The hardening on my stock cam failed
08-03-2012, 05:28 PM
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The hardening on my stock cam failed
What the hell causes that? Long story short, i was driving home from work and got an intermittent squeak. I thought is was a pulley so i unhooked the serpentine belts and it continued. Called the stealership and they said it was the hardening on the cam failing and it was eating the cam and lifter away. What kinds of cams can i get so i don't have to tune, what are you guys running un-tuned? I was thinking the TR224 as i am leaving the truck stock for now except for the cam. Can i get some opinions or advice on cams with the option of tuning and getting some performance out of it I'm also not against a swap and drive cam that requires no tuning...? Every cam I've picked has sounded great on paper but would make my truck a dog on the road... Thanks guys.
08-03-2012, 11:19 PM
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something in the range of like 202/206/210 @ .050 on the intake side with a 114 or so LSA should work pretty well without tuning. Any bigger on the @ .050 or tighter on the LSA will require tuning to keep a steady idle. Any cam change will benefit from tuning, but the smallest ones should idle and run closest to stock without anything else.
08-04-2012, 02:13 PM
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The lack of zinc in modern oils causes it. Zinc helps protect the hardened surfaces if the cam and lifters It's not so much a problem with the LS roller cams, but a big problem with SBCs etc. with flat tapper cams. Make sure to buy an oil with enhanced zddp or use a zinc additive. Friggin environmentalists have created regulations peohibiting high zinc content in motor oil.
08-06-2012, 11:01 PM
#6
LOL. The hardening does not fail on its own. It's either good or bad. What typically happens is either the core is not hardened deep enough, or the core material is inferior. There is other factors that will play into failure as well like if you run these engine low on oil. Just because you don't notice a fluctuation in pressure doesn't mean its not happening.
It helps to under stand how a cam is made and finished. It is typically cast or forged in a general shape. Then they are heat treated in large batches so it's possible the cam in the middle of the batch may not have been hardened as deep as the rest. Once heat treated the main journals are finished before being sold to company that specializes in finishing them. It is possible that the operator of the cam grinding machine went to heavy on the cut or that he did not index it correctly in the machine and ground to much off of one side. Even though they use a large stone wheel with coolant, if you grind to much material at once it is still possible to ruin the heat treated surface.
If you attempt to heat treat a blank after it has been finished ground it is possible for the cam to twist and not stay true. That's why they are heat treated first and then finish ground.
The problem with Comp Cams and there early Soft Cams was that they Chose to use an inferior blank material that was not a good choice for a roller cam.
It helps to under stand how a cam is made and finished. It is typically cast or forged in a general shape. Then they are heat treated in large batches so it's possible the cam in the middle of the batch may not have been hardened as deep as the rest. Once heat treated the main journals are finished before being sold to company that specializes in finishing them. It is possible that the operator of the cam grinding machine went to heavy on the cut or that he did not index it correctly in the machine and ground to much off of one side. Even though they use a large stone wheel with coolant, if you grind to much material at once it is still possible to ruin the heat treated surface.
If you attempt to heat treat a blank after it has been finished ground it is possible for the cam to twist and not stay true. That's why they are heat treated first and then finish ground.
The problem with Comp Cams and there early Soft Cams was that they Chose to use an inferior blank material that was not a good choice for a roller cam.