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Thread: purty dumb question - 2 cyl marine plans

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    purty dumb question - 2 cyl marine plans

    I have an old set of plans from a 1950's magazine for a model 2 cylinder open frame marine engine. The problem is a missing dimension for the cylinder block.
    It is shown as 1.5" by 4.0" by ?? for the height.
    OK The stroke is 0.875" and the piston height is 0.250" so what should be the depth of the bore? Also what would be a reasonable clearance between the piston and the cylinder head?
    Thanks,
    Bob B.


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    I have decided to just go for it. I will allow 1/16" clearance at each end of the stroke. That should be enough not to crash a piston. Thanks anyway all, Bob B.


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    2 Cyl Launch Engine

    Bob B, you stated you have plans from a 1950 magazine. Which engine and which magazine please? The John-Tom site has quite a few 2 cyl engine plans. There are photos and a video (short) of my PMR 3BI runnming on HMEM. Under Photos and Videos, I think. Ray (ironman on HMEM), miniengine here


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    Quote Originally Posted by miniengine View Post
    Bob B, you stated you have plans from a 1950 magazine. Which engine and which magazine please? The John-Tom site has quite a few 2 cyl engine plans. There are photos and a video (short) of my PMR 3BI runnming on HMEM. Under Photos and Videos, I think. Ray (ironman on HMEM), miniengine here
    Hello Ray,
    PS January 1953, "Model Marine Engine Requires No Castings"
    Thanks I will check out the photos and video.
    Bob B,


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    Good evening Bob,

    I've got this set of drawings and, accorded to the text, it's clearly stated that the cylinder block dimensions are the following: "Bore is 1" and stroke .875"." Then the cylinder block is 4" x 1" x 1" 1/2 (length x heigth x width).

    Hope this helps.

    Akitene


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    Thanks Akitene,
    I could have guessed, but it is better to know for sure.
    Bob B.


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    If you have to guess, it's always better to guess a little bit on the long side. You can always add some shortness.

    Tom


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    Thanks, I have good supply of shortness if needed. LOL
    Bob B.
    Last edited by 40fordcoupe; 05-17-2010 at 05:11 PM. Reason: forgot something


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