I would like to make a main engine bracket

Discussion in 'Boat Design' started by the brain, Apr 1, 2025.

  1. the brain
    Joined: Sep 2016
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    Location: AL

    the brain Senior Member

    I'd like to try an make a 26" setback. my transom is 16*. apparently this example pods transom end is 90* angle

    home made pod

    [​IMG] an the pod is only angled at engine end is it easier to just have one end angled. do you minus the vessels transom angle to the pods engine ends angle?
    my current pod a early90s armstronge is angled on both ends.

    90degree

    [​IMG]

    I believe my pod has a 90* on both ends an will basicely extend/duplicate any vessels transom angle whatever it's angle is? is this true of false

    This is the only angle I see at top

    Start top as square then cut desired kickup angle

    [​IMG]

    duplicating my pod

    [​IMG]

    when the transoms 16* angle is added the top of pod is 180 horizontal.
     
  2. Barry
    Joined: Mar 2002
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    Barry Senior Member


    False unless your original transom angle is zero degrees, with respect to vertical and you want the engine to sit at the same height as if it was mounted on the transom.
    If your transom angle is 14 degrees, (somewhat of an industry average but you can check the information on your particular engine on the internet, normally you can find the
    recommended angle in an Installation Manual) then your extension has to have the 14 degrees angle off vertical and there needs to be a corresponding parallel 14 degree angle where the motor is attached to

    Certainly you would be able to have the TOP of the pod flat, with respect to say the keel, as many boats now incorporate a swim grid as part of the engine mount.

    If your boats transom angle is 14 degrees and you have 90 degrees on both ends of your mount, then the engine mounting location will be lower than it should be.

    A quick calculation if your extension is 26 inches horizontally back off a 14 degree transom, it drops the motor about 6 1/2 inch.

    I am using the term horizontal as parallel to the keel
     
    Last edited: Apr 5, 2025
    fallguy likes this.
  3. fallguy
    Joined: Dec 2016
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    fallguy Boat Builder

    False.

    Barry has explained it well.

    The angle of the transom-hull bottom is 90 plus the transom angle. In order to maintain the hull in a straight line (if desired and to keep the sheer of the pod level, for a 14 degree transom, the angles are 104 on the bottoms and 76 on the tops. Unfortunately, doing so will reducd the transom height. This is why the transom is raise in all cases shown. Barry also explained this well, but as a drop and not as corrected..
     
  4. fallguy
    Joined: Dec 2016
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    fallguy Boat Builder

    If you need help with the math, dm me.
     
  5. Barry
    Joined: Mar 2002
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    Barry Senior Member

    The reference to the OP wrt the drop is if he just took say a square tubing bracket 10 x 10 inch x 26 inches long and cut the ends at 90 degrees to the length. So he would have a drop of 6 1/2 inch prox

    While your angles are correct, my combination square shows 90 degrees as zero. So I would put in 14 degrees and take a 14 degree cut off that side. The square resting say on the bottom then switch to the other side of the and take the square to the other side and put the square on the top, and scribe that line. That will give me parallel 14 degree cuts off the END of the bracket and
    no drop.
    26 x Tan (14 ) = 6.47 inches = drop if he used 90 degree ends, or zero on my Starret combination square.

    You are correct if your combo square gives you 90 as a starting point. Just depends on where you take the starting point
     
  6. Tops
    Joined: Aug 2021
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    Location: Minnesota

    Tops Senior Member

    I would consider making some cardboard templates/mock-ups on the boat before committing to metal.
     
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  7. the brain
    Joined: Sep 2016
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    Location: AL

    the brain Senior Member

    I'm holding off on a new pod an am sealing the current pod to use w/ new transom.thanks all for advise.
     

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