Any Completed 4.0 Swaps Running Around?

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Nikkormat
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Any Completed 4.0 Swaps Running Around?

Post by Nikkormat »

I've worked up some pretty grand travel plans, and the major limiting factor is guzzolene. Stuffs expensive yo. And I'm pretty jealous of my buddy's 300k mile renix cherokee pulling down an honest 23 mpg in the mountains with a teenager behind the skinny pedal...

So are there any completed 4.0 swaps running around out there? I'd really like to get some real world mileage numbers from people who have actually done it. I'd also like to hear from people who have done it about what they've done to the rest of the drivetrain. I'm thinking overdrive and deep gearing would be the way to go. Ideally an AX15 and a 242. Far into the future an underdrive.

If I could get 16 mpg out of this swap vs the 12 I expect from the 401(and that's optimistic) that would save me about 100 gallons of gas on a 5000 mile trip. That's a pretty extreme example but if I'm driving 15k a year that's like $1000 bucks. Or a whole month of work for a bum like me. And then I can save the 401 for something more fun... Like a J Truck.

And yada yada yada LS swap blah. I can get a renix donor rig for $600 and then pass on the rest to a buddy in need. Worst case scenario rebuilding a 4.0 is cheap potatoes. All in I figure $1500 with new clutch, sensors, etc...

One of my biggest concerns is drivetrain length. I can't be much longer the stock waggy drivetrain to make it fit with the Aero fuel tank. Again I'd love for someone with a completed install to chime in there.
Gabe, "reformed" Jeep hoarder.

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Re: Any Completed 4.0 Swaps Running Around?

Post by Nikkormat »

Which begs the question... Why not just buy an XJ? I can't get 58 gallons of gas under one and I think a waggy is way more comfortable for a long trip. Plus if you were going to buy a house. A crappy little house. Would you rather have the 60's style midcentury modern or the mid 80's split level ranch?
Gabe, "reformed" Jeep hoarder.

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Re: Any Completed 4.0 Swaps Running Around?

Post by AwesomeJ10 »

Cause XJ's have no soul (frame).

Remember I got like 15mpg in the honcho going down to ouray.

Engine swaps will never provide an ROI unless you drive like a million miles.

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Re: Any Completed 4.0 Swaps Running Around?

Post by Nikkormat »

Yeah but I've got to replace the engine anyway. And like I said it'd save me like $1000 a year in has assuming I could get those mileage numbers.

And yeah the honcho is like magic, but it's also got overdrive. Rebuilding the 360 (or finishing the 401), getting the TBI set up properly, and swapping in an nv3550 or an ax15 would set me back more than the swap.
Gabe, "reformed" Jeep hoarder.
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tgreese
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Re: Any Completed 4.0 Swaps Running Around?

Post by tgreese »

Ask Anthony (Cecil14) on IFSJA - maybe he's here. http://www.ifsja.org/forums/vb/member.php?u=760
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
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tgreese
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Re: Any Completed 4.0 Swaps Running Around?

Post by tgreese »

You might ask on the JeepStrokers forum about running the Renix (Renault-Bendix) EFI outside the native chassis. I recall some have done the Megasuirt conversion to the Renix engine, using the Megasquirt brain and the Renix hardware.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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tgreese
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Re: Any Completed 4.0 Swaps Running Around?

Post by tgreese »

What year chassis would this be going in to?
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

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Re: Any Completed 4.0 Swaps Running Around?

Post by csuengr »

Jeep used to advertise 23 mpg with a Grand Wagoneer equipped with a 258 six and 2.73 gears, going 55 mph on level ground.

There have been people on hear that have done LS swaps with a 4 speed auto that can get in the low 20's. That there is probably the only way you will see anything close to 20 mpg in a FSJ. I don't see a 4.0 doing this.

