New GM LT1 engine

[Ferzerp]

Is anyone else pretty unimpressed by the specs?

Direct injection, 11.5:1 compression ratio
6.2L

Only 450hp/450 lb ft.

http://www.autoblog.com/2012/10/24/meet-the-lt1-the-corvette-c7s-new-6-2-liter-small-block-v8/

I would think that they could squeeze more out of that with the switch to direct injection.

 

[96Firebird]

Why would they name in the same as a GM engine from the early '90s?

 

[AdamK47]

I wonder if we'll see some of those direct injection top end parts make their way to the LS series engines in the aftermarket.

 

[Vic Vega]

Is anyone else pretty unimpressed by the specs?

Direct injection, 11.5:1 compression ratio
6.2L

Only 450hp/450 lb ft.

http://www.autoblog.com/2012/10/24/meet-the-lt1-the-corvette-c7s-new-6-2-liter-small-block-v8/

I would think that they could squeeze more out of that with the switch to direct injection.

That's the base model engine. They aren't going to make it have 650 HP - that's for the specialty models, this engine is for the volume models.

 

[herm0016]

and it will probable get better mpg than current too. sounds like a great step for small blocks. I hope the tech gets into the 5.3 for the trucks soon too.

 

[phucheneh]

Why would they name it the same as a GM engine from the early '90s?

This?

What's the point in engine codes if you're going to reuse them? It's not like 'Boss 429' or something that is more associate with a car model...it's just an identifier for the factory (and enthusiasts). Nothing ever wore 'LT1' badges, did it?

Also, the LT1 was...not that great. I mean, it was a great step forward, linking the old small blocks to the LS1. But it wasn't a terribly high output engine. Better than Ford's 302 that was still kind of stuck in the smogger 80's, but still, 275hp (I think?) isn't exactly going to blow your pubes off.

 

[Zivic]

it seems like natural progression, but IMHO 450 hp out of 6.2 liters is nothing to right home about.. I am sure they will be able to get more out of it, but a big engine should make big power

 

[Zargon]

This?

What's the point in engine codes if you're going to reuse them? It's not like 'Boss 429' or something that is more associate with a car model...it's just an identifier for the factory (and enthusiasts). Nothing ever wore 'LT1' badges, did it?

Also, the LT1 was...not that great. I mean, it was a great step forward, linking the old small blocks to the LS1. But it wasn't a terribly high output engine. Better than Ford's 302 that was still kind of stuck in the smogger 80's, but still, 275hp (I think?) isn't exactly going to blow your pubes off.

it was not that great but it was a great step forward?

how does that make sense

compared to now its not great, at the time it was a significant improvement and it was walking over its competition.....

it seems like natural progression, but IMHO 450 hp out of 6.2 liters is nothing to right home about.. I am sure they will be able to get more out of it, but a big engine should make big power

again, base model engine.

power is up ~25 hp and ~25lb/ft, fuel economy is up, displacement is the same


they put a ton of new tech, almost the entire engine is new save a small handfull of parts
"Some 99.9 percent of the engine is new, with the engine’s carryover parts fitting in a Ziploc bag. Two starter bolts, a piston pin and a retainer bolt or two are all that remain of the LS3"

I'd expect output to claim in the next model years as they flesh it out

 

[phucheneh]

it was not that great but it was a great step forward?

how does that make sense

compared to now its not great, at the time it was a significant improvement and it was walking over its competition.....

I think that makes perfect sense. It was good progress and made decent power for the time, but why would you want to associate your brand new high-tech engine with it?

'Small step for a man, giant leap for mankind? Neil Armstrong, you're stupid.'

 

[Vdubchaos]

Another amazing engine from GM. :thumbsup:

 

[yottabit]

Personally I'm dissapointed if this is true

There has been so much hype about his engine and the billions of dollars of devleopment that went into it

All the rumors up until now have been saying the new corvette would have a 5.5 liter engine with ~450 hp, to see that they did it with a 6.2 liter well you could do the same with an LS3 with intake/exhaust

The claim 26 MPG Highway, the 6 speed manual Vette already gets that with the LS3

Hopefully these are just messed up statistics from Autoblog

 

[yottabit]

Why would they name in the same as a GM engine from the early '90s?

The 90's "LT1" was named after the 70's "LT-1" so I guess GM just loves recycling numbers

 

[phucheneh]

The 90's "LT1" was named after the 70's "LT-1" so I guess GM just loves recycling numbers

I feel dumb for not knowing that.

