A yet-to-be-revealed engine that’s kept the rumor mill in Mopar circles churning continues to make its possible presence known. It’s an engine supposedly tapped for a new line of Fiat Chrysler products, and might find a home in existing vehicles, too.
It’s an engine that comes to the table with (arguably) the sexiest cylinder layout on the market: six of ’em, all in a row.
We’ve discussed the existence of this engine development program before, but a not-too-recent patent uncovered by MoparInsiders sheds a bit of new light. The FCA patent isn’t for an engine; rather, it’s for an exhaust gas recirculation (EGR) system that’s mated to one. However, the engine this EGR system is shown with happens to be an inline six of the turbocharged variety. That’s the same engine type that’s kept the rumor mill alive.
Sources tell the publication that the engine, of unknown displacement(s), will offer somewhere between 360 and 525 horsepower — perfect for lugging around large vehicles with authority. Large, rear-biased vehicles. Should it arrive, its output and layout would make it an obvious choice for the Ram 1500 and a number of rear-biased SUVs, among them the upcoming Jeep Wagoneer and Grand Wagoneer. With FCA paying big bucks to offset its man-sized fuel economy footprint, a turbo six could offer meaningful MPG improvements to several popular large models.
The rumored engine is expected to utilize FCA’s upcoming E-Booster; essentially, an electrically operated turbocharger that builds up boost right from idle, eliminating turbo lag. Mild electrification is already spreading through the FCA stable via the company’s eTorque engines.
While it’s too early to declare the Pentastar V6 and Hemi V8 endangered, the patent is another hint that their presence could soon become less dominant among full-size FCA vehicles.
[Image: Fiat Chrysler]
Hopefully it’ll be angled 30° from the vertical.
Leaning Tower of Power v2
The new engine family could then be called LToP II.
I have fond memories of rebuilding a 225 slant 6 in the garage.
It was almost impossible to kill.
The 170 wasn’t worth rebuilding.
What was wrong with the 170? It was the 170 Hyper-Pak that killed off compact stock car racing through its dominance of Ford and GM. 198s weren’t all that exciting though.
I had a slant six that broke and oil ring and smoked horribly so I stopped putting oil in it.
I went a full month with no oil before it finally told me the end was near but it still got me home that day.
Mine actually had broken oil rings seized from carbon buildup, I’m sure the oil was changed once a year whether it needed it or not. Had the infamous whining gear reduction starter motor that required the periodic rap with a hammer handle to get it to hook up.
If even FCA is caving, the naturally aspirated V8 really is critically endangered.
This is what saddens me as well.
I wouldn’t even be that upset if the V8 lived but put out smaller power. Its the layout that I love.
Don’t get me wrong, the I6 is great, but V8s there is just nothing like the feel and sound that an I6, even turbo, can’t touch.
But with you needing every last drop of MPG, 6 cylinders of same power is going to win EVERY TIME vs the V8 of similar size and displacement.
Going the way of the manual transmission. Its pretty sad to watch everyone zeroing-in on the same target (automatics, 2.0L turbo I4/3.0L turbo I6, sedans with no headroom, everything the same shape).
Boring stuff.
The 2.0T stuff is Chinese displacement regs, and everything else is the pedestrian crash regs and CAFE crap.
No, it’s that ~500cc per cylinder is about the “sweet spot” for efficiency.
And emissions
Still makes me wish that the Atlas I-6 had been offered as the base engine for Silverados when it was in production.
At least an I-6 has a distinctive sound and smoothness. After getting familiar with one most enthusiasts could guess they are dealing with an I-6 without even opening the hood.
I came here to post the same thing. I was really hoping that Atlas found its way into a truck. Love those straight sixes.
Back in the day many Jeeps had the AMC 4.0 L (242 cu in) I6. It was a very good engine. Just copy that FCA
@lie2me
“It was a very good engine.”
–for its (long ago) era. No way could that mill be made to return acceptable emissions or fuel efficiency.
The 4.2 was a good engine, worked well in the Jeep Cherokee. I had a chance to drive one–a manual no less–several times. It worked well!
I’ve wondered why no one has yet pursued the idea of an electrically powered “charger” (Vs exhaust driven turbo or belt driven supercharger). I figured there was some good reason no to do it.
Now that FCA is doing it, we will find out in short order why the Japanese and Germans didn’t do it.
I do like the straight six though. And I agree, I thought GM’s Atlas gasoline engine was a good motor, on paper at least. And pretty rugged–a friend of mine has 190k on a GMC Envoy with the original engine
I’ve thought that restomodding an AMC with a straight six and replacing the engine with the Jeep 4.2 Fuel Injected version would be cool. Lot’s more power and torque but still keeping it “in the family” so to speak.
I recall seeing a couple of AMC Eagles where the owner did just that.
The old AMC 258ci (4.2L) was kin to the smaller 232ci (3.8L) engine. Those two engines did not have cross flow cylinder heads and were of course carbureted. When Chrysler redesigned the engine it became 4.0L and received a cross flow head.
The 4.0 does NOT have a crossflow head. Intake/exhaust are on the same side, just like the 258.
Mopar guy is right. Crossflow means the intake and exhaust manifolds are on opposite sides of the cylinder head. The 4.0 has both manifolds on the driver side (North America version)
https://www.allpar.com/mopar/40DOThtml
(insert a period instead of the DOT)
Btw, the 4.0K debuted in ‘87 right after the Chrysler buyout took place. The bulk if not all of the development of the 4.0 would have happened under AMC.
The GM Atlas engine supposedly was developed off the old I-6 block that was nearly as venerable as the AMC 258. That actually did get a crossflow head, and I think it even got a 24v, DOHC upgrade. Someone who knows those better than I do can clarify.
