What's up with Comp Cams ?
01-04-2014, 12:50 PM
#321
FormerVendor
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Location: Santa Ana, CA. USA
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Chinese Cam Cores We received our first Chinese Camshaft Core (LS-x) in March 2013.
The rods I sell often are made in the same factory as Comp Star rods and use the same forging, a quality rod for the price. (we replace the bolts here)
I found the chance for a $60.00 cam core so I inspected the one form China, a sample.
What I found was inferior to Engine Machine/GM OEM cores.
Thus no purchase was made at that time.
I also heard from Crower that LS cores "take a while to get at times" though they are most often in stock.
I would like to inspect your core ?
Lance
The rods I sell often are made in the same factory as Comp Star rods and use the same forging, a quality rod for the price. (we replace the bolts here)
I found the chance for a $60.00 cam core so I inspected the one form China, a sample.
What I found was inferior to Engine Machine/GM OEM cores.
Thus no purchase was made at that time.
I also heard from Crower that LS cores "take a while to get at times" though they are most often in stock.
I would like to inspect your core ?
Lance
01-04-2014, 02:19 PM
#322
TECH Fanatic
Very good post. I always thought that when you do a cam, you need to address the entire valvetrain personally. Not just throw in a cam. Think lifters, springs, retainers, rockers, valves and pushrods. That being said, I did not do valves on this last cam that I put in, but I did get a fresh valve job. I DID A TRUUNION UPGRADE as many folks were saying that the stock rockers are quite good and are very light. MIGHT I REGRET THIS LATER? Maybe. But I made the most informed decision I could at the time.
As you stated, many look to the internet and the more knowledgeable people in the forums when making these decisions. The tough part is weeding out the BS and the people just trying to sell parts!
As you stated, many look to the internet and the more knowledgeable people in the forums when making these decisions. The tough part is weeding out the BS and the people just trying to sell parts!
01-08-2014, 04:28 PM
#323
6600 rpm clutch dump of death Administrator
All the OEM lobes are pretty mild by comparison to anything in the aftermarket. It has to be to pass the 100K torture tests GM puts them through. I am sure the occasional cam has a bad heat treatment, but I would think if it were an epidemic you'd see it like you did the oil consumption/low tension ring issue in the '01 Z06.
I have a takeout 6.0L that has flat cam, but it also had well over 200K miles and was a company work truck with an unknown maintenance schedule. But, for $200 I couldn't argue with it.
What I have seen that is cam related is that GM has a Phaser issue and I know of several motors that have sheared the pin recently. GM has released an updated phaser. The phaser and cam are cheap compared to similar GM products which is a pretty good indication they know there is an issue and are making the part available at low cost for those who run into an issue.
I've know of two engines recently which both had the same issue at nearly the same time.
01-09-2014, 09:47 AM
#326
There are two posts in this thread about the failure of stock cams (yours and one other). I have not seen huge amount of failures in stock cams, and I have not been looking for thread on them either. So, if there is a huge issue with stock cam failure I'll be honest I have just not kept up with it, and I am not aware of it. It also was not prevalent in this thread. I've been overseas for several months, so my time on tech was somewhat limited.
All the OEM lobes are pretty mild by comparison to anything in the aftermarket. It has to be to pass the 100K torture tests GM puts them through. I am sure the occasional cam has a bad heat treatment, but I would think if it were an epidemic you'd see it like you did the oil consumption/low tension ring issue in the '01 Z06.
All the OEM lobes are pretty mild by comparison to anything in the aftermarket. It has to be to pass the 100K torture tests GM puts them through. I am sure the occasional cam has a bad heat treatment, but I would think if it were an epidemic you'd see it like you did the oil consumption/low tension ring issue in the '01 Z06.
01-10-2014, 09:24 AM
#328
I can't find the post right now, but I believe Brian Tooley has stated that cam/lifter failure comes from not controlling the valve properly.
1) Not enough spring pressure
2) Not stuff/thick enough pushrods
3) valves too heavy
4) Combination of 1-3
I had a cam wipe out and take out all my lifters before. When in reality, it was probably loss of valve control, which took out the lifters, which in turn took out the cam lobes.
I haven't had any cam related problems in 30k miles since I switched to 3/8" pushrods and BTR dual springs. I did drink the zddp coolaid and I do throw in a bottle of rislone every oil change, but me stating that is even remotely helping is just a guess. @ 6/bottle I'll continue to use it though.
1) Not enough spring pressure
2) Not stuff/thick enough pushrods
3) valves too heavy
4) Combination of 1-3
I had a cam wipe out and take out all my lifters before. When in reality, it was probably loss of valve control, which took out the lifters, which in turn took out the cam lobes.
I haven't had any cam related problems in 30k miles since I switched to 3/8" pushrods and BTR dual springs. I did drink the zddp coolaid and I do throw in a bottle of rislone every oil change, but me stating that is even remotely helping is just a guess. @ 6/bottle I'll continue to use it though.
