GM DOHC plans, shelved in '08

[tpepmeie]

Picked this up on another forum. I have no way to confirm it, but if anybody else has contacts in GM it would be interesting to ask them...It would appear the "LT5" designation was set for a comeback. Too bad the economy tanked and GM went bankrupt. Maybe someday.

2012/2013 DOHC plans that were cancelled/shelved in late 2008.


LT5 was to replace LS3
6.2L DOHC
500HP @ 6500RPM
500lb-ft @ 4400RPM
Direct Injection
Displacement on Demand hardware
Cam Phaser
376 cu/in
11.0:1 C/R
11mm Intake valve lift
41mm Intake valves
Steel Crank.


LT6 was to replace LS7
6.2L DOHC
600HP @ 7500RPM
550lb-ft @ 5000RPM
Direct Injection
Cam Phaser
376 cu/in
11.0:1 C/R
13mm Intake valve lift
41mm Intake valves
Steel Crank.


LTC was to replace LS9
6.2L DOHC
700HP @ 6500RPM
700lb-ft @ 4400RPM
Direct Injection
Cam Phaser
376 cu/in
9.0:1 C/R
Supercharged + Intercooled
13mm Intake valve lift
41mm Intake valves
Steel Crank.

[USAFPILOT]

That would be cool...but it is just a dream

[Ccmano]

Direct injection, generally with DOHC, is the latest generation of production engines. Great fuel economy, power and low emissions. Just look at the Hyundai 4cyl in the new Sonata doing 30+ mpg and 200 hp or the Ford and GM 6cyl @ 30mpg and 305hp. Currently only Mercedes, BMW, Ferrari and Jaguar have DI V8's, with power in the 450 to 600 hp range. 500hp should be the benchmark. GM will make the move, it will just take a little longer. Heck, I can still remember when Corvettes barely had 200hp. (yes I'm old)
H

[Paul Workman]

Originally Posted by Ccmano

Direct injection, generally with DOHC, is the latest generation of production engines. Great fuel economy, power and low emissions. Just look at the Hyundai 4cyl in the new Sonata doing 30+ mpg and 200 hp or the Ford and GM 6cyl @ 30mpg and 305hp. Currently only Mercedes, BMW, Ferrari and Jaguar have DI V8's, with power in the 450 to 600 hp range. 500hp should be the benchmark. GM will make the move, it will just take a little longer. Heck, I can still remember when Corvettes barely had 200hp. (yes I'm old)
H

At the round table discussion at the end of the GTG at Bowling Green, our Dominic told me he asked them why after spending the money to develop the LT5 (which was at the heart of the celebration) did they go back to a 50-YO technology?

Dom told me one of the GM people got flippant and responded with (in effect), "If I can beat you, I don't care how many cams I have!"

I wasn't there, and maybe that's a good thing. That comment pissed me off!!. I've long harbored the feeling that it may have been expedient and cheaper to go with the LS, but in the long run, it was a mistake to shelve further development of the DOHC design. GM my find themselves in a game of "catch up" when they had the gold ring in there hand and talked themselves into giving it up!? Case in point: Look a the performance of the new 5.0L 4-valve, DOHC Coyote. They're at 412 hp N/A and haven't even begun wringing out the performance software yet. Do we have to discuss the Hondas?

In the future, it is going to require even greater performance - in spite of tighter fuel efficiency and emissions standards to keep Corvette in the hunt. I just hope GM/Corvette has not squandered the opportunity to have been further developing the DOHC by being distracted with 50 year old push-rod designs. Sooner or later going to the CID well is not going to be the answer, methinks. Others seem to have taken the hint...Just not GM, apparently! (I hope GM has a garage similar to Pete's Skunkworks where super secret-squirrel stuff goes on out of the glaring eyes of the masses! (Big inch LT5s anyone?)

Rant off (sorry)

P.

[Polo-1]

I was there for that "If I can beat you, I don't care how many cams I have!"

They were very touchy about their ohv motor.

the LS motor. whatever

[XfireZ51]

Originally Posted by Polo-1

I was there for that "If I can beat you, I don't care how many cams I have!"

They were very touchy about their ohv motor.

the LS motor. whatever

Well based on Todd's posting maybe now I can understand why!

[Aurora40]

There was definitely a plan for a Northstar replacement, and they did shelve it around 2008. I believe the target was more Cadillac than Corvette

[DaveK]

I think it was pretty hilarious when the guy made his "if I can beat you" comment. Yeah, you can beat us, by adding considerable eaxtra cubic inches and having 20 years of technology and engineering refinement.. yep, you can really beat us...

Also at the JVD BBQ, didn't the last speaker say in his slideshow that they had already done the engineering on how to fit the LT5 in to the C5 package?

It was the bean counters winning yet again. Dave M as much as said so. The LS series was cheaper because they could share it with the trucks, standard cars and other assorted farm vehicles... which is why they never achieve the legendary status that the LT5 has.

You don't see Ferrari putting truck engines in their cars, or Porsche or any of those other super cars!

[Aurora40]

Originally Posted by DaveK

You don't see Ferrari putting truck engines in their cars, or Porsche or any of those other super cars!

You do see both Porsche, and especially Ferrari, going to the same displacement well, though.

The performance of LS equipped Corvettes has been impressive. And it was suitable for cheaper cars like the G8 and even Impala.

Would it have been interesting to see where the lt5 program would have gone? Hell yeah. But was going LS the wrong move? I'm not sure how anyonecan look at the cars to date and say so.

Abandoning the DOHC V8 altogether though, yeah I too think that will bite them. I don't see how Cadillac can hope to run with the big boys without one.

[Aurora40]

http://www.insideline.com/car-news/g...e-in-2009.html