olrightythen

New to the forum so apologizing ahead of time for any errors. I've been reading past posts about engine swaps for 90 xj's and seeing that there is an issue with replacing engine assy with a newer model HO. I'm in the same boat and was looking for some details on what would need to be done for the purchase and swapping of say a 99 4.0...Mine does have the closed radiator system(sucks), and 5 speed. Any other info needed for further discussion just ask.--thanks

EVcherokee

Welcome to the Cherokeeforum!

All those posts you've been reading have all the answers you'll ever need and if you don't want to go with an HO motor, theres tons of info on swapping to other motors including diesels(even mercedes 5cyl.), V8's, Ford 300 I6's etc...I've even seen a writeup on how to turn a cherokee electric using a forklift motor bolted to the front of an AW4.

Swapping to an open cooling system is a snap and theres tons of writeups on that too. I've done it myself on my 90 XJ

Just a heads up, posting vague questions will usually get ignored or met with less than cordial attitudes..don't be afraid to ask just always search first and try to answer things yourself. We're here to help, but we're human and get tired of repeating ourselves. You'll probably tell this same thing to some other newbie down the road and the circle jerk of life continues on. Just trying to help you out

olrightythen

will take your advice and RRRRUUUUUNNNN with it. I understand about the vague questions so will work on that. So lemme get this straight--I can take a 99 engine and use the original fly wheel and sensors of mine and should bolt in? Or i it the opposite way around? Will i need to swap to open cooling system at time of motor swap or would it work for now? Preciate it.

Bustedknuckle

I would mark on you for being newbish, but you have a 90, so I guess I gotta let it fly.

What exactly is your motor doing that's making you want to swap in the first place? And in regards to the 99, get all the sensors, wiring etc etc.

olrightythen

268000 miles, motor just started with real deep heavy knock comning from block (srewdrivertest) to veerify location. Was a daily driver to knock started so parked it. Had it for ten years now and really miss it ya know. Just looking for used options and figured a newer model would have lower mileage to get more bang for the buck. Am open to any option really just figuring...

EVcherokee

You can swap to an open system anytime you want. I just went down to carquest and got all new parts and hoses and am very happy with it

The OBD2 EFI doesn't use all the sensors that the Renix does and some are in different locations. Get all the HO sensors with the new motor, I wouldn't use the old renix sensors. I'm not the hugest fan of the HO motor...its an awsome motor, but its only rated at 13 more hp and 1 more ft.lb. of torque over the renix motor.

However a 4.0 with a 258 crank(a stroker) will basicly give you a 282(4.6L) and those where rated at 10hp and 55ft.lb. of torque over a HO motor and those where carburated. The 282 was ended in 86 and only available in Mexico or from Mexico(VAM motor). I'm planning on building a 4.6L stroker

Also in 98 Chrysler redesigned the 4.0 head to a lower flowing designed head to help meet emmissions. If your gonna go with a HO, stay between 91 and 97. '96 and 97 are the best years, because in '96 the 4.0 got reinforcement ribbing and a stud girdle over the main caps..To answer your question I think a 99 will use the same flywheel. The renix and HO blocks are really close in design and most things are interchangable. Most of the change was in the fuel deliverly, emmisions and electronics

olrightythen

OK, im not much of an engine guy but do understand hp vs torque. So, if you were in the same position as I, what would you look for in going with a used engine swap being prepaired for basic rebuild of gaskets and sensors? Ease of swap, but yet somewhat best bang for buck? Money is obviously an option but am willing to eat beans to getter done right the first time.

olrightythen

I think your gonna say go with same renix but with different crank...or is that possible with fuel injection instead of carburated?

mwdouglas

i got a 90 with 218,000 on it its my dd and wheeling toy i wouldn't go ho either rebuild yours to spec or stroke it but that's just my opinion i got a buddy with a 00 ho motor and it seems to be weaker than our renix motors mine has more torque than his and i can do in 2wd everything he has to be 4wd to do

olrightythen

K but I was under the impression that having to start at lower end rebuild and work up is indeed more costly, or are you saying that it is indeed more benficial in the long run to go that route?

mwdouglas

i have found its more beneficial in the long run if the head is ok i would rebuild the lower end have the head checked if you feel it needs it put back together and enjoj for another 300,00 miles

olrightythen

Olrigtythen. Gonna take your advice and start pricing out the repairs. Def preciate your help and will keep the forum posted on updates. (course will be abit since i'm curently frickin broke) Will post pics of the jeepster later also. Very intuitive forum! Look forward to carrying on in the future--L8r bro!

EVcherokee

Here's what I got in the works:

-4.0 with a 258 crank
-Motorcraft 2150 carb
-Ford Duraspark ICM and dizzy with a 65k volt coil
-Relocate the TPS to the carb and setup a manual override of the tranny functions.(I have an AW4)
-Also working on making it run on propane too(duel fuel setup)

I can't recommend anything for you because I don't know what you want to do with it. You might be better swapping in a new renix, you might be better swapping in a 350 chev with a 100hp shot of nitrous...I don't know..Figure out what your objectives are, then build a mission based on logistics. Easypeezy-Japoneezy

EVcherokee

You can run EFI on a stroker a lot of guys do

mwdouglas

if you wanna swap in a chevy motor the 250 inline 6 is a hell of a beast motor my old 69 c10 had it and it would hall ***** and had the torgue too but i would rebuild and stay mopar in a jeep im not much on running a gm or ford motor in a mopar and vise versa