2012 Yukon XL Denali 6.2L Cam Swap Thread

[Geotrash]

So I am equal parts: 1/would totally buy a brand new XL Denali if they were available nearby right now and weren’t experiencing teething pains, 2/putting a brand new engine in this one, and 3/installing just one more cam and hoping for the best.

This isn’t about pennypinching… We make plenty of money to buy a brand new truck, but I genuinely believed I would be able to extend the life of this one indefinitely by getting rid of the AFM system. Had I had any clue the probable implications of what I was about to do, I would have just had AFM tuned out and moved on.

 

[wsteele]

So I am equal parts: 1/would totally buy a brand new XL Denali if they were available nearby right now and weren’t experiencing teething pains, 2/putting a brand new engine in this one, and 3/installing just one more cam and hoping for the best.

This isn’t about pennypinching… We make plenty of money to buy a brand new truck, but I genuinely believed I would be able to extend the life of this one indefinitely by getting rid of the AFM system. Had I had any clue the probable implications of what I was about to do, I would have just had AFM tuned out and moved on.

I think you are nearly there. Just put the good stuff back into the top end and you almost certainly will be there. You know so much about how to optimize this very rig, don’t give up in the 9th inning!

 

[Geotrash]

I think you are nearly there. Just put the good stuff back into the top end and you almost certainly will be there. You know so much about how to optimize this very rig, don’t give up in the 9th inning!

Thanks for the encouragement, Bill. Third time's a charm, I hope. But honestly, my main worry is the potential for damage to the main bearings. They're next in line after the lifter oil galleys in the oil circuit flow. Worst case, I'll drop a new engine in it. Still way cheaper than a new rig and this one is cherry in every other way.

 

[wsteele]

Thanks for the encouragement, Bill. Third time's a charm, I hope. But honestly, my main worry is the potential for damage to the main bearings. They're next in line after the lifter oil galleys in the oil circuit flow. Worst case, I'll drop a new engine in it. Still way cheaper than a new rig and this one is cherry in every other way.

I understand the concern on the mains. Not sure with these production engines if this is considered bad practice or not, but when I was racing, if we had some doubts about the lower end, we would pop the caps off and look for scuffs and scratches on the bearings. If everything looked OK, we just popped them back on and away we went. Of course, we were rebuilding the whole kit and caboodle after each season anyway, so maybe a bad analog.

I think with oil analysis and maybe cutting the filters down with each change, you will likely know what is going on pretty quickly.

I totally agree with sticking with it, regardless if it ends up needing a replacement engine down the road. My truck is in similar shape as yours overall and I literally have looked and looked for something that would fit my needs better and I am convinced they aren't out there. The last thing I looked at was a brand new Land Cruiser, fell in love and got all excited when I found the exact colors I wanted at a local dealer. After driving it, and I went down the checklist of all the things I really like about my Yukon and how it compared to the LC and the Land Cruiser came up short, with only it's off road skills beating the Yukon. Nope. I will just keep fixing it. The really positive thing is all my friends think I have become an eccentric about my truck...

 

[wsteele]

Thinking about it some more, I think your fears of debris making it to the big bearings are probably unfounded.

On the pressure side, I can’t think of a way the loose metal finds its way into the circuit.

If the metal is small enough to stay suspended, I could see it getting pulled up through the return and into the pump, but unless the filter bypasses, can’t see how it ever gets back into the pressure side of the circuit again.

 

[Foggy]

Put it back together with right parts.. You prob have this down to science now...
Change your oil several time in very short intervals... Use cheap walmart oil if you want.
Use good filters though.. If nothing else, it will run very well in the short term and
you can decide then if you want to trade it off for new...
Keep on going !!!! You've found your smoking gun

 

[Geotrash]

Thinking about it some more, I think your fears of debris making it to the big bearings are probably unfounded.

On the pressure side, I can’t think of a way the loose metal finds its way into the circuit.

