donjetman
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Why The Gen-V LT Outshines The LS
- Thread starter donjetman
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petethepug
Michael
LOL, there’s so much traffic on that link going to the article, it’s frozen.
Pretty sure the current issues with the LT aren’t what’s covered in that article. It’s focused on upgrading the known deficiencies of the LS.
Pretty sure the current issues with the LT aren’t what’s covered in that article. It’s focused on upgrading the known deficiencies of the LS.
Marky Dissod
Full Access Member
Pretty sure it's the first GM V8 generation specifically designed NOT to outlast the previous generation.
I can see why the cylinder case, the bottom end, and the oiling are clearly improved.
However, although direct injection does appear to be partially responsible for improved BSFC and MpGs during the CAFE MpG testing sessions,
DI lets motor oil accumulate on the intake valves' backsides, diminishing BSFC and MpGs and increasing oil consumption over time.
Note that the higher-performance versions of this V8 ALSO use port fuel injection in tandem with direct injection.
GM has upped the Active Fuel Management system's ante (aka Engine Half@$$)
with Dynamic Fuel Management (aka Cylinder Confusion - is it a V8? a V7? V6? V5? V4? V3? V2? I2? V-naught? SEVENTEEN firing orders?),
its valve-deactivation components have not been improved in terms of durability, yet now there's twice as many ... unless it's an L8T.
I can see why the cylinder case, the bottom end, and the oiling are clearly improved.
However, although direct injection does appear to be partially responsible for improved BSFC and MpGs during the CAFE MpG testing sessions,
DI lets motor oil accumulate on the intake valves' backsides, diminishing BSFC and MpGs and increasing oil consumption over time.
Note that the higher-performance versions of this V8 ALSO use port fuel injection in tandem with direct injection.
GM has upped the Active Fuel Management system's ante (aka Engine Half@$$)
with Dynamic Fuel Management (aka Cylinder Confusion - is it a V8? a V7? V6? V5? V4? V3? V2? I2? V-naught? SEVENTEEN firing orders?),
its valve-deactivation components have not been improved in terms of durability, yet now there's twice as many ... unless it's an L8T.
swathdiver
Full Access Member
In stock form the newer engines are better but to build an engine for performance, there are fewer options and it is more expensive to do so.
This is exactly why I purchased LS equipped trucks and not the newer ones.
This is exactly why I purchased LS equipped trucks and not the newer ones.
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DI sounds great in theory till you price fuel system parts like bigger injectors and high flow high pressure pump, then as said. if you really need fuel you gotta run port injectors as well. not to even get into how much harder they are to tune because of all the injector timing stuff.
for fuel system cost alone you can have a 4.8 ls with a small turbo making more hp and getting better mileage. it's going to be a very long time before someone picks a 3 times the cost LT build because the oiling system is said to be better. the same oiling system they will. which the will probably find it's causing the stock engines to lock up.
yeah.. hard pass on the LT stuff. they do sounds better exhaust note wise at wot thou.
West 1
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I have worked on several DI systems and they are pretty impressive. Better in every way, only negative is at high miles the intake valves can get a build up like a T pee on the intake side of the valve head. Eventually this can choke off the intake flow. There are Walnut shell blasters that clean this off and you are good for another 100,000 miles.
The ones I worked on had between 85 and 150,000 miles on them. At 85 there was some sign of carbon build up but no Tpee yet. At 150,000 the Tpee’s were starting to build up. I cleaned both and got them back in service, they came to me with other engine problems the valves were done just as maintenance.
The big advantage is direct injection sprays in at such high pressure it Cools the valve and piston head. this is great for power, since no fuel is in the cylinder as the piston compresses the air it also eliminates detonation so compression can be increased to much higher levels and compression improves both economy and power.
DI engines alslo work better for turbo applications allowing Diesel like low end torque in smaller gas engines.
There are many advantages for sure with Di but drive what you wish.
My old Yukon is a 2003 with 130,000 miles now and I keep driving it. My car is a DI engine from 2012 and I like it also.
