Renix to HO Swap?

[Eagle]

3.55s are NOT a "big" step up from 3.07s. Better, yes, but hardly better enough to be worth the effort in making the change. You'll need to go at least to 3.73s to make any significant improvements in performance.

 

If you have 3.07s, you have a 5-speed. So at 60 MPH you're turning approximately 1650 RPM (going from memory). Changing to 3.55s will raise that to about 1900 RPM. Not much of a change, and certainly not enough to bump you up to the "fat" part of the horsepower curve.

[smithe1811]

ok, so i will keep the 3:55's and rather than installing them, i will sell them to finance 4:10's. so that fixes that issue. thats twice you have swayed me from something i thought i was dead set on :cheers: but that doent fix the fact that i want an H.O MJ and the solution i suspect is rather than trying to make the swap, just try to find one that i can actually obtain.

[CRF136N]

Sorry Pete, I gotta chime in :roll: Now that my HO swap is said and done, I would absolutely do it again. Lots of work, but as long as you have both the donor (don't even try to do it without a COMPLETE running/driving donor) and some extra time, its really quite FUN! :banana: It's also easy as long as you transfer in sections, so you don't get confused as to what is what. As a huge benifit, it gives you the opprotunity to tear everything apart and re-assemble it right, doing more or less a full resto in the process. :thumbsup: Furthermore, it gives you (forces) the opportunnity to LEARN everything you could ever want to know about your jeep inside and out, every wire, hose, line EVERYTHING so should something go goofy down the road, you'll know that there is a wire harness behind that part, or whatever. Also, when re-assembling, you can see every part in detail, so you'll have confidence when everything is together that all vaccume lines are fresh, there are no corroded suprises in the electrical or plastic clip thingies that are dried out and ready to break.

I can drive my MJ anywhere with confidence because of this little piece of mind.

 

Sure, doing a stroker may be the better choice for getting more umph, but at what cost $$$$?! VS. a good running wrecked HO donor on CL for a few hundred bux that has a greater parts availability?...then you can persue the stroker thing as you financially plan for it.

 

FINAL point being, the whole XJ-MJ mating. NOT a big deal at all. Fuel lines, piece of cake. taillights, I had to go outside of the box a bit and do it the only way it made sence to me, but it works GREAT. The ONLY issue is my fuel gauge does read backwards :shake: but thats just something I have gotten used to for now, and I haven't given up on making that right too...there has to be a way, I just don't have time to figure it out right now.

 

If you should persue this option smithe1811, I got your back and would be happy to answer any questions you have and help you through it via phone, text, email, pics whatever. Just let me know if you pull the trigger so I'll know the fun has begun ;) :clapping: :banana:

 

-James

[smithe1811]

CRF136N, do you have a project thread for that swap? if you do and its a good enough jumping off point, then i would probably go with the swap provided i could find an xj for the right price. I'm assuming you just swapped the whole dash and everything, right?i will continue to hunt for a 91 or 92 MJ in the mean time though but i will sure let you know if i get froggy and jump. :brows:

[CRF136N]

CRF136N, do you have a project thread for that swap? if you do and its a good enough jumping off point, then i would probably go with the swap provided i could find an xj for the right price. I'm assuming you just swapped the whole dash and everything, right?i will continue to hunt for a 91 or 92 MJ in the mean time though but i will sure let you know if i get froggy and jump. :brows:

 

Ya; I wish I had taken more detailed pics as I was doing this, but I just wanted to get it done ASAP, so I didn't take the time...although I do have a few more pics I didn't post (and can still take some). I did, however do it all myself so I have the experience now, along with some tricks that I had to learn...and it was all just a couple months ago, so its still fresh. Been considering writing it all down in step-by-step detail and doing a DIY thread with pics if there isn't one on there already. Its funny how everything swapped so easily though w/o any major modification, I thought for sure I would run into some issues, but I really didn't. And yes, I basically stripped my MJ to a bare shell and rebuilt it from the donor XJ. Literally, everything.

 

viewtopic.php?f=7&t=17382

 

-James

[Pete M]

So what are you waiting for? Go write that DIY! :bowdown:

[Oizarod115]

what parts of the HO injection are you wanting? i'm working on an intake adaptation right now, only a couple hours of work away from being finished.

 

the truck has a 97 motor with a 00 intake and HO throttle body.

if all you're wanting is the higher flow intake/exhaust you could do that with a head swap/intake and some minor wiring/fuel lines

[cherokee]

Anybody ever solve the problem of a 'new' (i.e. non-renix) head not having the same location for the temp sensor? A simple adapter threaded into the new t-stat housing doesn't leave the old style sensor at the same depth.

[87MJJeep]

taillights, I had to go outside of the box a bit and do it the only way it made sence to me, but it works GREAT.

-James

 

What is the difference in the taillights? That is not what I expected to read in a Renix to HO swap thread!

[Geonovast]

The problem with the tail lights, I believe, only applies if you're using an XJ harness, as XJ tail lights operate differently than MJ ones.

[CRF136N]

taillights, I had to go outside of the box a bit and do it the only way it made sence to me, but it works GREAT.

-James

 

What is the difference in the taillights? That is not what I expected to read in a Renix to HO swap thread!

 

XJ donor. XJ's have separate turn/brake lights where as MJ's use both top and bottom bulbs for both functions. I'm just not that great with electrical to combine the two systems to function correctly the MJ way (flashing turn signals while brakes are applied, etc) so it was just easier to run an extra wire to the rear of the truck so it functions more like the XJ. The top bulbs are brakelights, and the bottom bulbs are my turn signals. Both bulbs still function for the running lights as they are on a separate circuit. It works great. :thumbsup:

[87MJJeep]

Very interesting. You swapped over everything!

[Automan2164]

Once I clear out some room in the garage, I also, will be doing the HO swap.

 

'90 4.0L, AX15, NP231, D30 disco/35, 3.07's....

 

To

 

'91 HO 4.0L, AX15, NP231, D30 non disco/ 8.25, 4.10's.

 

I have the complete harness out of the XJ donor, and engine, and will be attempting to use the trans/t-case from the MJ. Axles are sourced from a '96 XJ 2.5L AX5. I have the cluster, as well as some odds and ends from the '91. I still need all of the open circuit cooling stuff.

 

Should be fun. :roll:

Rob L.