403 Block crack
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Thread: 403 Block crack

  1. #1
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    Default 403 Block crack

    O well, it's my turn. I'm getting into the nitty gritty of doing the 403 engine and upon knocking out the sleeves I found a crack between the two front cylinders, down the bottom where the seals bear.
    It's hairline, not open, and from the blackness seems to be an old one. Glad I didn't do it as the sleeves were pretty tight to knock out, but there it is. I'm lucky I have another that isn't cracked so I'll be using that. No sense taking silly risks is there?
    Or is someone going to tell me it's common and I needn't worry?

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  2. #2
    Fellow Frogger!
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    Well I for one don't think that you are stupid but it is redeamable. If anyone wanted to use a cracked block without fixing it they are nuts. If you wanted to fix it chase a "V" along the crack and use an old cast iron ring and braise it together with that. An old trick used in cooling aluminium is handy here by using lime to cool it in as it cools more slowly and evenly which reduces the possibility of distortion, the metal weakening around the crack or even further cracks. Then the fun begins to make sure you machine and clean it up properly so the seals and then the liners "home" correctly.
    FLASH

  3. #3
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    If you say it's redeemable that's good enough for me Flash. Therefore it will henceforth take up space under my bench somewhere instead of going to the scrap merchant.
    Perhaps it might be of use to a mad pug nut in the future when no more blocks are out there.
    Interesting idea with the lime and then sounds like a nightmare at the engine machine shop.
    Thanks for your reply.

  4. #4
    Fellow Frogger!
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    No problems, I even had a 403 where crack in the block had been "stiched" with little plates and small bolts along the length of the crack ( 3 in 4"). I presumed that it had been welded on the inside but it looked interesting and was still in the car when I sold it. I often wonder if it still exists and maybe even still going. It was an off-white with a red side flash and red interior (weren't nearly all of them?) and I sold it in the early 80's to a bloke in Albury.
    (I forgot), I also had a Simca wagon that had the block "stiched" with staples, like you see on the side of a building, over a weld that ran down the block. The owners back then were more resourceful or new blocks were too expensive or difficult to source and "they" had to deal with cracked blocks probably due to frosts. In the current throw-away society I cannot imagine anyone trying to fix a cracked block on one of today's vehicles.
    Both vehicles had had the repairs done well before I owned them and both held water and oil so the fixes worked.
    FLASH
    Last edited by Flash Car 76; 2nd October 2011 at 11:06 AM.

  5. #5
    Fellow Frogger!
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    It is common and you needn't worry ! (larfing loudly) "anon"

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