Also I don't see the disappointment...isn't this a 'base' engine? I wouldn't want them to stick a 700hp engine in every Corvette that ends up on the road. 450 scares me enough in the hands of some Corvette buyers, especially with an equal amount of torque, probably at a pretty damn low RPM.

Although these days, 6.2L for 450hp is a little silly. Especially since they're running DI and a high compression ratio (or is that a low ratio, considering it's DI?). I know they don't wanna do forced induction...although that seems to be where direct injection really shines. But other companies are getting well over 300hp out of 3-4L NA V6's without DI. I wouldn't thought they could manage these numbers with a displacement closer to 5L...for all my GM hate, their engines are one place where I do have a lot of faith in them.

edit: hope the mileage stats are wrong. That's where modern tech like DI and a properly geared 6 speed trans should shine...granted, EPA numbers can be damned misleading. It could be rated at 26mpg and easily get 25-30 at 80mph with the right driver. Highway is easy, though...more curious about city.

 

[Zargon]

Personally I'm dissapointed if this is true

There has been so much hype about his engine and the billions of dollars of devleopment that went into it

All the rumors up until now have been saying the new corvette would have a 5.5 liter engine with ~450 hp, to see that they did it with a 6.2 liter well you could do the same with an LS3 with intake/exhaust

The claim 26 MPG Highway, the 6 speed manual Vette already gets that with the LS3

Hopefully these are just messed up statistics from Autoblog

they are both 6.2...........

Im guessing the EPA # they quoted is wrong since thats the rating of the base vette now

 

[Fenixgoon]

I feel dumb for not knowing that.

Also I don't see the disappointment...isn't this a 'base' engine? I wouldn't want them to stick a 700hp engine in every Corvette that ends up on the road. 450 scares me enough in the hands of some Corvette buyers, especially with an equal amount of torque, probably at a pretty damn low RPM.

Although these days, 6.2L for 450hp is a little silly. Especially since they're running DI and a high compression ratio (or is that a low ratio, considering it's DI?). I know they don't wanna do forced induction...although that seems to be where direct injection really shines. But other companies are getting well over 300hp out of 3-4L NA V6's without DI. I wouldn't thought they could manage these numbers with a displacement closer to 5L...for all my GM hate, their engines are one place where I do have a lot of faith in them.

edit: hope the mileage stats are wrong. That's where modern tech like DI and a properly geared 6 speed trans should shine...granted, EPA numbers can be damned misleading. It could be rated at 26mpg and easily get 25-30 at 80mph with the right driver. Highway is easy, though...more curious about city.

compare the torque, physical size, and weight of those engines with a GM small block V8.

example: BMW M5 V10 - 500hp, 5L vs. GM LS7 V8 - 505hp, 7L

at first blush you'd think "oh my god BMW's is so much more efficient" but the LS7 is a physically smaller package, 100 lbs lighter, and provides significantly more torque.

so just because "somebody gets 350hp from a V6" does not mean that someone else's V8 is crap. improved power, torque, and fuel economy are all good things - and keep in mind, that's all while meeting emissions requirements.

 

[Zargon]

yeah the specifically mention BMW

, all while coming in a claimed 40-pounds lighter and four inches shorter than the 4.4-liter twin-turbo V8 by BMW.

 

[phucheneh]

compare the torque, physical size, and weight of those engines with a GM small block V8.

example: BMW M5 V10 - 500hp, 5L vs. GM LS7 V8 - 505hp, 7L

at first blush you'd think "oh my god BMW's is so much more efficient" but the LS7 is a physically smaller package, 100 lbs lighter, and provides significantly more torque.

so just because "somebody gets 350hp from a V6" does not mean that someone else's V8 is crap. improved power, torque, and fuel economy are all good things - and keep in mind, that's all while meeting emissions requirements.

Hey now, I said I wasn't knocking it, just thinking they could probably squeeze more power out of less displacement. Especially considering they will probably offer a tuned-up version of this engine (or maybe they'll up it to 7L or something).

I think as long as you compare apples to apples, saying 'there are 350hp V6 engines' is relevant. I wouldn't compare it to, say, a turbo I6.

Nissan 3.7 is a good benchmark for an NA V6. And generally, it seems like V6's can indeed be scaled up to V8's and maintain about the same power/displacement ratio. Same for the power reduction when someone takes a V8 and lops a couple cylinders off.

