Mopar to release 4.7 liter straight 6 crate engine

Mopar will get racing and off-road enthusiasts buzzing with its enhanced
lineup of engines and components, which includes the industry's first aluminum
HEMI? engine blocks. Mopar will offer three aluminum versions based on the
popular 6.1-liter block, all of which are up to 98 pounds lighter than the
cast-iron production version found in the company's SRT8 products.

The first all-aluminum option is a 6.1-liter HEMI block--a direct replacement
for the factory production cast-iron 6.1-liter HEMI engine block. The second
option is prepped for a 426 cubic-inch (~6.9-liter) engine and the third
option is an engine-builder's special or "X Block," which has rough-machined
bores that allow for up to 468 cubic inches (~7.6-liter).

Beyond the new aluminum HEMI engine blocks, Mopar will continue to support the
traditional enthusiast with a broad range of HEMI crate engines including the
6.1-liter V-8, 5.7-liter V-8, 426 cubic-inch V-8, 472 cubic-inch V-8, 528
cubic-inch V-8, plus a new 572 cubic-inch V-8. With 650 horsepower and a
monstrous 660 lb.-ft. of torque, the 572 cubic-inch HEMI is the centerpiece of
Mopar's crate engine program. It continues the heritage of the 1960s HEMI
engines made popular in vehicles including the Plymouth Barracuda "HEMI
'Cuda", Plymouth Satellite and Dodge Charger.

Mopar will also introduce a new 4.7-liter I-6 Stroker long block, a powerful
upgrade for the 4.0-liter I-6 made famous in Jeep vehicles built from
1991-2006. Because off-road enthusiasts appreciated the dependability and
performance of the previous 4.0-liter engine, Mopar developed a more powerful
engine that delivers an expected 265 hp and 290 lb.-ft of torque. The engine
will fit in any Jeep vehicle previously equipped with the 4.0-liter I-6
For those who do not know the 4.0.

The original Jeep 4.0L inline-six was hewn from a solid block of granite by lightning bolts. Its cylinders were bored by the Imperial Winds and its rotating assembly was balanced by the Scales of Justice. The Ancient Egyptians used Jeep 4.0L engines to move the blocks which built the Pyramids, only switching to slave labor when it was found to be cheaper than the olive oil used to fuel the engines. Scientists have ranked the Jeep 4.0L engine as one of the strongest forces of nature, racking right up there with tectonic plate shifts for its low-end torque, and being surpassed by hurricanes only for its comparatively low redline. Mechanics have found imprints of fossilized dinosaur bones in block castings, and serial numbers in Roman numerals are a common sight. The design of the 4.0L's fuel injection system has been traced to the archives of Leonardo DaVinci, and early manuscripts of Shakespeare plays have been used as head gaskets for this engine (which, incidentally, explains the gaps in Shakespeare's collected works as well as the 4.0L's tendancy to leak oil). The engine's ancient roots also explain its ability to run on some very non-conventional fuels (original translations of the Rosetta Stone include evidence of Jeep 4.0L engines running on ox blood) as well as lubrications (during the Middle Ages, Jeep 4.0L crankcases were often filled with barley, with no detrimental effect on power output). Historians maintain that the fall of the Roman Empire hinged on their inability to design a superior engine, and had the Titanic been powered by a 4.0L Jeep engine, 1912 might have been a much happier year. Yes, had early-20th-century naval engineers had a touch more foresight, the Jeep 4.0L may have saved mankind from ever having to endure Leonardo DiCaprio and Celene Dion in the same sitting.
The only weakness in this otherwise unstoppable force of nature? Emissions. Yes, the engine's design may have come from the hand of Zeus, and its exhaust note at full throttle may have reverberated along the rock formations of Arizona to forge the Grand Canyon, but by the year 2007 its crude emissions control (originally consisting of papyrus strips soaked in the tears of the young Tutankhaman) had become outmoded, and the legendary, nay Biblical force of the Jeep 4.0L was put to rest.
I hope this new straight six enters their line-up.

Very cool. If only Ford had done anything performance wise with their 300 straight 6...that was an excellent engine.
Well Ford does have their Oz i6. And they did con the Australian government to bring it up to code emissions wise ...
Gotta love Jeep's trusty 4.0L sixer. Four cylinder power with eight cylinder fuel economy, all in a bullet-proof package that you just can't kill. Now Jeep gives us six cylinder power with eight cylinder economy. Oh yea, we're almost there now!


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What they don't say is that the 4.7l I6 makes 290lb.ft. of torque from cranking speed to redline ... which is probably a tick over 3000rpm. :p I'm glad to see them supporting the 4.0.
Please enlighten me as to a four cylinder automobile engine with 200ft-lbs of torque at what is essencially idle...
I'm pretty sure there are none, but that's a moot point anyway because I was being facetious. I used to own a Grand Cherokee with the sixer and I fugging loved that engine. It wasn't much of a highway cruiser but it had plenty of grunt for mudding, and it continued to run like a champ even though I was horrible with maintaining it.
The fact it could haul around a lump like the Grand is a real testament to how solid that motor was. Long live the 4.0!

Heck, both the 4.0 and 5.2 are stone-age designs, but damn near bulletproof.
My Dad's (and then sister's) 2000 Grand Cherokee had the 4.0L straight six. That was a great engine. Not the most powerful, but it did its job just fine lugging around the truck.

If I had gotten that truck instead of passing it to my sister (it was a "cooler" car than the 1990 Buick), I'd be saving up to drop a 4.7 in it!
Long live the AMC straight 6.

When my 4.0L eventually packs ups, I will definitely put a stroker in there. Then again, I probably have another half a million miles before it does.

Also, find me another engine, which I can run at idle in overdrive. There is so much torque at idle, I can shift 1-2-3-4-5 without touching the gas.
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Makes me miss my old F150 with the 300 straight six.

I've always liked the AMC straight six, my friend had a Cherokee with one, drove the wheels off and the engine always held up. I hope this rumor is true, the world need more torquey straight six engines.
I was thinking about this today. I really want Chrysler to do well; maybe it's an American thing to root for the underdog. Chrysler has been kicked around a lot thanks to Daimler (who needs to STFU about running Chrysler, by the way). I really want to be able to look back on this in 10 years and be able to say that this moment was the turning point for Chrysler, that when they announced these new engines and the return of the I6 that I just knew they would be ok.

GM can go fuck a goat for all I care. They got themselves into this mess and continue to find ways to dig the hole deeper and deeper. Chrysler at least has an excuse - if it weren't for Daimler's corporate raid Chrysler would have better quality, a cash reserve and a larger market share.
hmm, aluminum 6.1 sounds good too.

I must also vouch for the 4.0L, I was driving my dad's wrangler today and I found it awesome that I could accellerate no problem in 5th gear from 60kph onwards. turning over less than 1000rpm until about 85kph

might seem random but it reminds me of how much I want to drive a new Corvette...


New member
So I can buy an old cherokee for like a grand drop in this dream engine and a new tranny for what I hope would be under 7-8k and have about the coolest suv in the world!?