2012 Yukon XL Denali 6.2L Cam Swap Thread

[iamdub]

Potential for problems is why I take so many pics and notes to document critical details. This helps in references for myself and with others performing the same work. It may also be helpful in a warranty concern should a supplier need to see how a part was installed.

Off the top of my head, I documented in pics and text my head torquing process, crank pulley installation, torque converter filling and installation, piston height measurements, push rod measuring and length, lifter comparison and measuring, timing gear alignments, timing chain comparison and measurements, oil pump shimming, mods to oiling system and rocker tip wipe pattern. I'm sure there are others.

 

[Geotrash]

Potential for problems is why I take so many pics and notes to document critical details. This helps in references for myself and with others performing the same work. It may also be helpful in a warranty concern should a supplier need to see how a part was installed.

Off the top of my head, I documented in pics and text my head torquing process, crank pulley installation, torque converter filling and installation, piston height measurements, push rod measuring and length, lifter comparison and measuring, timing gear alignments, timing chain comparison and measurements, oil pump shimming, mods to oiling system and rocker tip wipe pattern. I'm sure there are others.

Yes, I will do that in the teardown and reassembly this time as well. That's a good call, thank you for suggesting it.

I pulled the cam fully out and laid it on rags on the kitchen counter so I could get a good look at it under better light, and the damage was worse than I initially thought. Several of the lobes had significant surface scars and gouges. Again, the oil pressure was lower than before the swap but definitely not zero (hot idle was 15 psi indicated, highway speed it was 35), and the cam was soaked in oil when I pulled it out. Can't wait to get those lifters out to see if there's anything wrong with them. The damage to the cam looks as if the rollers were seizing up, but the cam bearings look great. Strange indeed.

 

[ls1frc]

Yeah that cam is toast.

 

[thompsoj22]

YIKES! I understand loyalty, It sounds like your supplier is going to the extent he should to remedy the problem, However, Somthing is completely f'ing fubar in your project and i would highly suspect the parts you used. Your asessment of the stock engine on teardown was "no discrepancy noted" it looked perfect! Your asessment on teardown of your project is "fubar"! IMO, remove every component you installed from divinci and choose a different manufacture. Remember your intent was to build reliability and longevity into your vehicle, Dont compromise your end results?

 

[ls1frc]

I'd have to agree with thompsoj22 here...

I went down a rabbit hole once with Lunati cams. Every cam they sent me made a horrible whining noise. So loud you could hear it over the radio inside the cabin and it was a very high frequency. They basically took no responsibility for it.

I posted about that on the forums, I think it was like 2013. Cam Motion replied to it and said it was probably the finish on the cam lobes. He sent me a cam for FREE and it fixed the problem, dead quiet. They earned a customer for life. Every single cam I have purchased after that has been cam motion.

Cam Motion also cam doctors every cam that goes out, so you know the specs are what they're supposed to be.

Since you're doing the 3 bolt, order one up and get their 8620 core. I ran that alloy in my G8 for 40k daily driven miles, still looks brand new.

 

[ls1frc]

Ha, I still have the old videos

 

[Geotrash]

Okay, I'm getting more and more convinced to use a different cam. Two questions:

1. Do you think I should keep the Vinci dual springs? They're beautiful but I wonder if the pressure they require could be part of the problem.
2. Cam Motion makes a cam specific to the 6.2 rectangular port engines, but it's not in stock anywhere - estimated delivery 1/4. Should I wait for it or go with the Summit that has slightly milder specs (fits 6.2 but not 6.2 specific) that's available now.

Thanks for your thoughts.

Option 1: https://www.summitracing.com/parts/cxm-03-08-0031
Option 2: https://www.summitracing.com/parts/sum-8712

Vinci dual spring specs:
155 lbs @ 1.780"
360 lbs @ 1.230"
380 lbs @ 1.180"
400 lbs @ 1.130 "
coil bind @ 1.070"
od; 1.300
id: .509

 

[ls1frc]

Those cams are not ideal for your setup they are .500 lift. Now you could go that route if you just wanna run stock springs. I had to wait 4 weeks for my cam as well, everything is backed up right now.

Your springs are overkill for any cam under .600 lift, that's for certain. Though with good lifters, they should be ok.

You can contact BTR, I believe they use Cam Motion as their cam grinder now.

 

[Geotrash]

Those cams are not ideal for your setup they are .500 lift. Now you could go that route if you just wanna run stock springs. I had to wait 4 weeks for my cam as well, everything is backed up right now.

Your springs are overkill for any cam under .600 lift, that's for certain. Though with good lifters, they should be ok.

You can contact BTR, I believe they use Cam Motion as their cam grinder now.

Excellent. Thanks again for the help - gonna owe you a bottle of scotch even if you don't make a tutorial

Think I'm gonna go with the Brian Tooley Stage 2 truck cam.
Specs: 212/218 .553/.553 111+0
https://briantooleyracing.com/btr-camshaft-gen-3-4-truck-stage-2-v2-btr31218110.html

Spoke to them on the phone and confirmed that Cam Motion is likely the supplier but it's made to BTR specs. Going to go with BTR beehive springs and standard valve stem seals. I'll verify preload this time and will order standard length BTR pushrods as well.

They confirmed they have everything in stock and that it should arrive by Monday. That means I can get this wrapped up over the holidays, too.

 

[Geotrash]

YIKES! I understand loyalty, It sounds like your supplier is going to the extent he should to remedy the problem, However, Somthing is completely f'ing fubar in your project and i would highly suspect the parts you used. Your asessment of the stock engine on teardown was "no discrepancy noted" it looked perfect! Your asessment on teardown of your project is "fubar"! IMO, remove every component you installed from divinci and choose a different manufacture. Remember your intent was to build reliability and longevity into your vehicle, Dont compromise your end results?

Thank you, John. Your post is part of what tipped me over the edge to going a different route.