85 4banger, what are the down sides

Looking at an 85 xj with a four banger. What are the down sides to these?? Can a 4.o be slipped in.

downside its not a 4.0 unless the body is perfect why would you bother to buy it knowing you want a 4.0?

My rig started off life as a 85 with the 2.5L.

The biggest downer is the fact that it is computer controlled carb. That Carter YFA is a PIA. I got real good at dealing with it and can offer support if you have problems, but I converted to the computer and tbi injection from the 86. I also did headers and the purple MOPAR cam. It did a good job wheeling but here at altitude it lacked guts on the mountain passes. I did however like the 28mpg.

I ended up building a 4.0L stroker and putting it in. Talk about night and day performace.:doh:
If possible, make sure and get the 5 speed. Most likely it will have 4.10 gearing.

You can put in a 4.0L but it means replacing the tranny as well. You also have to swap the computer, wiring hood, front facia, cross member, and radiator. A BFH will modify the firewall to clear the head.

It's an arizona xj(rust free) 2.5 5 speed been sitting for 10 years. Needs hatch glass. $450. Also has factory spare tire carrier on back

Thanks for the Info. thought I'd read something about needing BFH to put in a 4.0

I'd buy it. Maybe offer 300 and see if he'll go for it, if not, pay 400 or 450.

The fact that it's rust free, has a tire carrier, and has a 2.5/5spd combo (4.10 front axle) makes it a decent purchase. Rear axle will be a d35 but you can't walk into a junkyard with Fords and NOT find an 8.8 with 4.10s out of a 95-whatever Explorer around here.

If you keep the 2.5L, the D35 holds up pretty well. Heck, guys run 4.0L's and 35's for years.

With the stick, the biggest improvement you can make for wheeling is to add a flywheel weight to give it more stored kenetic energy. I got mine from TriCounty in Cali.

That is a great deal for any XJ, especially a rust free one. Snatch it up. I have a 4.0 in an 86 that started life as a 2.8. Installing the 4.0 isnt that bad, just make sure you get wiring diagrams for both the 85 and the 4.0 to match things up. Just about every driveline component, except axles of course, needs replaced from the donor. Change fuel tanks too.

4 bangers are almost impossible to find in any condition in Houston anymore. Been looking for 3 years.

Unless it is a diesel 4 banger, then all I need to do is look in my driveway!

:sunshine:

Also, check the front driveshaft. Some early ('86 and earlier, I think) XJ's used a funky CV joint set-up affectionally called the "stick in a can" joint that is not very strong. It was a flange mount to the Transfer Case, so conversion is possible, but I don't know what it takes (new front output shaft?).

The tcase is a NP207 IIRC. Yes it uses a funky front driveshaft but if you don't like it, you can swap in a NP231 very simply. That is what I did.

It was straightforward but I don't remember that much, as it was over 10 years ago.

4.0 into a 86-earlier chassis is not an easy thing to do. That chassis is designed for the V6. I did that once and had to hack the firewall and front crossmember. That would be a better candidate for either a V6 or V8 swap. Look at the GM 2.8/3.1/3.4 as those basically slip in with factory parts.