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Keep the odd fire 231 in the 63?

Discussion in 'Early CJ5 and CJ6 Tech' started by Moneypit, Sep 6, 2004.

  1. Moneypit

    Moneypit New Member

    It's been a long time since I posted here - mainly because I've had no time or money. Well, now I have both, so this project will finally start moving.

    I'm more of the kind to take a few years to build this thing right, other than slapping it together and getting it on the trail asap, so I want to get this right the first time.

    I have a 63 CJ that the PO swapped in a 231 odd fire, casting number 1249432. It runs, but needs a rebuild. I've been reading this is the strongest V6 Buick ever built. At first I was planning on dropping a 350 in it, but eventually the added weight up front turned me off & after reading that this is "the strongest V6 Buick ever built, I've been looking into a rebuild.

    Is it good or bad to have the odd fire? My choices are down to rebuilding what I have, trying to find a newer 231 with fuel injection or lately I've been hearing about a 4.3 Chevy.

    I'd just like to get anyone's opinon on what they like or don't like about what they have. Opinions on positives and negatives are very welcome.

    Thanks ahead of time for your help!
     
  2. Hill

    Hill Member

    I would stay with the V6. I am not sure if your 231 is a "oddfire" or not, but I sure would keep it.
    I run around in a 58 with the 225. I love it. The torque is amazing. Might have to do with that heavy flywheel........
    -Hill
     
  3. mb82

    mb82 I feel great!

    my opinion is keep the odd fire 231. i seem to remember something about someone here adapting a TBI injection system to a 231. i might be wrong about that.
     
  4. Warloch

    Warloch Did you say Flattie??? Staff Member

    I like the odd fires - I with both 225 OFs and 231 EFs - we try to put the bigger flywheels on EFs to help. I don't think you can beat the power to weight ratio on these things.

    FWIW - just rebuilt the 231 - everything but bore the cyl's and replace piston rods... $1170 with them putting it back together and a 1 year warr. Getting ready to do it to one of the tired 225s as well.

    :stout:
     
  5. 181jeep

    181jeep Banned

    keep the 231.

    jb
     
  6. Boyink

    Boyink Super Moderator Staff Member

    If fuel injection is high on your list, you'll struggle to get a system on the 231. I was after that for a couple years, and finally decided that the Chevy 4.3 route was just easier.

    There's an article on oddfire fuel injection here:
    http://www.earlycj5.com/modules.php...x&req=viewarticle&artid=10&page=1

    This was way past my abilities, and I wanted a "junkyard" system. There is one aftermarket supplier offering a setup for the oddfire: http://www.affordable-fuel-injection.com. But when I inquired I received estimates of $1300-$1500 - not "affordable" to this Dutchman, when I could likely buy 4.3 adapters and a donor vehicle for around that.

    Another board member was installing a Holley Projection setup, not sure we ever heard back on how that went. If that approach worked then you could probably find a setup on eBay and a 4 bbl manifiold and be in business.

    I just got the CJ6 in my avitar, and it had the 4.3 installed by the PO. He didn't do the FI, so I plan to add that soon. Seat-of-the-pants-couple-laps-around-the-block driving impression was that it had a bit more power than my CJ5 with the 225 Dauntless, but the gearing is lower and I don't claim to be that great of an engine tuner, so someone with more skill could have probably tweaked my old Dauntless better than I had it.
     
  7. Duke47

    Duke47 Member

    I agree with the others, stay with the V-6. I run a 225 V-6 in my '74 CJ-5 and it's got allthe power you need, lotsa' tourqe. It's not a complicated engine to have to have to rebuild. I know you're talking about a 231 but Iv'e heard that theres not a lot of difference betwene the two. So I would lean towards the 231.
     
  8. cla451

    cla451 Member

    Fuel Injection...Thats the real issue. If your planning on running hard core trails you may want to seriously consider it. I have a rebuilt '68 225 oddfire. I've had some trail issues but cant be sure its not my rats nest of an electrical system yet. I have a 390cfm Holley carb in it and am planning to put an msd ignition control box to time the spark better.

    I love the way it sounds and, geared at 5.38 , it will crawl over ANYTHING at idle. I love it.
     
  9. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    If you are considering FI, you could buy the JTR book from Novak or Amazon (?) - and have a notion what your getting into.

    I really like the valve covers on the 4.3L :D
     
  10. Keep it. FI is probably best done with a Holley Pro-Jection set-up. John should be able to shed some light on the subject. I'm planning on using an Autolite/Motorcraft 2100 on mine.
     
  11. Boyink

    Boyink Super Moderator Staff Member

    But Johns doing it on a 4.3. Someone else was putting it on a Dauntless. Eric?
     
  12. cla451

    cla451 Member

    If you find an out of the box fuel injection system for an odd fire - please let me know. All the tech departments I have called had said its impossible to FI an odd fire.
     
  13. The Pro-jection set-up should work. I think someone else on the board has it a 225. The problem with factory FI is the odd firing pattern confuses the ECM, but holley's set-up has its own computer and doesn't interface with the ignition at all so it should work. I'd try (and will) if I can come across one cheap enough on ebay.
     
  14. Boyink

    Boyink Super Moderator Staff Member

    There you go.

    This application is all outside any "support" that Holley might offer, based on my past conversations with them.....
     
  15. cla451

    cla451 Member

    hey thanks...I'll look it up!
     
  16. wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    xxx

    You got time AND money. 4.3 would be my choice. As for the OF V6's, aside from the HEI on my 231, I would rather have a 225. I had a 225 originally and I think it was a stronger engine. Had a higher stock compression ratio than this 231, too.