Is a marinized diesel necessary if....

Discussion in 'Diesel Engines' started by pha7env, Mar 26, 2012.

  1. pha7env
    Joined: Aug 2011
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    Location: Lake Dannelly, Alabama River

    pha7env Junior Member

    Is a marinized engine necessary when using dry stack exhaust and closed loop keel cooling? If so, what parts would be "marinized"? Thanks!
     
  2. whitepointer23

    whitepointer23 Previous Member

    no, but if you plan on working the motor hard you would be better off with a water cooled exhaust manifold. a full dry exhaust is fine if not working to hard. there are good lagging products available.
     
  3. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    Totally false! If something like that is your experience there has been something wrong..
    BR Teddy
     
  4. Frosty

    Frosty Previous Member

    Real boats are dry , show me a tug with wet exhausts.
     
  5. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Some people like the dry stack with its noise, smell, heat and the vibrating deck under their feet, or at least take all that for granted.
    So no, if you use a dry stack and keel cooling on an engine that accepts an SAE flange without modifications, there is nothing to marinize.
     
  6. whitepointer23

    whitepointer23 Previous Member

    i didn't mean water cool the whole exhaust, just the manifold. my old gardner had the wet manifold and dry stack exhaust, it worked well. why don't you explain yourself a bit better instead of trying to make other people look stupid. if you think a dry manifold doesn't get hot under load you don't know what you are talking about.
     
  7. michael pierzga
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    michael pierzga Senior Member

    The heart of a marinized engine is the water cooled exhaust manifold.

    Very difficult on a small craft ,with a small compact , engine room to insulate the exhaust manifold and keep the engine room from overheating. I wouldnt fool with dry exhaust on a small craft.
     
  8. Frosty

    Frosty Previous Member

    Why does a dry stack Vibrate and come to think of it what noise and smell. A wet exhaust has no less smell and no less gasses.


    And the constant sploshing of water can be equally as annoying.

    A dry stack does not have stuck valves or corroded valve seats.
     
  9. TeddyDiver
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    TeddyDiver Gollywobbler

    Well sorry for my misunderstanding. Better thou to say its water jacketed, not wet IMO
    Chears Teddy
     
  10. whitepointer23

    whitepointer23 Previous Member

     
  11. CDK
    Joined: Aug 2007
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    CDK retired engineer

    With a wet exhaust you can use flexible engine mounts, U-joints and a splined shaft coupling, so no transmission of vibration. A dry stack requires the engine to be rigidly mounted.

    Also, the wet exhaust has much less gasses because the exit temperature is low causing the gas to contract to approx. 1/4 of the volume at the entrance of the manifold, greatly reducing noise. Smell is also reduced because the smelly part of the exhaust products like sulfuric oxides dissolve in water.

    Of course calculated by weight, the output is the same as from a dry stack.
    Compare it with a water closet: you do not really dump less, but most people don't want to trade it for a bucket.
     
  12. michael pierzga
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    michael pierzga Senior Member

    Dry exhaust emits soot balls...wet doesnt.

    As CDK states The transition between vibrating engine and dry exhaust needs special detailing to prevent vibration from entering the hull superstructure.
     
  13. FAST FRED
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    FAST FRED Senior Member

    "needs special detailing to prevent vibration from entering the hull superstructure."

    Other choice is a smoother engine , usually a 6 cylinder.

    FF
     
  14. pha7env
    Joined: Aug 2011
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    pha7env Junior Member

    Thanks guys. I thought as much. We are in the market for an ~45 foot semi older semi-displacement to cruise the loop, gulf and intercoastal. I surely will have wet be fully marinized with wet eshaust and one(hopefully) or two six(es). Not a big fan of the high revving fours. While doing that we I am studying boat architecture and systems in order to buy or build a true displacement passagemaker. This will be the boat with the dry stack and keep cooling. As a side note, it will work very, very hard as do all sea boats, few of which have wet exhaust. There are a number of reasons i will go dry. Some of those reasons or that the same engine costs pennies on the dollar compared to the identical marinized version. Also, limiting through hulls on a deepwater vessel surely is a good thing. And, i am a farmer and rancher and Dodge truck fan and have lived my life with diesel smoke, and the purr of a six cylinder diesel. Must be genetic, because as a teen, i worked and skippered some river tugs and when not working would find myself sitting in the engine room with two 1750 horse cats vibrating me to sleep. Strange i know, but i love that feel and smell. Also, it would seem that going closed loop and dry would provide for much less long term maintainence. My "second boat" has to have a standup engine room, with enough room for a napping chair! I realize there will be more heat to deal with, but i am pretty handy with forced ventilation also. Again thanks, and i hope to learn much from you gentlemen( and surely ladies too).
     

  15. pha7env
    Joined: Aug 2011
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    Location: Lake Dannelly, Alabama River

    pha7env Junior Member

    CDK, interesting about the flex mounting verse hard fixed. My freight liner has rubber flex mountings and uses stainless flex from the manifold to the fixed exhaust. Would something like this be possible or is fixed a must?
     
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