Houseboat conversion

Discussion in 'Boat Design' started by bill knight, Jan 14, 2021.

  1. bill knight
    Joined: Jan 2021
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    Location: corpus christi tx

    bill knight New Member

    Hello, yall I live on the Texas coast and I love our water here, but those damm sand bars are a pain, so being I am rebuilding my old houseboat to accommodate the skinny water at times I have removed the inboards and I am going to install a bracket with twin 250s with a jack plate. I am reading the posts on here trying to see if it's feasible to install twin tunnels. I have about 8 ft length to install them between the existing stringers. I am thinking from 0 to 18 inch tunnels. Please inform me of your thoughts. Thanks
     
  2. gonzo
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    gonzo Senior Member

  3. bill knight
    Joined: Jan 2021
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    Location: corpus christi tx

    bill knight New Member

    Interesting idea. I have no experience with jets. Do they have as much power as props? Can you tell me what are the pros and cons? Thanks for your input
     
  4. gonzo
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    gonzo Senior Member

    They are a direct bolt-on. On a houseboat you won't notice much of a difference of top speed; maybe 10% less. The installation height of the motor is about 6 inches higher. The intake goes flush with the boat bottom. That means it is at about the same height as the anti-ventilation plate on an outboard. Most problems with jetdrives come from sucking debris or weeds. This forum is a good source of information on jets: JetBoaters.net - The World's Largest Jet Boat Forum! https://jetboaters.net/
     
  5. bill knight
    Joined: Jan 2021
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    Location: corpus christi tx

    bill knight New Member

    Thanks for that but in the shallows, a lot of weeds and crap. Not that I'm going to be in them, but a prop is easier to clean up and repair.
     
  6. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Jet pumps on outboards are very inefficient, HP is reduced by about 30% or more, fuel usage is similarly worse. They are also very load sensitive, so pushing a heavy load isn't their best application.
     
  7. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Welcome to the Forum Bill - do you have photos of your houseboat that you could post on here please?
    Re how she previously had inboard engines, I presume that these were with outdrive legs, rather than shaft drives?
     
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  8. DogCavalry
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    DogCavalry I aim to misbehave.

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  9. DogCavalry
    Joined: Sep 2019
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    DogCavalry I aim to misbehave.

    As a part time mechanic I would really prefer to pull wrenches on an inboard rather than an outboard. Crowded systems those!
     
  10. Pyro Chuck Scheerschmidt
    Joined: Tuesday
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    Location: Snyder, TX

    Pyro Chuck Scheerschmidt New Member

    Our houseboat was originally equipped with twin Chrysler 318 V8 engines w/Dana outdrives. That was back in 1966 and I just bought her last year. Luckily for me, the inboards and outdrives have already been removed. Having been in and around boats all my life and having been a Marine Technician for many years in FL I prefer outboards hands down. I am 6'3" and 235lbs and absolutely despise having to be a bilge rat.

    I understand where you are going with the tunnel idea but it may not even be necessary if you build/buy a proper outboard bracket to hang your motors on, depending on setback of course. This will generally allow you to lift the motor up an inch for every 10" of setback ... averages of course nothing being set-in stone really.

    I am going to find me a nice pair of old 200-250hp 2-strokes to hang on the back of ours at about a 30" setback which will allow for a very nice swim-platform as well back there. Way back when motors were rated at crankshaft and not propshaft as well so the 210hp-rated factory engines were more likely about 175 at the prop maybe a smidgen more whereas my 2-strokes will be putting between 200-250hp to the water at the prop. All together it will still way less than the original setup as well, So with less weight, higher mounted motors (less drag) and more actual horsepower at the prop it's a WIN/WIN/WIN if you ask me.

    What year, make and model is your houseboat Bill? What motors and outdrives does it currently have? Where are you in TX?
     
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  11. DogCavalry
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    DogCavalry I aim to misbehave.

    Can't argue with your experience Chuck. I'm 6'4" and 225. For me its trying to jam the paws I got instead of hands into small spaces. I'm on my 5th chevy astro. I love the damn things, but I hate working on them.
     

  12. gonzo
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    gonzo Senior Member

    Brackets sometimes work fine going forward. Usually that is in boats that are trimmed down by the stern so the propeller is in the water. A houseboat is not likely to have a huge difference in trim. Also, in reverse the propeller is probably going to ventilate whether it is a bracket or a tunnel.
     
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