I just found this out, but GM's inline6 in the Trailblazer mix and match does have VVT. GM will make a I4 and I5 variation of that engine.

 

I wonder how big the displacment of the 4cyl version will be. I mean its a good engine in its 4.2l inline 6 form, but if it kept the same bore and stroke itll be a 2.8L 4cyl and i dont see that happening.

 

GM does a lot of concept crap and get a lot of attention, but I seriously doubt we'll be seeing this in production anytime soon, if ever. Sorry, but their announcements and publicity carries no weight with me; I'll beleive it when I see it.

And if they do end up actually producing those engines, I feel sorry for whoever has to work on them. That belt setup looks like a PITA. And I don't even want to imagine how much you have to disassemble to change the spark plugs. Of course, being a GM engine, they could just put platinums in there and they'll out live the engine. :rofl:

 

The 1989 Caddillac Allante had variable valve timing. PITA belt setup? you've obviously never changed belts on a GM vehicle. It's beyond easy. Why would'nt you believe the motors are on the way? GM's already got plenty of effecient OHV engines, hell the Z06 iss classified as a low emissions vehicle

 

The 1989 Allante had a 273 cid motor. The same engine that was in every other Caddy at the time. They switched to Northstar on the Allante in 1991, and brought it out on the rest of the Caddys in 1992. Neither the old 4.5 liter, nor the Northstar engine ever had variable valve timming. Even to this day, not a single Caddy has had VVT.

 

Yeah the brand new Z06's engine is also when GM discovered that D shaped ports flow better.

 

D shaped exhaust ports had been used on Chevrolet big blocks as far back as the 60's.

 

The Porsche 944 S2 and 968 had a 3.0-liter inline four. Of course the cylinder dimensions were grossly oversquare in comparison to the GM inline six but that displacement in an inline four is most assuredly possible.

 

Of course its possible, but will it be sensible? For the S-10 replacement truck sure, I'm sure itll have gobs of low end torque for a 4cyl. But I do hope they wont shove it in cars. I jsut cant see a 2.8L 4 cyl Malibu.