Engine for Antarctica

Discussion in 'Motorsailers' started by Letsgosailing, Sep 13, 2018.

  1. Mr Efficiency
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    Mr Efficiency Senior Member

    Engines drowning is a function of the wrong shaft length for the application. If you haven 't specified 25" for yours, you will likely have problems.
     
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  2. fallguy
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    fallguy Senior Member

    The specification was made by the designer and F70s are 20".

    A bit late now that we are built.

    I am still ever so curious about Keith's comments. I missed that biggy on my alarmist list.

    Any use of outboards is restricted to April to October here and if you put in too early in April; there is a real risk of trouble.

    I was on the lake on Memorial day and the water temp was 37-38F. Certainly not a problem for outboards, but even 20F overnite is bad.

    The only way to run an ob in the upper or lower regions would be nonstop.

    All the polemics aside, Mr E, do you think a 5" jackplate wise for me, if I change to an engine with the 25" option? Or rather, do you think it would be wise to change to such a setup?
     
    Last edited: Aug 21, 2019
  3. Mr Efficiency
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    Mr Efficiency Senior Member

    You have your engines, or not ? certainly not too big of a deal to adapt to a 20" transom, with 25" motors, you can bolt a thick alloy pad to the transom, that sits 5" higher than the ledge, and bolt the engine to that.
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    What, that carb outboards won't start in freezing weather ? I think your engines will be fuel injected, should not be a problem.
     
  5. fallguy
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    fallguy Senior Member

    The engines would freeze solid if they were not run full time.
     
  6. fallguy
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    fallguy Senior Member

    No. I do not have the engines.

    Buying enginee in 2020, but the hulls are done for 20". A commercial jackplate might ne easier and would offer me adjustability. I could run one inch or a half inch deep perhaps and rev limit less...

    We changed the engine plan to 90hp from 70hp and the 90s are available in 25", but I had not considered it until you mentioned it!
     
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    Absolutely, I would go for 25". Jacking plates would be fine, but it is a more complicated solution. But see what Richard says about it, first.
     
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  8. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    Here is an excellent write up about another aluminium almost bullet proof yacht designed for high latitudes cruising -
    Qilak: The super-rugged yacht built for fast high latitudes cruising https://www.yachtingworld.com/extraordinary-boats/qilak-fast-high-latitudes-cruising-121332

    This is what her Builders have to say about her -
    KM YachtbuildersQilak • KM Yachtbuilders http://www.kmy.nl/yachts/qilak/

    And her Designer, Owen Clarke -
    20m Custom Aluminium High Latitude Explorer and Blue Water Cruising Yacht : Owen Clarke Design - Yacht Design and Naval Architects https://www.owenclarkedesign.com/20m-high-latitude-explorer-and-blue-water-cruisi

    A quote from the YW article -

    "Crouched in Qilak’s excellent and spotlessly clean engine room, Carlier explains the fuel system which is supplied by four separate diesel tanks which can be linked together, isolated or paired up in any combination. They feed a 200lt ‘day’ tank warmed by the fuel return lines from both the main engine and the generator. In very cold conditions heat is needed to avoid increased viscosity and ‘waxing'".

    They also mention that:
    "The machinery is cooled using a heat exchange system relying on a large reservoir of glycol stored in two 400lt tanks set in the bottom of the hull. They are located well aft where there is less threat to their integrity in the event of a collision.
    The same glycol that circulates around the machinery is used in a multi-radiator central heating system running throughout the yacht making for extremely comfortable conditions below."

    An effective way of heating the yacht would be a priority in high latitudes, and they appear to have found an excellent way of doing this with the glycol heat exchanger. An outboard engine (or two), even if they are diesel, are going to be hard pressed to compete with a system like this.
     
    Last edited: Aug 24, 2019
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  9. fallguy
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    fallguy Senior Member

    I want to thank Mr. Efficiency publicly for highlighting the engine height. I am indeed planning to jackplate my engines and get them up about 6" and back about the same based on his remarks.

    The interesting post by bajansailor speaks volumes to another of the many problems dealing with the cold. In my own boat, using outboards offers no opportunity to heat the cabin, so we need a diesel heating system. What I find more interesting is the trouble they must go to avoid the diesel gelling. My system is gas.

    Even heating water cannot be done without a separate system. And even if your only preheating the water, the energy used will be higher. My boat will have a diesel boiler that will heat the water and radiators for heating, but at the dock I can use electric and the electric sort of replaces the hydronic inputs you could get from an engine (not an outboard).
     

  10. KeithO
    Joined: Jul 2019
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    KeithO Senior Member

    Our boating season (for most people) is June to August. Some diehards will persist till the first frost but by end of September the lakes are deserted. I have had to chip ice that was 1/2" thick to get back to the ramp on one occasion. Most hulls will not survive the winter freeze since the lake ice can get to 3-4ft thick and there is a lot of pressure generated and ice fracturing that takes place. Here, most of the older Mercury IO boats are raw water cooled, especially since its all fresh water. Any time those boats are not properly winterized and the block, exhaust elbows etc drained or filled with antifreeze, the castings will split at the first hard freeze. Ice will produce up to 1000psi if it is trapped and cast iron is no match for it. Every year there are a great many boats sold without a working engine for a couple hundred $ on ebay for this exact reason.

    Anyway, Im pretty sure no-one is going to go to such high latitudes on an outboard and be coming back to report on it... The hazard of just having enough gasoline on board should be discouraging enough.... The methods being used by the pros are fairly well known and managing heat in the core of the boat (including the engine room and fuel supply) is a key part to survival. Skip Novak has been acting as an antarctic guide for many years and has had his yachts custom built for the purpose and Youtube has several videos with him showing exactly how all of his systems are laid out and why. Good information, even if not going to Antarctica !
     
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