AMW 392 (6.4) installation and experience

[ltdodge]

Congrats first off. Super interested in your outcome. I've been inbetween the new 5.7 and 392 myself. Looking to take the plunge this year and just get it done! I'm torn between the extra output of the 505 package but also don't need to destroy driveline with extra torque/hp as I'm on 40's already with 5:13's and the stock Dana's. I did upgrade axles/cv shafts but don't want to jump to 1 ton's. However I love performance lol. Definitely keep up posted with your experience.

i was torn on a cheaper 5.7 or 6.4. im glad i opted for the 6.4. i think i would have kicked myself if i went the 5.7 route and its not that much more expensive.

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[JTdiRtyD]

Mine won't be for a few years but even the wife's on board when it's passed 100k miles that it is cheaper than buying a new truck. Of course I'll probably go 392 so it'll be $40k plus or minus.

Agreed. Unless Jeep surprises us all and releases a 5.7 option in the future, and as long as MN winters haven't destroyed my frame, I'll look into a 5.7 or 392 swap when the ecoD bites the dust. Assuming AMW can swap a diesel chassis.

 

[ChrisNLA]

Agreed. Unless Jeep surprises us all and releases a 5.7 option in the future, and as long as MN winters haven't destroyed my frame, I'll look into a 5.7 or 392 swap when the ecoD bites the dust. Assuming AMW can swap a diesel chassis.

I believe AMW has swapped diesels before. If anything I'd guess just slightly more cost.

 

[Zachanadandy]

I believe AMW has swapped diesels before. If anything I'd guess just slightly more cost.

I don't know if the bell housing is the same, but the EcoD already has the 8hp75 transmission so if it is it could potentially be cheaper if the reused the trans?

 

[ChrisNLA]

I don't know if the bell housing is the same, but the EcoD already has the 8hp75 transmission so if it is it could potentially be cheaper if the reused the trans?

Could be. Didn't consider that.

I was thinking about the diesel having the smaller fuel tank and the DEF tank riding behind it - and probably wanting to swap that and all the lines.

 

[JTdiRtyD]

I don't know if the bell housing is the same, but the EcoD already has the 8hp75 transmission so if it is it could potentially be cheaper if the reused the trans?

I'm not positive on the ZF, but a lot of trans bell housings are removable, so could prolly just swap it with the gasser variant. But on that same token, I'd probably opt for a new or lesser mileage trans anyways.

 

[ChrisNLA]

I'm not positive on the ZF, but a lot of trans bell housings are removable, so could prolly just swap it with the gasser variant. But on that same token, I'd probably opt for a new or lesser mileage trans anyways.

The ZF case appears to be one piece. I'm hardly an expert, though.

 

[MaximusTX]

Agreed. Unless Jeep surprises us all and releases a 5.7 option in the future, and as long as MN winters haven't destroyed my frame, I'll look into a 5.7 or 392 swap when the ecoD bites the dust. Assuming AMW can swap a diesel chassis.

There is a thread about this already and someone stated that they talked to AMW and they said it was cheaper to sell the Diesel and purchase a high mileage Rubicon to do the swap than to pay them to do the swap. See post #9

Ecodiesel to hemi conversion?

Although with people with highly modified vehicles not sure that is a viable option or would take a lot of time to swap parts over.

 

[JTdiRtyD]

Although with people with highly modified vehicles not sure that is a viable option or would take a lot of time to swap parts over.

Yeah I think this will be a big deciding factor if/when the time comes. Not considering the mods, I'll maintain my chassis and components and everything else, where as a high enough mileage gasser to be had for low enough to offset the cost will likely need everything gone through and quite a bit replaced.

Might be a toss up, at least at my level of detail.

 

[ericw.]

There is a thread about this already and someone stated that they talked to AMW and they said it was cheaper to sell the Diesel and purchase a high mileage Rubicon to do the swap than to pay them to do the swap. See post #9

Ecodiesel to hemi conversion?

Although with people with highly modified vehicles not sure that is a viable option or would take a lot of time to swap parts over.

That might be assuming someone doesn't already have over 20-30k++ in modifications to the rig they already own.

I think in the last thread on AWM, someone said that a diesel swap just adds a few thousand bucks. (2-3k IIRC)

 

[FLY-DOG]

I don’t understand why they don’t use a 392 hood with cold air directed right to air box plus under hood cooling.
Your truck looks great enjoy!….Jack

That is an extra cost option if you don’t already have the Mojave hood….explore their website for pricing and options.

