At least according to the following article the truck V8s at the very least will be DOHC
http://www.pickuptruck.com/html/news...eunionuaw.html

Which would tend to make me believe they might all be going OHC since the gen IVs are all part of the same family despite being in a car or truck.

 

GM has to be just a wee bit fumed the media has access to and is picking apart its product plans thru 2013 ....wow .

 

I'd say it's still way to far out for too much speculation.

 

"Up until this point, it’s been conventional wisdom that implementing cylinder deactivation on OHC engines is impractical for reasons of cost and complexity."

Seems kinda easy to implement on OHC valvetrains that use a cam follower and lash adjuster, just need to make the lash adjuster long enough so that when the cylinder is deactivated, the follower will drop below the lobe on the cam. I imagine that it would nothing for a compact head design, but this sort of OHC valvetrain seems to lend itself well to cylinder deactivation without unnessecary complication (while its a totally diffferent beast, BMW's vanos system is perhaps the poster child for a mechanically complex valvetrain - or maybe thats ducati????)

 

What happened to those designs for a chevy engine with two cams in the block? that sounded really cool...

 

according to http://www.futureoftheunion.com/docs...er149pages.pdf only the 6.2 will be OHC. The Gen V 5X (I'm assuming the 5 is for 5.something liters) will still be OHV. Tons of engine and veice info starting on page 50.

 

Might have been a PITA? or didn't lend itself well to VVT or the like? Chrysler made a slick little system with its cam-n-cam for the new Viper, That would really be neat in a SOHC engine. OHC cam engines make it easy to implement VVT (especially DOHC) so thats maybe why they are considering going it, killer low and mid lift aside with relatively wimpy cam profiles.

 

It still holds the patents but may choose not to use them.

 

I'm wondering if they figured out a way to physical package the cams up on top, to keep the engine's overall size similar to a pushrod engine of the same displacement.

I guess its possible.. Mercede's 6.2L DOHC V8 isn't much heavier than a LS7? Dunno about external size.

 

The LS7 is also packing a dry sump oiling system.

 

I think AMG / M-B charge like $40k or more for that engine. That makes the already expensive (at ~$12k, IIRC) LS7 look like a screaming bargain).

 

Yea, but IMO, GM's got a knack of making powertrain's cost effective. If there's any company that could do it, it would be GM.

 

Compared to Chevy charging $25k for the LS7 over the LS3. You just get the bigger wheels/tires, CF body parts, etc for free

And I'm pretty sure the AMG 6.2L is dry-sump also.