2012 Yukon XL Denali 6.2L Cam Swap Thread

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Geotrash

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Dave
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Yup, Ill second the opinion of soft/defective cam, Possibly the hardened rollers started destroying the soft cam material from the first startup. Shame how our perception of "quality" is based upon a small companys intent of putting out a good product but you might have an employee with a F'it attitude on a monday/friday and somthing like this happens. This project educated me, And when i do need to reman our engine i will only use OEM components. No hacking intended, It is simply getting so hard to find quality that is real as opposed to simply a verbiage marketing strategy.
Yes, this is increasingly my thinking as well. I don't know who actually grinds Roger's cams, so it could be a supplier issue at the root of it. And you may remember that one of the lifters I received was too big to fit into the lifter bore, so there is reason to suspect the quality of the lifters as well.

I forgot to mention that when I got the remaining 8 lifters out of the passenger side, all of them looked like new and rolled like new. Apart from that one damaged lifter, all 15 of the other lifters had zero damage to the rollers that I could discern with my 50-year-old eyes and reading glasses. Y'all saw the cam so I would have expected the lifters to be at least a little pitted since their Rockwell hardness is supposed to be significantly less than the cam.

My working theory now is that I essentially had three problems: 1/ The cam wasn't as hard as it was supposed to be and did indeed start receiving damage from the very beginning. 2/ I had 2 bad lifters - one never made it into the engine because it was too big, and another had a metallurgical issue that caused the roller to crack and lose a chunk under pressure. 3/ ~20% lower oil pressure than before the job with an as yet unknown root cause.

Given that I had 40-45 psi on cold startup and 15-20 at hot idle, it should still be sufficient for this engine. It never tripped the low oil pressure warning either, which it would have if oil pressure had dropped to a dangerous level.

Y'all may remember from earlier in the thread that the loud clacking noise that became a chirping noise with time, started when I made a full-throttle merge onto the highway. It makes logical sense to me that that was the point of failure for that lifter. Whatever caused the roller to fail, likely happened then. It follows that the failure happened when the pressures on the roller would have been at a peak, lending credence to the idea that the roller failed due to metallurgy or manufacturing defect, not due to a foreign object in the oil. The timing would have been miraculous if that were the case.

In any case, I'm feeling relieved to have the BTR cam and Morel lifters in the engine this time. I'm hopeful that it will run great and last many years and miles.
 
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Small but important update:

Roger tested the hardness of the cam and says it's within spec. He already agreed to warranty the cam though so I trust that he's telling the truth. I'm going to send him the lifters and give him a chance to test those as well. He continues to make himself available and offers helpful guidance.
 

ls1frc

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19-22 hot idle is what I am getting at 600 rpms, but I have VVT cam which I am sure effects that.

15-20 does seem a little low, but if it rose with RPMS still likely enough.

Looking forward to your first start.
 
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19-22 hot idle is what I am getting at 600 rpms, but I have VVT cam which I am sure effects that.

15-20 does seem a little low, but if it rose with RPMS still likely enough.

Looking forward to your first start.
Thank you, Mike. That's helpful. Which cam motion cam do you have and are you glad that you retained the VVT?

One of the things about my new setup I'm concerned about is losing the benefit of VVT on the low end for towing. The BTR stage 2 cam should still be a good puller, but I installed a new Melling high volume pump instead of standard volume in part to leave the door open to going back to a VVT cam at some point in the future. I cut some 5/16" wooden dowels to hold the lifters up when removing or installing a cam, and found they work great, so changing just a cam should be a much easier proposition. I don't want to ever have to pull that oil pan again.
 

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I just ordered my own specs directly from them.

215/225 .600 .600 115+7

I like the VVT because it's just cool to change the cam timing with software. I have it fully advanced unless it's at 4k rpms, then I start retarded it. I also retard it at cruise so I can get .2 better MPG lol.

It is the best of both worlds. We're talking maybe 20 ft/lbs of torque here though down low, nothing earth shattering. I wouldn't pull a cam just to put it in, especially with already having a 6.2.
 
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I just ordered my own specs directly from them.

215/225 .600 .600 115+7

I like the VVT because it's just cool to change the cam timing with software. I have it fully advanced unless it's at 4k rpms, then I start retarded it. I also retard it at cruise so I can get .2 better MPG lol.

It is the best of both worlds. We're talking maybe 20 ft/lbs of torque here though down low, nothing earth shattering. I wouldn't pull a cam just to put it in, especially with already having a 6.2.
Okay great - that's exactly the perspective I need. Thank you, Mike.
 
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As of 30 minutes ago, WE ARE RUNNING!!!! Fired right up, had almost immediate 50 psi oil pressure 60 psi at 2500 rpm, and almost ZERO lifter noise. Pic below was taken after I took my foot off the gas so the pressure hadn’t come down yet. Hooray!!!! Gonna finish buttoning it all up and take it for a test drive. That BTR stage 2 cam has a sweet lope to it too.

b2ebb4f8ddfe59ac2da7f95c867093e5.jpg


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wjburken

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As of 30 minutes ago, WE ARE RUNNING!!!! Fired right up, had almost immediate 50 psi oil pressure 60 psi at 2500 rpm, and almost ZERO lifter noise. Pic below was taken after I took my foot off the gas so the pressure hadn’t come down yet. Hooray!!!! Gonna finish buttoning it all up and take it for a test drive. That BTR stage 2 cam has a sweet lope to it too.

b2ebb4f8ddfe59ac2da7f95c867093e5.jpg


Sent from my iPhone using Tapatalk
WOO HOO!

06c1f0c0709b0888a77b289bfbd1036c.jpg
 

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