Outboard Bracket Hydrodynamics Help

Discussion in 'Hydrodynamics and Aerodynamics' started by flboats, Aug 7, 2016.

  1. TANSL
    Joined: Sep 2011
    Posts: 6,726
    Likes: 491, Points: 93, Legacy Rep: 300
    Location: Spain

    TANSL Senior Member

    Nobody wants to increase the volume on that way. Wrong assumptions and therefore inappropriate response. Think of hydrodynamics, which I know is an issue that you like, and water flow into the propeller.
     
  2. flboats
    Joined: Mar 2016
    Posts: 13
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Grant FL

    flboats Junior Member

    I'm not too worry about drain holes, I can relocate them to the inside bottom of the pontoons close to the keel like on many inboards and ski boats, so I can lower all away even with bottom, also I will have better access from inside the hull to the drain plug when I have my boat on the boat lift.
     
  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,179
    Likes: 966, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    I don't know why you think the same pod will accomodate different shaft lengths, it won't.
     
  4. SamSam
    Joined: Feb 2005
    Posts: 3,900
    Likes: 197, Points: 63, Legacy Rep: 971
    Location: Coastal Georgia

    SamSam Senior Member

    If he remounted the pod 5" lower, why wouldn't it?

    But, it does look to be that if the pod was lowered, the motor head would be in a good position to get periodically swamped by waves, plus it looks so low that you wouldn't be able to tilt the leg out of the water when moored at anchor or at the dock. The tilt and trim mechanism would always be in water and would fail earlier than normal.
     
  5. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,179
    Likes: 966, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Well, it isn't just a matter of lowering the pod 5" and everything is good, it could well be (depending on the dimensions of the pod) that the cavitation plate is higher than the bottom of the pod by some inches, with a 25" motor fitted. It is hard to imagine that the 30" setting has the cav plate well below the bottom of the pod. At best you would periodically have the leg above the cav plate submerge in a shower of spray, and considerable drag.
     
    1 person likes this.

  6. flboats
    Joined: Mar 2016
    Posts: 13
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Grant FL

    flboats Junior Member

    Thank you for all your help, today I bought 2 30" shaft engines, so I will put back to the original position
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.