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Motor Decision

Discussion in 'Early CJ5 and CJ6 Tech' started by Phillip Sladek, Aug 22, 2019.

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  1. Aug 22, 2019
    Phillip Sladek

    Phillip Sladek New Member

    Mogadore ohio
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    Aug 3, 2016
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    I have a 1969 CJ5 current configuration is 134f with T90a trans and 3.73 gears.
    The motor needs rebuilt (rod bearing knocking). My question is am I better served just rebuilding this motor
    and spending the 1k to do it right or would it be better to replace it with a different motor. What motor would be the best swap and can I find one local in the Mogadore Ohio area.
    Fab work is not a issue I have full access to a plasma table to make what ever I need.

    just looking for ideas and option

    Thank you

    Phillip
     
  2. Aug 22, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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  3. Aug 22, 2019
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    Guessing you are not going to find a lot of love for dropping a bunch of money rebuilding the F134 around here...I am not the most knowledgeable, but seems like the F134 would not have come with 3.73 gears but rather something numerically higher? The 3.73 was standard with the v6. How 'original' or time period correct do you want to keep it? I really like the buick v6, others really like the v8 power of a sbc, and yet others really like the modern 4.3V6 etc.
     
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  4. Aug 22, 2019
    matt johnson

    matt johnson Caretaker of family Jeeps

    chesapeake, va
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    I'm biased. The 225 would be my choice.
     
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  5. Aug 22, 2019
    Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Virginia Beach, VA
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    134 remove rebuild . drop back in no problem
    engine swap . buick or gm or ford . lots of time needed for changes required
    might be worth it . if your looking at more power
     
    Last edited: Aug 22, 2019
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  6. Aug 22, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    The two biggest questions:
    1. What do you use the Jeep for?
    2. Are you generally happy with the 134?
     
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  7. Aug 22, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Was the 134 and T90A swapped into the Jeep? As mentioned 3.73 gears would have been combined the the Dauntless V6.
     
  8. Aug 22, 2019
    SIDSCJ

    SIDSCJ Jeep addict

    14th State
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    Pull it, check the crank, and stuff some bearings in it.
    Plop it back in and drive it.
    That's the cheap and least amount of non Jeep time you can get.
    I had an F-head with horrible rod knock, bearings were shot.
    Had a parts plow rig with a motor that was quiet, ran well, but had a crack in the block.
    Pulled them both, stuffed the crank and bearings out of the cracked block motor into mine.
    Was into it for a set of gaskets and seals.6 years later it still run 40lbs oil pressure hot.
    If you hate the f-head, you'll see how deep the rabbit hole goes...….;)
     
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  9. Aug 22, 2019
    Jw60

    Jw60 Sitting up n buckled down. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Sedalia MO.
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    I would look deeper into what you have. Your profile pic doesn't look like a 69 driver's quarter panel shouldn't it have a reflector or hole for one Transmission should be a t90c. With i thought 4.27s
    If it is already a mutt and you are in the hills or highway you might want to look at the Chevy 4.3 or Buick 225 / 231 they will adapt to a t90a but not a t90c.

    Otherwise run the 134 it will be a good introduction if you keep it or not.
     
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  10. Aug 22, 2019
    Phillip Sladek

    Phillip Sladek New Member

    Mogadore ohio
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    I purchased the CJ5 in this configuration overall I am happy with the 134f that is in it I use it as my daily driver back and forth to work and mostly in town driving. occasionally on the expressway
    at 60 mph the RPM'S run about 2500 but it will top out at 68 on a flat road. Since purchase I have completely gone over the jeep. I could tell it was a mutt when I purchase it. The Steel tub and fenders looked brand new as well as the floor. (I think it was a new reman) . I updated the dash with all digital gauges . Drew out new dash and burned it out on plasma table at work turned out real nice. new seats and added complete carpet kit. New springs shocks front and rear. Did full rebuild on the Dana 25 front axle hubs. Rebuilt the ross steering and replaced all the linkage with new partsit is nice and tight now play. My son in law made new front and rear bumpers and custom rear seat with locking tool box with sliding drawers. I purchased to redo and keep. will be passed down to my grandson who just loves it.

