convert outboard to inboard jet drive engine

Discussion in 'Jet Drives' started by centrinoblue, Oct 26, 2014.

  1. centrinoblue
    Joined: Aug 2014
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    centrinoblue New Member

    This may be a naive question but is there anything in the design of a conventional outboard motor that would prevent one from laying it on it's side inside the boat to act as a motor driving an internal jet pump via the shaft?

    My guess is that there would need to be some modifications to the exhaust system.

    Maybe the lubrication system would't work as well horizontally?

    any insights appreciated
     
  2. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    meaning a 2 stroke
    then you need it to be EFI or rotate the carbs, then the onlyu thing then is not to get a high spot in the cooling system that can trap air, but addign a tell tale to that area would fix that.
    Then there is the puddle drain system and lubrication of the top and bottom main bearings and where is the new low areas that will collect the oil.
    There are quite a few laydown efi Merc's in all sorts of vehicles
     
  3. whitepointer23

    whitepointer23 Previous Member

    Look up mercury sport jet. I think thats what they were.
     
  4. powerabout
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    powerabout Senior Member

    Merc and OMC had inboard jets but the engine was upright as the pump was under the engine, not that efficient but they worked
     
  5. centrinoblue
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    centrinoblue New Member

    thanks for the replies.

    the whole carb/efi thing makes a lot of sense.

    I can only assume Merc. looked into a fully horzontal arrangement when designing the sport jet

    seems like a simpler design to have a single shaft straight out through the impleller than to pass it through some kind of diferential with the vertical arrangement
     
  6. powerabout
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    powerabout Senior Member

    They used centrifugal pumps not axial flow.
     
  7. drmiller100
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    drmiller100 Junior Member

    someone made an outboard jet which used a gear box to make the impeller shaft parallel to teh boat. not as efficient as the old school red pumps, and they died quickly.

    Water in the outboards gets swirreled. the water changes direction anyway - doesn't matter as much as you think.

    A guy could put a berkeley jet behind an outboard laid on its side, but why?
     
  8. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Some good insights from powerabout here, who knows his engines.
     

  9. powerabout
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    powerabout Senior Member

    Brp are now selling their sea doo engine n jet as a package
     
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