Marinizing Small Diesels

Discussion in 'Diesel Engines' started by AtlanticPeter, Nov 3, 2010.

  1. AtlanticPeter
    Joined: Oct 2010
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    Location: Atlantic Canada

    AtlanticPeter Junior Member

    Recently posted about repowering a sailboat from gas to diesel.

    Have been doing my homework and the Yanmar 1GM10 is looking about right.

    Some respondents suggested marinizing terrestrial engines. Would be interested in opinions on the feasibility of marinizing small industrial/utility diesel engines for marine use. For the average backyard mechanic is marinizing: a) a great lower cost option - many of us do not fully appreciate; or b) a potential headache of hard to match components and escalating $ and time costs. This article would suggest the latter

    For example this Yanmar 2TNV70 seems like a deal- However might there be aspects of this tractor/generator engine which make it inherently unsuitable as a starting point for marinization? What might these be? What about transmissions - are most non-marine Yanmar's matchable to some Kanzaki unit - are there other transmission options?

    Any suggestions re: specific marininzing projects (e.g. posts, articles) would also be appreciated.

    Thanks in advance for your opinions.

  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    It is a high cost option that a capable backyard mechanic can acomplish. There will be a fair amount of welding, fabricating and machining. It can be a great hobby and will keep you busy on those snowy winter weekends. The Kansaki is the same as a Hurth. They are built under license and parts will interchange.
  3. Stumble
    Joined: Oct 2008
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    Stumble Senior Member


    The short answer is that unless you know how to perform the work, AND consider your time worth 0, it is going to be cheaper to buy a marinized engine than do it yourself.

    Just think of all the parts you will either have to buy or fabricate at full price to marinize the engine, then think of all the scrap parts with little to no value you will have in your shop when you are done.

    Joined: Oct 2002
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    FAST FRED Senior Member

    One cheat might be to get a crapped out boat engine , and rebuild it.

    A good rebuild will usually last longer than the factory new engine if machined during the re build.

    A second option might be to locate an "industrial " running engine that duplicates the marine engine and swop all the parts.

    The kicker in the origional article is at the end,

    "The best marine engines utilize heavy-duty industrial base engines, typically used in agriculture and construction
    industries. These engines all have replaceable wet liners and very robust construction that allows very long life (typically
    40,000+ hours) and economical rebuilds - this is vitally important to commercial customers who will accumulate over
    8000 hours per year of running time if their application runs 24/7. <That type of construction is completely unimportant
    and needlessly expensive in a pleasure boat application that is lucky to run over 200 hours a year."

    He is talking HUNDREDS of HP,

    For most of the smaller boats with under 2 GPH of fuel burn at cruise 30-40hp ANY small industrial engine will work just fine.

    AS the small sailboat burn of .5gph , and only a hundred hours a year , a Roto tiller geared Honda will be fine.

    One big advantage of Do It yourself is a commercial transmission (like a Twin Disc) is no harder to install from scratch than a Hurth or other short life Yachtie unit.

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