Rudder propeller drives?

Discussion in 'Surface Drives' started by OCB, Sep 2, 2016.

  1. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    Race boats have been using surface props on outboards for decades. They work very well at high speed going forward. Reverse has always been an issue. Personally I have been working on large surface drive props on yachts using ventilation at lower speeds, 700 800 rpm, issue again is reverse. They are just not designed to go backward. For a small boat, under 30, outboards are way to go. Just so many reasons, including better use of space, lighter overall installation, and yes better performance because prop is not under hull
     
  2. tom kane
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    tom kane Senior Member

    If you have a Retractable, Steerable surface drive you can just lower the drive from S/P mode down to subsurface mode then the drive works the same as a fixed shaft except you can use the prop to steer forward and in reverse. Fixed shaft drive installations work pretty well and have been the preference and mainstay of boats for a long time.

    Why spoil the best place on a boat by hanging a cumbersome and hungry and expensive outboard there?
     
  3. Alumination
    Joined: Oct 2013
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    Location: Knoxville, Tennessee

    Alumination Junior Member

    How about mounting a sterndrive higher up on the transom so it operates as a surface piercing propeller or surface drive at speed but is fully submerged and has all of the ease of a stern drive when maneuvering at slow speeds? Provides F-N-R, thru hub exhaust etc.

    What kind of hull do you have in mind and what speeds do you intend to operate over?
     
  4. gonzo
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    gonzo Senior Member

    That is a common installation on high speed boats. Outboards are also set like that.
     
  5. Alumination
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    Alumination Junior Member

    Yes, I was wondering if this would satisfy the needs of the OP?
     
  6. gonzo
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    gonzo Senior Member

    No, he doesn't want something that works and is commercially available. He wants to reinvent the wheel and the reassurance that the whole world will buy the new invention.
     
  7. OCB
    Joined: Dec 2015
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    OCB Junior Member

    Low RPM surface dirve

    How is your testing going? What type of drive are you using?

    OCB
     
  8. OCB
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    OCB Junior Member

    Surface drive with subsurface for reverse

    This is what i had in mind for reverse to help. Fix inboard is best for my needs!

    Thank you,

    OCB
     
  9. OCB
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    OCB Junior Member

    Hull design

    I am looking at a planing hull 24'- 28' inboard. What is the best hull to use with with surface drives?

    Thank you,

    OCB
     
  10. gonzo
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    gonzo Senior Member

    Surface drives have been used on every type of hull with success. There is no best hull. You need to determine the operational parameters or SOR and then decide which hull, and drive are best suited.
     
  11. Alumination
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    Alumination Junior Member

    Are you looking to go fast on smooth water?

    Surface drive on a tunnel hull/catamaran type hull is a great combination.
     
  12. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    I custom built it, boat was originally fitted with arnesons, mine are similar but have rudders between them. Next question is what happened to the arnesons. The previous owner didn't pay for then, and engines and they repossessed. The drives and props were like $150k. So I decided to changer to home built. Presently boat is out of water, and next week I start moving rudders, and moving exhaust into a better position. It is a lot of trial and error because of lack of information and contradictory information on things as simple as prop rotation.
     
  13. OCB
    Joined: Dec 2015
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    OCB Junior Member

    pickle fork

    I have a blown pickle fork i can use for test bed. I will use it for going fast on smooth water.

    OCB
     
  14. OCB
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    OCB Junior Member

    Custom surface drive

    Very nice to see someone doing it custom. 150K is why i,m doing this! Is there a thread i can see your SD project

    OCB
     

  15. Alumination
    Joined: Oct 2013
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    Alumination Junior Member

    That should be perfect.

    Who made the hull?
     
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