29' blackfin convert to outboards

Discussion in 'Powerboats' started by dimfiber, Apr 3, 2006.

  1. dimfiber
    Joined: May 2004
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    Location: FL

    dimfiber Junior Member

    Let's just start here. She is an '85 with Twin 454's. The vessel took on water during a florida huricanne ,Imagine that. Inboards prob. are gone. Intersted buyer, but would like to convert to outboards on a brackt. 1,000 + h.p.????????? I read all the time and this is actually my business. Very concerned about weight displacement.
    Thanks so much in advance. SE
    .
     
  2. Willallison
    Joined: Oct 2001
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    Location: Australia

    Willallison Senior Member

    The only way of really knowing what kind of effect converting to outboards would have is by establishing what the displacement, centre(s) of gravity (and buoyancy) of the boat in it's existing form are.
    Then it's simply a matter of doing a thorough weight calculation to establish what your new displacement and CG / CB positions are.
     
  3. Willallison
    Joined: Oct 2001
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    Location: Australia

    Willallison Senior Member

    Sorry - should also have said -
    In general though, you can expect the resulting boat to be quite a bit lighter. It should be faster and (depending on which o/b's you choose) will probably use less fuel. However, as this is a deep-vee (I believe) you may also find that it becomes rather uncomfortable (and noisy) at rest. This is because the boat will (probably) float with the chines out of the water, making it very tender to transverse movements on board and wind / wave action - ie it will be rocky-rolly!
    It's unlikely that it will simply be a matter of whipping out the old donks, bolting a bracket to the back and away you go. You will probably have to make significant changes to the on-board weights of the boat - batteries, tanks etc in order to get the trim correct.
    Bertram brought out what was effectively an outboard powered version of their 25 and 28 footers - powered by OMC Seadrives. They were - as I suggested above - lighter, faster, more economical than their inboard (or sterndrive) counterparts. They never took off - partly for the rocky-rolly at rest - and partly because people weren't quite ready to accept that "big" boats couls be powered by outboards
     

  4. blowhole
    Joined: Mar 2006
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    Location: Naples

    blowhole Junior Member

    I had a 25 bf with a 200 ficht 40 mph,30 inch bracket ran great and floated perfect
     
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