VW 1.9TDI Engine (AFN) to the boat...

Discussion in 'Diesel Engines' started by kieshaplius, Jan 6, 2014.

  1. michael pierzga
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    michael pierzga Senior Member

    Yah, engine rating is load factor and hours. Most recreational marine engines are only auto engines tweeked for marine use.
  2. groper
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    groper Senior Member

    One thing I've found with turbo charged engines is that the cooling system is often not upto the task when high continuous power output is demanded. This is certainly the issue with car engines when output is increased by hotting up a stock engine, and it's no different in principle when converting to marine applications - higher demanded output. Provided the cooling system and heat exchanger has enough capacity, there should be no problem. However there is another issue, its with the design of the engine cooling galleries within the block. They are often undersize and cannot cope with the high cylinder and head temperatures of sustained high boost pressure and power output, regardless of the external cooling heat exchanger. This can lead to hot spots within the engine and associated engine wear or damage.

    At the end of the day, most engines should be fine unless too much is demanded of them, running at moderate boost pressures with significant headroom in rated horsepower from the standard cruising speed should allow a lengthy service life.
  3. essenmein
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    essenmein Junior Member

    :) I think we are all agreeing.

    the 1,9TDI is fine if you want the 140hp for speed boat or runabout, but if you need the 140hp to cross the Atlantic you might consider something like 3208 instead (only big ish diesel I can think of off the top of my head lol).

    Its up to the end user to decide what they are going to do with it really. If you are only putting a few hundred hrs on it a year blasting around a lake or harbor, then that's really no different than how its used in a car.

    Re the comment on over heating, thats part of how these things are designed to reduce cost, in a car the average long term power use is some low number like 20% of max, so they design the cooling system to work with the average heat load and cope with short transients (accelerating) with thermal mass of the coolant, in situations where engine out put is higher for extended periods they over heat, more power at the same effy means more heat in the radiator. Towing a load up a long hill for example would do it, or pushing more hp out of an engine by tuning it would too.

    Just a general comment to add to the conversation, what determines engine life in terms of mechanical wear is things like operating temperature, oil quality, rpm and bearing loads/combustion loads (eg rings), bearing load is directly related to combustion pressure, which directly related to mechanical output. More power at a given rpm = more combustion pressure = higher bearing load = lower life expectancy.

    If you want to dramatically extend the life of an engine, run it at lower rpm (assuming oil pressure is ok) and lighter loads, for diesel, not too light though lol.
  4. WestVanHan
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    WestVanHan Not a Senior Member

    Cummins 5.9 based tractor pull engines:mechanical injection+ 125 psi boost+ methanol water injection = 400 hp per litre and about 500 lb.ft per litre.
  5. astat101
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    astat101 Junior Member


    I am not sure if this will help at all but there is a company that manufacture diesel engine charge air coolers, you should try Vestas aircoil A/S in Denmark (www.vestas-aircoil.com)

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    FAST FRED Senior Member

    Looking at any diesel engine for cruising 3 cubic inches of displacement producing 1HP at cruise RPM will run a long time.
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