Batass

How are these newer engines holding up? Anyone have 300k on one yet?
I've heard some things when they came out that made me question their longevity and have held off on buying a new truck.....
I see they are still using the LY6 basically in the work trucks.

FFDP

iTrader: (2)

I've seen a couple people with over 200,000+ miles on a 2014+ truck with the DI engines and I'm sure there are way more than just the few I've seen. Even many on here are pushing well over 120-140k miles and still going.

The LY6/L96 stopped last year and was replaced by the new 6.6 gas engine. The 6.0 is a great engine, very well proven and of course people don't buy them for fuel mileage.

cheyenne383

iTrader: (25)

We're up to 107k on my wife's 2016 5.3 Suburban... knock on wood it hasn't had any issues. Fluid changes and that's really it... sounds like a damn lifter is going out but apparently the auxiliary fuel pump ticks and makes that noise. It's been like that since about 70k and hasn't let go yet, not looking to do an AFM delete/cam swap since it's mama's daily.

Batass

Well I'm embarrassed that I didnt even know about the 6.6 gasser. I saw that somewhere and assumed it was a typo. Too bad it isnt offered with 4.10 gears like the 6.0, keeps the wheel torque fairly similar with a little increase in mileage however. That's my presumption anyway.

I know about the lifter issues and have experienced those in person, but that started back at the beginning of AFM. I have an ly6 without that.

I was told by an engineer that they changed the pistons and rings to a design that wouldn't last as long as gen IV.

Good to hear they are doing well. Surely someone out there must have close to 300k on a 2014+.

1994Vmax

iTrader: (4)

Thats the piston from a 6.6 gas truck. Other than the dish for the injector it is very much a gen iv type piston with a similar skirt and coating. I just built a 2015 L96 for a guy and they are identical to every gen iv made since 2007 more or less. I still want to build a 6.6 from the L86 6.2 I have and that's still my plan utilizing all GM parts for the rotating assembly which I talk about in my thread on here.

Mileage is definitely why they chose the 3.73 axle but I do have a guy at work who just got a 2020 HD with his service box in it now to replace his 2014 L96 powered 4.10 geared 3500HD. The L8T 6.6 blows the L96 6 liter away for power and this is under the exact same load in the exact same configuration truck. Mileage I haven't asked but he won't even have a 1000 miles on this new truck yet so time will tell.

Will the direct injected trucks last as long? They should... inside they are just as heavy duty as an LS. The 6.6 is not plagued with collapsible lifters either which should be a good test of life but that will take some years.

Batass

That's awesome! I always wondered why they didnt have a large displacement engine with ls style heads. The 8.1 was kind of a let down. Looking forward to them turning up in junkyards and seeing what people can do with them. How far they can be reliably stroked, etc.
A reliable 550 lb/ft mild mannered "LS" would be a lot of fun.

The 6.6 is a stroked 6.2 as far as dimensions go, am I right? Would swapping the pistons over net more compression?

I'm going to have to do more reading. I might like this better than a supercharged LY6 for a DD....

1994Vmax

iTrader: (4)

Dimensionally yes the 6.6 is nothing more than a stroked 6.2. I have the one 6.6 piston and will pull a 6.2 piston to compare one of these days for pin height and cc dish. The 6.6 piston has a huge dish in it compared to the 6.2 to compensate the stroke change and the fact the 6.6 is rated at 11:1 compression instead of 11.5:1 like the 6.2. Since the 6.6's rod is identical to any other LT or LS rod they only raised pin height to make up for the additional 1/4" of stroke.

Yeah the idea is make a high compression 6.6 and have it with an aluminum block (not that i care but some do).

Batass

I can see that in a car where you might worry about suspension changes or weight distribution. I'm nervous about replacing the aluminum ls2 with an LY6. Really probably wouldn't change the characteristics much at all as far as handling. Idk

Thanks for the info, awesome that you're already on it!

tjmath

I am about to roll 109k on my 14 L83. Just installed an L86 intake manifold, TB, and long tubes about a month ago. Had some trans issues over summer, but other than that it has been perfect

Batass

Shop owner just told me he has rebuilt a couple 6.2s where a piston broke. 150k miles.....