AMC 232 - one cylinder out of round?

Discussion in 'General IH Tech' started by Evan McGinnis, Mar 24, 2020 at 7:14 PM.


  1. Evan McGinnis

    Evan McGinnis Farmall Cub

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    1971 800B w/ AMC 232
    I've pulled the pistons from my engine today. 5 of the cylinders and pistons look fine. On cylinder #6, however:
    The piston had a broken ring
    The conrod bearing was damaged.
    The piston itself looks OK; no damage to the skirt, just the same level of wear I see on the others.
    The cylinder differed by .0049" when I did a roundness measurement (I will do taper tomorrow. The others were all below .003")
    The manual states that .003" is the limit. How concerned should I me with this?
    Full disclosure here -- I am not particularly adept at doing these measurements, so this may also be operator error.

    Thanks,
    -Evan-
     
  2. WRENCH MAN

    WRENCH MAN Dreams of Cub Cadets

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    What are you using to measure the cylinders with?
     
  3. Evan McGinnis

    Evan McGinnis Farmall Cub

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    A telescoping gauge and a micrometer
     
  4. WRENCH MAN

    WRENCH MAN Dreams of Cub Cadets

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    That is rather minimal wear for an AMC six, has it been rebuilt already?
    You can probably cut the ring ridge out and run it, I helped one of the guys at work overhaul his 4.0 in his Jeep, it was so sloppy that I had to knurl his pistons for him!
    I find snap gauges are a PAIN to get consistent readings with!?, I have a dial bore gauge to measure cylinders with.
     
  5. Joe Hurley

    Joe Hurley Farmall Cub

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    You are relatively lucky if you have a broken ring and the cylinder doesn't have and deep gouges. The broken ring and spanked bearing would indicate a detonation issue. I would measure the lobes of the cam on that cylinder vs the rest.
     
  6. Evan McGinnis

    Evan McGinnis Farmall Cub

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    It does not seem to have been overhauled in the past. Yes, i did consider getting a bore gauge, and I now regret going the way of the telescoping gauges. I don't get consistent results with my (probably) poor technique.
     
  7. Evan McGinnis

    Evan McGinnis Farmall Cub

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    Unfortunately, I'm trying to do all of this with the engine in place. And it gets worse for me -- the main bearing I examined (nearest that cylinder) had some deep gouges/grooves. so I will need to replace those as well, looks like.
     

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