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Best Bang For Buck Engine Configuration.

Discussion in 'Intermediate CJ-5/6/7/8' started by jasonw, Nov 13, 2023.

  1. jasonw

    jasonw noobster

    Howdy all, I've got a 75 CJ5 that I'd like to get going this winter, I've got a few choices for engine and just curious if there's a better choice or even a Frankenstein configuration that'll be worthwhile. I currently have the complete original 232 (non power steering) engine that smoked a lil, a "running" YJ 258 that I picked up cheap, and a 4.0L long block from an early 90's, I believe, Grand Cherokee. My initial thought is just slam the 258 in it and go (after I swap the carb and add HEI) but I figured since all the engines are out and on stands i'd ask the question. I am fairly mechanically competent and I have owned many jeeps over the years including a YJ with the 258, a Jeepster, a couple TJ's and many XJ's and a few Grand Cherokee's of various vintages lol.
    Thank you for your time!
     
    Dwins1 likes this.
  2. oldtime

    oldtime oldtime

    My opinion is that the 232 is the least desirable.
    Go with the 258 if you prefer carbureted.
    Go with the 4.0 if you want fuel injection.
     
    73cj5 and vtxtasy like this.
  3. Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

    I have always thought of the 258 as the best engine ever put into a AMC Jeep.

    So, the 258 would be my choice. It has a longer stroke than the 232 producing more torque at lower RPM.

    It is a simple, nearly bullet proof engine, it will fit right in as a replacement for the original 232, and you don't have to track down the parts to complete the "long block" nor rig up the electronics needed to run the 4.0L.
     
  4. RATTYFLATTY

    RATTYFLATTY I think you need a little more throttle

    Could you stab the 258 rotating assembly into the 4.0 block and build a stroker?
     
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  5. Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

    It has been done, but the 258 already is a "Stroker", and with some improvements to aspiration it can deliver impressive results.

    From what I read in the original post, and the title of the thread, he is interested in the best bang for the buck. He has a running 258, but only a long block 4.0L engine. The best bang for the buck is to use the 258 rather than doing a complete rebuild of the 4.0L engine.

    I did find an interesting article on building such an engine if you want to read about it.

    https://www.rockcrawler.com/techreports/stroker40/page2.asp
     
    Last edited: Nov 13, 2023
    vtxtasy likes this.
  6. OldAdobe

    OldAdobe Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Keep it simple. Go 258 but I would ditch the YJ carb and put the 232 carb on the 258 and see how it runs on good engine stand that won't tip over.
     
  7. Dwins1

    Dwins1 Member

    X2
     
  8. Dwins1

    Dwins1 Member

    That is what I have in my YJ. I bored 60 over and shaved the head and block installed a mild Rv cam with mc2100
     
    vtxtasy likes this.
  9. 71CJ54WD

    71CJ54WD Sponsor

    The 258 is awesome but once a V8 Jeep goes past you'll be kicking yourself for not going straight to the V8. My 258 is out and my 360 is going in...
     
    Ol Fogie and Dwins1 like this.
  10. Tralehead

    Tralehead Member

    Anybody remember the old juice commercial where the guy slaps his head and says "wow, I coulda had a V8!"
    ;)
    Wish I had never sold my V8 '5 :(
    But the 350 Wagon doesn't suck :)
     
    Ol Fogie, Dwins1 and vtxtasy like this.
  11. Lane Meyer

    Lane Meyer Member

    I have a 360 in my '74. It has intake, 4bbl, and headers and scoots the Jeep along quite nicely. It's a lot of fun but it has a different vibe (to borrow a term from my kids) than a good old inline six CJ. I doubt that I would remove a good running 258 to install a 360. Well... maybe not. :D
     
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  12. Jw60

    Jw60 That guy 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Those engines are only 11% different in displacement so your not going to gain much swapping stock stuff onto the other motors. best bang for the buck will be with whichever motor is most ready to go... slap the 232 in then you can build the 258 with 4.0 Frankenstein motor.

    Camshafts make a huge difference in how a vehicle drives so that would be something to look into for the fuel injected long term motor that you build and swap in when ready.
     
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  13. vtxtasy

    vtxtasy oldbee 2024 Sponsor 2023 Sponsor

    Add fuel injection and a good ignition system and the 258 is perfect. Stalled on too many hills and it is not a good position to be in. Mexico had a 282 c.i. version of this engine.
     
  14. algmmech

    algmmech Member

    To add my 2 cents. I'm running a 232 bored .040 over, Comp cams High Energy 260 cam, Later model 258 intake and exhaust manifold fitted with a weber 38. The pistons for a 258 that had a taller compression height and gave me a .002 deck height. Calculates out to 9:1 compression. I have to say this engine far exceeded my expectations, it holds it's own pulling hills on the highway and has more than enough power off road. All I'm saying is, don't rule out using the 232 or use the 232 crank with a 4 liter and make a mini stroker.
     
    vtxtasy likes this.
  15. 71CJ54WD

    71CJ54WD Sponsor

    The 232 in the 4.0 makes a stroker? What displacement would that be?
     
  16. algmmech

    algmmech Member

  17. AndyinTexas

    AndyinTexas Member

    You get a few more cubic inches if you put the 258 crank in the 4.0 block. I'm not sure, but I think that combo requires that you use the head off the 4.0. That may or may not be a little issue if you want to run an earlier carb and manifold.

    I choose the 258. Mine runs great all stock with the exception of an Offenhauser manifold and Motorcraft 2150 combo.