2012 Yukon XL Denali 6.2L Cam Swap Thread

[swathdiver]

And on my other shoulder is a blue angel saying in my dad's voice: "Remove the pan fully so you can do the job right, clean it out and get a new pan gasket in there." Of course, that means dropping the cross member, lowering the steering rack and the front diff. All doable, just a PITA.

Pull the motor and put it on a stand. It'll save your back and you can take your time with the motor and with the motor out, take care of the engine bay needs too.

 

[Geotrash]

I would if I had the space. My wife’s father moved in with us (he’s a fantastic guy), and he brought 74 years worth of accumulated stuff with him that he needs time to go through. So until that happens, I only have one garage stall to work with. Got the pan off no problem anyway.


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[Geotrash]

Got the heads all finished up tonight. Installed new dual springs and valve stem seals, and Brian Tooley trunnion upgrade on the rocker arms.




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[Geotrash]

I was on track to get everything buttoned up today, but hit a snag. One of the new lifters has a high spot on it somewhere and won’t slide into any of the lifter bores easily without being tapped with a mallet. Not going to risk that so I’ve asked Roger Vinci for a replacement, but I’m wondering if it would also be safe to replace just one lifter with a brand new one I just happen to have on hand made by Melling. Any thoughts?

 

[langsbr]

What made you use a cathedral port cam on rectangle heads, or did they just send you a messed up sheet? Did Vinci say what kind of power gain you could expect when running it with stock manifolds and cats? Seems like it will choke out very early.

 

[wjburken]

I was on track to get everything buttoned up today, but hit a snag. One of the new lifters has a high spot on it somewhere and won’t slide into any of the lifter bores easily without being tapped with a mallet. Not going to risk that so I’ve asked Roger Vinci for a replacement, but I’m wondering if it would also be safe to replace just one lifter with a brand new one I just happen to have on hand made by Melling. Any thoughts?

If it were me, I would go with a matched set. You’re this deep into it, don’t need it to get to work, and from what you’ve posted, you don’t like to take short cuts. It will always be in the back of your mind if you use the Melling lifter, “was that the right call?”

 

[Geotrash]

What made you use a cathedral port cam on rectangle heads, or did they just send you a messed up sheet? Did Vinci say what kind of power gain you could expect when running it with stock manifolds and cats? Seems like it will choke out very early.

An excellent question, thank you Brian. I saw that on the sheet, and assumed that it was alright but maybe shouldn’t have. I gave him the detailed specs on my truck, including the engine, and the way I use it, which is for both getting groceries and hauling a camper. I will send him a note now and just do a double check.

 

[Geotrash]

If it were me, I would go with a matched set. You’re this deep into it, don’t need it to get to work, and from what you’ve posted, you don’t like to take short cuts. It will always be in the back of your mind if you use the Melling lifter, “was that the right call?”

Thank you, Wade. You’re right and that’s the kind of feedback I was looking for. I’ll wait for the matched lifter before I button it up. There’s indeed no rush. And it seems that you understand why I don’t like to cut corners!

Side note: the lifters Roger sent are otherwise flawless. The roller on each one is tight with no play but rolls easily and smoothly. The Melling has a tiny bit of side play in the roller.

 

[Geotrash]

Roger’s personal touch to customer service is great. He already got back to me on the lifter, and has asked me to send it back so they can figure out what happened in QA. He runs 3 different inspections on each lifter, and was mortified that anything got through.

I took a micrometer to it this morning and there’s one spot above the roller shaft that measures about .006 proud of everything else around it. I can’t detect any other anomalies.

Update: Actually it looks like most of the lifter body above the roller shaft is .849 while the small portion that's below it is the standard .842. Roger's working theory is that inserting a slightly oversized plunger may have expanded the lifter during manufacture, but he seems intent on getting to the bottom of it, which is fabulous. I sent the lifter back to him this morning and he has a new one on the way. Meanwhile, he has people running through his warehouse doing spot checks as a result. Very happy with his support and that he took this seriously. I wouldn't hesitate to use Vinci again, and will when it's time to do the upgrades to our '07.

 

[Geotrash]

Got the updated cam card from Roger today as well. This particular cam works in both cathedral and rectangular port applications. Here's the correct cam card. That said, I accept that the stock airflow components may hamper breathing. We'll see how it goes...if I need headers, I'll make the investment.