New GM LT1 engine

[overst33r]

I don't think anyone said "my 200hp 2L Honda is better because it has more HP/L."

Just that GM has a somewhat absurd displacement fetish that causes them to keep manufacturing V8's with big block era displacement...and if the power's not that impressive, it's rather silly.

Also, wow, a spring-loaded, oil-activated cam pulley/gear? CRAZY. Wait, that's generally just how it's done...

And just to go ahead and get all the negativity out...



This is a baffling comment. Why in the world would an 'ideal performance engine' not be forced induction? Also...what's an 'ideal performance engine,' anyway? I would think it would be one that could handle boost and not require a shitpile of mods to make it suck air more efficiently.

Given the choice, I'd always choose cram over suck.:whiste:

Why would anyone want less displacement if the design goals can be reached with more? We don't have a displacement tax. I fail to see how a 6.2L V8 getting nearly 30mpg is unimpressive.

Can you explain more about VVT in pushrod engines? I didn't realize it was so popular.

 

[Howard]

Because nobody likes big displacement, that's why.

 

[JackBurton]

To be competitive with what? The base corvette was already whooping up on cars costing 2x as much.

At $60K (which will most likely be the new Vette's price point) you will have the Camaro ZL1 at 580hp and the GT500 at 662hp to compete against.

 

[overst33r]

At $60K (which will most likely be the new Vette's price point) you will have the Camaro ZL1 at 580hp and the GT500 at 662hp to compete against.

Why the $10k jump?

The Corvette doesn't really compete against pony cars. Different demographic I would say.

 

[LTC8K6]

Why would anyone want less displacement if the design goals can be reached with more? We don't have a displacement tax. I fail to see how a 6.2L V8 getting nearly 30mpg is unimpressive.

Can you explain more about VVT in pushrod engines? I didn't realize it was so popular.

GM had/has several "cam in block" V6 engine with VVT for a long time now. Goes back to the 3500 and 3900 V6 in 2006, I believe.

EDIT wiki: In 2005, General Motors offered the first Variable Valve timing system for pushrod V6 engines, LZE and LZ4.

The 5.7L Hemi V8 has VVT since 2009

And also the GM V8's have had it as well.

http://www.mechadyne-int.com/vva-products/concentric-camshafts

 

[overst33r]

GM had/has several "cam in block" V6 engine with VVT for a long time now. Goes back to the 3500 and 3900 V6 in 2006, I believe.

EDIT wiki: In 2005, General Motors offered the first Variable Valve timing system for pushrod V6 engines, LZE and LZ4.

The 5.7L Hemi V8 has VVT since 2009

And also the GM V8's have had it as well.

http://www.mechadyne-int.com/vva-products/concentric-camshafts

:thumbsup:

 

[JackBurton]

Why the $10k jump?

The Corvette doesn't really compete against pony cars. Different demographic I would say.

A decently equipped base Vette is in the mid $50K to $60. And I'd disagree with you, the Vette does compete with the GT500 and Camaro ZL1. Someone that wants a sports car with a $60K budget will more than likely shop these cars.

 

[Howard]

GM had/has several "cam in block" V6 engine with VVT for a long time now. Goes back to the 3500 and 3900 V6 in 2006, I believe.

EDIT wiki: In 2005, General Motors offered the first Variable Valve timing system for pushrod V6 engines, LZE and LZ4.

The 5.7L Hemi V8 has VVT since 2009

And also the GM V8's have had it as well.

http://www.mechadyne-int.com/vva-products/concentric-camshafts

1000 hours of durability? What?

 

[KentState]

A decently equipped base Vette is in the mid $50K to $60. And I'd disagree with you, the Vette does compete with the GT500 and Camaro ZL1. Someone that wants a sports car with a $60K budget will more than likely shop these cars.

I agree as well. I cross shopped the Vette, CTS-V, ZL1 and some other and they all come up in conversations on the Corvette forum.

 

[JeffreyLebowski]

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.

They could squeeze more power out of it but then more you squeeze out of it the closer you get to the limit the engine can last. Remeber, these are production engines for people that will just change the oil when the light goes on.
People tend to forget that the euro engines that have lower displacement but higher horsepower are either turbo charged or any that are N/A require lots of "scheduled" maintanence.

 

[phucheneh]

1000 hours of durability? What?

I dunno what that's about, but I will give kudos to the cam design- I didn't know they had tech for changing intake/exhaust valve timing independently on an OHV.

Oh, and to the above- I can agree, for the most part, but I just don't think a 450hp 6.2L is getting close to running on the ragged edge...I'm sure they can still have a durable engine with 500hp plus...and I would be willing to guess that that's what will happen, anyhow.

 

[Throckmorton]

Why the $10k jump?

The Corvette doesn't really compete against pony cars. Different demographic I would say.

Same demographic - rich white guys

 

[SparkyJJO]

I dunno what that's about, but I will give kudos to the cam design- I didn't know they had tech for changing intake/exhaust valve timing independently on an OHV.

Oh, and to the above- I can agree, for the most part, but I just don't think a 450hp 6.2L is getting close to running on the ragged edge...I'm sure they can still have a durable engine with 500hp plus...and I would be willing to guess that that's what will happen, anyhow.

Oh you could pump the 500HP+ but 1) this is just the base number of the engine, it will be undoubtedly adjusted for whatever vehicles it goes in, and 2) they also plan on them lasting quite a long time, so having it not quite on the bleeding edge but generally hitting 200k miles is a good thing. Besides, just think about it - 6.2L and "only" 450HP can mean there is sooo much more room to boost the output :awe:

 

[Ferzerp]

The reason I think 6.2L 450 is underwhelming is that it is barely better than Dodge's 6.4L 470 which has been around 2 years now.

