Prop hub matched to gearbox

Discussion in 'Outboards' started by DogCavalry, Sep 24, 2022.

  1. DogCavalry
    Joined: Sep 2019
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    DogCavalry Senior Member

    Is this the correct relationship between prop hub and torpedo? It looks like turbulence to me.
    IMG_20220922_141743635_HDR.jpg
     
  2. baeckmo
    Joined: Jun 2009
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    Location: Sweden

    baeckmo Hydrodynamics

    Does not seem correct, the important thing is if there is a shortcut path for the exhaust from torpedo outlet into prop hub outer surface. Could you come closer to the critical area with the camera? Also check the shape of an original Evinrude prop. There are a number of small differences in the thrust washers for the available variety of engine-prop combinations.
     
  3. fallguy
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    fallguy Senior Member

  4. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

  5. DogCavalry
    Joined: Sep 2019
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    Location: Vancouver bc

    DogCavalry Senior Member

    Thanks fellows. There doesn't seem to be an option to select a large diameter prop hub to go with the large diameter gear case on the HO engine, so I guess the flow discontinuity is considered acceptable in the industry.
     

  6. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    its creates less drag, common on many large outboards when the case is a little bigger but uses existing range of props
     
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