Just wondering if the 4.0 had a 4 valve head could it have been a cleaner engine .

 

Until you provide evidence, it's conjecture

 

A 4 valve head wouldn't have helped it with emissions at all.A short stroke big bore is the only way to pass emissions now anymore.The stroke of the inline 6 is the reason it was hard on emissions.I don't know any other inline 6s in America that made it longer then the xjs.Ford canned the 300 in 97 with the f150s body change,Gm canned theirs in the 80s as well.

 

Interesting. I only say that because the GMC Envoy and Chevy Trailblazer both came standard with a 4.2L I6 through 2009. Weird. Aren't they part of GM?

This thread is so full of misinformation, LOL.

 

[QUOTE="F1Addict;2222642"]

Interesting. I only say that because the GMC Envoy and Chevy Trailblazer both came standard with a 4.2L I6 through 2009. Weird. Aren't they part of GM?

This thread is so full of misinformation, LOL.[/QUOTE/]


Well everyone doesnt know everything... Ppl are posting to the best of their ability... Sorry we all don't know everything... Those that do have answers or corrections just post them.

 

I apologize, I didn't mean to sound like a know-it-all (and a smarta$$) towards andrewmp6 (sorry, andrew).

 

Incorrect... the HO was slightly updated by chrysler, but it was still a variation of the same AMC motor. The renix and the HO are not different motors, just the same motor at different stages of it's evolution. Chrysler dropped it because it simple was not their motor. Yes they bought the tooling from amc, yes they made some changes, but it was still the old amc motor. Why did you think two different companies made motors you could swap parts on? You can put an HO head on a renix block, or run an HO motor with a renix ECM and harness (With minor modifications of course)

 

Yep, dunno why they label it an L6 but it's an inline 6 dual overhead cam in those.

 

There are such things as short stroke inline 6's. A few of which have been named in this thread. We are not trying to turn 10,000 RPMS with no crawling power here... That's why we need the longer stroke. As a matter of fact, When you build a stroker motor, weather it's based on this AMC block or a small block chevy... you are adding more stroke becasue more stroke = more torque!

 

thank you Captain Obvious.

 

I wouldn't get caught dead with that HO crap anyways. I got an IH motor with more torque than Chrysler anyways. And yes they did retool but still different motors.

 

Dude, it's the same base! Hell, you can still put an old 4.2 crank in them! I agree though, they were better before chrysler started putting their finger in the mix. chrysler = junk

 

All they did was destroke the 4.2L your right. There for 4 years I ran a 4.2L w/ a 4.0L head n injection unit. The only things the 4.0L had on the 4.2L (aside from injection) was a higher flowing head and higher revs. (You and I both know high revs are unnecessary, you want low end torque)

 

GMs 4.2L was designed from the outset to meet current and upcoming emmisions/ fuel economy standards; a brand new motor. The 4.0L was not. The 4.0L bas based on an old design and would not of been cost effective to retool to make the 4.0L meet the upcoming EPA rules. Its just that simple. Long stroke, big bore, poor head and intake design, poor EFI system..OLD TECH lead to the 4.0L demise, not solely packaging. And to compare the GM 4.2 to the ChryCo 4.0L is comparing apples to oranges. Sorry if someone feels this is "full of misinformation" but it is what it is.

 

I dont think either of them was referring to the GM 4.2, the AMC 4.2 inline six was designed and built by AMC.. Not GM.

Also, the AMC is a 258, while the GM is a 256 IIRC