Well according to another leaked document( thanks for keeping the secrets UAW), the 6.2 V8 might be making the move over to an overhead cam design for the Gen V Small Block. While the little brother, 5300 is going to be replaced by a mystery engine, but will remain OHV.



More here

IMHO, doesn't sound very cost effective having two versions of the Gen V Small Block. Especially with the Ultra V8 coming.

I think someone's made a mistake.

Small Block Gen V is OHV, Ultra is DOHC.

 

I think someone's made a mistake.

Small Block Gen V is OHV, Ultra is DOHC.

Even without your insider information, I agree. GM seems to be getting much better at avoiding duplicate engineering effort.

I see no possible benefit to engineering two different OHC V8 engine families. If GM wants OHC V8s in future pickups, they can drop in a slightly detuned version of the Cadillac Ultra.

 

While I don't like the idea of having DOHC on an engine that seems to be doing just fine with OHV and 2 valve per cylinder (and hasn't even used 3 valve pushrod heads or DI on any engine, let alone AFM or VVT on the Vette), the document does seem to support the DOHC 6.2L V8 engine. See around pages 51 and 55:

http://www.futureoftheunion.com/docs/delphi/Ex1toproposedorder149pages.pdf

I also wonder, since we've heard absolutely NOTHING about the Ultra V8 in recent memory, if Cadillac just got lazy and decided to slap a set of DOHC heads on a Chevy smallblack (as in the original ZR-1) and call it a day. That engine would be well placed to go up against the Mercedes AMG "63" DOHC V8 (which actually has 6.2L as well). The only problem then, is with the tall DOHC heads on a big V8, while these engines would fit into the Escalade and pickups just fine, how well would they fit under the hood of the cars?

I really hope GM knows what they are doing with this move. The simplicity of the OHV motors has made them affordable, durable, torquey, fuel efficient, compact, light, and led to a loyal following--something you can't quite say about Ford's modular V8s.

 

Hmm, interesting.

But I am inclined to believe that there is some sort of typo.

No one writes OHC, everyone puts down DOHC or SOHC.

 

While I don't like the idea of having DOHC on an engine that seems to be doing just fine with OHV and 2 valve per cylinder (and hasn't even used 3 valve pushrod heads or DI on any engine, let alone AFM or VVT on the Vette), the document does seem to support the DOHC 6.2L V8 engine. See around pages 51 and 55:

http://www.futureoftheunion.com/docs/delphi/Ex1toproposedorder149pages.pdf

I also wonder, since we've heard absolutely NOTHING about the Ultra V8 in recent memory, if Cadillac just got lazy and decided to slap a set of DOHC heads on a Chevy smallblack (as in the original ZR-1) and call it a day. That engine would be well placed to go up against the Mercedes AMG "63" DOHC V8 (which actually has 6.2L as well). The only problem then, is with the tall DOHC heads on a big V8, while these engines would fit into the Escalade and pickups just fine, how well would they fit under the hood of the cars?

I really hope GM knows what they are doing with this move. The simplicity of the OHV motors has made them affordable, durable, torquey, fuel efficient, compact, light, and led to a loyal following--something you can't quite say about Ford's modular V8s.

Yes it's true..there wasn't any information about ultra v8 for long times, but in this text they are mentining gen V. And few weeks ago there was also some information about small block OHV with DI which will probably be used on Gen V.
And if GM put dohc heads on small block i don't think it would be so small any more

 

Dropping a DOHC engine that is the size of the 6.2 liter engine currently that powers the Escalade requires significant engineering fleets. DOHC engines need cam holders and with the size of the 6.2 liter engine, that will add weight to an otherwise heavy engine.

 

Dropping a DOHC engine that is the size of the 6.2 liter engine currently that powers the Escalade requires significant engineering fleets. DOHC engines need cam holders and with the size of the 6.2 liter engine, that will add weight to an otherwise heavy engine.

Very true, and look at the size of Mercedes V8's. 6.2L is AMG class.

 

Um....where in that whole article does it say that the Gen V's will be OHC?
Gen V to be OHC would mean that it would require an all new engine block design. Its not just as simple as bolting up some OHC heads and calling it a day. There will be an Ultra V8 that will have OHC with DI, and of course VVT. Perhaps GM will use its own VANOS technology with Ultra, and AFM as well. Could be a technological tour de force!! But things we do know is that it will have things such as VVT, optional DI, and AFM. A VANOS technology would be icing on the cake.

 

DOHC architecture gives GM freedoms they can't get with OHV, plain and simple. Perhaps they can't get big power (specifically torque) out of their big OHV V8's without throwing expensive materials at them like in the vette. The every-mans 6.0L, makes about 373 ftlbs of torque - in a truck application. That is not very impressive when you look at the current and coming competition. Even Ford's outgoing SOHC 5.4L makes about 365 ftlbs.

Controlling both cams is very useful for FE, torque and emissions. THings that are driving a lot of future programs.

 

Um....where in that whole article does it say that the Gen V's will be OHC?
Gen V to be OHC would mean that it would require an all new engine block design. Its not just as simple as bolting up some OHC heads and calling it a day. There will be an Ultra V8 that will have OHC with DI, and of course VVT. Perhaps GM will use its own VANOS technology with Ultra, and AFM as well. Could be a technological tour de force!! But things we do know is that it will have things such as VVT, optional DI, and AFM. A VANOS technology would be icing on the cake.

from page 49...i didnt read everything but there is 6.2 l ohc gen V from page 49.
http://www.futureoftheunion.com/docs/delphi/Ex1toproposedorder149pages.pdf

 

Maybe Gen V will be in trucks while thr ULTRA is cars only.

