V8 Motor Swap

[lwhibbs2888]

I have a 87 comanche that I am wanting to put a V8 into it. I am wanting to put a 318 out of a 87 ram. What is the best way to go about? Will the 5 speed out of the jeep bolt up or do i need to find a bell housing adapter to reuse it? PFC Hibbs

[bigd44889]

:hmm: :dunno:

[Darren]

Whatever 5sp you have in your 87 won't handle a 318. and no it won't bolt up. also a 318 won't just drop into the engine bay, have you done any research on the subject? my guess is you havent.

[bigd44889]

:doh: :rotf:

[Pete M]

To put a 318 into your truck would require a lot of custom adaptation and a whole new drivetrain, as nothing there (except maybe the t-case) would be able to handle a v8. advanceadapters.com is a great place to start v8 swap research. :thumbsup:

 

Also, when it comes to v8 swaps, the rule of thumb is, "just because the engine is cheap/free, doesn't mean it's a good candidate for swapping". I'm assuming from how specific you are about which engine you want to use, that it's already in your possession?

[Pete M]

have you done any research on the subject? my guess is you havent.

 

 

Everyone has to start their research somewhere. He started his here. :thumbsup:

[pingpong]

don't know enough about dodge drivetrains, but at the very least advance adpapters is the place to start.. then check out Novak site as well. I would swap motor and trans out of the ram, and then find the appropriate drivers drop t-case. D44 rear, and at least a built d30 up front or a d44

[possum]

If your truck has the 2.8 piece of crap a chevy v8 will go in fairly easy. I am not sure about making it 4 wheel drive as my rig is only 2wd. I am doing research on making my truck 4wd and I do not think it will be that hard. Just kinda expensive because I am going to have to have the drive shafts made among other things.

[Jerry]

If your truck has the 2.8 piece of crap

aye aye! Stop picking on the V6 man ;) First, they're not that bad! Especially when you look at gas milage figures or compare it to a 2.5L. Second, we all have to start somewhere and if you happens gets a 2.8L it's better than no Comanche at all :thumbsup:

[DirtyComanche]

Well, the 2.8 is really slow.

 

Things to consider:

-Engine width, praticularily with the headers (or exhaust manifolds and downpipes) installed. Typically, you can't make anything fit but the stock manifolds, or in some cases block hugger headers. Oh, watch the driveshaft and oil pan clearance - a 4.0L is installed 2" to the passenger side to help with this, but you WON'T have the space to do that with a V8.

-Engine height, with whatever gizmos go on top (carb, EFI, etc) and the oil pan you plan to use. You might not clear the hood, unless you sit it right down (or run a cowl hood) and you might not clear the oil pan.

-Cooling. The V8 needs more radiator, no way around it. Guys have used 4.0L rads with SBCs, but I think they're asking for trouble if they really drive it. The avaliable space for a larger rad is not so avaliable. I've seen a WJ steering box used to allow for a taller rad that sits between the frame rails. I would probably go that route, as I think a 'standard' sized rad will then fit.

-Clearance for accessories. Jeepcomj had to do some hacking to make his 3.8 with A/C fit, which I don't think he would do over again. Lots of truck engines will mount the accessories all over the damn place because they had plenty of room in the factory install. And on some V8s you might find the starter is in a bad place.

 

Anything else? Well, not that I know. I know a bit more for a SBC swap. They've been done and documented. I think there is a 318 swap or two on NAXJA.

 

Personally, I don't consider a V8 swap to be ideal for MOST usage of THESE trucks. A V8 is fine in my 76 K25, I can carry over 160L of fuel, and it is a full size/heavy truck. I think a smaller (better) V6 is more ideal for a MJ simply to keep things light, keep the fuel consumption to a reasonable level, and leave enough space under the hood to keep things easy. If its a hardcore wheeler, I could see throwing an aluminum V8 in. Hardcore mudder, sure, whatever V8 you want (mud trucks don't need to be fancy, that'd be a real waste). Track? V8, you could work with whatever but again aluminum would be best. DD? I6 (4.0) or V6 (3.8 or similar, shortstars are kinda cool too).

[Eagle]

If your truck has the 2.8 piece of crap a chevy v8 will go in fairly easy.

Define "easy." A SBC engine does not just "drop in" to an MJ engine bay. It's a tight fit, and it requires a bunch of adapters. And after you get all that worked out -- you can't fit a radiator big enough to cool it effectively. Everyone seems to think a SBC is the answer to all situations, but it's not. Even with the sheet metal changes needed for an '86, a 4.0L swap is a lot easier and more practical, and better suited to the way most people drive/use an MJ.

 

For an '86 with the 2.8L, the simplest, most cost-effective swap is a GM 3.4L V6.

[brdhntr]

:agree:

 

i'm not sure why you'd go to a 318 considering all the work and cost. a 4.0 would be easier and the hp and torque would be pretty close. a 318 of that age is probably about 180hp, maybe 200. a 4.0 ho is about 190hp stock. torque are pretty close as well between the v8 and the i6. there are tons of mods for a 4.0 that can be made. helk, stroke it if you feel you need that much power. but i think the extra weight of all the drivetrain parts that would go with the swap would make the 4.0 a better swap.

 

a gm v6 might be a good option if you have the earlier motor. a 3.4 or 3.8 would be a good bet to go then. the 3.4 and 3.8 in the later models will put out better than the older 318 as well and you don't need to make all the changes for the added weight and size of the 318.

 

if it were me, i'd go with a 4.0ho. but a 318 could be used, it'd just take alot of work. 8)

[possum]

I had to do a little cutting and some searching for the right motor mounts but that was the hardest part. The oil pan cleared the axle fine at stock height even at full flex. I am not saying it is "easy" but it seemed a heck of alot easier than when we put a 350 in my friend's S-10. Just be prepared to get creative and have a case of beer on hand so when you get frustrated you can grab a cold one and take a moment to think. Also having the complete donor vehicle on hand is a definite plus.

[Ryno MJ]

I'm in the same situation. I want to get rid of the 2.5L in mine, but am unsure of the engine to use. My first thought is a 4.3L Chevy with a 700r4 trans. A small block Chevy would be cool also, Guess I'll be watching this thread closely.

[HKB3]

if I was going to swap in a GM V8 it would be a LS motor, check out this thread on NAXJA

http://naxja.org/forum/showthread.php?t=945920

[Eagle]

If I were going to swap in a V8, it would be an AMC 401.

[brdhntr]

:agree:

[possum]

I am actually looking for a Willy's L-head 4-cylinder to replace my V8. I really don't need that much motor.

[pilotblake]

I have a V8 in my MJ, Gotta love the small truck with the big sound and the heads turning when it fires off after half a crank everytime. Heat was definitly my biggest issue, then oil pan clearance, and inability to run headers without frame massaging, and................