    So as you can see I have done a lot of work to it. My wife hates it but I love it
     
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  11. Aug 22, 2019
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Sheboygan
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    put the Fhead back in. its a great motor for that jeep. 68mph isnt really a great idea in these little guys, but if you are brave enough, anything goes!

    im a fan of the Fhead. they dont take much to maintain, and once its rebuilt, your grandson will have that same motor for the rest of his life too, most likely.

    so, rebuild the engine, steering you said is good, now just do a disk brake conversion and you and your grandson can go enjoy the heck outta that jeep.

    (but my money would go to a 4.3 if i wanted to undertake a huge project like a motor swap)
     
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  12. Aug 22, 2019
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    I would first be real sure that it's actually 3.73 gears with a F134 - I kinda doubt it. The F134 Jeeps were a well-tuned balance of available power and gearing with either 5.38 or 4.27 axles. I would expect you to lose a quite a bit of top speed with 3.73 gears ... I expect there's not enough power at those low engine speeds to overcome the wind resistance. Plus it would be a very sensitive hill detector.

    If it's really 3.73s, forget the F134. I think the best option then would be a 4.3L Chevy V6.
     
  13. Aug 22, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    I personally love the F-head with 3.73s. :shrug:
     
  14. Aug 22, 2019
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    You've already answered the question. You're already happy with the F-head so rebuild it, keep it running good and continue to enjoy it. :)
     
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  15. Aug 22, 2019
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    agreed...if you decide you really want a V6 or sbc in a jeep, you'd probably come out ahead to just buy a different jeep that already has it installed.
     
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  16. Aug 22, 2019
    Boyink

    Boyink Super Moderator Staff Member

    Tulsa, OK
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    Unless, of course, you'd enjoy the process of repowering this Jeep.

    It's not always strictly a financial decision...;)
     
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  17. Aug 22, 2019
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
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    Ya - I one of the 'strange' ones in that building the rig is as much or more fun than using them to me. We re-powered with small V8s, and then in the late 70s went to the 225/231s and have not looked back since. I do like the 4.3 options, mostly for the modern motor and FI. But now that there are easy ways to EFI the 225/231s, my desire to explore the 4.3 has pretty much disappeared.

    I will also say the 134 is just too light on power for out here in the Mts. When I'm wheeling, I spend a lot of time from 10 - 13.5/14K in elevation. The 134s just run out of gogo that high up.
     
  18. Aug 22, 2019
    Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I live South of...
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    Phillip, Welcome from Michigan. I have a 64 that I rebuilt with a 66 V 6 donor Jeep, I had already bought a NOS F 134 military surplus motor. I used the 66 axels, 10"X2" brakes, 3:73 gears, T 90 transmission from the F head with single stick Dana18 transfer case. I use it for cruising the Fire trails, and cruising two lane Blacktop roads in Northern Lower Michigan. I like it just fine at 50- 55 mph. I do run out of power on long up hill roads if I don't keep my speed up to 50 or more it slows down. I belong to a Cruise Club Up North and we go on cruises to dinner and car shows around the Tip Of The Mitt. I like my F134 just fine and don't want to change a thing, but that is just me. You are going to decide for yourself what you like and want, but I like mine just fine. Maybe just pull the F head out and fix enough to drive it a little longer and make your decision. Pull the crank have it ground put in new bearings and seals, drive it a little more then make your decision, you can always find a buyer for that motor, if you change your mind. Good luck what ever you decide. PM me if you want to talk about your project you can call me if you do. Oh yea, my Wife Hates it too.
     
    Last edited: Aug 22, 2019
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  19. Aug 23, 2019
    Phillip Sladek

    Phillip Sladek New Member

    Mogadore ohio
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    Aug 3, 2016
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    I have verified the gears they are 3.73 date stamped 1969. I think I will pull into garage tomorrow and pull motor and start the break down and see what I have going on in it and go from there.
    if i could find a V6 locally I would not have a problem installing it. but have never do a conversion before. Many rebuilds but no conversions. I have a mig welder and plasma cutter and not afraid to use them lol. I am grateful for the help and insight you guys are offering.
     
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  20. Aug 23, 2019
    Chilly

    Chilly Active Member

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    Maybe do the minimalist refurb of the current engine, get it on the road, then spend some time researching repower options for "someday". Then you have the luxury of looking for deals on already-adapted components. Build up the combo on garage floor, then someday swap it in.

    Personally, I'm becoming a fan of retaining the charm of old Jeeps as they came, for better or worse, but with tasteful improvements here and there.
     
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