Evinrude E-TEC as an inboard sailboat auxiliary

Discussion in 'DIY Marinizing' started by Snapdragon, Nov 27, 2018.

  1. Snapdragon
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    Snapdragon Junior Member

    Hi Folks,

    I dislike the smell, roughness and noise of diesel engines as auxiliaries in sailboats.

    Has anybody taken an E-TEC powerhead from say, a 40hp twin and attached it to a marine gearbox and fabricated an exhaust manifold to suit?

    If it was run at 3000rpm to produce around 25hp, it would make a nice auxiliary.

    Am I breaking new ground here?

    OMC used to produce a sail drive unit as an auxiliary for yachts using the 25/30hp conventional 2 stroke twin powerhead, but I would be looking to install it as a conventional shaft-drive setup.

    Direct injection with a sealed fuel system would be pretty safe, too.

    Thanks to anyone who can shed some light on this. :)
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

    You envisage running it vertical as in the outboard mode ? That would not mesh too easily with your gearbox, I don't know what the implications would be of running one horizontally. The innards of these things are lubricated by oil that maybe relies on gravity for proper re-circulation, we know not much is burned, but whether lying it down mucks that up, I don't know. You also have issues of cooling water and exhaust to complicate matters, and the extra revs may mean your prop selection is a problem.
     
  3. Snapdragon
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    Snapdragon Junior Member

    Thanks for your thoughts.
    I envisaged running it horizontally. Two strokes are lubricated by oil mist, so orientation shouldn't matter.
    It will need to run a raw water pump, and the exhaust could be tricky, I'll grant you!
    By using a larger engine (say 40hp) at a maximum of 3600rpm to get my 25 hp, I should be able to run a 3:1 gearbox for reasonable prop revs.
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    I really don't think it is a practical proposition. Or maybe no more practicable than using a conventional outboard set-up.
     
  5. Snapdragon
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    Snapdragon Junior Member

    Thanks.
    My other options are a rebuilt Atomic 4 or a marinised Kohler water cooled T win or a Westerbeke triple as used in their generators.
    I just happen to like the simplicity and low maintenance requirements of a 2 stroke.
    I was just checking to see if anyone else had gone down this path. :)
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    When you think about it, the circulation of cooling water in the powerhead would be problematical, the discharge of water to cool the exhaust, etc etc, this is not an idea to follow through on, imo.
     
  7. trip the light fandango
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    trip the light fandango Senior Member

    Is it possible to mount the outboard inboard and run a prop shaft from the original prop position with extra bearing guides or journals on the new shaft etc. From there it is relatively easy to organise water and exhaust and access to the motor should be excellent, plus your leaving the integrity of the original engineering, just a thought, from a bloke who should be working on his boat not reading and waffling.
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    Ya reckon ? Maybe for someone of my abilities, not so easy !
     
  9. trip the light fandango
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    trip the light fandango Senior Member

    An extra water pump and maybe a clear header tank and alarm [ 5- 10litres per minute?? I don't know}..ha , I did say relatively,as in compared to the original idea of Snapdragons , I wouldn't say it was easy to change the original intention for the motor.
    Quickly changing the subject because Mr Efficiency is right ,..ETEC s are a proven good idea, Dolfin or one of the manufacturers of inboard 2 strokes should use direct injection . The 12hp dolfin motor would be too small but I 'm a fan, the smell of diesel is pretty carcinogenic and nauseating, people just put up with it because it is better on just about every other level.
     
  10. trip the light fandango
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    trip the light fandango Senior Member

    A direct injection 40hp motor bike would be a better, . relatively..easy[ha].. donor, I only know of 50cc Italian scooters with that set up.
     
  11. Milehog
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    Milehog Clever Quip

    The new direct injection two strokes will die on just an oil-gas mix. They have oil pumps and reuse lube oil. Laying it down will kill it.
     
  12. gonzo
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    gonzo Senior Member

    Even though the lubrication is through the mist, there is oil accumulation at the bottom of the crankcase chambers. The oil gets recirculated through vaccuum, which would not work on a horizontal motor. The carburetors would dump all the fuel and not work either. The water jacket is designed for a vertical position. On its side the water circulation would not work as designed and also there would be air pockets and hot spots. Further, the electric and fuel systems are not certified for inboard use because they may cause an explosion.
     
    philSweet likes this.
  13. Mr Efficiency
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    Mr Efficiency Senior Member

    I assume the motor has no carbs, being a fuel injected engine, but there are nothing but problems trying to adapt it for this purpose, it doesn't hurt to think about it, but after a few minutes you start to see the issues are too many, and too difficult.
     
  14. Yellowjacket
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    Yellowjacket Senior Member

    These engines do not "recirculate" oil, they are total loss lube systems. As noted above, the oil is injected into the crankcase where it "puddles" and excessive oil is ingested into the incoming air and passes through the combustion process. Note that I said it mixes with incoming air, since these are direct injection engines, there is no fuel in the crankcase. There could be issues with running the engine laid down, but it may work fine. Most of that would have to do with how the crankshaft bearings are lubed. Most 2 strokes nowadays have a passage that goes from behind the bearing to the intake ports. When the engine breathes, some air mixed with oil is drawn through the bearing and this insures good bearing lubrication. Depending on how you orient the engine, it should be fine. More than likely the best orientation would be with the cylinders laying on their side, this provide a place for oil to puddle in the crankcase where a vertical orientation would have the oil pooling in the inlet and then getting mixed with the incoming air prematurely.

    The real issue here is that the cooling water is mixed with the exhaust and then dumped into the tower. If you have the motor deep in the hull, below the waterline the water mixed with the exhaust will have to be pumped up to the waterline level. Moreover, outboards are meant to be continuously cooled by total loss cool water inlet cooling system. That means that there is a lot of excess cooling capability available compared to motors that rely on recirculated hot water. What most outboards do is cool the exhaust area of the powerhead with a water jacket. Since there is excess cooling available this is no big deal, and if you're going to use a total loss water system that's fine, but corrosion is always an issue with such systems. If you want the engine to last a long time it should be stored dry, or have sweet water cooling system installed, but with the water mixed exhaust that's more difficult do. Not impossible, just more difficult. You will have to plug the previous water exit and recirculate the water through a heat exchanger. Then you have a dry exhaust (heat issues again) which are not horrible, but need to be designed around. The ETEC motors use a thermostat, so they are more modern than some other motors in that regard, but with a recirculating system it will have to be larger since the exhaust area is being cooled increases the heat load.

    The ETEC 40, 50, and 60 hp are all the same motor, just different levels of tune. One thing to note is that this is a 2 cylinder motor with a pretty healthy displacement. It is not know for its smoothness. While better than a 4 stroke diesel, until you get the motor up to a reasonable rpm it isn't going to be smooth.
     

  15. Mr Efficiency
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    Mr Efficiency Senior Member

    All outboards have thermostats, but this idea of conversion to an inboard motor just opens a can of worms, and is fighting against the in-built design on so many levels as to be verging on insanity to attempt it.
     
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