If the metal is small enough to stay suspended, I could see it getting pulled up through the return and into the pump, but unless the filter bypasses, can’t see how it ever gets back into the pressure side of the circuit again.

I agree with you on the capabilities of these trucks being unmatched in the industry today. The new ones are much more complex in both mechanicals and electronics (delicate), and no other manufacturer offers such a wide range of capabilities in the same truck. It's a refined limo, family hauler, trailer puller and off-roader with very few compromises.

I'm not so much worried about the fragments once they get to the pan. Yes, it could come through the screen on the pickup tube and muck with the oil pump, but I think that's low risk. I'm more worried about where the pieces went as they were breaking away from the lifters before they made it to the pan. The oil flow in an LS engine has it going through the oil galleys to the remaining lifters and main bearings before making it to the pan.

 

[Geotrash]

Put it back together with right parts.. You prob have this down to science now...
Change your oil several time in very short intervals... Use cheap walmart oil if you want.
Use good filters though.. If nothing else, it will run very well in the short term and
you can decide then if you want to trade it off for new...
Keep on going !!!! You've found your smoking gun

Good advice. This is the approach I'll take. Fingers crossed.

 

[wsteele]

I agree with you on the capabilities of these trucks being unmatched in the industry today. The new ones are much more complex in both mechanicals and electronics (delicate), and no other manufacturer offers such a wide range of capabilities in the same truck. It's a refined limo, family hauler, trailer puller and off-roader with very few compromises.

I'm not so much worried about the fragments once they get to the pan. Yes, it could come through the screen on the pickup tube and muck with the oil pump, but I think that's low risk. I'm more worried about where the pieces went as they were breaking away from the lifters before they made it to the pan. The oil flow in an LS engine has it going through the oil galleys to the remaining lifters and main bearings before making it to the pan.

View attachment 350240

I understand what you are saying, but from what I can tell the only damage you have is to the lifter rollers and cam lobes. Any oil carrying the debris from that area isn’t getting back into the pressure circuit going downstream.

If there were internal damage to a lifter, then maybe that might happen, but that doesn’t look like your situation. At least I hope I am right about that.

 

[Geotrash]

I understand what you are saying, but from what I can tell the only damage you have is to the lifter rollers and cam lobes. Any oil carrying the debris from that area isn’t getting back into the pressure circuit going downstream.

If there were internal damage to a lifter, then maybe that might happen, but that doesn’t look like your situation. At least I hope I am right about that.

I think that's right, that roller and cam lobe fragments should stay out of the flow circuit and drop directly into the pan. Gonna do 500-1000 mile oil changes for a few months and hope for the best. Ordered up a bunch of Wix filters and gonna hit Walmart to buy a bunch of oil.

 

[wsteele]

I figured you might already have one of these, given your aviation experience, but if you don’t, I can put it in a box and ship it out to you. It makes very clean and short work of opening a filter.

 

[Geotrash]

I figured you might already have one of these, given your aviation experience, but if you don’t, I can put it in a box and ship it out to you. It makes very clean and short work of opening a filter.

View attachment 350242

Thanks for the kind offer! You're right, I do, but it's a different design and is a little bit of a PITA to use, but works.

 

[donjetman]

Small bits of metal coming off the cam/lifters and dropping into the pan will get by the pickup screen and damage the oil pump.
Change the oil pump.

 

[Geotrash]

Small bits of metal coming off the cam/lifters and dropping into the pan will get by the pickup screen and damage the oil pump.
Change the oil pump.

I was really hoping to get by without dropping that fargging oil pan again, but I'm afraid you're right. In the same breath, one more issue and it's getting a crate motor anyway. Then I can have the one that's in it to tear down and build from scratch for a future project beastie. My son is 13 and is starting to understand the value of personal transportation. I can see us putting a project together with that 6.2 at the center. Only problem is they don't build garages in suburbia like they do a few miles further outside of town. We need a real shop space. www.zillow.com.........