 

[Fritzo]

Why is it Germans and Italians can get 500HP out of a 5.0L engine and we get 450 out of a 6.2L?

 

[phucheneh]

Why is it Germans and Italians can get 500HP out of a 5.0L engine and we get 450 out of a 6.2L?

When you put it that way, you make me wanna switch sides.

The answer is generally expensive, failure-prone electronics. Made by Italian and German companies.

Eat your damn pride and just let the Japanese build them. Christ, Italy, your electronics are just expensive Chinese-grade crap. Magneti Marelli, I'm looking at you.

 

[Howard]

Why is it Germans and Italians can get 500HP out of a 5.0L engine and we get 450 out of a 6.2L?

You Americans can, you just feel like it's not worth doing.

 

[Fenixgoon]

Why is it Germans and Italians can get 500HP out of a 5.0L engine and we get 450 out of a 6.2L?

because you don't understand mathematics, engine design, and the differences between OHC and OHV?

horsepower = torque*RPM / 5252

OHC = can rev very easily (see the RPM part of the above equation)

OHV = very power dense (in terms of physical size and weight) but doesn't rev as easily.


as i previously stated, the last gen BMW V10 was ~100 lbs heavier than the LS7 despite one displacing 5L and the other displacing 7L, yet both produced 500hp. And the LS7 did so with significantly more torque available throughout the powerband.

 

[LTC8K6]

Why is it Germans and Italians can get 500HP out of a 5.0L engine and we get 450 out of a 6.2L?

Ford's 5.0 would easily hit 500 horses, I think.

OTOH, Audi's 4.2L V8 makes 450 horses...

But things are different...

 

[Fritzo]

because you don't understand mathematics, engine design, and the differences between OHC and OHV?

horsepower = torque*RPM / 5252

OHC = can rev very easily (see the RPM part of the above equation)

OHV = very power dense (in terms of physical size and weight) but doesn't rev as easily.


as i previously stated, the last gen BMW V10 was ~100 lbs heavier than the LS7 despite one displacing 5L and the other displacing 7L, yet both produced 500hp. And the LS7 did so with significantly more torque available throughout the powerband.

It's just something I noticed about our cars vs. European cars...especially with V6 engines. We'll make a 4.0L V6 and it will have an embarrasing 250HP, while someone like BMW or Porsche will make a 2.8L with 280HP. Why are American engines so gimped? You would think by better tuning you could get more out of less and get better performance/fuel efficiency.

 

[yottabit]

It's just something I noticed about our cars vs. European cars...especially with V6 engines. We'll make a 4.0L V6 and it will have an embarrasing 250HP, while someone like BMW or Porsche will make a 2.8L with 280HP. Why are American engines so gimped? You would think by better tuning you could get more out of less and get better performance/fuel efficiency.

This was the case a lot in the 90s and early 2000s but you also have to look at other things like people are mentioning- that 4L V6 might make 250 hp but it might get 28 MPG on regular gas, while the 280 HP 2.8L gets 25 MPG on premium, or something like that.

You can always add at least 20% bhp for a motor that's tuned on premium and Euro cars love that. Also all the great DOHC motors of the 90s and 2000s had pretty terrible fuel economy (the beloved VQ35 as an example)

Then the package size comes into play, that a pushrod V8 can often fit into the same package and weight as a DOHC V6, etc. that give us a preference toward higher displacement. It's not really a matter of being gimped, it's more like (as others pointed out) if you can have more displacement, still have the right weight/package size, and get the same or better MPG, why wouldn't you?

Larger displacement engines producing the same horsepower will generally have a much more usable power band. That and the fact that any engine I've ever seen designed to rev over 7-8k RPM usually has terrible fuel economy.

 

[iamwiz82]

It's just something I noticed about our cars vs. European cars...especially with V6 engines. We'll make a 4.0L V6 and it will have an embarrasing 250HP, while someone like BMW or Porsche will make a 2.8L with 280HP. Why are American engines so gimped? You would think by better tuning you could get more out of less and get better performance/fuel efficiency.

Simplicity means lower costs, less to break, easier to repair, less maintenance. For example, the BMW S54 engine is one wrung out to the ragged edge. It produced more than 100hp/L at a time when that was the bar for production. It also requires a valve job every 30,000 miles or so. That's not exactly normal oil change maintenance.

 

[Throckmorton]

I bet most of those American pushrod V6 engines from the 90s have lower torque everywhere in the powerband than German and Japanese engines.

Also, not all of the low tech engines are efficient. The 190hp 4.0L Jeep straight 6 that offroaders love is a notorious gas guzzler. You get better gas mileage and performance with the 4.6L SOHC V8

 

[Ferzerp]

Also, not all of the low tech engines are efficient. The 190hp 4.0L Jeep straight 6 that offroaders love is a notorious gas guzzler. You get better gas mileage and performance with the 4.6L SOHC V8

The Dodge 6.4L is thirsty too. It's not thirsty compared to something like that from 10-20 years ago, but it is compared to cars now. Only car I've ever paid a gas guzzler tax on. The one I'm looking at now is almost 200hp more, and gets better mileage (and is DOHC).

 

[Howard]

It's just something I noticed about our cars vs. European cars...especially with V6 engines. We'll make a 4.0L V6 and it will have an embarrasing 250HP, while someone like BMW or Porsche will make a 2.8L with 280HP. Why are American engines so gimped? You would think by better tuning you could get more out of less and get better performance/fuel efficiency.

HP/L is a meaningless number.