• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

motor transplants

Any.

1987-90 (early) will work without any changes to electronics - they're all RENIX.

1991-1995 is OBD-I, and will either require a brain transplant and possibly an underhood donor harness, or some adaptation to make RENIX sensors fit up and talk to the rest of the system (you'll have to drill & tap the knock sensor boss, and the TPS can be finicky.) Make sure you grab the manifolds, since the RENIX ones don't bolt up to OBD heads.

1996-2005 are all OBD-II, and will require more electronics swap - or similar work to the OBD-I for adaptation to RENIX. Don't forget the manifolds

It is possible to swap the heads all about - in which case, you'll want to find a cylinder head with casting #7120 (OBD-I, this one's generally regarded as the best for swaps) and associated manifolds - I seem to recall, tho, that the manifolds from pretty much any HO head (#6120, #0630, #0331) will swap back and forth.

Also, watch the mounting bosses on the intake. The later models changed how they hold on to the power steering, and you might have to make sure you get the associated bracketry to compleat the swap.

Are you losing your engine, or just looking to upgrade? A stroker based on the RENIX block with the #7120 head (and adaptations) is a good way to go! If I couldn't get the 7120, I'd probably keep the #2686 (RENIX) head and do some work to it instead.

5-90
 
I blew a rod out of the oil pan of my current motor, soo i need a new motor, could u suggest a year rang that would be easiest. I was kindve wanting to upgrade to a 4.0L HO.
 
Like I said, you can put anyting in - mechanically.

You can put in an HO - it would probably be easiest to use a 91-95. You can either grab all the donor electronics (easiest if you have the vehicle to hand - otherwise, be greedy when you go get things) or drill and tap the knock sensor boss and adapt the rest of the sensors to RENIX. You'll still get benefits from the HO engine - since the extra power is made by a cylinder head modification, rather than electronics.

5-90
 
I believe the 91-95 cams are different than Renix also. They, DC, did it to eliminate the egr, probably among other benefits. I believe it has more valve overlap.

Maybe the Renix ecu wouldn't take full advantage of the different grind. Then again, maybe I don't know enough about the subject to comment.:laugh3: I'm sure others will.

K
 
From what I've been able to find, the cam didn't change at all from 1987 to 1995 (or so - I think it changed with OBD-II.) So, it should be no trouble for the RENIX ECM to keep up.

Also, the RENIX setup seems to be the most adaptable of the lot (ask people with forced induction on their RENIX - there seem to be a few) and it works well with strokers as well. I doubt it would be an issue.

Fuel tuning can still be done with MAP adjustment, and there's no real reason to play with the timing curves on the RENIX - it does that on its own (that's why there's a knock sensor in the system.)

It's theoretically possible to eliminate the EGR on RENIX - when I had to get my 87 smogged (and found out my EGR was shot) it was nearly zero emissions all the way across. The only reason I failed was because they manually checked the EGR valve (after I told them they weren't allowed to do ANYTHING under the hood but clip on the #1 ingition lead and the tailpipe sensor. I crossed that stuff out on the work order as well before I signed it.) I'd like to get rid of the thing myself, but I'm stuck in California, and I can't do anything until I leave.

No reason for the RENIX setup to have any trouble with the later engine - and the RENIX adapts well to aftermarket cams anyhow.

5-90
 
corbinafly said:
Then again, maybe I don't know enough about the subject to comment.:laugh3: I'm sure others will.

K
Click to expand...
Like I said.:lecture:
Thanks for setting me straight 5-90.

K
 
I think im going to try to try to swap in a 91-95 HO. I'm pretty sure ill try to find a wrecked vehicle, and use it as a donor. Will i need to swap out the ECU for the newer one, and if soo does it matter it the donor vehicle has the same drivline components. I myself have a BA10/5 transmission, and an NP231 TC.
 
