Outboard diesel engines

Discussion in 'All Things Boats & Boating' started by Albert Jr., Aug 1, 2013.

  1. Albert Jr.

    Albert Jr. Previous Member

    Hi guys.
    As a few of you know, my dad owns and runs a marine and motors shop.
    I've tried a lot of things to expand but he has always said no.
    Suddenly he gives me a call to look up a brand called Selva outboards.
    Putting aside the fact that this is annoying me, I still think it's not worth
    doing (it sounds Chinese to me)

    Anyways, does anyone know anything about these engines ?
    I've looked at the website but there isn't anything that says that these are
    diesel engines.

    Also, does anyone know of any good quality 6 to 15 hp diesel engines ? (I don't like letting my dad down)
  2. Ilan Voyager
    Joined: May 2004
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    Ilan Voyager Senior Member

    The brand Selva is italian, founded in 1945. At my knowledge the 4 strokes are re-branded Yamaha (Yamaha had or has a big stake in Selva) but 30% less expensive. They worked also a long time for OMC Europe. The brand is well known in Europe.
    No diesel outboards.

    Sorry for your dad, but there are no more Diesel outboards; Yanmar made it years ago, mainly 27 HP but the indecently too high price killed any perspective. In fact on outboards, diesel is not interesting as the initial investment is too high, and the return in savings on fuel is too low to be interesting in a decent delay.

    In small engines, Diesel are used as inboard engines mainly for questions of security (a gas engine would be problematic in a sail boat for example) or durability in working boats (in this case a 16-20 HP engine weights 300-400 pounds).

    You have also light industrial small diesels from 5 HP, almost all running at 3600 RPM. Many brands. Lombardini, Yanmar, Kubota, etc... and low cost Chinese that are getting better and better. Can be very expensive compared to a gas 4 stroke, so, except for specific applications, you won't get back the initial investment by the fuel savings and durability.
  3. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    I think you will find a thread on here about a Chinese line of diesel outboards, (Klaxon ?) but hard to find out much about them.
  4. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Hatz diesels work well and are available in small sizes.
  5. Albert Jr.

    Albert Jr. Previous Member

    I understand, thanks.
    I'll tell him when he gets back from work.

    We saw the klaxons but my dad said no because it's chinese and he doesn't
    like the shape of the engine :confused:

    Do they sell outboards ?
    I saw the link and they've only putted the #KW and #RPM
    How do I know how many hp the engine has ?
  6. Olav
    Joined: Dec 2003
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    Olav naval architect

    1 SAE hp = 0.7457 kW. Or 1 kW = 1.341 SAE hp. ;)
  7. jonr
    Joined: Sep 2008
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    Location: Great Lakes

    jonr Senior Member

    I think Suzuki still makes their outboards that run on kerosene. But that's mostly of interest where kerosene prices are heavily subsidized and for some reason, it cuts engine life in half.

    IMO, a natural gas outboard would be interesting on a trailered boat (or where the marina has a compressor). The tanks are heavy but the fuel price is attractive. Safety is good (nat gas rises).
  8. El_Guero

    El_Guero Previous Member

    Only if your natural gas has zero ethane in it ....


    And no sparks.
  9. jonr
    Joined: Sep 2008
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    Location: Great Lakes

    jonr Senior Member

    My understanding is that all natural gas rises, whether the ethane has been removed or not. Mixed gases (like methane and ethane) do not separate when released into the air (it's actually quite hard to get the ethane separated out of nat gas).
  10. Albert Jr.

    Albert Jr. Previous Member

    Alright, thanks.

    Kerosene is the cheapest we have for sale, only outboard I know that can run
    on it is the e-tec 55 mfe which is extremely expensive.
    There is a brand called Lehr that sells gas engines if by gas you mean propane.
  11. Ilan Voyager
    Joined: May 2004
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    Location: Cancun Mexico

    Ilan Voyager Senior Member

    Thanks, Mr Efficiency about the Klaxon brand. I got a lesson; never be too affirmative...
    I made a search. The fact it's Chinese does not bother me too much, the true problem is the real quality...The 9 HP is awful and noisy in a video in You Tube. A guy in Ebay is trying to sell them. The 40 HP is around 8500 USD, if I'm not mistaken, so at 150 hours/year of yachting use it's not valuable compared to any gas 60 HP.
    Also diesel engines revving at 5000 RPM doesn't seem to be enough reliable to justify the price. The stinky problem with diesel on a small boat is that fuel is smelly and greasy...no one drop outside, or seasickness guaranteed.

    LPG woulld be more useful for outboards and small engines than natural gas, as it liquefies at low pressure so the tanks are smaller and cheaper. Precautions are similar to gasoline, and finally it's no more dangerous with the good installation. Gas detectors are imperative on a enclosed boat. The actual problem is the short life of the ordinary tanks because of corrosion.
    I think that the over cost of the initial investment and the eventual problems of tanks are not worth the trouble for a "yachtman", unless you are using the engine professionally and having enough hours (at least 500 hours a year) to get significant savings. The difference of price between gasoline and LPG must be high enough to make the thing interesting....

    For example in the Mexican context, with diesel almost as expensive as gasoline, on small diving boats (26 to 30 feet) working 1200 hours/year, it's not worthy to go to diesel, as it's too long to get a return of investment. And the boats being on the beach, with no marina services, LPG tanks are highly unpractical.

  12. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

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