My point being that the end of the line Jeep I-6 would be a cool way to update an old AMC instead of just slapping a SBC in it like every other idiot with a checkbook.
P-Dan: you’re not wrong on that, and it gets done all the time, particularly to the Eagles. Its a relatively easy swap, and the 4.0 can be built into a pretty gnarly beast. Plenty of upgrades for these, including turnkey strokers.
“The GM Atlas engine supposedly was developed off the old I-6 block that was nearly as venerable as the AMC 258.”
The Atlas was developed off the GM Quad 4. You can see the GM donated development prototypes in the Oldsmobile museum in Lansing.
” No way could that mill be made to return acceptable emissions or fuel efficiency.”
Yeah, I figured, I meant more durability wise
I’d be surprised if there was any commonality between the Atlas block and the previous generation six.
Lost foam aluminum casting with deep skirting vs sand cast iron and splitline at bearing caps.
Oil pump concentric with crankshaft vs bolt on in pan.
No camshaft (DOHC) vs cam in block.
All accessories direct bolt to block vs brackets.
This. It was stout but a wheezer. Despite all the wailing and gnashing of teeth from the Jeep crowd over the 2007 Wrangler’s “minivan motor,” the 3.8 V6 had more power and torque than the 4.0 it replaced.
Still vaporware. The new Ram and 2 Jeeps just debuted without it, which means they’ll have to spend millions re-certifying the 3 of them to use it. One of them said it’ll be in the new grand cherokee, but that isn’t likely as by now if it was being built, even in pre-production capacity you’d know about it. The new GC will have the turbo 4cyl as the base engine with the single exhaust.
What’s old is new again. Never thought I would see the return of the I-6 with the exception of BMW which already has one. Future is looking up not all turbo 4s.
It’s all very ironic. Way back when, the I6 was the cheapskate motor, if you had any self respect you got a V8 in your Detroit iron. Now the I6 is becoming fashionable again.
“rumor mill…” I see what you did there.
A decade plus ago, the story on inline 6s was that they made for a bad frontal crash design (obviously the engine doesn’t compress). The V6 has a lot more crush zone distance.
Sounds like the crash guys have some new ideas.
That was BS from when Mercedes-Benz jumped the shark and replaced their inline-6s with awful 90-degree V6s that they could make on the same transfer lines as their increasingly-popular V8s. Now, V8s are under threat and they’re going to inline-6s that can share architecture and tooling with inline-4s.
This is my understanding as well.
BMW has explained it in the last few years.
1 cylinder = approx 0.5L displacement.
Line them up as necessary and turbocharge as necessary.
With V8s on the way out, the turbo I6 is becoming the top end engine. Makes more sense to make them share design with I4s instead of V8s.
I still don’t like it.
Wonderful news. I think if I hear about another 2.0L turbo four I’m going to puke.
I was expecting a 2.7 2 cylinder superturbo so FCA could join the 2.7 engines in full size trucks while following GM’s lead of lopping off 2 cylinders for reasons.
sarc
I want to know why no one has done a 2.0T I6. Today’s 2.0T engines are making plenty of power for everything but the biggest vehicles. Would it really be that much less efficient to have six cylinders than four?
Yes. For a given total displacement, fewer cylinders are more efficient. Fewer cylinders= lower ratio of cylinder surface area to volume, which means less heat lost to the cooling system.
Fewer cylinders also mean lower friction, not to mention weight due to the longer block and head.
There was the Mazda K engine. Remember when Mazda made a 1.8L V6? I don’t recall it getting much positive publicity though. My friend bought one (MX-3). Looked at me like I had two heads when I asked why he didn’t get the V6 option. I think the paper specs with the 4cyl were similar?
This is great news. I hope that FCA can keep the I6 fairly simple. I have owned many old Cadillacs with V8’s, but the best was an ’80 DeVille with a 368 (6.0L, before the 8-6-4 debacle). The 4100 and Olds 307 were pretty much junk in the Brougham body. Driving an ’86 short-wheelbase Dodge cargo van in the early ’90’s turned me on to the straight (slant) six layout. That van was a four speed manual, but was really a delight to drive. Three years ago, when replacing an old Blazer, I searched for a 2WD GMT360 (TrailBlazer, Envoy, etc), and came across a nice ’06 Envoy with 145k at a good price. The Atlas I6 is a wonderful motor, and I’m now just a bit over 200k with it. I’ve done a few routine things like replace the water pump and thermostat, belt tensioner, etc, but the thing is marvelously smooth and quiet, even though I need to install the new motor mounts sitting in my shop. That’s next, as I recently put new control arms, ball joints, and tie rod ends on the wagon, as well as all new brakes and calipers. I tow a couple of smaller travel trailers frequently, and the Envoy is just about perfect for the application. I’m a bit different from most gearheads…to me, the best-sounding engine is one that you cannot hear at all. A smooth and quiet ride for me and anyone I am driving is paramount, and even in that old Dodge van, the I6 layout was a winner. I recently came across an article with good details of the Atlas (link below). Long live the I6!
https://www.topspeed.com/cars/car-news/the-forgotten-inline-engine-gm-s-42-liter-atlas-i-6-ar174949.html
I might add that in the mid-1980’s, driving a ’78 Chevy pickup with a 250 I6 and three-on-the-tree was also a revelation. So easy-going, and so easy to drive.
Makes sense for Ram…they already design their engine compartments around the Cummins 6 and the Wrangler/Gladiator isn’t shared and so it can be designed for anything.
Given the trend of 4cyl everything having an engine that can share some engineering seems to make sense. I know at one point Pentastar was going to be a family of engines, but I guess a combination of economics and emissions killed that plan.