LY6 to L96

[CTX-SLPR]

Howdy,

For the purposes of an engine swap/upgrade, is the only difference between the gas LY6 and the flex fuel L96 the injectors and fuel lines? Considering turning my Yukon XL into a DIY "heavy half" to get a bit better towing performance out of it on hills. Both of the Gen 4 6.0L 2500 motors look to be pretty much drop in replacements other than the flex fuel difference and of course the matching tune.

Thanks

 

[Bigburb3500]

Howdy,

For the purposes of an engine swap/upgrade, is the only difference between the gas LY6 and the flex fuel L96 the injectors and fuel lines? Considering turning my Yukon XL into a DIY "heavy half" to get a bit better towing performance out of it on hills. Both of the Gen 4 6.0L 2500 motors look to be pretty much drop in replacements other than the flex fuel difference and of course the matching tune.

Thanks

I think there is some more information on the Sierra/Silverado forums where they talk about the engines a bit more. I THINK they are nearly identical with the L96 having a new newer improvements from it being a newer gen of the same engine. I think the L96 puts out a bit more power across the board.

 

[Marky Dissod]

LY6 6.0L LS Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for the 6.0L LY6 LS engine.

www.onallcylinders.com

L96 6.0L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for the 6.0L L96 LS engine.

www.onallcylinders.com

According to those two pages they both make about 360horse & 380 ftlb (same cam & heads). Only difference between LY6 & L96:
LY6 uses 30lb/hr injectors
L96 uses 50lb/hr injectors because L96 is flex-able

If you're feeling froggy, use your 5.3L 243/799 heads for a static compression ratio boost (sell the rectangle heads).
It'll improve fuel economy, engine throttle response, AND torque / power across the board.

 

[CTX-SLPR]

Not sure that's the direction I'm looking for when it comes to towing performance with the higher static compression. To even consider it I'd have to be within the range that a 50/50 tank of premium and 87 would keep it happy. I wasn't even really considering a cam despite having the engine out.

 

[Marky Dissod]

Not sure that's the direction I'm looking for when it comes to towing performance with the higher static compression.
To even consider it I'd have to be within the range that a 50/50 tank of premium and 87 would keep it happy.

That's what tuning is for, but ok ...

 

[CTX-SLPR]

That's what tuning is for, but ok ...

Yes, tuning would be required. I'm just not willing to pull out the HPTuners laptop every time we need to go tow something. That's also the reason for the 50/50 gas tank so I don't have to try and empty it beforehand.

 

[j91z28d1]

Yes, tuning would be required. I'm just not willing to pull out the HPTuners laptop every time we need to go tow something. That's also the reason for the 50/50 gas tank so I don't have to try and empty it beforehand.

I'm confused? what are you worried about?

having to mix 87 and 93? they sell a mid grade most places. as for tuning, these ecm's have a timing map based on load and rpm. they do calculate load in a complex way in this os, but in it's still lower timing numbers at higher load given the same rpm. so it's not like you tune it to run say 25deg timing at 2k rpm, but now that you're towing a trialer it runs the same timing so you need higher octane fuel. it knows you're working harder and is on a different part of the timing map.

plus these have knock sensors that work well they also have a low octane timing table and high octane table. if your sensors do see some ping it will drop down to the lower table, as well as it can blend the 2 tables together on the fly.


compared to some older style head design, the ls isn't super picky about timing to make hp. a few deg less than optimal isn't a significant amount of power like it used to be. most ls engines run pretty conservative timing Maps

I didn't look up the 2 engine codes you're swapping to see the details. but in general, a decent tune to get you going and alls good. a baby truck cam can make decent amount of difference too. and if you already have the engine out and are having it tuned anyways. it's worth the extra. some guys here tow large campers and can recommend nice driving cam options that pick up good usable power.

 

[CTX-SLPR]

The short of it is I want improved towing performance when I need it without having to do more than check the tires, fluids, and top the tank up. If hybridizing the heads and intake between my current LMG and the bottom end of either of the 6.0's (with the larger L96 Flex Fuel injectors) can be tuned to run happily on the street on 87 but when I need to hitch up the 6000lb+ scout trailer all I do is fill the rest of the tank up with 93 or E85, that's the sort of convenience I'm looking for.

What I'm worried about is taking the 9.6:1 static compression of the LY6 or L96 and upping it to 10.1:1, then towing with that. I will admit at this point that I put LM7 head 61cc chambers into the calculator the first time and had 10.7:1 that really worried me. I'm still concerned about a long hill with my foot at or near the floor trying to hold 60mph on 10.1:1. It's also added expense beyond a basic reseal and oiling system upgrades for changing the heads, cam, or both. See the above mission requirements for what I'm after.

 

[j91z28d1]

personally I think you'd be happy with a cam and tune on your 5.3 with a lot less work. maybe even a rear gear change but if you really wanted to go with a 6.0. you can adjust the compression down to something you're happy with by head cc choice and head gasket thickness. other guys here have researched the 6.0 swap alot. @petethepug I haven't but they come in a 2500. what ratio do they run and with what heads? might just copy that combo.

if you have a tuner in mind, like most here use black bear. I'd shoot them a pm and ask what ratio they would feel comfortable with for your application.