Others have swapped in an HO in place of a RENIX motor. I am doing it also, but I am replacing the electronics to a '95 specs. I don't think you will have to do that. Here's a link that might help:
http://www.rockmodified.com/2003/april/TB/tb_perf.htm
A few words of caution, First is if you need to retain the EGR setup for smog checks. The HO's don't have EGR. SO if you need smog emmisions, then you'd need to retain the EGR system or change the complete wiring to 91- and up. I think there was a discussion on this many months back and most though to cut out and weld the EGR boss section into an HO or 99+ manifold.
You might want to update the cooling system to an open system at the same time. Check Cherokee America's website. You might need a newer exhaust manifold or redrill the holes to your present one. If you have after market headers, then this should be a problem.
You might need to think about the throw out bearing or pilot bearing on the tranny. They changed through the years. For certian swaps, and I think yours is the the particular years, Advanced Adapters sells the only bearing for it. Check this website, it might have the bearing info:
http://www.jeep4.0performance.4mg.com/stroker.html
Also, 99+ heads are a more restrictive than earlier heads on the exhaust ports. 96+ blocks are suppose to be a bit more sturdier. Up to 2000, your motor mounts should/will swap directly. I have a 2003 block. I had to modify one of the motor mount brackets and use a spacer with the other. The '03 block also had the newer (better) style of water pump. They have a different bolt pattern than earlier water pumps.
My setup is an '03 block with a '95 head and an NV 3550 tranny and '95 wiring. '95 is the last year for OBD I. And a '99 intake manifold with Clifford ceramic coated headers. I also had the intake manifold ceramic coated. Its not running yet, but hopefully soon.
If you were closer, I have an '88 4.0L sitting in my garage. $100. It ran OK, with some ticking, from the lifters I think.
Tom

Knew I forgot something. The fuel rail is different between the years. The Renix one won't bolt up to later year manifolds. Also the fuel and fuel return hose connections are in different locations. THe Renix has one front and rear. The HO's are both at the front. I think the fuel pressure regulator is different spec too. 96+ are different also. I think only one fuel port. If you change electronics, then you'll need to probably change fuel pumps. I bought a '95 fuel lines for mine, the metal lines. I need to adapt the rubber lines though.
 
Last edited:
Also, the block will swap directly, except maybe the 2003 and up (see my pervious post). YOu could buy a good short block and put your head on it. You might check you area DC or Jeep dealerships and see if they have a block they used to replace a motor. The 99+ heads have been know to crack. Sometimes this caused other problems. I have a 2000 block, that I got everything but the head for $40 from the local dealership. The mechanic couldn't get a missing problem solved. He figured it was a sticky lifter. It might be worth a few phone calls. Also try Car-Parts.com. You can search in your state or region. You could use any block and put your present head on it. If the block assembly is in good shape, then I'd think about rebuilding or reconditioning your head. At least if it didn't sustain any damage. Then you can keep your intake and exhaust manifold etc.
Tom
 
i am in the prosses of swapping in a 2003 4.0 out of a grand cherokee.i have an 88 renix motor with an nv 3550 in it already.so far i got the p/s bracket set up for 2000 xj-only $48 including tax from jeep dealer.and purchased an ex manifold for $80 on line to replace the 2 piece manifold.and had to drill and tap the bosses for renix brackets-i also d & t for my 88 water pump.wanted to keep mine.have not completed yet.and i am using the renix sensors-except for tps i am using the 2003 one came with motor.mine came with almost everything from the 03 grand set up less accesories like p/s pump,alt,a/c comp etc...came with intake and t body!
 
Check out the article at Cherokee America on swapping in an HO for a blown non-HO engine, at http://www.off-road.com/jeep/cherokee/99/09_sept/engswap/engswap.html
You are talking about a lot of unnecessary work swapping the ECU and wiring harness. If your old ones work fine, I'd stay Renix.
Using the HO TPS with the Renix computer- this reportedly doesn't work. That is why people go to the trouble of adapting the Renix TPS to the HO throttle body. There is a good article on the web on how to do this- I don't have the link.
 
My Question Is Y Would'nt It Work.mine Is A 5 Spd Nv3550 I Do Not Need A Signal For The Trans Puter.all Tps Sensor Are The Same Add A Reference Volt And It Will In Crease Lineraly Like A Potentianometer-don't Know Speelling Of That One.so I Am Going To Try It That Way.if It Does Not Work Well Then I Will Use The Renix One.i Already Made Mine Adjustable By Slotting The Mounting Holes.
 
Just Tested My Theory On Tps---it Does Not Change Up To What The Renix Tps Is At Max Tps.5.0 V Mostly Y People Modify Theirs But If You Were To Add More Input Volts Like In Using A Map Adjuster It Will Work. So Yes It Can Be Done But To Modify The Renix To Work Is Cheaper If You Have The Ho Tps--if Not Making An Adjustable"map"box U Can Use The Ho Tps What Ever Is Cheaper For U.
 