The ones I worked on had between 85 and 150,000 miles on them. At 85 there was some sign of carbon build up but no Tpee yet. At 150,000 the Tpee’s were starting to build up. I cleaned both and got them back in service, they came to me with other engine problems the valves were done just as maintenance.
The big advantage is direct injection sprays in at such high pressure it Cools the valve and piston head. this is great for power, since no fuel is in the cylinder as the piston compresses the air it also eliminates detonation so compression can be increased to much higher levels and compression improves both economy and power.
DI engines alslo work better for turbo applications allowing Diesel like low end torque in smaller gas engines.
There are many advantages for sure with Di but drive what you wish.
My old Yukon is a 2003 with 130,000 miles now and I keep driving it. My car is a DI engine from 2012 and I like it also.
petethepug
Michael
LS are ez pz for injector swap and diagnostics. LT needs to have the intake removed to access the DI units being serviced.
GM may be feeling the pain of having a V8 as robust as a Kalashnikov. Unfortunately they may be forgetting that boring out said component to 6.2L and new technology may not mix with old.
GM may be feeling the pain of having a V8 as robust as a Kalashnikov. Unfortunately they may be forgetting that boring out said component to 6.2L and new technology may not mix with old.
Last Summer my buddy that works as a tech at the local GM dealer, mentioned they have a lot of seized up engines under 20,000 miles. Waiting sometimes weeks for replacement engine. Wasn't a design flaw, iirc he said it was a problem with a batch of bad main bearings.
So here we are wanting to hang on to our LS engines. Which in fact I will do. LOL, we sound just like everybody did when Chevy moved on from the SBC generation one and two. And come to think of it, I still have my generation one SBC in my 86 Jeep CJ7. Holley 650 carbureted. It never throws me a diagnostic code. I can rebuild it for less than one cylinder head on an L92. And when it comes down to it, I would trust it on a 5000 Mile road Trip more than our 2014 Escalade.
This LS crowd is no different. Due to sheer popularity, the aftermarket will thrive and I expect prices will come way down. And you guys that are under 35 years old right now will be 62 in the near future....LOL.... Talking about how reliable your LS engine is and refusing to spend $10,000 for that contraption to pull codes on your flux capacitor on your 2052 Escalade
So here we are wanting to hang on to our LS engines. Which in fact I will do. LOL, we sound just like everybody did when Chevy moved on from the SBC generation one and two. And come to think of it, I still have my generation one SBC in my 86 Jeep CJ7. Holley 650 carbureted. It never throws me a diagnostic code. I can rebuild it for less than one cylinder head on an L92. And when it comes down to it, I would trust it on a 5000 Mile road Trip more than our 2014 Escalade.
This LS crowd is no different. Due to sheer popularity, the aftermarket will thrive and I expect prices will come way down. And you guys that are under 35 years old right now will be 62 in the near future....LOL.... Talking about how reliable your LS engine is and refusing to spend $10,000 for that contraption to pull codes on your flux capacitor on your 2052 Escalade
I consider myself a tech person, I actually like electric equipment and hybrid vehicles. but I also just don't see any point in the LT hassle. the reward isn't there. direct injection is said to be nice for turbo daily drivers, but not as good has having control of cam timing In a dual overhead cam engine is when boosted on e85.
I follow a channel that plays with the gm inline 6 engines boosted. that seems more interesting than any LT does. there's even a small amount of time being put back into the old northstar engines. once guys realized how good dual over head cams and boost is. it's a combo worth looking back into. sorry to gm, and these manufacturers that put a lot of money into designing and developing parts for LT engines but I just don't see it as even mildly interesting. either in stock form, or modified.
never say never, but meh.
I follow a channel that plays with the gm inline 6 engines boosted. that seems more interesting than any LT does. there's even a small amount of time being put back into the old northstar engines. once guys realized how good dual over head cams and boost is. it's a combo worth looking back into. sorry to gm, and these manufacturers that put a lot of money into designing and developing parts for LT engines but I just don't see it as even mildly interesting. either in stock form, or modified.
never say never, but meh.
swathdiver
Full Access Member
The things with OHC motors is the cost and complexity of repairs and performance mods. The aftermarket has enough trouble dealing with VVT, I can't imagine them mastering higher power Coyote camshafts better than the millions Ford already spent save for the gains you get ignoring emissions requirements that they have to follow.
