4BT in an XJ
4BTSwaps.com is the premier Cummins Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 30 of 41

Thread: 4BT in an XJ

  1. #1
    Registered User
    Join Date
    Jan 2007
    Location
    North Central Wisconsin
    Posts
    28
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default 4BT in an XJ

    I've seen a bunch of conversions with CJ's, YJ's and TJ's, but I haven't seen anyone put a 4BT in an XJ (older square style small Cherokee).

    Has anyone out there done one or better yet doing one with pictures to see?

    Thanks. I was thinking of a full size Chevy Blazer, but there are several nice litttle XJ's floating around that would make a good swap (If the motor fits, that is).
    Av8r

    '94 Cummins 6BT wrapped in a Dodge 2500 4x4
    '01 VW TDi

  2. Remove Advertisements
    4BTSwaps.com
    Advertisements
     

  3. #2
    Supporting Member
    Join Date
    Jan 2007
    Location
    Knoxville,TN
    Posts
    4,072
    Thanks
    0
    Thanked 7 Times in 3 Posts

    Default

    The problem with the xj they don't have a frame (body is the frame) Anything can be done with time and money .Now if your talking about the jeep waggie that would be a better choice.

    Scott

  4. #3
    Registered User
    Join Date
    Jan 2007
    Location
    Ontario
    Posts
    16
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Totally Doable!
    Last edited by jeepcummins; 02-01-2007 at 04:27 PM.
    Jeep Comanche Powered by Cummins

  5. #4
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Quote Originally Posted by CrewCab59 View Post
    The problem with the xj they don't have a frame (body is the frame) Anything can be done with time and money .Now if your talking about the jeep waggie that would be a better choice.

    Scott
    you know, I don't really get this whole "it doesn't have a frame, it's like tissue paper" mentality.

    Any of you ever take an engineering class?

    At the very worst-- it's a little channel and some welding time. However, that's overkill. Keep the engine mild and the XJ is a fine platform, frame or no.

    (the simple fact of the matter is-- unibody vehicles are MORE torsionally rigid than simple ladder frames-- and it's torsional rigidity that concerns us)

    Other poster who said "totally doable" and posted the pic- DETAILS, man! Details!!

    I have a 90 X and have been planning a swap. Have it all figured out I am pretty sure, just haven't had the $$$ to purchase the engine yet.

  6. #5
    Registered User
    Join Date
    Jan 2007
    Location
    Ontario
    Posts
    16
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    I also think these platforms are very sturdy as long as rust hasn't got a hold of them. When I did the conversion I found no need to weld anything to the frame. The original motor mounts bolted the main part of the frame in about 6places over an area of about 5 * 8 inches, which I felt was quite adequate so I reused them.

    The support the frame strength I got into a small head on collision with a 3/4 ton ford and bent the frame on it, and my vehical had no damage that I could tell other then the bumber tilting slightly.
    Jeep Comanche Powered by Cummins

  7. #6
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    speaking of motor mounts-- what did you do for them?

    more pics, particularly of motor mounts, would be greatly appreciated!

  8. #7
    Supporting Member
    Join Date
    Jan 2007
    Location
    Knoxville,TN
    Posts
    4,072
    Thanks
    0
    Thanked 7 Times in 3 Posts

    Default

    Quote Originally Posted by JAFO View Post
    you know, I don't really get this whole "it doesn't have a frame, it's like tissue paper" mentality.

    Any of you ever take an engineering class?

    At the very worst-- it's a little channel and some welding time. However, that's overkill. Keep the engine mild and the XJ is a fine platform, frame or no.

    (the simple fact of the matter is-- unibody vehicles are MORE torsionally rigid than simple ladder frames-- and it's torsional rigidity that concerns us)

    Other poster who said "totally doable" and posted the pic- DETAILS, man! Details!!

    I have a 90 X and have been planning a swap. Have it all figured out I am pretty sure, just haven't had the $$$ to purchase the engine yet.

    1. Not to be a jerk but if you know everything than why did you ask !
    2. I never said it couldn't be done,I just said tha fact's that there was no frame.
    3. Your quesstion was very general like you didn't have a clue where to start!
    4. no hard feelings here !!!
    Last edited by CrewCab59; 02-01-2007 at 04:09 PM.

