Diesel outboards

Discussion in 'Diesel Engines' started by Pericles, Jul 19, 2020.

  1. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    It is said Lehrs engine supplier is Parsun, but Lehr never confirmed.
    For me at least the site does not function correctly, I can not find dealers for example. Last "news" article is from 2017.
    Fork lift tanks are liquid draw, like every other automotive tank. The problem are not the tanks. Legislation prohibits filling of loose tanks at Autogas stations (yes I know it is often ignored). Fix some straps over it and drive the vehicle to the gas station and it's legal.
     
  2. Pericles
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    Pericles Senior Member

    So where do fork lift truck operators refuel their equipment legally in Germany?
     
  3. KeithO
    Joined: Jul 2019
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    KeithO Senior Member

    Most likely a propane distributor has a full for empty exchange program with the company and delivers full cylinders and takes away the empties to refill at his premises. Certainly no-one is driving the forklift around to fill it. Larger companies may even have their own filling station on site fed by a large propane tank.
     
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  4. Boatman1011
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    Boatman1011 Junior Member

    This site has quite a lot of press on the different products. www.dieseloutboardnews.com

    It looks like they are trying to make a real push in 2020, at least that was the intent before COVID.
     
  5. Rumars
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    Rumars Senior Member

    Exactly like KeithO said above. Plus, over here, at least one of the big hardware store chains sells them individually.

    I already said, if your use patterns fit the fuel availability, there is nothing wrong with propane as a fuel. Up to 5HP you can use normal household cylinders without any problems. Since those are usually available at marinas, gas stations and other stores you can always find replacements nearby wherever you go.
    With liquid draw tanks you must arrange for the fuel beforehand, either buy (or get delivered) full cylinders or go yourself to an authorized LPG refill point.
    What you can not do legally is use the wide network of LPG gas stations for cars, because those are only allowed to fill tanks that are fixed in a vehicle. So for a bigger engine you have three legal options and two illegal ones.
     
  6. Rumars
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    Rumars Senior Member

    Oil gets delivered to the carb by metering pump from a separate oil tank. Basicly the same thing some modern outboards with postmix have.
     
  7. Rumars
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    Rumars Senior Member

    You can do it that way also, and you can also spray oil directly into the crankcase at strategic locations, all has been done. But the simplest way is to use the carb, since it is designed to atomize liquids, and it does not care what the liquid is. Basicly what we are talking about is just another jet in the carb throat. I am not aware of any carb mixing liquid oil and gasoline then atomizing them trough a common jet.
     
  8. Boatman1011
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    Boatman1011 Junior Member

    FREE ABYC webinar tomorrow Thursday, July 23 @ 12pm EDT. This week's topic: Propane Systems on Boats.

    Liquid propane gas systems aboard boats. Sound like a good idea? A bad one? Join Mike Bonicker, ABYC's Lead Instructor to find out what it takes to have a safe, ABYC compliant LPG System onboard. Register here: https://register.gotowebinar.com/register/5407841696978964239
     
  9. Magnus W
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    Magnus W Senior Member

    Not true. Both some conventional flat aircooled avgas engines and the newish diesels (like Thielert Centurion in Diamond aircraft) are geared.
     
  10. Pericles
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    Location: Heights of High Wycombe, not far from River Thames

    Pericles Senior Member

    Thanks for that ABYC link. I see a plethora of information.
     
  11. Rumars
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    Rumars Senior Member

    Yes, those premix liquid and would not be suitable for LPG use, but they premix before the carb, not in the carb.
    Simplest system to use is carb atomization (like the Yamaha Autolube). That can be added even to a carb without separate oil circuit. For a single fuel engine the carb is redundant anyway, all that is needed from it are the butterfly valves.
     
  12. fallguy
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    fallguy Senior Member

    I checked into the diesel outboards. The problem I had was first the price. It was like 30k for the 50hp engine. Four times the price?

    Two crankshafts vs one; so more to do wrong. Since I needed two engines; engines would have been 60,000 vs 16,000.

    I gave it some serious thought for about three minutes. That is a lot of petrol. 44,000 dollars at 4$ is 11,000 gallons of gas. Some serious hours to payoff. My tanks are about 100 gallons. 110 fills..4 fills a season will be like 1200 miles
     
  13. Eric ruttan
    Joined: Jul 2018
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    Eric ruttan Senior Member

    Thilert is dead right? Pointing at that dead abomination of a motor with a gear box that could not even get 1200 h is not a great look for you, my guy.

    Virtually every boxer motor, which is 95+% of general aviation motors actually flying hours, is direct drive.
    Pointing at some really rare weirdos and saying 'but, but this one' does not validate the point.
     
  14. Eric ruttan
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    Eric ruttan Senior Member

    Thilerts motors were crap, right? Thats why they went under and didn't Contental buy thier stuff for pennies on the dollar?
    Ya, the little rotax have gears, cause they spin crazy fast. But since prop speed is about perfect for a diesel, and traditional aviation gas uses huge bore low speed gas, the need for a gear box is low.

    Gear box on a diesel makes no sense.

    Yes, there are geared flying aircraft, but pointing at who sold the most in a declining industry, where the most sales of one type is a small portion of fleet size and overall sales is deceptive.

    There is no problem with the torque pulse of a diesel. Not that you could fix it with a gear box anyway. The problem is you cannot put the wrong prop on it. For the guys coming from a world where all GA was air cooled 4 banger this was a big adjustment.
     

  15. KeithO
    Joined: Jul 2019
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    KeithO Senior Member

    Well, I guess the P51 and spitfire must also have been "crap" and the P38 Lightning etc... That entire era of fighters had reduction drives.
     
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