Brake specific fuel consumption slow running marine diesels.

Discussion in 'Diesel Engines' started by Lemans, Feb 21, 2016.

  1. Lemans
    Joined: Nov 2011
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    Lemans Lemans

    From what I know at this point, I would be surprised if I need such a big flywheel that it becomes an issue. Nevertheless, the flywheel is going to get some extra attention...

    A useful engine must have at least 30 HP. So the engine should have 3 cylinders.
     
  2. Lemans
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    Lemans Lemans

    Completely forgot about that.
    As I like to use an engine at 500 to 1000 rpm, I need also a much taller prop. (or gear-box?)
    But, it all boils down to flywheel dimensions – no?
    Is this something I need to figure out before I start designing and building/testing a 'donkey' engine?
     
  3. Lemans
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    Lemans Lemans

    For a starter? Deutz engine parts.

    Not Ø136 but Ø128 piston size.
    Bore/stroke 128mm/78mm
    Displacement: 1003cc or 61.2 cu inch
     

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  4. FAST FRED
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    FAST FRED Senior Member

    But, it all boils down to flywheel dimensions – no?

    I would start with the SAE dimensions for bell housings , so you don't have to build a transmission too.
     
  5. Lemans
    Joined: Nov 2011
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    Lemans Lemans

    I have downloaded the drawings. Valuable information- again!
    Thanks.

    Before I start looking for parts to scan&draw, is there a reason why I should not use an air-cooled engine ore, a for every cylinder 'stand-alone' injection system?
    (see drawing)
    I have the 'unusual' idea of building up the engine in several 'sections' so it would be possible to
    connect part A+B+C to have a functional one cylinder engine or
    connect part A+B+...+B+C to have a functional multi cylinder.

    One more question. In witch forum section should I post drawings and progress?
    Comments along the way will be much appreciated. As I said earlier, this is not my domain of experience – need to learn a lot...
     

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  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

    Most older DD engines (like a 6-71 ) simply use an extra lobe on the cam to operate the injector .

    If fed with fuel it is a complete injection system,

    rebuilt you can select the amount injected ( rated in CC per thousand strokes) and there $35 or so each.

    They are fed at modest pressure but high volume with unused returned to tank, for cooling.
     
  7. Lemans
    Joined: Nov 2011
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    Lemans Lemans

    Just perfect. I have spend some time on the inter-net locating a supplier for those parts but no luck so far.
    Before starting the actual build I create the engine in 3D solids (drawing level) and use simulation programs to see if the real engine has a chance to fulfill my expectations.
    As I never have build a very low speed diesel engine I like to verify if the program I use (Lesoft)
    produce correct results. The Detroit Diesel is a two stroke so can't use the specs to check this.
    I need to look out for specs from a low running diesel 4-stroke.
     
  8. WestVanHan
    Joined: Aug 2009
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    WestVanHan Not a Senior Member

    As mentioned before,John Deere had large twin cylinder engines. The largest being the 830 with 471 cid,or 7.7 litres.

    A few years ago I bought one of these engines at an auction,turns out it had been built for tractor towing and had a stroker crank and overbore to almost 950 cubic inches.

    With today's CAD/CAM and laser scanning stuff, I've thought it'd be fun to make a billet 2800 cid/ 46 litre 6 cylinder diesel.

    But if you're looking for ready made engine parts to fiddle with I'd suggest Chinese or Indian built Lister clones. Cheap to buy,if you mess something up it's not a $$$$ Deutz part.
    They often pair up cylinder to add hp,note the cylinders and hp.
    Many sellers online:
    http://www.listeroidpower.com/

    Ywo of several Indian factories:
    http://www.vidhataindia.com/lister.html

    http://www.slowspeedengine.com/engines.htm

    Chinese clones as well.
     
  9. Lemans
    Joined: Nov 2011
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    Lemans Lemans

    Thanks to you guy's, the Lister engine has caught my attention. I found almost all technical information I need, I'm missing only valve dimensions.
    After a few runs on the virtual test bench, it looks as the Lister could produce 50% more power only by injecting more fuel. Maybe this setup has been chosen to counter any future wear or to extract as much power as possible from the burning fuel.

    At this point I have two engines I like to find as much info and pictures from all parts as possible.
    One is the Lister 3-1, the other is the Yanmar L40.
    Cut trough drawings (blue-prints) are very valuable as they show very use-full information.
    Let's see what I can find.
     
  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 looks as the Lister could produce 50% more power only by injecting more fuel.

    No engine can produce more power with out more fuel.

    Sure there is optimization, better cam profile , clean intake and exhaust , but this gets only a bit more power , at one specific RPM.

    A Turbo or nitrous oxide will only add more power WITH more fuel.
     
  11. Lemans
    Joined: Nov 2011
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    Lemans Lemans

    Looks like I ran into my limits of the English language.
    I mean that the engine breaths more than sufficient air to burn more fuel.
    It's as you inject not the full amount of diesel – see it as 2/3 % throttle.
     

  12. FAST FRED
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    Every diesel has the air throttle wide open and limits the power/rpm by the amount of fuel injected.

    Any Detroit dealer should have a rebuilt fuel injector (6-71) avilable for $40 bucks or less.

    Usually operated by a similar rocker and push rod as the exhaust valves.
     
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