  9. #8
    Registered User
    Join Date
    Jan 2007
    Location
    Ontario
    Posts
    16
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    The mounts consisted of some 5" channel and some heavy flatbar across for added stiffness. The assembly was mounted to the orignal points on the frame using part of the the original motor mount brackets. I am not good on the explanation but the picture will help. I used ford flat style mounts and have no vibration problems and the best part, those mounts are about 10 dollars a piece and very easy to get.
    Attached Images Attached Images
    Jeep Comanche Powered by Cummins

  10. #9
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Quote Originally Posted by CrewCab59 View Post
    1. Not to be a jerk but if you know everything than why did you ask !
    2. I never said it couldn't be done,I just said tha fact's that there was no frame.
    3. Your quesstion was very general like you didn't have a clue where to start!
    4. no hard feelings here !!!
    1) At that point I hadn't even posted in this thread. So how does this apply?

    2) Didn't say you said it couldn't be done. but like many, you said "the problem with the xj is it doesn't have a frame". Well, it's not a problem.

    3) See number 1, above. I hadn't at that point even posted, let alone asked a question. so what are you referring to?

    4) none here. Give my love to the wife and kids.

  11. #10
    Supporting Member
    Join Date
    Jan 2007
    Location
    Knoxville,TN
    Posts
    4,072
    Thanks
    0
    Thanked 7 Times in 3 Posts

    Default

    Quote Originally Posted by JAFO View Post
    1) At that point I hadn't even posted in this thread. So how does this apply?

    2) Didn't say you said it couldn't be done. but like many, you said "the problem with the xj is it doesn't have a frame". Well, it's not a problem.

    3) See number 1, above. I hadn't at that point even posted, let alone asked a question. so what are you referring to?

    4) none here. Give my love to the wife and kids.
    Sorry for that I was talking and posing at the same time,:smile:

  12. #11
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Quote Originally Posted by CrewCab59 View Post
    Sorry for that I was talking and posing at the same time,:smile:
    not a problem sir. Good to meet ya

    see, that's what's cool about this board. It could have went the way of Pirate4X4 right there, instead it's two guys basically ragging each other, then tossing a fresh beer at the other guy with a grin and a muttered "dumbarse"

  13. #12
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    now- Jeepcummins-- you REALLY need to post more, man. I've got a 90 XJ that's just begging to go diesel. The transmission is leaking like crazy, I have a 700R4 in the shed just itching for a rebuild, and the motor is basically shot. So it's either put a rebuilt 4.0 fuel hog (I dislike this motor, and dislike having to buy $3 gasoline even more), or go diesel and run WVO.

    I know which way I wanna go. Now the only question is, how to get there. I'm looking at the 4BT as well as GM 5.7 diesels (yes, I know the old wives' tales about that engine- sorry, they're wrong- -and I can get 'em dirt cheap)

    will likely build it with the GM diesel to get it running on WVO, then keep my eyes open for a 4BT.

  14. #13
    Registered User
    Join Date
    Jan 2007
    Location
    Tooele UT
    Posts
    137
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Ever wheeled an XJ for long? They break.

    Have fun with those 5.7's MOOOAHAHAHAHAH

    a man has got to know his limitations

  15. #14
    Registered User
    Join Date
    Jan 2007
    Location
    MD
    Posts
    1,203
    Thanks
    0
    Thanked 2 Times in 2 Posts

    Default

    Quote Originally Posted by tacoma View Post
    Ever wheeled an XJ for long? They break.

    If abused enough, everything will break

    Some simple upgrades make them pretty solid up to 35" tires, and they will easily outflex an IFS tacoma beer

    Yes i have personal experience with this stuff, I wheel a ZJ (Grand Cherokee) on 35's.

    I'm not sure why you hate 4.0's. I've had good luck with mine, and so have many others. Mine is underpowered, but that can be fixed. i'm going to swap in a 360/46RE, but only because they came in my Durango. Otherwise i had plans to stroke it to 4.6 and put in an AW4.