 

[CTX-SLPR]

personally I think you'd be happy with a cam and tune on your 5.3 with a lot less work. maybe even a rear gear change but if you really wanted to go with a 6.0. you can adjust the compression down to something you're happy with by head cc choice and head gasket thickness. other guys here have researched the 6.0 swap alot. @petethepug I haven't but they come in a 2500. what ratio do they run and with what heads? might just copy that combo.

if you have a tuner in mind, like most here use black bear. I'd shoot them a pm and ask what ratio they would feel comfortable with for your application.

I'll poke them and hopefully Pete chimes in. The 6.0's don't have AFM to delete so that's another incentive for them straight out. Yes, a cam on the 5.3 would fix that issue too.

Gear ratio is already in the cards. Picking up a 3.42:1 9.5SF after the Christmas presents clear the budget.

 

[Marky Dissod]

The short of it is I want improved towing performance when I need it, without having to do more than check the tires, fluids, and top the tank up.
If hybridizing the heads and intake between my current LMG and the bottom end of either of the 6.0Ls (with the larger L96 Flex Fuel injectors)
can be tuned to run happily on the street on 87, but when I need to hitch up the 6000lb+ scout trailer all I do is fill the rest of the tank up with 93 or E85,
that's the sort of convenience I'm looking for.

To be redundant, that's EXACTLY what tuning is for.

What I'm worried about is taking the 9.6:1 static compression of the LY6 or L96 and upping it to 10.1:1, then towing with that.

LQ9 had 10:1 scr, basically made about as much power/torque as an LS1, on 87, and was rated to tow well over 6000lb (with 4.10, admittedly).

I will admit at this point that I put LM7 head 61cc chambers into the calculator the first time and had 10.7:1 that really worried me.

You worry too much. 10.7:1 is LFA/LZ1, both of which used 87 (although I don't know its tow rating).
Just in case you want to 'worry' less, YOUR 5.3L's heads are 65cc, not 61, so your scr would be lower than 10.7 for sure.

I'm still concerned about a long hill with my foot at or near the floor trying to hold 60mph on 10.1:1.

Again, LQ9 basically makes like an LS1 on 87 octane; with a few extra cubes, on 10.1:1 scr.
If you're really that concerned:
your tuner is not finished addressing your concerns, or your tune, yet
you can choose a slightly thicker GM OE gasket for lower scr

By the way, a blend of at least 33% E85 (meaning 66% 87 octane E10) guarantees at least 91 octane.
(Also, consider 3.73 instead of 3.42, so it'll spend more time in 6th & 5th & less time downshifting.)

 

[CTX-SLPR]

The LFA/LZ1 have a completely different thermodynamic cycle that bleeds compression back up into the intake (Atkinson Cycle vs. Otto Cycle) that dramatically reduces the effective compression. Not really a fair comparison there.

Fair point on the LQ9 form the GMT800 Escalade.

 

[Marky Dissod]

LFA/LZ1 have a completely different thermodynamic cycle that bleeds compression back up into the intake (Atkinson Cycle vs. Otto Cycle),
that dramatically reduces the effective compression. Not really a fair comparison there.

'Completely different'? It's still 'suk, squeeze, boom, flatulence'.
Think you're referencing dynamic compression vs static compression?
Yes, LFA/LZ1 sacrifice peak power for better efficiency (only 5100RpM).
It still illustrates that the cam selected has LOTS to do with how much static compression an engine can make work.

The L76/L77 used by cars (NOT trucks/suvs) both use 87 octane on 10.4:1 very well; L77 is flex-able.

 

[petethepug]

6.0 with iron block and aluminum heads is the unkillable motor that never came with AFM and runs on Reg fuel and later versions on e85 too.

Slap a cam in one, remove the needle bearing from the cam and replace with trunnion bearings after the motors been checked over.

It makes for very boring, reliable performance so you can mess with R&P ratios and trans kits to dial in your launch without distractions from the motor being venerable.

 

[fozzi58]

Not sure if your end goal is to have a LOT more power, freshen up whats in your truck, or just have some extra grunt to tow. However, I had an 08 Avalanche with the Gen 4 5.3 and I used an Edge Programmer. that I had mounted on my dashboard.

Obviously not as potent as HP tuners but I could switch between an 87 octane friendly tune and a 91 "performance tune" in 5 minutes and pick up a solid 25hp between the tunes. Plus they had a couple of extra tunes in there - towing was one of them. DOD\AFM disable capabilities and lots of other features in the Edge programmer. I never did the physical cam\lifter swap. And I sold it running (no ticks) with 167k.

If all you want is more towing power, you might want to look at the Edge programmers before you start an engine swap. Of course you can always get a couple of BBP tunes...one that is 87 friendly, and the other is for towing\performance and just swap between the tunes.

Just my 2¢