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Amc 304 Worth Saving?

Discussion in 'Intermediate CJ-5/6/7/8' started by Jon B., Sep 23, 2024.

  1. Sep 25, 2024
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Dunno - my '73 CJ-5 threw the rear driveshaft at about 20K original miles. Your mileage may vary. I would not look to the 304 CJ-5 as an example of good practice.
     
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  2. Sep 25, 2024
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb

    Southern...
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    I dunno either, you could very well be right, It might just be one of those things you just have to try it and see what happens.
     
  3. Sep 26, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    I’ve started tearing down the engine. This is what #7 cylinder shows:

    IMG_3424.jpeg

    IMG_3425.jpeg

    The exhaust manifolds are off - had to cut off the bolt heads due to rust. The bolts should come out OK.

    Tomorrow, I should be able to get the heads off to see what sort of destruction lies inside. Then the oil pan.

    Jon B.
     
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  4. Sep 26, 2024
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Just minor carnage so far! Back in the late ‘70s, I bought a Commando with a pair of rods sticking through the forward side of the block and pan rail area (Dauntless V6). The guy drove it off the beach like that to the local service station to find the problem. I ended up buying it for parts for $35. I added some oil, started it up, and drove it about 7 miles home. The pistons were pushed up near the top of the cylinders 1 and 2, and the rods were broken off with both big ends still more or less intact on the crank journal. I drove it around the neighborhood on 4 cylinders for the better part of a week before breaking it down for parts I got almost $250 selling parts off it.
    I’m curious what turned loose in yours. -Donny
     
    Last edited: Sep 26, 2024
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  5. Sep 27, 2024
    vtxtasy

    vtxtasy oldbee 2024 Sponsor 2023 Sponsor

    Tucson, AZ
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    Happy late Birthday and welcome to the club! I suppose Dandy dropped the ball on this one.:D
     
  6. Sep 27, 2024
    garage gnome

    garage gnome ECJ5 welder

    Western MA
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    Your engine is missing the rocker arm bridges.
     
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  7. Sep 27, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    On an AMC 304? Son 2’s didn’t have them, either.

    Jon B.
     
  8. Sep 27, 2024
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Ol Fogie likes this.
  9. Sep 27, 2024
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Pullman, WA
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    The elusive V-7!
     
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  10. Sep 27, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    It might be a V6! Number 8 piston looks as though it has/had about a 6” stroke; it’s way, way down in the cylinder. I have the bolts out of the mounts, so will likely lift the engine out tomorrow. The beetles & box elder bugs are thick, so I don’t want to open the big shop door to get the tractor in to lift.

    Jon B.
     
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  11. Sep 27, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    Picture of #7 piston top:

    IMG_3426.jpeg

    What doesn’t show is that it’s not “square” in the bore. I suspect that the top of the piston broke off. I’ll know soon enough.

    Jon B.
     
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  12. Sep 27, 2024
    garage gnome

    garage gnome ECJ5 welder

    Western MA
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  13. Sep 27, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    Now that I’ve had time to think on it, the 304 in Son 2’s CJ7 DID have the rocker shafts running full length on each head.

    Mine is a ‘72, so I guess it’s “period correct”.

    I wondered if someone had just slapped on the data plate from a ‘72 but the SN is partially legible in the frame rail, and what I can make out matches the VIN.

    Jon B.
     
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  14. Sep 28, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    More”Rapid Unscheduled Disassembly” pics here. This engine turned out to be the very rare, highly-sought-after V5!!

    IMG_3439.jpeg

    Both the block and the crankshaft are trashed:

    IMG_3438.jpeg

    Off to the scrappers it goes.


    Jon B.
     

    Attached Files:

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  15. Sep 28, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    Oh yeah…

    This collection was in the oil pan sump:

    IMG_3429.jpeg
    Three rod ends & caps, one wrist pin, piston skirts and block fragments. Ugh.:censored:

    Jon B.
     
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  16. Sep 28, 2024
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    Cool. Intentional destruction? :confused:

    Power through!
     
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  17. Sep 28, 2024
    Jon B.

    Jon B. Retired three times; still working.

    SW Minnesota
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    It does make me wonder. Throttle stuck wide open and driver panicked, maybe? It wasn’t overheated or run w/o oil.

    Maybe a PO’d buyer returned it to the seller to teach a lesson…? I’ll never know - or care, even.

    Jon B.
     
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  18. Sep 28, 2024
    Fireball

    Fireball Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    Awesome carnage. Can't say they didn't get everything out of it.
     
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