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Motor swap

Discussion in 'Wrangler YJ (1986-1995)' started by Bluejeep96, Jun 14, 2018.

  1. Jun 14, 2018 at 5:22 AM
    #1
    Bluejeep96

    Bluejeep96 [OP] Member

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    Its probly been asked but I'm gonna ask again what issues will I run into doing a 4 cylender swap to a 6 cylender
     
  2. Jun 14, 2018 at 5:44 AM
    #2
    OFFGRID

    OFFGRID Well-Known Member

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    You will have to replace both the motor and the transmission, and all the wiring harness and ecm. You'll find it cheaper to sell the 4 banger and purchase a jeep with a 6. Personally if I were to go to all that time and expense in swapping motors, I would do a chevy v8 swap.
     
    UrbanCowboy and Prerunner1982 like this.
  3. Jun 14, 2018 at 5:52 AM
    #3
    Bluejeep96

    Bluejeep96 [OP] Member

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    I have a motor and tranny from a xj laying around so I have it already to do plus i like my jeep too much to sell but thanks for the help... v8 would be nice but I have to go to work in it and that would give me problems I'd like to break it a lot more haha
     
  4. Jun 14, 2018 at 7:27 AM
    #4
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine Moderator

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    Welcome to the site! If you already have the motor and trans, only thing left should be the wiring. I think it would be a worthy swap.
     
  5. Jun 14, 2018 at 7:41 AM
    #5
    Bluejeep96

    Bluejeep96 [OP] Member

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    That's what I figured but wanted to make sure due to it being my daily cant be down long for something little holding me up I just wonder if I need to change the interior harness too
     
  6. Jun 14, 2018 at 8:26 AM
    #6
    Prerunner1982

    Prerunner1982 Well-Known Member

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    While I do agree with Offgrid, I understand you already have the drivetrain. You might need the tcase for the 6 cylinder as well.
    You didn't mention what transmission you had and what you are putting in it.
    If the YJ came with an auto (30RH) then it has a 23 spline output, if it came with a manual (AX-5) it has a 21 spline output.
    If the XJ is an Auto (AW4) it could be 21 spline ('90 and prior) or 23 spline ('91+), if it's a manual (AX15) it has a 23 spline output.

    Computer(s) and wiring from the XJ may be beneficial as well.
     
  7. Jun 14, 2018 at 8:31 AM
    #7
    Awrench

    Awrench Well-Known Member

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    did you check with Penn Motor vehicle emission - some states are 'restrictive' on swaps- Sorry I am not familiar with their rules- I would hate to find out after all the work and money...
     
  8. Jun 14, 2018 at 9:34 AM
    #8
    Bluejeep96

    Bluejeep96 [OP] Member

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    Its Manuel xj with ax15 and and I have a munle 4 banger now so I'm not changing much but the size of it.i dont have computer ir wiring for it tho
     
  9. Jun 14, 2018 at 11:53 AM
    #9
    aggrex

    aggrex Well-Known Member

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    Motor mounts may be an issue that needs to be addressed. Thus the V8 option is usually suggested.
     
  10. Jun 14, 2018 at 12:12 PM
    #10
    Bluejeep96

    Bluejeep96 [OP] Member

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    I got a new fram for it with 6 cylender mounts
     
  11. Jun 14, 2018 at 1:38 PM
    #11
    Prerunner1982

    Prerunner1982 Well-Known Member

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    Both are Manual?
    Don't think the tcase will work then due to difference in spline count.
     
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