 

[Backcountry ADV]

i was torn on a cheaper 5.7 or 6.4. im glad i opted for the 6.4. i think i would have kicked myself if i went the 5.7 route and its not that much more expensive.

Definitely. I saw your post on your experience. I have a buddy in NC that wants to do the swap as well. I was talking to him about road tripping down to MI to their new shop to check stuff out, and have both our Jeeps done at the same time, then flying out to pick them up for some trails and drive home. Bonus would be that I get some killer content for my channels

I'm leaning towards the same 505 set up for the additional TQ in case I decide to tow or get into overland trailers like the Mission or Turtleback stuff as it would definitely make a difference. Also having 40's, the extra power would likely turn em much easier.

 

[Zachanadandy]

Definitely. I saw your post on your experience. I have a buddy in NC that wants to do the swap as well. I was talking to him about road tripping down to MI to their new shop to check stuff out, and have both our Jeeps done at the same time, then flying out to pick them up for some trails and drive home. Bonus would be that I get some killer content for my channels

I'm leaning towards the same 505 set up for the additional TQ in case I decide to tow or get into overland trailers like the Mission or Turtleback stuff as it would definitely make a difference. Also having 40's, the extra power would likely turn em much easier.

I do the same mental gymnastics to talk myself into the 392 over the 5.7L, but I guarantee you won't tow anything with the JT that you'll ever feel like the 5.7L 410ftlbs is lacking. We towed our heavy 2019 JLUR on 38s on a steel 19' dovetail trailer over 3k miles in one roadtrip with my 5.7L ram 1500. Didn't matter if it was up a grade at elevation in the Rockies the thing pulled like it wasn't there. Cruising across Utah at 85mph. Accelerating up hills. Didn't matter. And that was 8800lbs all in. Aside from the 8mpg you wouldn't even know you were towing let alone a heavy trailer with a giant brick shaped wind sail on it. Will a 392 be more fun? Absolutely. Do you need it for towing? Not at all. Especially considering you are likely driving a little less aggressively when you have a trailer I doubt you'd even notice the difference between the 2 there.

 

[rezar1]

Is there a place in Ca that can do the conversion? And pass smog?

 

[whysoserious]

Is there a place in Ca that can do the conversion? And pass smog?

I would suggest no, in so far as an AMW, or similar company, engine conversion. The plain language of the "engine change" requirements in the California "Smog Check Reference Guide" would seem to make it impossible without CARB exemption. And I can't find any "engine kits" that have been approved by California (CARB) for the JT (they may be out there but I can't find any). So a company like AMW would have had to apply for an exemption to use their conversion in a California registered JT. And as I recall, the testing leading up to the exemption is pricey. You can check here for exemptions (if you type in "Mopar" for manufacturer you will see there are some engine swaps for other vehicles):

https://ww2.arb.ca.gov/applications/aftermarket-parts-database​

However, based upon the "Guide" mentioned above, it is legally possible to change out a 3.6 for either a 5.7 or a 6.4. The first requirement is Section II(a): "

All emission system configurations must be in the original emission control system configuration as the donor vehicle, including, but not limited to, the transmission, evaporative system, exhaust, and intake"​

So if you have a donor vehicle (which has to be the same model year or newer as your JT) with a 5.7 (has to be a light duty truck) or a 6.4 (can only be from a 392 Wrangler, not a 6.4 RAM as those are all HD trucks, I believe), you could swap. As an alternative, you should be able to use a 6.2 SRT from a TRX, as it is also a light duty truck. However, the problem with the truck engine swaps is getting all the smog stuff, like the cats, in the right place as there are specific location requirements for said cats as to where they can be located downstream of the engine. Seems there would be a lot of fabrication needed.

On top of that, your donor vehicle has to also be California emissions compliant; you would not be able to swap in a Fed only compliant engine. The complete list of requirements is in the link below.

The last hurdle is getting a BAR referee to certify the swap and get your label. I have no idea how difficult this would be but in theory would be straight forward if using a Wrangler 392 donor.

Look to Appendix D:
https://www.bar.ca.gov/pdf/smog-check-reference-guide.pdf

My $0.02

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