 

Its not just as simple as bolting up some OHC heads and calling it a day.

That reminds me of the 3.4L Twin Dual Cam V-6 in the Lumina Z34.

 

...if Cadillac just got lazy and decided to slap a set of DOHC heads on a Chevy smallblack (as in the original ZR-1) and call it a day...

The original ZR1 was not just a small-block with DOHC heads. It was a clean-sheet design built by Mercury Marine. Here's clip from Wikipedia:

It was an all-aluminum 349 in³ (5.7 L) small-block V8, but was entirely different from any of the other Chevrolet 350 engines. The bore and stroke were both different at 3.9 by 3.66 in (99 by 93 mm) instead of the usual 4 by 3.48 in (102 by 88 mm) and it featured Lotus-designed 32-valve DOHC heads. It was hand built by specialty engine builder, Mercury Marine. This engine produced 375 hp (280 kW) and 370 ft·lbf (502 Nm) for the 1990-1992 Corvette ZR-1 and jumped to 405 hp (302 kW) and 385 ft·lbf (522 Nm) for 1993 to its final year in 1995, thanks to cam timing changes and improvements to the engine porting. 1993 also added 4-bolt main bearing caps and an exhaust gas recirculation system. The engine was not used in any other vehicle.

 

That reminds me of the 3.4L Twin Dual Cam V-6 in the Lumina Z34.

Now that was the low-buck way to develop an OHC V6!

Ironically, the later OHC-from-scratch Oldsmobile Shortstar actually made equivilent power to the mongrel TDC V6 (210 HP, I think!). Of course, the Shortstar was smoother and more refined.

 

This shouldn't be news in 2007. Sadly GM is behind the curve in so many things.

Makes one wonder why Bobby Putz has so much time to blog when he should be DOING HIS JOB and to turn GM around.

Guess it is easier to blog and to insult the press and to claim credit in the world of Putzy instead of developing real innovation.

 

Now that was the low-buck way to develop an OHC V6!

Ironically, the later OHC-from-scratch Oldsmobile Shortstar actually made equivilent power to the mongrel TDC V6 (210 HP, I think!). Of course, the Shortstar was smoother and more refined.

Yeah, I heard that the TDC 3.4 was kind of a monster, in both good and bad ways...rumor was that it was pushing 275 hp but had to be detuned to preserve the transmission. Not a very efficient way to go, though, to have both a timing chain and timing belts.

 

That reminds me of the 3.4L Twin Dual Cam V-6 in the Lumina Z34.

Please god don't give GM any ideas. That engine was one of the biggest POS's that GM ever turned out. It wasn't worth the iron it was made of.

 

Now that was the low-buck way to develop an OHC V6!

Ironically, the later OHC-from-scratch Oldsmobile Shortstar actually made equivilent power to the mongrel TDC V6 (210 HP, I think!). Of course, the Shortstar was smoother and more refined.

The shortstar was a great engine. It's a shame they let it die when Oldsmobile joined the parking lot in the sky. It would have made for a great 3800 replacement for Buick, and offered some powertrain exclusivity to the GM lineup.

 

Yeah, I heard that the TDC 3.4 was kind of a monster, in both good and bad ways...rumor was that it was pushing 275 hp but had to be detuned to preserve the transmission. Not a very efficient way to go, though, to have both a timing chain and timing belts.

I thought it had a single chain driven off a pilot shaft where the OHV cam would have been.
EDIT: Did a little research and there were belts! What a horrible contraption!

 

Given that the Mustang will no longer be displacement limited because of the upcoming BOSS 6.2 liter DOHC, GM needs to at least ante up with a similar displacement 4 valve design. That is unless they are going to use the engineering crutch of S/Cing. Now that would be a sad role reversal, wouldn't it...

 

It could be interesting to see this DOHC version of the small-block engine

maybe this future engine could do well on NHRA drag-strips like the SOHC version of the Ford FE-427 engine did
http://en.wikipedia.org/wiki/Ford_FE_engine
Chrysler did attempted to made a DOHC 426 Hemi but NASCAR putted a ban on OHC engines http://www.thehemi.com/notable.php?id=010

I heard of some rumors then Ford attempted to do once a OHC version of the small-block 289 Windsor? Is it a urban legend?

 

OHV 2/3VPC NG V8 for Chevy/Pontiac and lesser GMC's and DOHC 4VPC for GMC DENALI/CADILLAC models??----That would be my guess if its true!

 

DOHC architecture gives GM freedoms they can't get with OHV, plain and simple. Perhaps they can't get big power (specifically torque) out of their big OHV V8's without throwing expensive materials at them like in the vette. The every-mans 6.0L, makes about 373 ftlbs of torque - in a truck application. That is not very impressive when you look at the current and coming competition. Even Ford's outgoing SOHC 5.4L makes about 365 ftlbs.

Controlling both cams is very useful for FE, torque and emissions. THings that are driving a lot of future programs.

Not entirely accurate. Dodge/Chrysler showed that an OHV engine can have independently variable valve-timing with dual camshafts. GM has also been working 3-valve heads for their small block architecture. There's a lot of room left in the OHV arena. I'm with DuSpinnst. I'm betting the supposed 6.2 L motor is really the new Ultra V8.

 

OHC LS engine?

if thats the case.... NO.

the pushrods are great for all of GMs performance vehicles.

 

I don't buy this article at all. I think, like others, ultra features got confused with the Gen V small block