Inboard to Outboard Conversion

Discussion in 'Boat Design' started by FrigidNorth, Mar 27, 2014.

  1. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    I was thinking 4lb might do it, but higher density is going to be more durable, but what volume is involved ? The weight could start to add up.
     
  2. whitepointer23

    whitepointer23 Previous Member

    this is wrong. I bet at least 80 % of outboard boats in Australia don't even do 30 knots. every outboard I have had cruised at 16 - 25 knots.
     
  3. Mr Efficiency
    Joined: Oct 2010
    Posts: 10,401
    Likes: 1,033, Points: 113, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    Were you powered by twin 250's, as is the matter under under discussion ? I think 30 knots would be the anticipated cruise for the performance boats I spoke of. This boat is not of that ilk. Here is an example, note the optimum speed given is around 35 mph.
    http://www.yamahaoutboards.com/site...hore_hs4_cnd_27t_t_f250xca_2011-06-15_occ.pdf
     
  4. FrigidNorth
    Joined: Dec 2012
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    Location: Kenai, AK

    FrigidNorth Junior Member

    After quite a bit of number crunching, evaluation of my fiberglass skill level and time available it appears that a bolt on aluminum bracket may be a better choice than a hull extension. I would lose the corrosion resistance and lack of numerous through bolt penetrations that a hull extension would grant, but I would gain quite a bit of time savings, a proven concept and design, and I wouldn't be guessing at the scantlings for the extension which I cannot find any information on. But... the prop pockets would have to be cut out, hull shell glassed in and reinforced as part of the bottom/transom.

    I'm guessing I'll save $2500 in materials to put towards a bracket which will probably cost $4-5000 dollars.
     

  5. rustybarge
    Joined: Oct 2013
    Posts: 533
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    Location: Ireland

    rustybarge Cheetah 25' Powercat.

    These are what you need, they bolt onto the transom:http://www.armstrongnautical.com/index.htm

    and the video:https://www.youtube.com/watch?v=mvcksCz0OBM
     
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