Great idea to prove/disprove the question of new TPS with Renix computer. Please post your results- if it works, it could save a lot of trouble for many people. None of the posts I've read said WHY the new TPS wouldn't work with the Renix (meaning 1990 and earlier) computer.
 
markaboo929 said:
i am in the prosses of swapping in a 2003 4.0 out of a grand cherokee.i have an 88 renix motor with an nv 3550 in it already.so far i got the p/s bracket set up for 2000 xj-only $48 including tax from jeep dealer.and purchased an ex manifold for $80 on line to replace the 2 piece manifold.and had to drill and tap the bosses for renix brackets-i also d & t for my 88 water pump.wanted to keep mine.have not completed yet.and i am using the renix sensors-except for tps i am using the 2003 one came with motor.mine came with almost everything from the 03 grand set up less accesories like p/s pump,alt,a/c comp etc...came with intake and t body!
Click to expand...
Mark,
My motor came out of an '03 GC also, and I am swapping in a NV 3550. The water pump on the '03 has a different bolt pattern than earlier years. I don't know what year they changed. The 2000 block I have has the same bolt pattern for the water pump as the '88 block and '95 block. The '03 water pump has the high flow impelor like HESCO's or Flowcoolers. I am going to use a TJ's tranny mount to adapt the NV 3550. A '95 cherokees tranny mount is to tall and the bolt pattern doesn't match up. I forget if I'm going to use the original tranny cross member or one from a '95. I think with both, I'll have to put a space plate in there. I haven't lifted it yet.
Tom
 
simple solution i also have an nv 3550 in my 88 xj i just got a tranny mount and adapter plate that bolts to the nv 3550 for a 2001 xj!the last year it came out had an nv3550 for the 5 speed how bout dat all bolt in for the cross member i had to tap 2 holes that lined up on the frame rails and rotated my cross member 180 degres side ways and the bolt holes lined up perfectly-for the pilot bearing my nv3550 came from advanced adapters as a kit so when i was at the jeep dealer gettin stuff i asked for a pilot bushing for an 03 wrangler sence i have an 03 block--it has been changed to a pilot bearing instead-cheap too under 10 bucks my cost.i had to modify./cut some bosses on the block and i used all of my renix block mounting brackets.i also got a ex manifold for an 91-99 xj 4.o exhaust ports are different but it bolts on and is not abig deal it will still seal regardless.i did not want custom front pipe to connect the dual manifold design for the 03 dual cat system.i just figured out/ordered on line from autozone .com the front pipe for a 92 xj with the bolt on flange same as 88 renix to bolt up to the ex manifold plus it has the needed threads for the o2 sensor the renix bolts to the manifold and the 91 up is in the pipe .now everything is bolt in.let me know how far u are to bolt your motor in mine is ready to go in when i get the exhaust parts. i got the front pipe the flange gasket and the donut gasket with tax and free shipping for $61 total.let me know what u still need to figure out i already done that also for the coolant sensor i let u know that too. here from ya soon
 
Mark,
Sounds like we have the same setup. I choose not to alter the bosses on the '03 block and alter the motor mount brackets. I think I bought my bearing from NAPA. I had heard the last year of XJs had the NV3550, but never confirmed it. Did you use the '88 cross member or a newer one. I have one from a 92, but I think the tranny mount sits deeper in it. I might see if the TJ's and last year XJs tranny mounts cross reference. I got one off E-Bay for about $30 or so. I am going with '95 wiring, so the wiring of the tempsensor won't help. I bought a Hi-Flow housing from Hessco. I also have rooler rockers, so I had to buy the valve cover spacer and thermostat spacer. I just need to get the tranny mount to work. To add to the confussion, I am putting in a Dana 300 transfer case. I have to rebuild it sometime. Thanks for the info on the NV3550.
Tom
 
You must log in or register to reply here.

Similar threads

3
1996 Cherokee obd2 port, any help appreciated.
Replies
3
Views
107
326Firefighter12
3
T
1986 XJ fuel sending unit . . . WHERE ARE THEY???
Replies
6
Views
174
lawsoncl
L
4
Timing gear?
Replies
3
Views
704
4x4JeePmaNthINg
4
R
Serpentine belt problems.
Replies
6
Views
178
Anak
Anak
H
High Idle at Start
Replies
6
Views
195
Ecomike
Ecomike
Back
Top