 2 of the 16 lifters, on the 2 most damaged lobes, were junk. 5 of the 16 lobes show significant distress, #8 exhaust is by far the worst....

 

Curious if you hit up cam motion with the pics to get their take on what happened?

https://americanheritageperformance.com/

 

Nope. What good would it do? Vendors admitting errors are as common as hens teeth. It may not be the fault of the CM cam. Just trying to see if anyone else has had any CM issues. Even if they offered a new cam, not going to come close to my own labor and related parts carnage. I'm over $6,000 so far, with me providing "free" labor. I could count the fingers on one hand, on a hand that had all 5 fingers cut off, the number of times over 50 years I've ever gotten any free parts replacements from anyone. Nobody has ever said "Yeah, we screwed up," and given me a free replacement anything. Warranties are made to exclude performance parts......

 

I will be testing the lobe hardness on our shops Rockwell tester soon. I'll report back what I find. However, even that may not be accurate, because work hardening may skew the results. I've always liked CM cams, and I'm not blaming them. Would just like to know what caused what, thats all.....

 

Yeah me too
Curious as to your Hardness findings


https://americanheritageperformance.com/

 

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

 

No, you are correct about mileage. Thank you for offering to test my springs. I still have them in my garage's metal circular file!! I'll dig them out, and send them to you. I'd like to know what actually happened. I'm not trying to point fingers. I've used CM cams for almost 20 years. Was told by several engine buiders, Kurt Urban being one of them, that CM cams were easier on valvetrain parts than other brands. Maybe my thread title could've been clearer/better worded, idk. Springs were left in for close to 50,000 miles based on two things. One was how I use the car. Second was an opinion by a PAC employee. He reasoned that my cam had only .009" more lift than stock cam, and only 2° more degrees duration on intake than stock Z06 had on exhaust. However, my exhaust did have 20° more duration than stock Z06 exhaust. You've been a great guy to work with, Tony, and I appreciate all you've done. You're the best. However, only I know how I drove the car. The fact that my 4L60E is stock and working great with over 140,000 miles on it is one testimonial. I guess I could relay something my wife said to me last year that may be another good testimonial; she asked me why I even have a Corvette. I asked her why would you even ask that? She said because you drive like an old man in a Buick!!! My wife isnt a speed nut, either, soooo.....

 

It's alright to drive like an old man if you is one My fairly new diesel half ton chevy pickup thew a code. My son looked up the numbers. He told me I drive like an old man and that I need to run the snot out of it occasionally. He was 100% correct. I run it hard on occasion now. The code hasn't come back. I do run my Vette hard quite often because I live in the country and the cows that witness my idiocy won't rat me out...

 

 

UPDATE:
Tomorrow is a busy day. I'm taking my old cam to the shop where I worked, to check lobe hardness. I'm also sending Tony my old 1905 valvesprings tomorrow, at my expense, of course. He will be testing the compression specs. As soon as he has any info, I'll post it, good or bad. Just want facts, and to see what happened....

 

UPDATE!!!! OK, we tested the cam lobes, cam bearings, and came heels/base circles. Measured 3 middle cam bearings first, as a baseline. All 3 measured 59-62 RC. All lobes we checked were mid to upper 50s (except the bad lobe), say 56-58RC, which is good. What somewhat surprised me was the bearings were harder than the lobes. You'd think it would be the other way around. Now for the bad lobe. It came in at only 51RC. Marginal at best, IMHO. How they weren't all the same within 2 numbers, I have no idea. I'm reasonably sure they induction heat treat the entire cam at once in an oven, so temps should be uniform. Perhaps uneven carburizing? IDK.... Now for the biggest surprise of all, and maybe the red flag. When we tested all the heels/base circles, all came in again in the mid 50s....EXCEPT the bad lobe. That came in at only just over 30RC, about the same as pre-hardened steel!!! That won't cut it. None of the heels showed any wear. We measured that #8 exhaust heel in 3 or 4 different areas, and never saw over 32RC. So maybe that lobe came in at only 51RC due to work hardening?? IDK. I can't say with 100% certainty it is a bad lobe. But a couple of arrows do point in that direction. FWIW......