Why isn't there a GM small block V6?

"Carbon Fiber Sasquatch" (turbopumpkin)
10/21/2016 at 19:07 • Filed to: None

GM is known for its small packaged, high displacement V8. Why has it never made a 4.7L V6 version for anything? The current GM V6 almost takes up as much room as the small block and weighs similar too. Seems like a great way to make an amazing V6.

On a similar vein, I’m surprised they’ve never done a 9.0L V12 either

DISCUSSION (26)

CRider > Carbon Fiber Sasquatch
10/21/2016 at 19:15

Who cares? Just buy the V8.

Carbon Fiber Sasquatch > CRider
10/21/2016 at 19:16

Insightful

Sweet Trav > Carbon Fiber Sasquatch
10/21/2016 at 19:17

You’re kidding right?

https://en.wikipedia.org/wiki/General_Motors_90%C2%B0_V6_engine

It has literally been in production since 1978. It continues at the base engine in the GM 1500 pickups

Kinja'd!!!

bob and john > Sweet Trav
10/21/2016 at 19:18

why isnt THAT used instead of the current V6 in the camaro? One the trucks get it.

Dusty Ventures > Sweet Trav
10/21/2016 at 19:19

I was hoping one of you would see this

Birddog > Carbon Fiber Sasquatch
10/21/2016 at 19:20

A 60 degree V6 is better (more naturally?) balanced than a 90 degree.

GM built millions of the 4.3 V6 (350 minus 2 cylinders) but it was a shaky beast.

Sweet Trav > bob and john
10/21/2016 at 19:21

Because comparatively, it’s a turd to the HF V6. The 4.3l makes less power, only a little more torque and revs like a truck engine. Not to mention fuel economy and packaging.

yamahog > Dusty Ventures
10/21/2016 at 19:22

Hell, when I read off the title he paused Madden to go answer it from the desktop :P

Jordan and the Slowrunner, Boomer Intensifies > bob and john
10/21/2016 at 19:23

I understand why it isn’t in the Camaro, as it’s kind of really dull to drive, but why it isn’t in the Colorado is a good question.

Dusty Ventures > yamahog
10/21/2016 at 19:34

Kinja'd!!!

bob and john > Sweet Trav
10/21/2016 at 19:41

well, wouldnt changing the cam and the accessories and tuning for HP do sort of the same thing that was the difference between the Vette and the truck motors?

gmctavish needs more space > Carbon Fiber Sasquatch
10/21/2016 at 19:44

They did make a V12, but it was essentially two of the old 60 degree V6s stuck together

https://en.m.wikipedia.org/wiki/GMC_V6_engine

Jordan and the Slowrunner, Boomer Intensifies > bob and john
10/21/2016 at 19:45

They just aren’t built to rev. That’s pretty much the only way to kill a 4.3. It hates to rev. A high strung small displacement V6 makes a lot more sense in this application.

LongbowMkII > bob and john
10/21/2016 at 19:48

That’s a lot of development costs for a compromised engine.

Frank Grimes > Sweet Trav
10/21/2016 at 19:49

How does he not know about these? The 4.3 was in nearly everything ever made and produced from 1985 until 2014.

bob and john > LongbowMkII
10/21/2016 at 19:50

basicly take the cam and crap from a LS and throw it in. V6 LS.

LongbowMkII > bob and john
10/21/2016 at 20:33

Aluminum block, high comp pistons, re balanced crank, testing, testing and more testing. Soon you’re talking real money for a motor that will have far too much NVH for a passenger car to sell.

bob and john > LongbowMkII
10/21/2016 at 20:44

And that is cheaper then building an entire new motor?

LongbowMkII > bob and john
10/21/2016 at 20:53

This new motor was better able to hit targets to be used throughout GM’s range. Could you imagine the shit GM would get for putting a glorified 2001 Blazer motor into every cadilliac.

You can tell a Finn but you can't tell him much > Carbon Fiber Sasquatch
10/21/2016 at 21:39

It’s been done as I’m sure you’ve seen the thread about the 4.3L. Turning a V8 into a V6 by lopping off cylinders doesn’t work very well. There are serious issues with balancing a 90° V6 that aren’t easy to work around. You end up with things like the split pin crank in the 4.3 that causes serious problems when trying to make the engine rev.

jdrgoat - Ponticrack? > Carbon Fiber Sasquatch
10/21/2016 at 22:01

As was already mentioned, there’s the 4.3L V6, which is a 350 with two cylinders chopped off. That lasted through a lot of changes and updates, and there was Gen I and Gen II SBC-related versions.

The new 4.3L (in the new full-size trucks) is actually not related to the old 4.3L at all, and it’s a Gen V engine. It shares the displacement with the old engines, but not with the bore or stroke. It has the same bore as an LS1/LS6, which are Gen III and the only SBC engines that had that bore. Well, and the LT5... believe it or not. Funny that it came back for the new 4.3L V6 (lets them use the Gen III/IV/V stroke).

This is not the only Chevrolet V6 engine family, though. The 60° V6 was actually designed from the start to be a V6. The engine is a naturally even-fire V6 due to that bank angle. It came in many flavors through the years, starting in 1980 with a displacement of 2.8L. There were, I think, three generations of this family. Eventually they got aluminum heads. And there was a DOHC version (on an engine never designed for it), and there was a turbo version. And they even put VVT on it, pushrods and all. It came in 2.8, 3.1, 3.4, 3.5 (two flavors), and 3.9L versions. Oh, and guess what, the 3.9L and one of the 3.5L had that same LS1 bore, too.

Now, I think it would have been great if they had continued even further with the pushrod 60° V6. Give it the tech that they’ve been putting into the pushrod V8s. Make it all aluminum with a composite intake. It’s wonderfully compact, and being all aluminum it should be the lightest engine in its class. And fit in seriously anything.

jdrgoat - Ponticrack? > Sweet Trav
10/21/2016 at 22:05

I would have to guess that the LV3 should package better than the LGX. It’s 90°, sure, but it doesn’t have those huge DOHC heads.

What I want to know is, why isn’t the LV3 in the Colorado/Canyon? It’s a better truck engine than the LGX.

bhtooefr > LongbowMkII
10/22/2016 at 05:50

To be fair, the 2014+ Silverado’s 4.3 V6 is unrelated to the old one.

It’s got an aluminum block, it’s got highish (not as high as the 6.2) comp pistons, it’s got direct injection - all of this is standard parts of being a Gen 5 small block. It’s actually bigger bore than the 5.3, although not as big bore as the 6.2.

DipodomysDeserti > gmctavish needs more space
10/22/2016 at 09:31

My ‘66 GMC originally had the 305 V6. I kinda want to find a V12 and droo it in.

Sweet Trav > jdrgoat - Ponticrack?
10/23/2016 at 08:26

And the 2.0l LTG Turbo 4 is better than both. 260 ft lbs at 1700 rpm.

jdrgoat - Ponticrack? > Sweet Trav
10/23/2016 at 23:04

Kinja'd!!!

~260 ft*lb @ 2000rpm, LTG 2.0L turbo.

Kinja'd!!!

~260 ft*lb @ 2000rpm, LV3 4.3L

Looks like they’re both equal at 2000. But then the LTG is tuned to flatten out, whereas the LV3 isn’t as technically advanced, and has a more traditional torque curve that peaks a little under 4000. I stand by saying the LV3 is the greater truck option. Lack of turbo means that the torque curve follows the throttle a heck of a lot more closely and quickly