MaddXJ85

Hello everyone,
I need to do a engine swap in my 85 XJ.
I have the crappy 2.8 V6.
Wanted to go to the 4.0 but not sure (expense and need for new tranny).
I've been tossin around the idea of a four cylinder.
Anyone have one? How strong, reliable? Will it mate up to my tranny?
I would appreciate any help or info...
Thanks

NewXJaddict

not sure where you are located but I saw an I6 on craigslist that the guy had already pulled out and was selling for 300. Sounds questionable but he said it had a fresh oil change and ran when he pulled it

humboldt2door

I have a '85 2 door with the crappy 2.8

I hear the 4 cylinder is a reliable, good engine, but its not much of an upgrade in power.
Look into swapping in a GM 3.4L V6 from a camaro. It is the same dimensions and there's very little / no custom fabrications to make it work.

The I6 probably wont fit without a lot of headache. The firewall is moved back in jeeps with the 4.0 to make room for it, so it would be a royal pain to stuff it into our jeeps.

go with the 3.4L...my .02

MaddXJ85

sounds good but how dependable is the 3.4? i have problem after problem with this 2.8 and i just cant get the stupid thing to run right... i was considering the 4-banger based on reliability.. im not too concerned about more power cause when the 2.8 was runnin good it had plenty.. I'm just at my wits end with this engine...

radio flyer

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The I6 probably wont fit without a lot of headache. The firewall is moved back in jeeps with the 4.0 to make room for it, so it would be a royal pain to stuff it into our jeeps.

go with the 3.4L...my .02[/QUOTE]

Here we go again!! Fire wall is same- Radiator support is different. All parts will swap out by drilling out the spot welds. If you want to go with the 4.0 you will be way ahead in the power and reliability aspect. However you will be in need of a complete donor in order to avoid the headaches of chasing down all of the pieces that you will need including but not limited to wiring harness, computer, etc.

MaddXJ85

yeah I wasnt worried about fitting the I6, I didnt want to have to buy another just to fix mine... thanks

radio flyer

Buy one that has been hit in the rear, you won't regret the the time needed to do the swap unless you have limited mech. skills. Evan so it's a great learning experience!

MaddXJ85

Oh I have the ability to do it... it's money thing that's the big issue... I'm just worried if I cut corners now will I regret it later...

radio flyer

Any swap is gonna cost you unless you have a freebie- still you will have other unforeseen cost that can add up fast. If you really want to get rid of the lemon 2.8, shop around and go for the 4.0 Time and money tend to hold all of us back, but if you can limp the 2.8 along for awhile you won't regret installing a 4.0

MaddXJ85

Yeah thats what i figured... Thanks for the advice man... I see that you have a '91 4.0 in your 85. Did you do that swap?

radio flyer

Yep, spent 3.5 weeks gutting both of them to build the 85 as the 91 was hit on pass side and in the front. It can be done faster, but i swapped out everything including the entire interior, wiring harness front to rear. Mine had the bare bone tan plastic interior and the 91 had gray cloth and carpet.I went from a carbed 2.5 with a 4 speed to the 4.0 with the 231 and the ax15 5 speed. Lots of work, but well worth it!!

MaddXJ85

Sweet.. so when I get ready to do this (it'll be a while) would you be willing to help with details? It would be a huge help to have some advice and pointers from someone who has been through the exact same swap...

cherokeesteve

The 4.3 is a way better engine than the 2.8. That 4.3 is a small block chevy v8 with 2 cylinders cut off, and if you get the vortec v6 it is a real good engine with big valves, roller cam, and a real good intake system.
Rebuild one that was in my ski boat, the engine was a real good runner!

radio flyer

No problem, let me know when you get ready-I've got some info that will save you some time and frustration.

ktmracer419

the 4 cyls are good motors just as reliable as the inline 6 if not more

a little low on power but you get used to it.

i would rock one before i rock a 2.8 v-6