You definitely would need the chin spoiler.
1977 Cherokee S, Ford 5.0, 5 speed, BW 1356, 33 x 10.50 BFG's. No longer my DD.
2007 Mercury Milan, 2.3L, 5-speed, now my DD. 29 mpg average.

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Re: Any Completed 4.0 Swaps Running Around?

Post by Nikkormat »

csuengr wrote:Jeep used to advertise 23 mpg with a Grand Wagoneer equipped with a 258 six and 2.73 gears, going 55 mph on level ground.

There have been people on hear that have done LS swaps with a 4 speed auto that can get in the low 20's. That there is probably the only way you will see anything close to 20 mpg in a FSJ. I don't see a 4.0 doing this.

You definitely would need the chin spoiler.
I'm only looking for sixteen or seventeen. The 23 mpg figure is what a buddy is getting in an xj.
Gabe, "reformed" Jeep hoarder.

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Re: Any Completed 4.0 Swaps Running Around?

Post by Nikkormat »

tgreese wrote:What year chassis would this be going in to?
1990, and the prospective donor is a 90.
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Stuka
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Re: Any Completed 4.0 Swaps Running Around?

Post by Stuka »

Before my J10 was lifted I easily got 17 on the HWY going 70. Going 55 I could see getting 8-19 with it. It had 2.73 gears, T176, 31" tires, and a Weber Carb with TFI ignition.

A 4.0HO has more power, but about the same economy. Swapping from a V8 to an i6 isn't simple (although it is simpler than going from i6 to V8). But not sure it would be worth it. Mileage would be better, but you have to drive a lot to make it worth while.
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Stuka
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Re: Any Completed 4.0 Swaps Running Around?

Post by Stuka »

Blake wrote:Cause XJ's have no soul (frame).

Remember I got like 15mpg in the honcho going down to ouray.

Engine swaps will never provide an ROI unless you drive like a million miles.
They have a frame, they just are not body on frame. Their uniframe is more rigid than the frames we have in our FSJ's. You need to box our frames to be equivalent.
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tgreese
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Re: Any Completed 4.0 Swaps Running Around?

Post by tgreese »

I would lean toward the modern SBC for a '90, since it already has a V8. The 4.0L is great for a FSJ that now has a 258. And with the SBC, you will not have a problem with fuel tank interference. I know that the B-W Quadratrac with a 258 cannot have the low range, because of gas tank interference. I suspect you could leave the transfer case location the same with the SBC, not with the 4.0L.

Do you have a donor with an AX15 lined up? Are they plentiful? I kinda think they are not.

If there is fuel tank interference with the 4.0L, there is plenty of experience with moving the fuel tank to the rear. Just something to consider.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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REDONE
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Re: Any Completed 4.0 Swaps Running Around?

Post by REDONE »

Nothing wrong with day dreaming Gabe, but putting a 4.0L in place of an AMC V-8 will gain you nothing except more gremlins. I know there are those who dissagree, but the ONLY engine swaps worth doing (outside of same-same) are to modern rollerized aluminum MPFI engines. Like Blake said, you need to drive a million miles to get the money of the swap back (not save a single penny, just to get yours BACK), and no engine can "reliably" guarantee you'll get a million miles out of it. With most of the junk I see you drive, the engine won't even be the limiting factor, their miles are numbered already from a thousand different angles. I know you love FSJs, but you don't love them for what they are. To get what you want (from your own expectations you share here) you need a different car, probably a ZJ or WJ, or Ram 1500. I know you've got "reasons" why none of these will work for you, but those "reasons" will probably make as much sense as your expectations for an FSJ. :P

Also, split levels are F***** awesome! Garden level basements are conforming to start with, and I don't have to worry about my toddler dying if she falls down the stairs because there's a landing in the middle of them. Most houses from the 60s have aluminum wiring and bad basement poors, too. ;)
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Re: Any Completed 4.0 Swaps Running Around?

Post by FSJ Guy »

I have to agree with most everyone else here, too. Get another (reliable) vehicle that gets better mileage for your roadtrip. Keep your FSJ's for 4 wheeling and running around town.

