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Re: MICRO TRAWLER

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  • michaelnotigan
    Message 1 of 42 , Nov 16, 2012
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      --- In bolger@yahoogroups.com, "nezih" <gencahm@...> wrote:
      >
      > Nezih, further thought into the matter brought me to an engine Yanmar used to produce.....a diesel outboard. I believe these were probably more popular in your part of the world then here in the US. When I first started construction of my MT I seriously considered this engine. The high cost (over 10 grand) did me in and shortly thereafter I purchased a new 40 hp 4 stroke Suzuki DF40 gasoline outboard instead, at 1/3 the cost of the Yanmar. If you can locate one of these Yanmars, it would meet a lot of your criteria: it's diesel so there will be a cost savings for fuel along with greater economy.....it's all self contained meaning there will be no engineering think trying to design a power plant (inboard power) into a boat design that was never considered for anything but outboard power. And, finally, it came from a reputable manufacturer in Yanmar. Rarely do they come up for sale on Ebay and when they do, they are not cheap. But it is something to consider if you can acquire one. I believe your small, lightweight air-cooled diesel outboard was feasible on the MT, but in my humble opinion, automotive style engines like the water cooled Subaru flat four would add a lot of weight. I don't think the VW flat four is going to neatly fit into the lower cutwater hull of MT, let alone the Subie flat 4.....
      >
    • JOHN WALLIS
      True Doug, Ford FE gas truck engines had larger diameter crankshafts and cam profiles designed more for low RPM torque, compared to the equivalent car engines.
      Message 42 of 42 , Nov 16, 2012
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        True Doug, Ford FE gas truck engines had larger diameter crankshafts and cam profiles designed more for low RPM torque, compared to the equivalent car engines. Some GMC truck gassers even had exhaust valve rotators and stellite valve seats, anticipating heavier engine load demands. 

        Your Isuzu may have had oil starvation issues if the oilpan capacity was not increased and the pickup lowered. I have a marinized 1956 Packard V8 with the oilpan capacity increased from 5 quarts to 4 gallons and an integral oil cooler built in. Most working boats of 25-30 feet and up have gone diesel but that may not be a practical option for the MT being discussed. 4 cycle outboards have been around for several years now and have a good track record even in small commercial fishboats that get hard use.


        From: Douglas Pollard <dougpol1@...>
        To: bolger@yahoogroups.com
        Sent: Fri, November 16, 2012 12:33:28 PM
        Subject: Re: [bolger] Re: MICRO TRAWLER

         

        Yes this is all true. Back in the 1960's we used to marinize v8 gasoline engines for Chesapeake Bay work boats. WE always looked for a truck engine because they had four bolt main bearings and I think maybe an extra main though I am not sure about that. Most Of the small diesel boat engine are industrial stationary engine that the manufacturer has marinized. There is not much difference between an engine running a boat and one running a water pump 24-7.   I think that the Volkswagen 4 cylinder automobile diesel engine did not hold up well.  I had a 3cylinder Izuzu diesel in a boat and it was a marinized industrial engine.  I had trouble with the #1 cylinder and again after rebuilding. I figured it was designed to set flat when running and the incline may have been a problem??   My experience with outboard engines is that they don't last long in my experience. This may be due to running wide open all the time??   I can't speak for the 4 cycle high torque engines with propellers intended for slower none plaining boats. They may be great?           Doug


        On 11/16/2012 12:29 PM, JOHN WALLIS wrote:
         
        Good points Susanne. Also consider that automobile engines typically only run @ about 20% of rated max HP around 80% of the time (coasting, idling at the stop light, flat terrain cruising etc). 

        On the other hand, when you consider hull drag, prop thrust and friction, marine engines are constantly going uphill towing a trailer and are designed accordingly. My recommendation is a 4 stroke outboard until you get into larger boats where a diesel inboard makes more sense. 


        From: "philbolger@..." <philbolger@...>
        To: bolger@yahoogroups.com
        Sent: Fri, November 16, 2012 4:57:13 AM
        Subject: Re: [bolger] Re: MICRO TRAWLER

         

        Every SUBARU engine is a flat -4 or -6 - and always water-cooled.

        Ultimately for the horsepower to get MT up on a plane no power plant will as light for the power as an outboard by the time you add up gearbox, shafting, propeller, pivoting of prop etc.

        Susanne Altenburger, PB&F
        ----- Original Message -----
        From: nezih
        Sent: Friday, November 16, 2012 3:35 AM
        Subject: Re: [bolger] Re: MICRO TRAWLER

         

        Sir,
        Any picture of the Engine,you saw in Fort Lauderdale in a Dunebuggy shop.
        Highly appreciated
        Nezih
         
        ----- Original Message -----
        Sent: Friday, November 16, 2012 4:24 AM
        Subject: Re: [bolger] Re: MICRO TRAWLER

         

        I read someplace that the engine designer was an airplane designer. It sure looks like and airplane engine. Back in the 1980's somebody built a water cooled aluminum block to bolt on to the crank case in place of the air cooled jugs.  They also had water cooled heads for it. I saw one of the engines in a Dunebuggy shop In Fort Lauderdale. That engine might well make a nice boat engine.  
                                                        Doug

        On 11/15/2012 09:00 PM, Mark Albanese wrote:
         

        Yeh, it was great to have it and the transaxle balanced atop a rolling jack. The heat is what burned the valves out. I expect in a boat one may also seem pretty loud.



        On Nov 15, 2012, at 11:49 AM, Douglas Pollard wrote:

         
        What the engine had going for it was it could be dropped out for rebuilding in 15 minutes.  Usually the valves were burned and new rings needed the lower end bearings and crank held up well... ...I would think it would make a far better engine for an air boat. In this case it can be standing above the boat where it can get free air circulation.  
                 Doug


        On 11/15/2012 12:52 PM, nezih wrote:
         

        Yesterday,I have been informed that boat builders here are installing old VW Beetle Engines(after marinise)
        as Inboard Engine.They are not heavy,like outbards.I think this engine eliminates the weight problem of other
        Inboard Engines
        Awaiting comments.
        Nezih





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