What's going on with my engine cases?

Discussion in '2 smokers' started by MikeGayner, Jul 26, 2014.

  1. MikeGayner

    MikeGayner Adventurer

    Joined:
    Jan 4, 2014
    Oddometer:
    33
    I've got my crank back and am getting ready to put my A7's engine back together. I was doing another clean-up and noticed this weird surface cracking on parts of the engine case. Mainly this is occurring in the part of the case that meets the barrels - not the mating surface but the inside surface. Does anyone know what's going on here? Is it cause for concern?

    http://imgur.com/a/x4Noe

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    #1
  2. XRGRIFF

    XRGRIFF Adventurer

    Joined:
    Mar 6, 2005
    Oddometer:
    74
    Providing there are no actual cracks, it's normal, something to do with the temperature of the mold when metal is injected, creates marks when surface in contact with the mold cools too quickly.
    #2
  3. MikeGayner

    MikeGayner Adventurer

    Joined:
    Jan 4, 2014
    Oddometer:
    33
    Thanks, no signs of cracks and the cases are in excellent condition. This is all a first for me, digging into an engine like this.
    #3
  4. MikeGayner

    MikeGayner Adventurer

    Joined:
    Jan 4, 2014
    Oddometer:
    33
    Tell me if I'm being a nuisance, but I've just noticed these "flaky" areas in the intake ports. None of the material is loose, but it still looks dodgy to my eyes - should I grind off these areas to be safe, or am I being a bit over the top? Thanks.

    Full resolution: http://imgur.com/a/6bI3B

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    #4
  5. XRGRIFF

    XRGRIFF Adventurer

    Joined:
    Mar 6, 2005
    Oddometer:
    74
    It's casting "flash". where metal has crept around the cores in the mold.
    If it hasn't moved in what is a lot of years, it probably won't go anywhere.
    Me. I'd tear it down to the last nut and bolt and clear the holes, de burr etc. But I am a bit fussy (understatement)!
    #5