Ls9 Dohc???...

http://www.digitalcorvettes.com/forums/showthread.php?t=49908

DOHC and only 6 liters :confused:

I'm down for the ZR1 again. Supercharge it!

Like I said over at digital corvettes, I don't know why they would go DOHC again. I really do not see the need for it, but I am sure Chevrolet put a ton of thought into it if that's what is coming................. and yes the document does appear to imply a supercharger (look under "Deliverable(s) towards the bottom of the page).

David

Maybe to meet future emissions standards. Just Guessing.

I don't see the need for it either, they are doing just fine with their pushrod engines. I was never a big fan of the DOHC 3.4L that GM use to have, I doubt I would be a big fan of the Ls9 either.

I also agree that there really isn't any need for it...But, if they really intend to put this into a "Super" 'Vette than maybe it's a decision that's been made from more of a marketing standpoint vs a performance standpoint, (though in theory a dohc s/c'd motor should outperform a pushrod version especially with respect to top end, gas mileage and smooth operation). Public perception still seems to be that pushrods are old tech and are outdated and while we all know that this is BS, GM could be making their top of the line motor dohc just to give it a more exotic appeal :shrug:

Maybe it is the new Northstar for Cadillac V-series cars.

next gen GTO engine. Something to differentiate it from a Chevy, finally. :D

Maybe it is the new Northstar for Cadillac V-series cars.
Could be a Ultra V8 derivitive for the next XLR, the Northstar's days are numbred.

Very interesting, though I doubt a Corvette will have anything but OHV for quite a while.

Either its BS, which I suspect, or the code V8GDOHC DOESNT mean V8 Gas Dual Over-Head Cam, but rather V8 Gas Direct Over Head Cam (as we know GM is moving toward Direct Injection engines).

Who knows, but I dont see GM going DOHC. No need, and the LS7 already pushes silly high revs. RPM is what kills an engine, and we need to keep our engines low in revs and high in grunt. Thats what makes them last, and makes them reliable, which makes customers happy.

Also DOHC is more expensive, a larger engine size, heavier, and more likely to break.

Either its BS, which I suspect, or the code V8GDOHC DOESNT mean V8 Gas Dual Over-Head Cam, but rather V8 Gas Direct Over Head Cam (as we know GM is moving toward Direct Injection engines).

Even if the "D" stood for "direct" (and it doesn't), the last part still says "overhead cam".

Who knows, but I dont see GM going DOHC. No need, and the LS7 already pushes silly high revs. RPM is what kills an engine, and we need to keep our engines low in revs and high in grunt. Thats what makes them last, and makes them reliable, which makes customers happy.

- GM has already "gone" DOHC for many of their engines.
- The primary benefit of OHC is not to simply to rev high.
- High RPM does not kill an engine; that's an old wives' tale that might have been applicable 30 years ago but certainly isn't today.

As 91_z28_4me noted, it's most likely the next generation of premium V8. It's been rumoured for some time that the next "NorthStar" would be based on the LSx. There would still be an OHV variant for the masses though.

As 91_z28_4me noted, it's most likely the next generation of premium V8. It's been rumoured for some time that the next "NorthStar" would be based on the LSx. There would still be an OHV variant for the masses though.
So the next N* would likely have the same bottom end as the LSx motors, good for cost cutting to be sure, and good for the performance crowd.

Don't the N* and LS motors already share firing order?

Most likely a Cadillac application, but i could see this in a premium chevy like the corvette. Maybe it'll be a replacement for the Ls2 in the base corvette and CTS-V which'll allow the corvette/CTS-V to have a different engine than the other mainstream GM performance vehicles like the camaro, GTO, SSR, TBSS, etc.... I could see GM going this route. A supercharged version could also see special use in the cadillac STS-V, XLR-V, and maybe Z06. I wouldn't mind the z06 moving up to a S/c'd Ls9 Dohc and it leaving the Ls7 for cars like the camaro/GTO.

GM does need a high output Dohc v8 for their premium cars. Not so much for performance, but for image, etc... In this day and age when companies are toting things like Double Vanos, Individual Throttle Bodies, direct injection, vartiable turbine turbochargers, 5valves/cyl, etc.... the public looks at GM's rather simple pushrod v8 motors as lacking (even though we know for a fact that isn't the case). In this industry, image is almost more important than the practicality of the application because people just love having things for the sake of having things. It's dumb, but that's the masses for you.

I imagine a 6.0L Northstar/Ultra with direct injection would put out some serious #'s

at least 450HP would be my bet.

Don't the N* and LS motors already share firing order?

No, but that's not really a defining characteristic of an engine. It wouldn't prevent an engine from being adapted to another application.

It's a big price to pay to convince the technophiles that OHVs have many advantages over DOHCs. It's a price GM will have to pay (unfortunately) as no matter what real world evidence is presented to people, some just stop listening. Nothing will satisfy their 'requirements' more than knowing their engine's valvetrain is actuated by DOHCs.

Of course, DOHCs are inherently more refined that OHVs... so that also plays a part in buyer's minds when forking our dollars for high-end vehicles.

No, but that's not really a defining characteristic of an engine. It wouldn't prevent an engine from being adapted to another application.
I know but I just thought that they did when the the Gen III changed firing order from the Gen II.

What about the Cadillac V12, is that for trucks only?

I think the people that know the difference between DOHC and OHV are likely ones that will be able to look past their basic nature and see how each has its benefits. Most consumers would hardly know the difference anyways. For Caddy- sure. For Corvette- no need.