So that 3.7 would become 4.9L, and if the power scaled up...327hp (iirc) divided by six, take that number and apply it for the two extra cylinders...you get 436hp. Even if that's optimistic, I would think 400hp+ is reasonable to expect out of a ~5L V8. But at engines of this size, I think arguing over an extra liter is splitting hairs.

That 'wouldn't' was supposed to 'would've,' btw.

 

[LTC8K6]

http://www.gminsidenews.com/forums/...ock-v-8-direct-injection-wardsauto-com-54138/

 

[yottabit]

they are both 6.2...........

Im guessing the EPA # they quoted is wrong since thats the rating of the base vette now

Yes, that's my point.

The rumor mill seemed to think GM's new V8 was going to be significantly smaller displacement, AND have more horsepower.

Rumor mill:
5.5 L V8 that will have at least as much HP as the LS3 (6.2 L 430 hp) and much better fuel economy

Actuality:
6.2 L V8 that has a ~20 more HP than the LS3 (also a 6.2 L) and the same fuel economy?

I read through a Motortrend article that suggested the changes are much deeper. Cylinder deactivation is going to be used extensively. I'm just puzzled by the "26 MPG" number, and hope in actuality it will be higher than that

I thought the C7 being smaller, lighter, and having a "5.5 V8" actually had a shot at breaking 30 MPG

I get them sticking with the 6.2 though. A lot of the Corvette market are older folk who wouldn't necessarily be happy about "upgrading" to a smaller engine

I also am thinking now that maybe there is a lot left on the table with this design. Like maybe a new Z06 will also use this same 6.2 L but tuned to 600 hp or something. Maybe the ZR1 will get a turbo 5.5 L

I guess I should also remember that the LS motors in general already have the bar set really high, so any incremental improvement like this is a big step.

I think honestly this is going to have much larger impact on other cars than the Vette though. The 4 cyl deactivation, assuming this goes into the truck line, will probably single-handedly cut the nation's CO2 production in half once all the soccer moms in their suburbans can idle on 4 cyl instead of 8

 

[ND40oz]

yeah the specifically mention BMW

Yeah, but the S63 is a 550 hp engine, BMW will be getting LT1 numbers out of the new M3 next year with a turbo inline 6, which will be considerably lighter.

 

[LTC8K6]

The experimental engine is based on GM’s current all-aluminum Gen IV 6.2L V-8 (L92) found in the Escalade, GMC Yukon Denali and Hummer H2. Depending on the application, the powerplant, which sports port fuel injection, variable valve timing (VVT) and dual-cam phasing, is rated between 380-403 hp in stock form.

However, with a little tweaking to accommodate the auto industry’s latest fuel-injection hardware, the prototype V-8 is producing “well north of 450 hp (on gasoline),” says Dave Sczomak, development engineer-GM Powertrain Advanced Engineering.

That was in 2007, a direct injected 6.2L V8.

 

[Vdubchaos]

Yeah, but the S63 is a 550 hp engine, BMW will be getting LT1 numbers out of the new M3 next year with a turbo inline 6, which will be considerably lighter.

Lighter? Show me the proof, cause right now no one really knows how much this engine weighs, or what BMW engine will weight. LS1 was 409 pounds, which is VERY light.

Yeah but German Engines cost 3-4 times the price of this one. Heck most 4 cyl German engines cost on par with new LS3. M54 from E46 was 375+lbs (add Turbo to that). VERY small difference.

I remember in the early 2000s one of the LOWEST end German 8 cylinders (W8 in the Passat) was 25-30k new. And we are talking worse performance, PITA to work on, not great reliability amongst many other things. I won't even get into the fact that they are a nightmare/expensive to modify.

Germans have a LOT to learn still cause frankly they still haven't learned anything from their WW2 engineering failures.



For now, I suggest they get the basics right.....like say, making a badge that doesn't chip and peels off within 5 years of ownership (BMW).

:biggrin:

Please don't compare an overpriced, overly complex for no apparent reason, overly PITA to work on, overly expensive to maintain and fix German engines.

 

[LTC8K6]

Hard to believe they are at the same point as they were in 2007 with this engine.

 

[Ferzerp]

Guys, why are you making HP:Liter comparisons between pushrod and DOHC engines?

The pushrod engines always have a lower HP:liter ratio, but pack higher displacement in to less weight. The important metrics to look at are engine size/weight, power, and mileage (if you care about that)

 

[LTC8K6]

Too bad they didn't stick with that LT5...