Before anyone says "Why not go with the 318 or 3.9 v6?"- its because I have a 4.0 readily available and I want to do it.

Now, does anyone have any tip, tricks, or helpful resources to do this? (What jeeps to look for parts in, how to fabricate custom engine/transmission mounts, how to edit cross members, etc.)
I'm currently thinking about getting a AX-15 to go behind it because I don't believe my NV1500 can stand the torque.
Will I need a bigger radiator for the 4.0 or will the 2.5's stock with a electric fan do the job? And will there be enough room to have it pull rather than have a push fan?
Will the rest of the drive train line up or will I need to get a new drive shaft and rear diff?
Will I have clearance issues with my tires? I have 255/65r16 on it rn and they are barely clearing as it is.

A huge thank you in advance for any help!

 

4.0???? Out of what? I am guess the straight six? Real possibility that there simply isn't enough room for it in the engine compartment.

 

Yes. Its the i6 4.0 out of an 94 Cherokee. I'm lead to belive it will fit one way or another because people have put 12v cummins in there and Viper V10s (Ill be it with a lot of work but none the less)

 

A viper V-10? In a dak??? They must have had a REALLY big hammer, and shoehorn. Although I think it is still shorter than the I-6..... I have seen 4BT diesels in various places, but, never seen a 6BT in a dak.

I would expect that some MAJOR bodywork would be required....... just to get it to fit. Are you good at fabricating? Got the appropriate weapons for the job? Would be a fun project, and the 4.0 would be a good motor for the dak.... Still and all, I think I would still be more inclined to do the 5.2 or 5.9 swap. All the parts are already out there in the world. Could always sell the 4.0 to help finance the project......

 

I don't disagree that the 318 or 360 would be the much easier and probably better choice, however I like the idea of the 4.0 in the Dakota. The 4.0 is just the 2.5 + 2 cylinders anyway. And who can say they have a 4.0 powered Dakota?

 

I know of two viper-powered dakotas and one 5.9 cummins powered kota.


Yes the 4.0 will fit. Best transmission option would be whatever they had in the jeeps - NV3500 I think? Don't think it was an NV4500.

You will need to run a 2001+ style radiator, mounted inside the core support instead of behind it (99- style). I don't think there will be room for the clutch fan, but you can probably fit a thin-body spal. Both engines use a TC style power steering pump I believe, so no fab work there. Exhaust should clear the obstacles no problem.

May have to make your own engine mounts. Willing to bet you can mock up with the ZJ mounts and be pretty close.

Oil pan might be an issue. Again, I'm thinking ZJ pan will be close. If not, XJ pan might be closer. May still have to trim the K-member.

 

Thank you! That's actually a lot of help!
I didn't know different jeeps had different oil pans!
Do you have any tips on how to modify the K-member without loosing too much integrity?

 

Hard to say. Depends on the amount of interference. My 408 has a sheet metal pan that's designed to clear the K-member, but i'm going to notch it 1/2" just to be sure. Depending on who you ask, it's not needed at all, some have trimmed it with no backfill, others have trimmed and filled the cut.

Per Google, looks like 84-06 YJ/TJ/XJ/ZJ is one oil pan, and it looks similar to my oil pan in the sump. So you might have to section it an inch, or you can slide the engine back a bit, or both. I know the front clip of the ZJ/XJ/Dakota/Durango are "similar", but not sure about relative position of the firewall. It's going to be a "try and see" thing. I helped a friend with a 4.0 ZJ but I didn't look at it very close.

Biggest issue I know if is physically routing the lower radiator hose without it kinking, since the water pump is damn near against the radiator. If you plan to have AC, that can also complicate things.

Other issue will be electrics. Being a 2.5 and in this second-gen forum, I automatically know it's a 97-99 dakota. Your best option (you didn't hear this from me) is going to go get yourself a 97-99 4.0 XJ powertrain harness. ZJ might work too. The PDC is in the same location (and the same layout even, I think) on X/Z/Dak/Dur, PCM is almost in the same place (Pass Fender on D/D, Pass Firewall on X/Z), and since there's not much actually going on to the cab, you can splice across the CCM Databus wires going from the PCM to the Cluster and CTM.

 

This past spring, I replaced the transmission in a 95 jeep 4.0 for a friend of mine.
It was a NV3550..... very sim. to a NV3500 but the 3550 is a 2 piece design, (removable bell housing) vs 1 piece on the 3500.
Also, I may be wrong, but I thought the jeep 4.0 used a different bolt pattern vs the dodge.....

One other question or concern.... I assume your 2.5 dakota is 2wd? Did jeep even make a 2wd transmission in a manual 5 sp.?

 

You are correct that it is 2wd and I honestly have no idea. Most the 2wd jeeps I see have either the 2.5 or an automatic. The transmissions I'm really considering are the NV3500, NV3550, and the AX15.
If need be, I wouldn't mind yoinking the 4wd pieces- but I would prefer to not add the extra time and weight as I don't find myself in 4wd situations often.
So if anyone has ideas how I could do that too, that'd be great!