Robert91RS

iTrader: (2)

After scrapping there OHC V8 platform, investing billions of dollars in the Gen5 DI OHV motors, and converting everything else over to the 60* DOHC V6 motors I will be surprised if they really invest any money in a new OHV V6 design that may only see use in one or two vehicle lines(fullsize & midsize pickups). Fun to ponder though for sure.

Fun Fact: the truck version of the CTSV/ZL1 supercharged 6.2 was supposedly scrapped too, but if I do an RPO search in my GM catalog for "LST"(the rumored designation for the engine) it brings up-Aluminum 6.2 supercharged. Is it really dead or just on hold for the GMT900 redesign? We shall see.....

Interesting. I wonder if that is good or bad from an emission and effeciency stand point.

Bama2door

"Fun Fact: the truck version of the CTSV/ZL1 supercharged 6.2 was supposedly scrapped too, but if I do an RPO search in my GM catalog for "LST"(the rumored designation for the engine) it brings up-Aluminum 6.2 supercharged. Is it really dead or just on hold for the GMT900 redesign? We shall see....."


^ that would be pretty badass to see!

Whitecrewcab

iTrader: (2)

With direct injection, the no plug design might work and theoretically would give better mileage and hydrocarbon and NOx emissions. The higher the compression, the more energy you get from the fuel you burn. The only drawback I see is carbon monoxides will go up from the increase in cylinder temps, but modern cats should have no problem scrubbing that out.

1FastBrick

iTrader: (17)

Ford/ Mazda already havve something similar check out the SKYACTIV-G Engine With 14:1 compresion...

http://www.mazda.com/mazdaspirit/sky...kyactiv-g.html

they also have a clean diesel varient

offroadrider12

What GM needs to do is use the 4.2L I6 from the trailblazer, slap on a turbo, and there you have the GM solution to the Ecoboost engine. These engines sound awesome with a turbo. I would prefer an I6 over a v6 anyway for the torque advantage.

51 GMC Stock vortec 4200 turbocharged 1 - YouTube

CC05

iTrader: (2)

I couldn't help but laugh when the 4.3 was stood up for, when claimed "weak". We owned a 4.3 Blazer, and its reliability was definitely no issue. Parts were cheap when something did go wrong and all, but the power was honestly a joke. I can't begin to elaborate on how many 4.3 rcsb S-10's I outran with my Colorado, when it had the 2.8 in it...with 20's...with a 200 lb. system...only tuned.

hog

The I-6 4.2 is a gutless pig under 4000rpm, it does have a nice pull over 5300rpm though. For a part throttle cruiser, the 4.3 is all over the 4.2. If you do a lot of WOT driving over 4000rpm, the 4.2 is the clear winner.

The 4.2 I drive is rated at 291hp@6000rpm/277 lb/ft@4800rpm, the 4.3 was 195hp@4600rpm/260lb/ft@2800rpm.

The only torque advantage the 4.2 I-6 has over the 4.3 V6 is over 3000rpm. I am forever holding 1st and 2nd gear in my 4.2 equipped Trailblazer, I cant imagine what it owuld be like with a trailer, blahh. Some 4.10's/4.30;s with a even higher stall TC would make it more fun. The 4.2 makes great power from 5300-6300rpm though.

peace
Hog

offroadrider12

so it's kinda like a Gen I vs Gen III thing lol. Isn't a lot of the gutless feel of the 4.2 from the tuning? I think the DOHC 4.2L I6 should have lots of potential.

MikeGyver

iTrader: (5)

They should bring back the 250 inline six. I haven't driven anything with the 4.2 I-6, but I liked the 250 much more than the 4.3 V6. The 4.3 always felt and sounded to me like a V8 with a plug wire disconnected. The 250 I-6 was turbine smooth, and sounded like a six should.
A 250 I-6 with a modern, LS inspired, cylinder head design would be great.

ls six

I can tell you as a Mazda fanatic that it is definitely not ford/mazda anymore. Skyactiv was developed by mazda largely to replace the duratec/MZR engine that has fomoco stampings all over it.

When ford dropped Mazda they left them in something of a bind because the ford-volvo-mazda developed platforms under the fusion/mazda6 and focus/mazda3 will not be made available to mazda soon and the same goes for the MZR engine that is technicaly ford propriatary even though it contains lots of Mazda developement.

In the next few years though you will see lots of changes from mazda from this situation and imo they will be good. Lighter weight platforms and more refined drivetrains with better suspensions from not needing to platform share with high volume fords and big heavy volvos.






But back on subject has anyone mentioned yet that the gen III and newer V8s are stemmed from an aborted V6 developement program designed specificaly to replace the 4.3?

It was called the Venture engine and when the GM brass decided against moving forward with a DOHC motor for the C5 (and likely high spec F bodies) the developements in the venture program were the perfect opportunty to revive the pushrod engine in a big way.


From the erly 90s it was pretty much assumed that DOHC was the only way in a modern engine to get much more than 300 CHP in a modest displacement.

The LT5 was the product of that idea and it was specificaly designed with the idea that it could be built as a pushrod motor for low spec vehicles and as a DOHC motor for the vette and other performance variants.