Then there's the cost. 1 cam for an LS or LT versus 4 for an OHC V8. Plus the chain and all the ancillary equipment. No thanks.
We can modify our LS engines to run reliably and for a long time at about 650 horsepower at the flexplate and that'll take a 6,000 pound truck into the mid 12s down the 1/4 mile.
The L84 can be deleted and cammed and supercharged and make maybe 50 horsepower more. Their fuel system is more expensive. I don't know how the performance world is coping with those 8-speeds that so many of them have. We know they are putting 10-speeds in GMT900s.
And that brings up another point, you can have two trucks with the same motor and rear axle ratio. One with a 6-speed and one modded with a 10-speed. That 10-speed truck is going to smoke the 6-speed all day long. That's a better bang for your buck than an LT motor at present.
Then there's the cost. 1 cam for an LS or LT versus 4 for an OHC V8. Plus the chain and all the ancillary equipment. No thanks.
We can modify our LS engines to run reliably and for a long time at about 650 horsepower at the flexplate and that'll take a 6,000 pound truck into the mid 12s down the 1/4 mile.
The L84 can be deleted and cammed and supercharged and make maybe 50 horsepower more. Their fuel system is more expensive. I don't know how the performance world is coping with those 8-speeds that so many of them have. We know they are putting 10-speeds in GMT900s.
And that brings up another point, you can have two trucks with the same motor and rear axle ratio. One with a 6-speed and one modded with a 10-speed. That 10-speed truck is going to smoke the 6-speed all day long. That's a better bang for your buck than an LT motor at present.
OP
OP
donjetman
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Brett LaSala with his coyote powered Mustang "Snot Rocket", fastest competitor at Sick Week at the moment, fells differently at 5.05 in this video:
swathdiver
Full Access Member
Pretty cool but don't LSs run the same? It takes a lot of dollars to make 3,000 horsepower and run that fast.
I just googled a Borowski engine making 3K horses for $73K.
can't go that fast or make that power with a ls, even with a aftermarket block. not enough head clamping. they pop head gaskets and fire etch blocks long before that. LT has the same amount of studs. might turn out to he a little better if decks are thicker but not enough to matter matter currently. one of if not the fastest stick shift car runs a Gen 1 small block for the extra head studs it has. by then normal people go big old school big block chevy or maybe even hemi?
what that green mustang is doing has kinda wild.
swathdiver
Full Access Member
Well, that's exactly what Borowski is selling, a 3,000 horsepower LSX.
I don't know the details. but if so, he's doing something that no one else seems to be about to do.
swathdiver
Full Access Member
Borowski Built Twin Turbo 427 LS - 3,000 HP Dart LS Next2 | Borowski Race Engines
Bullseye NLX 83MM Turbos, Dart LS Next2 Block, Callies Billet Crank, Callies Ultra I-Beam Enforcer Rods, Custom Diamond pistons, All Pro Heads, Crower Rockers
Well, why don't you buy one and let us know?
I learned something from my machinist last week about the
new 6.6 L Gas DI engines that the newer (2021+?) trucks..
The 's etc.. Have...
Because I thought about building one.. They have a great block
and a sweet 3.90 stroke...BUT
A new camshaft is over $1200+ YIKES
I'm old school and think that pre-covid LS3 cams for $400 was
way to F'n high (they are over $500+ now )
And even an old school SBC roller cam is 450-550 OUUCH
as I'm rebuilding one of my 421 sbc engines and "thinking"
about a cam change
new 6.6 L Gas DI engines that the newer (2021+?) trucks..
The 's etc.. Have...
