Engine Swap to stroked 6.0 (408) and general vehicle refurbishment

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Just Fishing

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No wideband. It could possibly be rich as it is on an initial tune. But I thought it would be a darker color smoke if it were rich? I'll get a video in the morning in light so the color of the smoke is more clear.

Nearly white colored smoke exhaust smell from my vette if it's too rich.
Vette is exept from kitties
 
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Chooko

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Ok, after looking the car over today more closely, there is definitely oil in the exhaust. There is a coolant leak too, which I believe is coming from the rear steam crossover. I'm probably going to pull the intake, and maybe just block off the rear steam crossover. Whatever the case, I am less concerned about the coolant leak as I think it is a nuisance.

The smoke is definitely being caused by oil. Its windy here today so the color is hard to see, but I took apart a portion of my bolt-together Y-Pipe, and oil started coming out from the joint, and was inside the pipe.

Here is my theory...I am running aftermarket valve covers. The driver side one has a nipple for the PCV hose, but it is not in the factory orientation so i cut the factory line and spliced it with rubber hose. It has a baffle inside, but in hind sight I don't think there is a valve in there. I think its just a direct line from inside the head, through the PCV nipple, and into the top of the intake. I pulled the hose off the intake and it had a lot of oil on it. I pulled it off the nipple, and oil dripped out from the end of the hose. I guess I'm not entirely certain how the PCV valve functions. I know I had one go bad and cause the engine to smoke several years ago, but my assumption was that it stuck closed, although now that I think about it that probably wouldn't cause smoking. At any rate, would a complete lack of a PCV valve cause the smoking I am seeing?
 

iamdub

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Ok, after looking the car over today more closely, there is definitely oil in the exhaust. There is a coolant leak too, which I believe is coming from the rear steam crossover. I'm probably going to pull the intake, and maybe just block off the rear steam crossover. Whatever the case, I am less concerned about the coolant leak as I think it is a nuisance.

The smoke is definitely being caused by oil. Its windy here today so the color is hard to see, but I took apart a portion of my bolt-together Y-Pipe, and oil started coming out from the joint, and was inside the pipe.

Here is my theory...I am running aftermarket valve covers. The driver side one has a nipple for the PCV hose, but it is not in the factory orientation so i cut the factory line and spliced it with rubber hose. It has a baffle inside, but in hind sight I don't think there is a valve in there. I think its just a direct line from inside the head, through the PCV nipple, and into the top of the intake. I pulled the hose off the intake and it had a lot of oil on it. I pulled it off the nipple, and oil dripped out from the end of the hose. I guess I'm not entirely certain how the PCV valve functions. I know I had one go bad and cause the engine to smoke several years ago, but my assumption was that it stuck closed, although now that I think about it that probably wouldn't cause smoking. At any rate, would a complete lack of a PCV valve cause the smoking I am seeing?

Aside from the some of the very first LS engines, these don't have a PCV valve. They have a nipple with an orifice of a specific diameter. The way the PCV system flows is: Clean air is pulled from the intake tube, after the air filter and after the MAF. It goes into the passenger side valve cover and down into the crankscase. The tube running from the top center of the intake manifold to the nipple/PCV port on the driver side valve cover uses intake manifold vacuum to suck the PCV vapors out through the driver side head. The stock valve cover has a baffle to help separate the oil from the PCV air flow.

To have excess oil in the PCV system, either you have an obscene amount of air volume overfilling the crankcase or oil is filling the valve cover (not draining back efficiently enough) or an obscene amount of manifold vacuum. I'd rule out the manifold vacuum since the cam would reduce this from the factory amount.

I'm not saying the valve covers are your problem. But, things like this and the oil pan stuff are why I don't see the point of race parts on a street vehicle if they're not functionally necessary. They could do more harm than good. For example, a race engine with a huge cam and/or boost wouldn't have any use for the stock PCV system. They might even run a vacuum pump to vacate the crankcase.

Something in yours is pushing oil into the PCV. I hope it's just the heads filling with oil and not the crankcase being over-pressured by blowby. Although, that's usually only a problem at higher RPM. Are you sure your oil level is correct?
 
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donjetman

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Ok, after looking the car over today more closely, there is definitely oil in the exhaust. There is a coolant leak too, which I believe is coming from the rear steam crossover. I'm probably going to pull the intake, and maybe just block off the rear steam crossover. Whatever the case, I am less concerned about the coolant leak as I think it is a nuisance.