    When it comes to Unibody's they can take some abuse, but when they're done they're done, gotta start over, at least that's the easiest route most of the time. With a frame, if it goes you can either buy a new one or build a new one without replacing the body. Good news in this area for XJ's is one with a decent body is readily available and dirt cheap.

    Personally i think that a 4BT is a lot for an XJ. If you want a unibody Jeep, a better choice, in my eyes, would be a ZJ. The XJ's were the first AMC vehicles to be computer designed, also the first unibodies. There were a lot of advancements in design from when the first XJ's were designed to when the ZJ was designed, the ZJ unibodies are a lot heavier and stronger than XJ's. Personally I'd still rather have a frame.

    Can it be done? well that's already been answered. Will it hold up in the long run? if done right and not abused, probably.

    I know you already have the XJ so it's an easy platform to choose. It also depends on what you want it for. If it's a weekend warrior/DD then it will probably do the trick. If you think you want to tow things somewhat heavy, you might want to consider something stronger and with a longer wheelbase. This is how I ended up in a Durango. A solid front axle is pretty much a must in order to have 4wd, but That's not a terribly hard/expsnsive operation either.

    When it comes to money, it's not a cheap swap. It's definately cheaper to stroke the 4.0 that's in there now than to put a 4BT in. Unless a 4bt falls into your lap, then it still might not be cheaper. Will you save it all in fuel prices? maybe, but it will probably take a while. reports on mileage of a stroked 4.0 are pretty decent from what i've seen.

    Sorry if this is a lot of rambling, hopefully something decent came out of it all.

  16. #15
    Registered User
    Join Date
    Jan 2007
    Location
    Muskegon, MI
    Posts
    37
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    We have been doing alot of stuff with some Cherokee's latly, and I tell everyone of my customers the first thing they should do is add a set of these
    http://www.tntcustoms.com/webv5/xjstiffeners.asp
    This way you can weld all over them for your rails, or suspension links, or whatever. They fit great, and work great as far as I can tell. I havnt had any frame rails ripping apart since we started using them.

  17. #16
    Registered User
    Join Date
    Jan 2007
    Location
    MD
    Posts
    1,203
    Thanks
    0
    Thanked 2 Times in 2 Posts

    Default

    Quote Originally Posted by BigWheelBob View Post
    We have been doing alot of stuff with some Cherokee's latly, and I tell everyone of my customers the first thing they should do is add a set of these
    http://www.tntcustoms.com/webv5/xjstiffeners.asp
    This way you can weld all over them for your rails, or suspension links, or whatever. They fit great, and work great as far as I can tell. I havnt had any frame rails ripping apart since we started using them.
    TNT makes some pretty awesome products.

    I did a similar thing with my zj when i went to a long arm style of suspension. I took 4x6x1/4 box tubing and cut it in half. stitched it to the unibody every couple of inches and plugwelded it as well. It's held up so far though i've only make it to the trails once since i put it on.

  18. #17
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Quote Originally Posted by Diesel Durango View Post
    -I'm not sure why you hate 4.0's. I've had good luck with mine, and so have many others. Mine is underpowered, but that can be fixed. i'm going to swap in a 360/46RE, but only because they came in my Durango. Otherwise i had plans to stroke it to 4.6 and put in an AW4.

    -Personally i think that a 4BT is a lot for an XJ. If you want a unibody Jeep, a better choice, in my eyes, would be a ZJ. The XJ's were the first AMC vehicles to be computer designed, also the first unibodies. There were a lot of advancements in design from when the first XJ's were designed to when the ZJ was designed, the ZJ unibodies are a lot heavier and stronger than XJ's. Personally I'd still rather have a frame.

    - know you already have the XJ so it's an easy platform to choose. It also depends on what you want it for. If it's a weekend warrior/DD then it will probably do the trick. If you think you want to tow things somewhat heavy, you might want to consider something stronger and with a longer wheelbase. This is how I ended up in a Durango. A solid front axle is pretty much a must in order to have 4wd, but That's not a terribly hard/expsnsive operation either.

