Repair-It

It depends on the engine architecture. The 90-95 Corvette ZR-1 used the LT5 which was definitely a small block architecture engine but everything was pretty different from the heads up. It's not unreasonable if they want to bring back this setup and call it the LT5 again. Then there's the flat crank rumor. Is that not an LT-architecture engine? The DOHC alone doesn't make it NOT an LT architecture.

You do have a good point about Cadillac also supposedly working on a DOHC V8. There is really no modern precedent for having a dedicated Cadillac engine. Even the Northstar made it into non-Cadillac vehicles, though that wasn't until toward the end of its life. I guess the last truly Cadillac-only engine was the entire evolution of the Cadillac V8, which ended in the early 80s with the 368 (of V8-6-4 fame).

So I would be surprised if they were totally unrelated DOHC V8s.

http://www.lsxmag.com/news/cadillac-ct6 ... -vi-lt-v8/
http://www.lsxmag.com/news/lt7-cad-rend ... vi-engine/

I'll continue the engine discussion here even though the thread title is kind of wrong. We thought the 6th gen Z/28 was going to drive stuff but that's not really how GM works. Cadillacs and Corvettes tend to drive powertrain development. And I am glad the CT6 is getting a V8.

So the conjecture is 5.5L naturally aspirated and 4.2L twin turbo, both DOHC. The 4.2L may be the LT7. I'll have to look back in this thread and see what was the last guess on RPO/engine associations.

I think what is going to happen is GM will evolve a new line of smaller displacement DOHC V8s destined for premium applications and continue the pushrod architecture for trucks. From an "LS legacy" standpoint this is actually fine as they are all aluminum now anyway and other than the weird people who pay 10x for an actual "Corvette engine," you are almost always going to be better off with a truck donor for your project.

What will be key for the aftermarket is the LT5 which if I recall offers direct injection and port injection. That's what high power Gen V engines will require and GM provides that with the LT5. So either that fuel system will trickle down, or we can at least grab an LT5 injection system for use on some other gen 5-based turbo project.

This is all conjecture on my part.

I haven't heard any news about the Z/28. There has been news of a twin turbo 700+HP Mustang GT500 though. Wonder if the Z/28 will get one of these new engines.

Also wonder what the setup is. Is the 4.2 twin turbo and the 5.5 NA? Is the 5.5 supercharged? When are they going to give up some info???