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Engine swap

Discussion in 'Wrangler YJ (1986-1995)' started by 91Wrangler, Feb 14, 2017.

  1. Feb 14, 2017 at 6:13 PM
    #1
    91Wrangler

    91Wrangler [OP] Member

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    Hello, I have just bought a 91' Wrangler and I have never really had a project so I am going to start with a toy.

    It has the 2.5l, 4 cylinder, with ax5 transmission.
    The head is blowen and I have a fuel injection 5.4 From a 99' Ford.
    From what I am reading this engine doesn't maryup very well with the ax5. Any thoughts?
     
  2. Feb 14, 2017 at 6:54 PM
    #2
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine Moderator

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    Its generally easiest to find an engine that compatible with your year of vehicle.
     
  3. Feb 14, 2017 at 7:23 PM
    #3
    91Wrangler

    91Wrangler [OP] Member

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    I already have this engine and it is newly rebuilt, so if there is an adapter plate and a plan for one I would love to hear about it
     
  4. Feb 15, 2017 at 6:59 AM
    #4
    OFFGRID

    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    The AX5 is so weak that no one makes an adapter for it. It will not hold up to the torque that a 4.0 (mated to the AX15) makes much less your 5.4. Is the Donor vehicle a 4x4. If so pull the whole drivetrain motor, tranny, tcase and swap it to the jeep. If not, find a similar year Ford and pull the tranny and tcase. Or if you want to stay stick, find you an AX15 for a 4x4, get an adapter from Novak-adapters or Advanced adapters to mate it to the motor. I believe your TCase may bolt to the AX15.
     
  5. Feb 15, 2017 at 7:14 AM
    #5
    91Wrangler

    91Wrangler [OP] Member

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    Yes donor is 4x4 so is the ax15 the best manual for the job? The Ford is automatic and I do prefer manual.
     
  6. Feb 15, 2017 at 10:21 AM
    #6
    OFFGRID

    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    Depends on how much money you want to spend. Adapters for Tcase to transmission can be expensive, more so than the tranny to motor adaptors. Staying with a jeep tranny (AX15) of the same model jeep should save you money in adapters, but if you can find a 5 speed out of a ford that will bolt right up to the motor you will then need to purchase an adapter for your tcase. You can possibly find a 5speed/tcase combo out of a ford truck that may bolt right up. No matter what you do you will probably need to get new driveshafts.

    Check out Jeep speed shop, and Novak-adaptors web pages for ideas. The both especially Novak have lots of research info to guide you on their pages.
     
  7. Feb 15, 2017 at 5:11 PM
    #7
    91Wrangler

    91Wrangler [OP] Member

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    Are all ax15 transmissions the same? I'm going to look for one in the junkyard and finding a Jeep in the junkyards around here is rare.
     
  8. Feb 15, 2017 at 6:40 PM
    #8
    OFFGRID

    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    Here's the deal. I can't find an adapter for the 5.4 to ax15. I would give Novak adapters and advanced adapters a call. I,m not sure how you would marry the computer harness and electrical harness together.

    After all my research I ran across this article.

    http://www.fourwheeler.com/how-to/engine/154-1006-top-10-dumbest-jeep-engine-swaps-ever/

    Don't do it!

    The 5.4 is a no-go. The best v8 swaps are chevy 305, 350, 400, and LS3s. Ford 5.0 and 351 Windsor; dodge gen III HEMIs. Whatever you choose you will have to drop that AX5 transmission you have.
     
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