Jet DIY

Discussion in 'Jet Drives' started by Duco84, May 19, 2022.

  1. comfisherman
    Joined: Apr 2009
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    Location: Alaska

    comfisherman Senior Member

    Aerated jets won't load. There is no way around it. Gonzo was being polite, I'll be a bit more to the point. You have a heavy boat with a bottom very poorly suitable for jet applications. We could talk about the low power mains, nozzle diameter, or weather or not 12 knots is an ideal speed for high rpm small diameter jets on a relatively heavy boat.... but as long as those intakes have a strake running in front of them it's a moot point. You could bolt a built ls1 in front of and still just make lots of bubbles.

    Maybe delta pads would be enough... but a jet aligned with a strake... not much helps that.
     
  2. anthony goodson
    Joined: Mar 2007
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    anthony goodson Senior Member

    This is the same jet, but the "inboard" version ,showing more detail of the impeller ,wear ring ,and nozzle
     

    Attached Files:

  3. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell . . . . .

    I think what's happening here is his brother failed so Duco is going to make it work come hell or high-water!
    Good luck Duco, be sure to let us know how this progresses, please.
     
  4. Duco84
    Joined: Feb 2014
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    Duco84 Junior Member

    Please advise HP of engine, impeller and nozzle diameter, also please if you have some photos of inlet
     
  5. anthony goodson
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    anthony goodson Senior Member

    See above for dimensions ,and no sorry no pictures of inlet.
     
  6. Duco84
    Joined: Feb 2014
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    Duco84 Junior Member

    Please advise Horse Power of subject engine. Also, if someone can advise Pitch of impeller.
     
  7. baeckmo
    Joined: Jun 2009
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    Location: Sweden

    baeckmo Hydrodynamics

    Ok Duco, we have tried to point your nose in the right direction for learning and examples. Now it seems to me you want a complete design, step-by-step, for a one-off waterjet for free??! Sorry, but that kind of designwork is what brings salt and bread to my table; I am willing to offer advice, but not the "full monty", so I'm out from here. Good luck!
     
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  8. Duco84
    Joined: Feb 2014
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    Duco84 Junior Member

    Thank You!
     
  9. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    The hull is not good for a jet drive. Nothing you can attach to it will make it perform properly. That is the best advice you can get. You have a square wheel and insist there is some way to make it turn smoothly. It won't work.
     
    DogCavalry likes this.
  10. Duco84
    Joined: Feb 2014
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    Duco84 Junior Member

    Thank You Gonzo, please advise what is problem with this hull? I saw similar boats with jets.
     
  11. Duco84
    Joined: Feb 2014
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    Duco84 Junior Member

    Let’s talk abt jets, why 190mm impeller didn’t load engine 80hp 4200rpm?
     
  12. Duco84
    Joined: Feb 2014
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    Duco84 Junior Member

    Cavitation?
     

    Attached Files:

  13. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    There is a hump in front of the intake. Also, the intake has large gaps around the edge. Unless you make a hull that allows smooth flow into the intake, it won't work.
     
  14. Duco84
    Joined: Feb 2014
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    Duco84 Junior Member

    You think on marked area?
     

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  15. DogCavalry
    Joined: Sep 2019
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    Location: Vancouver bc

    DogCavalry Soy Soylent Green: I can't believe it's not people

    The problem with the square wheel is too bumpy a ride. Soviet engineers have determined that a triangular wheel would have 25% fewer bumps per rotation. A huge improvemet!!

    But for this hull, no such improvement is possible. A basic surface drive, like Hickman's original work, is the only realistic way forward.
     
    gonzo likes this.
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