Because I thought about building one.. They have a great block
and a sweet 3.90 stroke...BUT
A new camshaft is over $1200+ YIKES
I'm old school and think that pre-covid LS3 cams for $400 was
way to F'n high (they are over $500+ now )
And even an old school SBC roller cam is 450-550 OUUCH
as I'm rebuilding one of my 421 sbc engines and "thinking"
about a cam change
fozzi58
Full Access Member
Didn't the LTs get a 1 or 2mm thicker head bolt? I remember reading that somewhere. Ford did the same thing with the Gen 3 Coyote.
I'm looking at fuel upgrades now cause my tuner said I am out of fuel. I think the LT is a better platform but you are correct, it does take more money. I have a 5.3 so I don't need to go berserk, but I would need an LT1 fuel rail and high side pump ($1200), OEM LT1 injectors ($700), the 6.2 Fuel rail ($200), and a dual in tank pump like Walbro or Racetronix ($800). That setup is good to about 900HP (depending upon the cam's fuel lobe %) which is well above my end goals for my truck.
I didn't mention the cost of the cam above cause I thought it was obvious that if you are going to force that much fuel down the LTs throat, you would assume a heads an cam package was going on the motor anyways.
The LS platform would eliminate the high side fuel pump and under-intake rail that supplies the 2200psi fuel to the DI injectors.
Simplicity equals reliability, one roller cam with 2 gears, a chain measured in inches & pushrods as a means to control valve events is infinitely cheaper & more reliable than multiple cams, multiple gears & a timing chains measured in feet with multiple tensioners to control the same valve events
VVT, DOD & DI are all technologies that provide additional tuning benefits but that add complexity, expense & failure points to the engine without a benefit significant enough to compensate for it
As these technologies were added to the LS the engine became less reliable but removing that tech was easy & restored the former benefits to the engine; if the LT is to ever become a staple like the LS it will be because of the ability to affordably ditch the unreliable aspects & simplify the processes back to a reliable engine that can handle significant performance increases without falling apart
What works is what works, all the claims about advantages with the more involved technology never matter if the added failure points nullify the benefits
You can hit & maintain a target AFR consistently with computer controlled port fuel injection, the injectors do not need to be introduced to the combustion chamber & its DESTRUCTIVE environment to achieve a reliable AFR; it just costs more to develop injectors that will work in a combustion environment & it reduces their lifespan to move them to the combustion chamber. VVT can expand the optimal rpm range of the cam profile beyond a static ground cam but not without adding cost & reducing reliability to a point that nullifies the benefit, DOD is just a gimmick to please the EPA that provides no real advantage in exchange for its failure prone design
The LT has a long hill to climb if it's ever going to become the lunch box standard that the SBC enjoyed from it's gen 1 beginnings all the way through the LS run, it will have to work in the real world driven by real people over real time periods; not just in the theoretical laboratory environments
VVT, DOD & DI are all technologies that provide additional tuning benefits but that add complexity, expense & failure points to the engine without a benefit significant enough to compensate for it
As these technologies were added to the LS the engine became less reliable but removing that tech was easy & restored the former benefits to the engine; if the LT is to ever become a staple like the LS it will be because of the ability to affordably ditch the unreliable aspects & simplify the processes back to a reliable engine that can handle significant performance increases without falling apart
What works is what works, all the claims about advantages with the more involved technology never matter if the added failure points nullify the benefits
You can hit & maintain a target AFR consistently with computer controlled port fuel injection, the injectors do not need to be introduced to the combustion chamber & its DESTRUCTIVE environment to achieve a reliable AFR; it just costs more to develop injectors that will work in a combustion environment & it reduces their lifespan to move them to the combustion chamber. VVT can expand the optimal rpm range of the cam profile beyond a static ground cam but not without adding cost & reducing reliability to a point that nullifies the benefit, DOD is just a gimmick to please the EPA that provides no real advantage in exchange for its failure prone design
The LT has a long hill to climb if it's ever going to become the lunch box standard that the SBC enjoyed from it's gen 1 beginnings all the way through the LS run, it will have to work in the real world driven by real people over real time periods; not just in the theoretical laboratory environments