 

[Geotrash]

Thought y’all might appreciate seeing a video of the difference between the Vinci lifter tray and a GM factory lifter tray. This is, I believe, why my lifters failed along with the entire cam swap, twice. What really ****** me off is that while I received good support from Roger Vinci throughout the process and he sent me a new cam (that I was ultimately afraid to use), he also continuously denied that any parts he sold me were faulty, even though I was clear I’m not out for reimbursement. I sent him an email about this earlier this week, purely as a courtesy to let him know that he may have a bad batch of trays, and he tried to claim that the trays he sold me are GM lifter trays, and clearly they are not. Conclusion: be very very careful about doing business with Vinci High Performance. And, use only new GM lifter trays.

I’m the kind of guy who will give people I do business with a lot of slack, but once they lie to me, we are done.

 

[Geotrash]

Just gonna leave this right here…

 

[iamdub]

Thought y’all might appreciate seeing a video of the difference between the Vinci lifter tray and a GM factory lifter tray. This is, I believe, why my lifters failed along with the entire cam swap, twice. What really ****** me off is that while I received good support from Roger Vinci throughout the process and he sent me a new cam (that I was ultimately afraid to use), he also continuously denied that any parts he sold me were faulty, even though I was clear I’m not out for reimbursement. I sent him an email about this earlier this week, purely as a courtesy to let him know that he may have a bad batch of trays, and he tried to claim that the trays he sold me are GM lifter trays, and clearly they are not. Conclusion: be very very careful about doing business with Vinci High Performance. And, use only new GM lifter trays.

I’m the kind of guy who will give people I do business with a lot of slack, but once they lie to me, we are done.

I can't conclude from the video, but could those be factory AFM lifter trays? Did you try the lifter fitment in the adjacent holes?

*EDIT* After watching it a few more times, it looks like they are NOT AFM trays. They're not even the same color of plastic and it looks like there's some mold flash on them, indicating lower-quality manufacturing. You can change the cam by removing the rocker arms and spinning the cam so the lobes push the lifters up and the friction fit in the trays will hold them. Of course, you should slide dowels into the oil galleys to ensure none slide down. But them other ones wouldn't hold lifters long enough to get the dowels in.

 

[Geotrash]

I can't conclude from the video, but could those be factory AFM lifter trays? Did you try the lifter fitment in the adjacent holes?

*EDIT* After watching it a few more times, it looks like they are NOT AFM trays. They're not even the same color of plastic and it looks like there's some mold flash on them, indicating lower-quality manufacturing. You can change the cam by removing the rocker arms and spinning the cam so the lobes push the lifters up and the friction fit in the trays will hold them. Of course, you should slide dowels into the oil galleys to ensure none slide down. But them other ones wouldn't hold lifters long enough to get the dowels in.

That’s right. The trays I got from Vinci are black in color and are non-AFM trays. And you’re right, they will barely hold the lifters in place when hung upside down with the lifters fully inserted, and as you slide the lifter out maybe 1/8”, they can no longer hold the lifter at all, and the lifter can easily rock and rotate in the socket. The brand new GM trays are more like a dark grayish brown in color and hold the lifters firmly in place upside down, even with the lifter barely slid into the socket, and they do not permit any rocking or rotation of the lifter at any point in the lifter’s travel.

Those brand new but $hitty quality trays from Vinci cost me 2 cams and another $800 in lifters, plus gaskets and all of the time wasted. It’s partly on me for using them the 2nd time, but after asking Roger about it after the first build and sending him the failed lifter and cam for “analysis”, he assured me that the failure was caused by debris and that the trays were top quality. BS. I trusted him at his word, and that was a mistake. Never again.

 

[swathdiver]

Tie bars next time?

 

[randeez]

Tie bars next time?

yep, with the counterfeit market on ls lifters now a days - link bar lifters is all i plan on using.... decent set is $800+ though. but two ruined cam swaps cost a lot more