New GM LS9 Supercharged Vette ZR1 engine

[Sinister Fiero]

620 HP - 595 TQ

http://jalopnik.com:80/337672/detroit-a ... ls9-engine

[Series8217]

I can't wait to start seeing these things on the road.

That block sure looks sturdy! 6-bolt mains FTW!

Interesting that they went with thick aluminum bore walls but very thin iron liners. Keeping the weight down?

[darkhorizon]

My friends that have had them on the dyno up here at the proving grounds have seen upwards of 560 to the wheels.

With pulley swaps and tuning, I doubt 620-650WHP will NOT be far off for these guys.

[The Dark Side of Will]

I can't wait to start seeing these things on the road.

That block sure looks sturdy! 6-bolt mains FTW!

Interesting that they went with thick aluminum bore walls but very thin iron liners. Keeping the weight down?

'Cause they didn't need thicker liners. DO, however, note that it uses a smaller bore than the LS7 because the LS7 bore size couldn't take the boost for production reliability.

The "flying butress" main bearing bulkheads with the cast in bay-to-bay breathing windows are things of beauty.

The "Dual Gerotor" oil pump... is one stage scavenge and one pressure?

[Series8217]

Is there any other way to do dry sump?

[Aaron]

It is a badass engine for sure, but I gotta be honest when I say I'd have rather seen a high output N/A 32 valve 6.2l, like an 8,000rpm 100hp/l engine. It would have really payed tribute to what the ZR1 was back in the day.

"The engine produces 90 percent of peak torque from 2,600 rpm to 6,000 rpm."

Damn, that's impressive!

Also, Will, it has a twin disk clutch setup too :thumbleft:

[The Dark Side of Will]

The first Corvette to bear the ZR1 name was actually back in the '60's...

Why does everyone want overhead cams?
The pushrod engine is smaller, lighter, simpler and cheaper. The supercharger adds weight and complexity, but you end up with WAY more torque than any 6.2 litre N/A engine would make.

[The Dark Side of Will]

Is there any other way to do dry sump?

Most of the aftermarket systems I've seen have four scavenge stages (two pulling from the pan, one from each valve cover).

I'd like to read more tech talk about the capacities of the pump stages.

[p8ntman442]

The first Corvette to bear the ZR1 name was actually back in the '60's...

Why does everyone want overhead cams?

cause ferrari uses them, and most BADASS motors from GM have been dohc's.

[whipped]

because valvetrain mass FTL

[crzyone]

It is really impressive how much power they can get from a 2V pushrod engine. If they can get 500hp NA from the LS7, I imagine they could get a lot more from a 4V DOHC design.

The supercharger probably adds the weight that a set of DOHC heads would. If they wanted to, they could make the heads a lot smaller than the old style DOHC heads and use hollow cam shafts as well.

A 600hp DOHC aluminum V-8 from GM would probably be a better showcase of what GM could do.

[Fastback86]

It is really impressive how much power they can get from a 2V pushrod engine. If they can get 500hp NA from the LS7, I imagine they could get a lot more from a 4V DOHC design.

The supercharger probably adds the weight that a set of DOHC heads would. If they wanted to, they could make the heads a lot smaller than the old style DOHC heads and use hollow cam shafts as well.

A 600hp DOHC aluminum V-8 from GM would probably be a better showcase of what GM could do.

I'm starting to think that's the point, GM wants to prove that pushrod technology is not dead and that they can build an OHV engine thats just as powerful as DOHC engines. I think GM and Dodge want to keep the old school (as it were) OHV style going just to be different than all the other car companies. They've proved they can do DOHC just fine with the N* and the N* SC (for example), and yet they still use the OHV engines.

[Aaron]

GM doesn't want, or need, to prove anything to anybody. They keep the pushrod design because it's cheaper, they modify existing designs instead of creating all new designs, it weighs less, it's a tighter configuration for the displacement, and it offers a performance curve that most people really like.

[Indy]

GM doesn't want, or need, to prove anything to anybody. They keep the pushrod design because it's cheaper, they modify existing designs instead of creating all new designs, it weighs less, it's a tighter configuration for the displacement, and it offers a performance curve that most people really like.

It offers a performance curve that most people THINK they really like. Most people don't have any experience with a DOHC 8...

[Aaron]

It offers a performance curve that most people THINK they really like. Most people don't have any experience with a DOHC 8...

No, the people know they like it. As I said in the other thread, I got the chance to drive a 300wtq TGP, which is a torque monster. It felt like it'd walk away from my car, it felt so much stronger. Then at the track, I posted consistently better times, by a half second! When Grandpa is getting on the highway and hits the gas in his 3800 Buick, it just goes. It doesn't make a lot of noise, he doesn't have to rev it sky high, it just does its thing. Sure I love watching the tach climb up to 4,500rpm just to get on the highway with traffic, but most people don't. The DOHC gets semi loud with induction noise, the pre-3500 power isn't that great comparatively, and with an auto it'd suck worse. No such problems exist with the 3800, even the 3X00. While they don't make the same amount of high end, the low end feels much stronger than the DOHC (Even though in reality it isn't).

[Blue Shift]

OMFG, can I like... find one at the junkyard for less than $100, and swap it into my 84 with the stock automatic? Will it hold? Does anyone make a kit? :la:

[FieroWanaBe1]

It offers a performance curve that most people THINK they really like. Most people don't have any experience with a DOHC 8...

honestly it looks like most poeple would like this curve inclued DOHC fans.
And it would also blow away a few DOHC v8 designs in a straight and through turns.

let the chart do the talking.


note this is the ls3 and if the curve on the ls9 is similar, it should not be a short rpm stump puller engine, it has a very high and relatively flat torque curve making 75% of its peak at all rpms in its range.

[The Dark Side of Will]

How'd someone get an '08 Vette in July '07?

[FieroWanaBe1]

it is supposedly a gm test dyno.
Here is the "superior" DOHC v8 from a F430


Note its torque is only above 300lb-ft for less than 1000 rpms and keeps falling.

If only a corvette could have the Ferrari's transmission.

[The Dark Side of Will]

Why the heck would GM use a Dynojet? Convenient source of relative break in data?

I reiterate... why's everyone so wrapped around the axle about OHC's vs Pushrods.

Pushrods are not relegated to low RPM... just lower than an equivalently built OHC setup. The LS7 revs to 7000 RPM... with pushrods and a 4 INCH (!!) stroke. Drag race engines with pushrods top 10,000 RPM; NASCAR engines run to 9500 and handle 500 mile races, which is twice as long as any F1 race.

It's just this compromise:
Pushrods:
Pro:
Light weight
Compact
Simple
Cheap

Con:
Reciprocating mass
Can not vary cam phasing independently (except it's done on the Viper...)


OHC:
Pro:
reciprocating mass
independent variable cam phasing

Con:
Heavy
Bulky
Complex
Expensive

I can NOT see why a design that focuses as obviously on bang for the buck as the Corvette's design would choose OHC over pushrods. Ferrari doesn't design to a price point. GM does. Pushrods should surprise absolutely no one and absolutely no one should be upset at their use.