The smoke is definitely being caused by oil. Its windy here today so the color is hard to see, but I took apart a portion of my bolt-together Y-Pipe, and oil started coming out from the joint, and was inside the pipe.

Here is my theory...I am running aftermarket valve covers. The driver side one has a nipple for the PCV hose, but it is not in the factory orientation so i cut the factory line and spliced it with rubber hose. It has a baffle inside, but in hind sight I don't think there is a valve in there. I think its just a direct line from inside the head, through the PCV nipple, and into the top of the intake. I pulled the hose off the intake and it had a lot of oil on it. I pulled it off the nipple, and oil dripped out from the end of the hose. I guess I'm not entirely certain how the PCV valve functions. I know I had one go bad and cause the engine to smoke several years ago, but my assumption was that it stuck closed, although now that I think about it that probably wouldn't cause smoking. At any rate, would a complete lack of a PCV valve cause the smoking I am seeing?
Sometime around 2011 or later, Gm came out with a service bulletin to install their new improved driverside vc, pt#12570427, on various GM vehicles ranging from yr models 2007-2015. The problem was oil being sucked out of the valve cover area and into the intake manifold causing oil consumption and/or stuck rings.

This was a problem on my 07 Yukon Denali L92 6.2L when I bought it in 2018. Per the advice of forumites here, I installed the improved vc, and an inexpensive catch can plumbed into the vacuum line between the vc and intake.

40k miles & 3 yrs later, no more oil consuption and my catch can doesn't catch mush of anything. If it ever does start, I'll know "HOUSTON, WE HAVE A PROBLEM".
 
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Chooko

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Its time for another update...

I installed a Morosso Catch Can that is marketed specifically for these vehicles (really just means that it came with a bracket that lines up with some factory bolt holes), and also installed a valve in the line going from the valve cover to the intake. No more smoke! I'm sure its the catch can doing all the work of stopping the smoke, but either way its good to go.

I've been chasing down other minor issues, such as finding the correct size stretch belt to work with the non-stock harmonic dampener, dealing with a few small leaks, and doing data logging in HPtuners for the engine tuner. I also got the car to the exhaust shop and got a proper Y-pipe with catalytic converters installed. The exhaust is buttoned up, and it sounds AWESOME!. Its not loud at all at idle, and inside the car you might not even notice that its not stock. But it sounds amazing as the RPM's come up. And goodness has this thing got a lot of power.

Today I did the final plumbing of the external transmission cooler and the stock in radiator cooler with -6AN hose and fittings, and I think it came out pretty well, but I damaged the terminals on the inline thermostat in the process so I currently have the fan for the transmission cooler jumped, and I have to unplug it when I shut the car off or it'll just run until the battery goes dead. Not to worry though because I ordered a new one today and its a super easy fix once the part is in hand. I also think I have FINALLY fixed all of the transmission cooler line leaks. There were only a couple, and they were minor, but I think they are good now.

Speaking of leaks though...the front crank seal is weeping oil. Its just a very minor leak, but obviously not something I want on my brand new engine. It wouldnt be that big of a deal except that I had a really hard time getting the harmonic balancer keyed properly on the engine stand, so I'm REALLY not looking forward to trying to put it back on with the engine in the car. I think that's the last mechanical thing that I have to fix for this swap to be considered complete, although there will be more tuning work once I put a few thousand miles on it, and I have other projects in the interior and suspension.

I'll try to get some pictures and maybe some video up tomorrow.
 
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Chooko

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I got the front main seal fixed, and also (finally) tracked down and fixed the transmission line leak. I don't think it'll ever be truly done, but the Tahoe is now completely drive-able, and a real blast on the road. I still have a list of things in my head that I'd like to do to it in the future, but for now I think I'll close this with a video.

 

Rocket Man

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I got the front main seal fixed, and also (finally) tracked down and fixed the transmission line leak. I don't think it'll ever be truly done, but the Tahoe is now completely drive-able, and a real blast on the road. I still have a list of things in my head that I'd like to do to it in the future, but for now I think I'll close this with a video.

Sounds awesome, congrats on getting things buttoned up. :happy107:
 
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Chooko

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Thanks Rocket Man! She's running great although, as with most projects like this, I am already looking at doing some more things to the Tahoe. Specifically, I think I need to upgrade the cooling system. I think an aftermarket radiator and fan set up is next. It also needs tires, and I think I am going to upgrade wheels while I'm at it. I'll post pictures of this stuff when it happens. For now, here are a couple of more start videos just because I think it sounds badass:


 

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