Blackfin 25 repower

Discussion in 'Powerboats' started by thoward, Jul 17, 2014.

  1. thoward
    Joined: Jul 2014
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Central Florida

    thoward New Member

    I have a Blackfin 25 Combi with twin 5.0L gas. I am moving to a 5.7L platform. It will be used for offshore fishing and I would like a 30 knot cruise if possible/reasonable. I am trying to figure out if it is worth the effort to put in mild 383 strokers(385-400hp) rather than the 350 300hp version.

    Boat is equipped with 1:1.5 velvet drives. To keep the props reasonable, the strokers would require bumping up a model and a 1:1 ratio.
  2. gonzo
    Joined: Aug 2002
    Posts: 15,494
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    Location: Milwaukee, WI

    gonzo Senior Member

    The new style 5.7 are 325HP. A mild 383 will produce about 350HP, so there isn't a huge difference.
  3. powerabout
    Joined: Nov 2007
    Posts: 2,925
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    Location: Melbourne/Singapore/Italy

    powerabout Senior Member

    when you say 5.0 to 5.7 are you going to use all the old marinising gear and carb etc?
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