hull design changes, slide VS unwanted cowboy's

Discussion in 'Metal Boat Building' started by emendel, Mar 7, 2017.

  1. emendel
    Joined: Mar 2017
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    Location: smitherss

    emendel Junior Member

    I do not. But as soon as the ice gets off the lake I'll be sure to take those shots and show them to you. Par, I appreciate you taking the time to respond to me and all the other people. I've been spending hours combing through this forum and I'm learning quite a bit from the other people you very tried to help. It's nice to see guys like you and Barry are willing to share your knowledge
     
  2. Barry
    Joined: Mar 2002
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    Barry Senior Member

    Is there any chance that you have a bow mounted fuel tank??

    If you can borrow a level that you can adjust one of the levels to read the trim angle of your boat on step at different speeds, take some trim measurements from say 15 to 30 mph. A flat bottom hull should have an attitude of about 4 degrees. If less, it might be because you have too much weight in the front, if it is more, then too much weight in the back. Of course the thrust angle of the jet will play a part in this.
     
  3. emendel
    Joined: Mar 2017
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    emendel Junior Member

    2 Saddle mounted tanks. Each one is 40 gal so 400lb per side approximatly 12 inches behind the driver/ passenger chairs in terms of hull. Their about the same distance back from the flat of the front as the engine is back from the flat of the end of boat. I do feel their the best ballance I'll get as this boat doesn't change handling with the tanks full vs empty. Considering that difference is 800 lbs I find this amazing...
     
  4. emendel
    Joined: Mar 2017
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    Location: smitherss

    emendel Junior Member

    Thanks Barry and par. I will try these and take photos and report on what my findings are. With all the reading I've done this is what I'm gonna try. Gonna use 1/4 angle try and get a maximum of 5deg angle to the horizontal water line and make the outside edge of my chine 45 degree. So as to attempt to prohibit chine tripping. I'm also gonna cut that horrible angle off the nose and try to draw the delta pad forward causing a smoother contacting surface on the bow (hopefully) from their I'll test things out and decide if I need a pair of strakes between the Chine and pad.
     
  5. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Leave it alone, and ease off the throttle, rather than hack into it here, there, and everywhere. It does need more lateral plane aft, it would need it if it were an outboard too.
     
  6. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Agreed, don't screw with too much at once, or you'll never figure out what worked or didn't. Playing with the pad will have horrible effect, if you don't know what you're doing and results can be exceedingly difficult to quantify, without tank testing. The chine strake in the forward portions can remain as they are. They'll sort of knock down spray, but this isn't the big concern. Address one issue at a time, so you can see results based on the problem your were addressing. In other words, sneak up on it, so you know if you're heading in the right direction.
     
  7. Barry
    Joined: Mar 2002
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    Barry Senior Member

    It sounds like you are only going to turn the chine down. That will not be enough. You need strakes between the centerline of the boat and the chine.

    You can use the dimensions that I recommended that work incredibly well for a 12 degree deadrise. Or you can use Pars, but as suggested, turn the chine down, add in another set of strakes between the keel and chine or if you are worried about jet intake interference, put the mid strake halfway between the chine and the side of the jet intake.

    Not sure how much experience that you have had with your boat, but as your are going upstream if you drop your speed so the chine goes below the water, the boat will turn quicker without spin out. It will draw a bit more but you can control it.
     

  8. emendel
    Joined: Mar 2017
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    Location: smitherss

    emendel Junior Member

    Well Barry, we managed to flip the boat today and I cut the channel. I'll post some pics when it's done. How far from the nose do you suggest ending my center strakes? I'm running one each side in the middle for now.
     
    VinTin likes this.
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