You and your wallet will be happier that way.
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Nikkormat
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Re: Any Completed 4.0 Swaps Running Around?

Post by Nikkormat »

I don't get this whole cost of the swap thing, the jeep needs an engine either way. Due to the work of some dirty SOB the 401 is still at least $1500 away from completion. Redneck rebuilding a spare 360 we have laying around back in CO would probably end up around the same price. If I can spend the same amount and get better gas milage (and unfortunately less power) I don't see what all the ruckus is about.
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Stuka
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Re: Any Completed 4.0 Swaps Running Around?

Post by Stuka »

Nikkormat wrote:I don't get this whole cost of the swap thing, the jeep needs an engine either way. Due to the work of some dirty SOB the 401 is still at least $1500 away from completion. Redneck rebuilding a spare 360 we have laying around back in CO would probably end up around the same price. If I can spend the same amount and get better gas milage (and unfortunately less power) I don't see what all the ruckus is about.
Well you figure int he cost of the engine, mounts, trans, t-case, both drive shafts, plus all the little nickel and dime stuff. It will be cheaper to put the same engine in.
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Cecil14
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Re: Any Completed 4.0 Swaps Running Around?

Post by Cecil14 »

I'm running a stroked 4.0L in my J-10. I didn't do it to get better mileage, I see around 14ish when I finally make it through a tank of fuel, which is rare anymore.

My truck already had a 258, so it really wasn't much of a swap engine-wise. All the mounts are the same externally on the earlier (at least pre-'96) blocks as are the bellhousings. I went with an NV3550 out of a 2000 TJ and I have a D300 behind that right now. My fuel tank is the 42 gal suburban tank where the spare tire normally goes.

Hardest part for me was the wiring, and even that really wasn't difficult. I'm running the ~'90-96 HO MPFI setup. I wouldn't touch a Renix setup with a 10 foot pole. Barely a step ahead of a carb and parts are far less available.

If you can get all the parts for free to reasonable cost, do it. I love the I6s. Mine takes a beating and runs great. Super simple and nowhere near the multitude of little problems the V8s have had over the years. Plus there's still a HUGE parts availability for the I6s, having been run into the early 2000s.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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Re: Any Completed 4.0 Swaps Running Around?

Post by REDONE »

Nikkormat wrote: I don't see what all the ruckus is about.
The ruckus is because you're too smart and have too much experience to do something as dumb as replacing an obsolete gas guzzling turd with an even WEAKER obsolete gas guzzling turd. You know the saying "round peg in a square hole?" It's like that, only instead of wooden pegs, you're using different shapes of turds. :mrgreen:

I don't like the "Slippery slope" logical fallacy, but it's real easy to see how this approach leads to your FSJ getting towed in the middle of a project when you're too broke to get it out of impound. You'll feel like a victim, but you'd only be a victim of your own decisions. Seriously, park that sucker and get a beater until you have the time and MONEY to screw around with it, college kid! You should be studying, not screwing around with Jeeps, anyways!
79 J-10 (Honcho Mucho) KE0LSU
304/Performance Fuel Injection TBI/MTA1/SP2P/Magnum rockers
T18/D20/D44s&4.10s/33" Mud Claws
Grizzly Locker Rear
4" front spring drop, 5" rear shackle flip
Chevy style HEI (ECM controlled)
Dolphin "Shark" gauges in a fancy homemade oak bezel
3/4 resto, rotting faster than I've been fixing it.
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Re: Any Completed 4.0 Swaps Running Around?

Post by fulsizjeep »

My 84 Eagle has a Renix 4.0 (90 XJ) with an NP229 and is good for 23 mpg in 2wd and 18 mpg in 4wd. I bought it that way and like the way it drives but not fond of the Renix. If I were to make the leap myself, I would have used a newer XJ 4.0 donor.
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