    -When it comes to money, it's not a cheap swap. It's definately cheaper to stroke the 4.0 that's in there now than to put a 4BT in. Unless a 4bt falls into your lap, then it still might not be cheaper. Will you save it all in fuel prices? maybe, but it will probably take a while. reports on mileage of a stroked 4.0 are pretty decent from what i've seen.

    Sorry if this is a lot of rambling, hopefully something decent came out of it all.

    First off-- I hate the 4.0 because it's a closed-source ECU. With my GM products, I can easily read the data in realtime via my laptop. That, coupled with the fact the garages I've paid to do a diagnostic are bull**** artists, and I think you see where I'm going. I do ALL my own work.

    I agree about rather have a frame for the reasons you mention. But this XJ was pretty much free. I'd rather have a framed Jeep, but then security comes into play owing to the soft top. Yes, hardtops are available, and then there's the SJ series (too big). But I already have the XJ.

    Towing will be done with my S-10 Blazer once it gets upgraded brakes by way of hydroboost. I know you'll say this is not optimum either-- but lots of folks tow with ZJs and the like. I'll never be towing anything heavier than what I've seen towed with ZJs.

    - the swap wil lpay for itself quite quickly. You can't run WVO in a gas engine. I will in a diesel.

  19. #18
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Quote Originally Posted by BigWheelBob View Post
    We have been doing alot of stuff with some Cherokee's latly, and I tell everyone of my customers the first thing they should do is add a set of these
    http://www.tntcustoms.com/webv5/xjstiffeners.asp
    This way you can weld all over them for your rails, or suspension links, or whatever. They fit great, and work great as far as I can tell. I havnt had any frame rails ripping apart since we started using them.

    Did the same thing with $30 worth of channel.

  20. #19
    Registered User
    Join Date
    Jan 2007
    Location
    Tooele UT
    Posts
    137
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    as far as security with an open top Jeep, the cage you'd be dumb not to put in is way stronger than the Cherokee roof.

    I had a nice little lifted XJ, flexed fine, drove ok, but made me very nervous due to the "frame" issues, and the more important problem: hardly any crush room between the door and my body.
    The 4-5 I've seen rolled (and not that bad a roll for any of them) just made me nervous.


    But! I believe in cages and it colors my expectations of safety. I also only own fullsize GM's right now, and they are all bigger than 85% of the vehicles I am on the road with at any given time. So I may be delusional as well.

    XJ's are fine vehicles, not sure I'd overburden them with a Cummins though.
    a man has got to know his limitations

  21. #20
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    since when does a rollcage have anything to do with security?

    give me a soft top jeep, and in 20 seconds everythng of value will be mine- were I so inclined.

    I'll take the dubious security of a metal roof and a locked door over a fabric roof and my Kershaw, any day.

  22. #21
    Registered User
    Join Date
    Jan 2007
    Location
    MD
    Posts
    1,203
    Thanks
    0
    Thanked 2 Times in 2 Posts

    Default

    i think there was confusion with security of life and security of valuables.

  23. #22
    Registered User
    Join Date
    Jan 2007
    Location
    Tooele UT
    Posts
    137
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Precisely. Stuff doesn't matter.
    a man has got to know his limitations

  24. #23
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    try telling that to the client when he's wondering where his $12,000 server and $15,000 router went to?

  25. #24
    Registered User
    Join Date
    Jan 2007
    Location
    Ontario
    Posts
    16
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    I like the commnet diesel durango made
    "It also depends on what you want it for. If it's a weekend warrior/DD then it will probably do the trick. If you think you want to tow things somewhat heavy, you might want to consider something stronger and with a longer wheelbase."
    Some combinations might work for some and not others, and really depends on what you expect from it. My truck has a very good body but the motor was not in very good shape so I thought I would try something different and so far I am happy with the results.

