Diesel Outboards

Discussion in 'Propulsion' started by Silverbreeze, Jul 4, 2016.

  1. Silverbreeze
    Joined: Feb 2009
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    Silverbreeze Bruno Tideman

    Just to give a quick overview of what is available at the moment:

    www.mercuryracing.com/wp-content/uploads/2015/05/2557_DieselOB_SS_NC1.pdf
    Mercury Optimax DSI, 175hp 240kg (only for commercial and military use, not very clean and fuel efficient but relatively cheap) (€ 21k)

    www.oxe-diesel.com
    OXE diesel, 200hp 340kg (quiet, clean and fuel efficient) (€ 42k)

    www.neander-dtorque.com/
    Yanmar D-torque, 50hp 175kg (quiet, clean and fuel economic) (€ 28k)

    http://coxmarine.com/
    Cox Powertrain, 300hp 300kg under development.....

    All these engines are using our HDPE Rigid Bouyancy Boats ad demo platform:
    www.tidemanboats.com
     
  2. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    Other than the merc that is not epa compliant anywhere there are rules, are any of the others in production?
    All the press talk above is the future...
    How about working engines?
     
  3. Silverbreeze
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    Silverbreeze Bruno Tideman

    Yes, the Oxe can be ordered!
     
  4. FAST FRED
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    Most large gas outboards are based on car engines.

    Today in rational commercial service these will go 2000, to 4000 hours before replacement or rebuild.

    The fuel burn is now in the 14HP/GPH area , about what a diesel not operated in its BMEP sweet spot might obtain.

    At 2x the weight and at least 3X the cost , and 5X the noise , what is the "advantage" of a diesel outboard?
     
  5. powerabout
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    powerabout Senior Member

    so thats not Merc BRP and Yamaha, so who is it?
     
  6. Silverbreeze
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    Silverbreeze Bruno Tideman

    Hi Fred, I guess you are in US and not in a country where gas is expensive?

    1. Safety: diesel has a much higher flame point than petrol, thus it is much safer to operate a boat which runs on diesel
    2. In Europe diesel is much better available than petrol and a lot cheaper too!
    3. Diesel burns 2x as lean than petrol (14hp/gph equals 50lph/100hp for petrol) as all modern common rail engine take about 210gr/kWh (equals 25lph/100hp)
    4. Weight difference in only minimal
    5. Diesel engines are now as quiet as their petrol equivalent
    6. Diesel engines have much more torque which is good
    7. Diesel engine are much more reliable than petrol

    Only advantage for petrol engines is that they are is cheaper to buy, but if you use your boat more than 200 h/y it is a better investment (specially for workboats)
     
    DogCavalry likes this.
  7. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    The Optimax doesn't qualify as a diesel engine because it has spark plugs!
    It is no more than a modified 2-stroke, noisy, inefficient and certainly not clean. Probably any outboard accepts diesel fuel if glow plugs are added. I know from earlier experiments with car engines you can add up to 50% diesel fuel in summer.
     
  8. powerabout
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    powerabout Senior Member

    and you cant own one unless outside of USA and Europe
     
  9. Silverbreeze
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    Silverbreeze Bruno Tideman

    Agree about the Otimax not being optimal for diesel. We can buy these in Europe because we only use them for military and commercial outside EU...
     
  10. FAST FRED
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    "Diesel engines are now as quiet as their petrol equivalent"

    Only if they have HP fuel rails and complex electronic injection .

    ." Diesel engine are much more reliable than petrol"

    Old diesels perhaps , once started would run till out of fuel, but fuel is the big downfall of a modern electronic diesel.

    The fuel MUST be cleaner than current US or Euro standards require.

    This means a complex in depth fuel cleaning setup on board, multiple filters to change , or an Expensive Alfa Laval centrifugal set up.

    Past issues of Professional Boat Builder will explain.
     
  11. Silverbreeze
    Joined: Feb 2009
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    Silverbreeze Bruno Tideman

    Fred, indeed bad fuel is a nightmare for common rail electronic diesel engines. That is why we only offer these in locations where the fuel quality is good enough. Old fashioned mechanical diesel with water jet in all other cases......
     
  12. FAST FRED
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    "That is why we only offer these in locations where the fuel quality is good enough."

    Where is the local fuel above the required standards for fuel?

    What is "legal" to sell most places is far too foul for long use..

    How do you clean up even "good " fuel?
     
  13. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    Many countries now have rules about sulphur as its imo mandated so they can no longer serve crap.
    Crap having lots of sulphur.
    Funnily enough sulphur was a lubricant but nobody noticed till they removed it
     
  14. Silverbreeze
    Joined: Feb 2009
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    Silverbreeze Bruno Tideman

    All diesel we get in Europe is good enough for common rail engines, we use two filters with water separator to clean the particles out. Why are you so stressed about the fuel quality? Bad experience?
     

  15. mydauphin
    Joined: Apr 2007
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    Location: Florida

    mydauphin Senior Member

    Reason you need at least two tanks. Buy the diesel separately, filter before you put it in, and spend the rest of your life cleaning it. Well maybe not that bad... But fuel has always been the only reason diesels stop running.
     
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