keel cooling

Discussion in 'Boat Design' started by richard gray, Oct 18, 2015.

  1. richard gray
    Joined: Mar 2013
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    Location: port coquitlam

    richard gray Junior Member

    how do i figure out volume and surface area of a keel cooling system for a 350 V8 in my amphibian? I intend on using a short length of double wall ,water cooled pipe from manifolds and recirculate the fresh water (back to small auto radiator after leaving sea bay to ensure cooling ,the sea bay will also be exposed to air ) .and run this into a sea bay ( using a grid type manifold for more area in the sea bay) to cool ,then discharge over board, it will be separate from engine e water cooling that will use a radiator and may add keel cooler into the null bilge. i am trying to avoid raw water cooling, but may add a raw water heat exchanger on demand to do both systems. I know KEEP IT SIMPLE STUPID .
     

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  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    If you use a radiator when you are on land, why not use it at sea? A double cooling system is an unnecessary complication and expense.
     
  3. richard gray
    Joined: Mar 2013
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    Location: port coquitlam

    richard gray Junior Member

    cooling

    I will try anything at this point> i am trying to avoid raw water cooling. so I hope to add a valve to isolate a heat exchanger. the lack of large air takes is the problem with my hull design. i have to add vents and ducting. i will make one top vent direct to anti flash carb air filter and put carb in a sealed box with only top venting and a viewable drain incase of flooding/leak. i can isolate the cooling systems or connect . with just a valve and extra hoses. i have drawn it out several ways but hope to get a formula on area and volumes? i just came up with the idea for sea chest ( similar to a double bottom ,with a removable tank top to service mufflers/tailpipes) P&S. i hope to put stainless steel exhaust pipe mufflers in sea chest that will also allow air flow when out of water. did not think of everything ? I am simple, but my solutions become compleX!!! thanks Rick
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    An amphibious vehicle can't run on raw water or keel cooling when on land. Why the complication? It will be a system of multiple valves, a radiator will be installed anyway, and there is no benefit. There will be the drawback of extra holes in the hull, and more possible corrosion.
     
  5. richard gray
    Joined: Mar 2013
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    Location: port coquitlam

    richard gray Junior Member

    Gonzo: some air flow through sea chest and on keel cooler pipe may help, like I said air flow to rad is the problem. even with engine fan and added electric fan(S) . using engine water pump and electric pump to recirculate water for exhaust system only . i have to add thermostats and recycle ports.
     
  6. FAST FRED
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    A larger air radiator will take care of cooling the wet exhaust manifolds , but simply wrapping auto style manifolds with an insulated blanket material is as quiet and far less co$tly.
     
  7. richard gray
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    Location: port coquitlam

    richard gray Junior Member

    i will probably use temp gauges on each system to see where over heating could occur. since the engine is like in a cabover truck, i will have to make an engine cover ,ventilate and insulate . it is like having an engine in your back seat ,so heat is the problem .
     
  8. CDBarry
    Joined: Nov 2002
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    Location: Maryland

    CDBarry Senior Member

    Contact Fernstum or another keel cooler manufacturer if you are using a standard system. You can do it yourself for home built systems by standard engineering principles out of a heat transfer text or Mark's (this was a question on the WA state NAME exam when I took it a few decades ago). It's kind of a tedious calculation to explain, but most standard texts will cover it, and it isn't too bad with Excel.
     
  9. richard gray
    Joined: Mar 2013
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    Location: port coquitlam

    richard gray Junior Member

    Thanks I will look into the sites > trial and error is unforgiving
     

  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

    it is like having an engine in your back seat ,so heat is the problem .

    Go to the fire house and look at a modern fire truck.

    The engine is behind the driver.
     
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