01-10-2014, 09:33 AM
#329
the stock cam was bad in my engine when I got it
also had a comp cam flatten out a lot of lobes, but that was probably my fault for not checking/changing springs
a friend just had a comp cam lose a lot of lobes with very few miles and fresh springs (and they were BAD), he is planning so send it to them for inspection
No opinion here, just posting some facts
also had a comp cam flatten out a lot of lobes, but that was probably my fault for not checking/changing springs
a friend just had a comp cam lose a lot of lobes with very few miles and fresh springs (and they were BAD), he is planning so send it to them for inspection
No opinion here, just posting some facts
01-10-2014, 11:12 AM
#330
the stock cam was bad in my engine when I got it
also had a comp cam flatten out a lot of lobes, but that was probably my fault for not checking/changing springs
a friend just had a comp cam lose a lot of lobes with very few miles and fresh springs (and they were BAD), he is planning so send it to them for inspection
No opinion here, just posting some facts
also had a comp cam flatten out a lot of lobes, but that was probably my fault for not checking/changing springs
a friend just had a comp cam lose a lot of lobes with very few miles and fresh springs (and they were BAD), he is planning so send it to them for inspection
No opinion here, just posting some facts
I'm getting ready to start my new engine with a comp cam, getting paranoid.
01-10-2014, 11:33 AM
#331
it was a comp custom grind similar to the Torquer V3 with the lsk intake lobe, stock rockers, stock lifters, and patriot springs then replaced with Tooley springs...low mileage car
his cam was the worst ruined cam I've ever seen and not just on the lobe tips, there were deep channels dug into the lobe nearly all the way around
his cam was the worst ruined cam I've ever seen and not just on the lobe tips, there were deep channels dug into the lobe nearly all the way around
01-10-2014, 11:38 AM
#332
it was a comp custom grind similar to the Torquer V3 with the lsk intake lobe, stock rockers, stock lifters, and patriot springs then replaced with Tooley springs...low mileage car
his cam was the worst ruined cam I've ever seen and not just on the lobe tips, there were deep channels dug into the lobe nearly all the way around
his cam was the worst ruined cam I've ever seen and not just on the lobe tips, there were deep channels dug into the lobe nearly all the way around
Hmm, it's so hard to pinpoint these things.
01-10-2014, 11:43 AM
#333
Again, not pointing fingers at any one of the parts or manufacturers...just putting out some anecdotal info. Comp told him to send the cam in for testing if he could scratch any of the lobes with a file (which you can).
My current cam is a comp ground EPS cam and I intend to use Tooley springs shortly when I swap out my current springs (per 20k mile rule of thumb).
01-10-2014, 11:52 AM
#334
Yeah the worn patriots starting the damage sounds plausible given their history of longevity..
But still I'd like to hear comp cams response after inspecting these cam failures, I mean they have dominated the cam market on these engines for so long..
They were doing something right for the past 10 years, hard to think that quality control shot to **** so rapidly..
Eh
But still I'd like to hear comp cams response after inspecting these cam failures, I mean they have dominated the cam market on these engines for so long..
They were doing something right for the past 10 years, hard to think that quality control shot to **** so rapidly..
Eh
02-17-2014, 04:24 PM
#337
TECH Apprentice
This Kip From Cam Motion I would like to let you know what we have found out about problems with cam cores going bad after reading this post. When we started in business we were buying cores 8620,5160 & 1050 and when we had problems the companies we bought the cores from would always say that they were not having any problems! So we started making our own cores out of 8620 we had better luck but still had some problems. After replacing hundreds of cams that broke down for two years we switched to 8620
Air Craft Quality steel we had much better luck but still some small problems. About 7 years ago we started polishing the lobes after grinding since then we have had NO problems it even cleaned up the sometimes cam whining. I do think that the 5150 cores are OK for street use but I think they MUST be polished after grinding. I do not think that aggressive lobe will make the cam brake down and cause the cam to go bad but they will shorten the life of the lifters, springs and valve seats. One reason 5150 is used it's because 5160 is induction hardened about .200 deep so you can grind many different cam profiles for one core. 8620 cost 30 to 40% more to manufacture and the Air Craft steel is almost 40% more expensive. With 8620 we can only harden it about .110 so we have 14 different cam core with different lobes and lobe separations.So if you have any question on cores please let me know.
Air Craft Quality steel we had much better luck but still some small problems. About 7 years ago we started polishing the lobes after grinding since then we have had NO problems it even cleaned up the sometimes cam whining. I do think that the 5150 cores are OK for street use but I think they MUST be polished after grinding. I do not think that aggressive lobe will make the cam brake down and cause the cam to go bad but they will shorten the life of the lifters, springs and valve seats. One reason 5150 is used it's because 5160 is induction hardened about .200 deep so you can grind many different cam profiles for one core. 8620 cost 30 to 40% more to manufacture and the Air Craft steel is almost 40% more expensive. With 8620 we can only harden it about .110 so we have 14 different cam core with different lobes and lobe separations.So if you have any question on cores please let me know.
02-17-2014, 04:37 PM
#339
TECH Apprentice
I have been hit hard with what we believe to be bad Comp CAMs now on 3 engines. Two of these CAMS failed with less than 2500 and 1500 miles. I have 2 of the bad CAMS ready to send out and a guy is hopefully sending me another one that failed in his car for testing that failed after less than 500 miles. I am planning to send these to 2 different independent engineering companies for analysis.
At a minimum I am having the test below done on these CAMs
Metallographic Testing
Failure Analysis
Chemical Analysis
Mechanical Testing
If you have or know of anyone with what you believe is a bad custom ground Comp CAM please PM me here....
At a minimum I am having the test below done on these CAMs
Metallographic Testing
Failure Analysis
Chemical Analysis
Mechanical Testing
If you have or know of anyone with what you believe is a bad custom ground Comp CAM please PM me here....
steel. Polish lobes after grinding. No problems now.