2012 Yukon XL Denali 6.2L Cam Swap Thread

[Geotrash]

The little light lines are nothing. If it was a deep gouge already, I'd be concerned. The noise you were getting was a lack of oil for sure. I remember when my relief valve stuck open in my oil pump in my GTO, the valvetrain sounded exactly the same.

Thank you again, Mike.

 

[Geotrash]

I cant find where you found the cause? The cam/lifters/stem seals/springs/retainers/pushrods you installed imo require no more "oiling" or a different viscosity than the cam and oem components you removed? If you cant find an installation error on teardown than i would not reinstall any of the divinci kit! can you compare oem /divinci cam journal measurements? Throw those lifters in the deepest pit you can find and replace with oem, are you certain there is no spring bind in your valve train setup? The wear looks like extreme pressure more than lack of oiling imo. you saw a 5 psi drop in oil pressure with the installation of the new parts, That should not have happened. We also tow a 4500 lb TT and i rarely see rpm in excess of 5k. Are you sure oem valve springs wont work? This rant hinges on the pick up tube o ring and the valley cover having no defect.

Not a rant at all - it's helpful. I have a caliper and can definitely compare cam journal measurements - that's a good call. And you're right - I'm still looking for the cause but presume it to be the one of the only two parts of the oiling system I touched - the pickup tube o-ring or the tops of the DoD towers. I'm certain that I made no installation errors on any of the hard parts though - I checked and triple checked everything, including the alignment of the lifters in the trays, lifter preload, everything. On the springs, this cam does require upgraded springs.

 

[iamdub]

Thanks Chris. Question though: I bought the Melling M395HV oil pump for this build. Should I just reconsider and buy a standard volume pump instead?

Where were your pressures averaging when stock and where are they now?

On a stock or nearly-stock engine, I'm a fan of stock-replacement pumps. If the pressure is a little low due to minimal, but normal wear, or even just to make you feel better when you look at the gauge, then go one step up with a high volume pump. You'll get your extra pressure from the extra volume. Good volume is more important than high pressure. An aged engine having a little lower pressure than when new is perfectly fine and expected. High volume pumps put more load on the engine, so if the extra pressure isn't needed, it's a waste and is putting undue stress on the seals. My pressures were good so I replaced mine with the Melling stock-replacement equivalent for an AFM engine. Just plugging off the potential leaks (the VLOM may have had pressure leaks) boosted my pressure. It now stays in the 37-47 psi range. At high RPM, it'll hit mid-70s. That's a bit much for my liking, but it's not worth tearing apart to change the spring in the pump.

 

[randeez]

you did generously lather everything up with assembly lube right?

 

[Geotrash]

you did generously lather everything up with assembly lube right?

Yes, though notably some cam manufacturers recommend against it on the cams because it can take a long time to clear the thicker goop from oil passages in lifters and such. So I used Permatex assembly lube which is thinner like an oil but with higher adhesion properties. It reminded me of aviation piston engine oil, which is designed to provide startup protection even after the engine has sat for months.

 

[randeez]

alright good, didnt see it mentioned anywhere. yea i use the comp cams lube when something wont be started for a while and the permatex if somethings going together and will be started soon

 

[Geotrash]

alright good, didnt see it mentioned anywhere. yea i use the comp cams lube when something wont be started for a while and the permatex if somethings going together and will be started soon

That's a good tip. I'll check out the comp cams lube and order some.

 

[Geotrash]

Where were your pressures averaging when stock and where are they now?

On a stock or nearly-stock engine, I'm a fan of stock-replacement pumps. If the pressure is a little low due to minimal, but normal wear, or even just to make you feel better when you look at the gauge, then go one step up with a high volume pump. You'll get your extra pressure from the extra volume. Good volume is more important than high pressure. An aged engine having a little lower pressure than when new is perfectly fine and expected. High volume pumps put more load on the engine, so if the extra pressure isn't needed, it's a waste and is putting undue stress on the seals. My pressures were good so I replaced mine with the Melling stock-replacement equivalent for an AFM engine. Just plugging off the potential leaks (the VLOM may have had pressure leaks) boosted my pressure. It now stays in the 37-47 psi range. At high RPM, it'll hit mid-70s. That's a bit much for my liking, but it's not worth tearing apart to change the spring in the pump.

They were running about 5-10 psi higher before the build, so that's why I suspect an issue. Good advice on the pump. I think I'm going to replace the relief valve at the pack of the oil pan and run the higher volume pump I have on hand. Too much pressure has a path to relief that way, but it's better than not enough.

 

[Foggy]

For the group wisdom: Given the oil leak-down issue I saw (big plume of blue smoke on each startup), I'm wondering if the dual spring setup and the finicky oil seals are more trouble than they're worth. Understanding that I'll have to buy a new cam and lifters given that the damage was caused by inadequate lubrication to the tune of $600, I priced out a Stage 1 truck cam kit at Summit with the springs and one-piece spring bases with integrated seals, new beehive springs and matching lifters for $650. Good reviews on all pieces. What say you? What I care most about is long term durability and hassle-free component service life. The Vinci setup, while higher performance, feels more experimental than I have the patience for, long-term.

Take a look at Gwatney Performance.. they do some nice low lift VVT cams
and you can use a run of the mill behive - like the blue gm springs..
I haven't pulled the trigger on a new cam... Yet
but I may go with them when I do as I want to keep my VVT (dod is disabled
thru the tune, but will eventually do non dod cam with "good" lifters)

 

[Geotrash]

Take a look at Gwatney Performance.. they do some nice low lift VVT cams
and you can use a run of the mill behive - like the blue gm springs..
I haven't pulled the trigger on a new cam... Yet
but I may go with them when I do as I want to keep my VVT (dod is disabled
thru the tune, but will eventually do non dod cam with "good" lifters)

I initially wanted to keep the VVT but it also adds a level of complexity to the build that in my situation wasn’t worth the added hassle and potential maintenance issues (degreeing the cam, high torque to install the single cam bolt, solenoid issues, etc.). It’s a good system but for the time that this engine was running with the new cam, I never missed it. Hard to say if I would later or not.


Sent from my iPhone using Tapatalk