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

[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

[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!

[FU]

The renewal of the DOHC LTX platform would have been a nice booster shot for us , no doubt.

GM =

[ZR1Vette]

Neither condemning nor defending GM...I too was at the session where the question/reply comment was said. Yes, GM/Corvette are strong advocates of the LS series engine and I can understand why. For the size of the engine package it produces more HP (LS2/3/7/9) that anything out there. It is a tried and true engineered design, allows for low profile cars (thus helps in the Cd area), is lighter than its DOHC counterparts (look at the LT5 and the Ford V8s for size, mass and height...thus why the Mustang looks like a brick compared to the C6) To wit>>


LS engines have technological growth potential... direct injection, variable cam timing, DOD, etc. So for now the LS family (and its future variants) makes sense to me...but they too will go the way of the dinosaur as the V8 becomes history and high performance V6s begin to reign.

Oh...there were several comments by the GM folks beyond "If I can beat you..." talking about several of the items I note above...particularly overall package size and weight considerations. Of course just my opinion...

[1989ZR1#74]

Well before you throw the Powertrain guys under the bus it was a bit of an affront to them. The tenor of that comment was basically

"How could you let the blue oval beat you in tech?"
"They have a cool DOHC motor and you have push rods?"
"Don't you think your design is behind the times?"

Then the "don't car how many CAMs comment." THen they went on to explain packaging and how the OHV engine is not by any means low tech.

Basically the their right. They will blow the doors off the DOHC ford...