JKlad

Was just wondering if anyone here has any knowledge about doing a 4.7 V8 conversion on the JK. I work with a guy who's teenage son rolled his Cherokee DUI (so, no insurance payout) wrecking every panel & totalling it. Engine & most of drivetrain are fine though & he's offered the motor to me for free if I want it.

I know everyone will say "if you're pulling the V6 out then you gotta go a Hemi" but if you're after a fair bit more power and driveability for your 2-door without going all the way to create a 40" wheeled Hemi monster (and have to replace most of the drivetrain along the way to cope with the Hemi's power & torque) then maybe the 4.7 would make more sense. I'm guessing it depends on whether anyone does the conversion kits though.

Scooter_Trash

I've got a 4.7 V8 Dakota and I love that motor. i can't tell you how many times I wish I had it in my Jeep. I can't tell you anything about the swap, other than I think it would work great in the Jeep. Perfect amount of power, weight, torque IMO. The Hemi swaps are just too much. I don't need that kind of power on the trail.

Doc_D

I'm guesing that would be a tough swap. Without a kit like AEV's for the Hemi, you'd have to fab up motor mounts, trans mounts, etc. The biggest hurdle would be the ECU. AEV worked closely with Chrylser I believe to create an ECU that would work with the Hemi but still have all the other JK stuff work (dash, brake lock differentials, anti lock brakes, traction control, power windows, cruise control, head lights,etc, etc). Believe it or not, I wouldn't be surprised to find out the windshield wiper switch wasn't just an input to the computer and no longer an actua direct circuit to control the wipers.

If you are serious about persuing it I'd give AEV a call and get their thoughts on it. Maybe they did some ECU work for the 4.7 but just haven't released it.

JKlad

Thanks for the input guys! Yeah, I figured the ECU would be the problem here. I had a few rides in my colleague's Grand before his son decided to put it on its roof & the V8 seemed supurb. Smooth, plenty of grunt when you hit the gas it & it seemed to like to rev without much fuss (I guess it's modern design with the overhead camshafts helps here). I find the 3.8 V6's power acceptable considering its primitive design (pushrods, 2 valves per cylinder, no balancing shafts, lack of variable valve timing, direct injection or other goodies) but as we all know its unbalanced design makes it really rough & coarse when you rev it, and unfortunately that's where the 3.8 makes all its power (at 3000RPM plus).

I'm a big fan of small capacity, well designed V8s; I also have an '83 Mercedes 380SE with the all alloy, multipoint-injected, twin overhead cam HO 3.8L V8 and though it is pushing on 30 years old (and its design dates back to the early 70's) it is to this day probably one of the finest motors I've ever experienced; turbine smooth, grunty and the thing redlines at 6800RPM & has no trouble getting there! (and sounds awesome at WOT).

From what I experienced the 4.7 just seemed a much better match for a JK (particularly an un-modded 2-door) than the overkill of a fire-breathing Hemi. I think I'll take the V8 off my friends hands & store it in my shed for the future & do some more research in the meantime. I'll keep everyone posted on what I find out.

JKAdam

I traded in a 4.7 dakota for my jeep, I'd LOVE to have that motor in my jeep.

rubydak

I have a 2000 Dakota with the 4.7L and I love that engine. Runs great and has tons of power. Plenty for the JK. I like the idea that this swap would let us keep the stock runing gea runder the JK. I doubt I will ever do the Hemi swap, but if a kit for the 4.7L was avaiable, I consider that. Also, I'll bet there are lots of these motors avaiable.

That being said: From JP magaizine "10 Dumbest Jeep Engine Swaps . . .

Chrysler/Jeep 4.7L V-8
The candidate: The Chrysler 4.7L overhead cam first saw Jeep duty in the '99 Grand Cherokee and wormed its way into the Dodge Dakota and fullsize Ram platforms as well.

The perception: For under $3,000, I can pick up a thrashed Grand Cherokee with the 4.7L and five-speed auto tranny and put it in my trail Jeep.

The reality: Have you ever looked under the hood of a 4.7L-powered Grand Cherokee? Besides looking like a nightmare to extricate, the WJ's overhead cam 4.7L is super-wide, very complex, and only puts out around 235-265hp. And again, there's very little in the way of aftermarket harness and ECU support to make the swap easy.

The exception: We really can't think of any.

azrwilkinson

Try to contact AEV and see what it would take. You never know there kit may work for that motor as well, or they might see a demand for this and create something for it. Good luck!

RA070424

I have heard that the Hemi and the 3.7L/3.8L are much closer in nature to the HEMI than the 4.7L. That being said, the horsepower advantage is not so much to look at but the torque is where it really shines. I'd love to have it as well.

Be prepared to install all new gauges and contact B&G Chrysler for a ECU tune.

Erockhopper

I had a 00 Grand with the 4.7 and now have an 05 with the 5.7. I like both engines, but I really loved that 4.7, I wish they would have dropes the 4.7 engine into the JK from the start.

I think what JP magazine is saying is the cost vs benifits just dont make it worth it, if your gonna drop that much into an engine swap, you might as well go with the Hemi. That does not take into account all the area's that need to be addressed to make sure you dont break anything with all that Hp and torque.

My exception, someone who wants alittle more grunt without replacing everything under the jeep to handle it.

I hope someone would address this, as it seems to be a less expensive alternative, especially with the amount of donor engines available, not to mention the free one!

fauxsuper

[QUOTE=no balancing shafts, lack of variable valve timing, direct injection or other goodies) but as we all know its unbalanced design makes it really rough & coarse when you rev it, and unfortunately that's where the 3.8 makes all its power (at 3000RPM plus).
QUOTE]

The 3.8 may be a primitive motor with pushrods, fixed valve timing and an iron block, but 60 degree V6's are not usually fitted with balance shafts for the reason that, unlike 90 degree V6's, they don't need them.

I'm not sure anyone makes a 60 degree V6 with a balance shaft.