    JAFO- I had also thought of putting various gm diesels, they weigh about the same as 4bt give or take, and probably would be easy to adapt in because they share the same configuration as a 350 chev. Cooling would probably be more of an issue with GM diesels, though they are great engines as long as they don't get too hot. The xj radiator is not that large and there is not really much room for a larger one. So this would be definitely something to look into. I heard that the 4bt is really easy to keep cool, as it has a lot of mass for displacement which really helps this. I used the stock 2 core rad in the conversion and there is still the option to go to a 3 core, but have not found it necessary at all. So if you have questions feel free to ask because I could ramble on all day about various issues with a 4bt or gm conversion as I did research both before completing mine.
    Jeep Comanche Powered by Cummins

  26. #25
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    well I have 3 GM diesels for damn near a steal, and they all have low miles. (yes, I know, "buyer beware" and all-- but I know the guy).

    I have leads on good radiator shops, so that will soak up some of the savings-- $400 will get me a rad that will cool anything I can fit under the hood. But I really think I'll be fine with what I have, given experience from folks on gm-diesel forum.

    Also, the GM diesel will bolt up with use of a $50 plate from Summit, in my Blazer. No bracketry fab, none.

    At the very least, here's my plan:
    -try the GMs. They're cheap, and there's no work to make them work that won't be required for the Cummins or Isuzu diesels.

    -Should that not please me-- and it well may not, as I dearly want a turbo - drive on it a while, free, running WVO. Save the $400 in fuel I'm paying a month now for purchase of a Cummins or Isuzu (is it the 4BDT?). Honestly, I'm leaning to the Isuzu, as I understand I can buy it cheaper than the Cummins, it's a good motor, will run on WVO, and is proven in front of a 700R4.

    Hell, if I buy an old panel truck with the Isuzu motor in it for 3 grand or so, I can get back the bulk of that by scrapping the chassis and panel body

  27. #26
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    BTW, Jeepcummins-

    have you got any larger versions of those motormount pics? I'd really be interested in any and all pics you may have of the install/installed motor, if you wouldn't mind.

    If anyone else is interested, I could even put the original images up on a website for folks to grab. This will save you from spending the next month uploading pics.

    Also, what transmission, tranny linkage, and what did you do with the stock ECU/TCU?

  28. #27
    Registered User
    Join Date
    Jan 2007
    Location
    Ontario
    Posts
    16
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    I actually used the original tranny and transfer case and is proving to be working out quite well. (ax-15 and np231) I am using a chev 12 inch clutch though. It has the right diameter and spline for input to transmission. I manufactured all adapters myself so this is why I thought I might as try it, I could not find anything of it done before. The rear has a dana44 and the front is a dana30 also thought I might as well try it until it breaks. The dana 30 and the extra weight, might not go well together. The stock computer is completely removed as it was no longer needed.

    As for pictures is there anyway to upload better quality to this site it gives a limit of about 75kb which is not much. If not I could e-mail them to you.
    Jeep Comanche Powered by Cummins

  29. #28
    Registered User
    Join Date
    Jan 2007
    Location
    Charleston SC, USA
    Posts
    126
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    if you'll email me the original pics, I can resize them as needed and post them up.

  30. #29
    Registered User
    Join Date
    Jan 2007
    Location
    Central Arizona
    Posts
    22
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Quote Originally Posted by jeepcummins View Post
    ... I heard that the 4bt is really easy to keep cool, as it has a lot of mass for displacement which really helps this.
    What we found was, here in the desert southwest where summer temps are regularly over 100F, an electric fan setup was not enough to keep the 4BT in the Scout runnning cool. We ended up with a mechanical fan, plus two smaller electric auxiliary fans which run when the air conditioning was running. We will be doing the same with the Willys Wagon.

    I'm not an expert, but if you live in an area with a milder climate you might find all that extra cooling isn't needed.

    Jeepcummins: I have a question about the 4BT installation in your Comanche. Was there enough room under the hood for the engine with the standard turbo pipe? Did you re-route it? Or did you have to get creative with the engine hood design?
    Last edited by p14175; 02-11-2007 at 05:40 PM.

  31. #30
    Registered User
    Join Date
    Jan 2007
    Location
    Cape Cod, MA
    Posts
    152
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    i would agree i installed the gm 350 conversion radiator in my cj7 i haven't been through a summer yet but its has had a piece of plexiglass blocking the radiator all winter....
    right now i wish i went with the 2 core radiator but we will see what summer brings...

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts