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cooling concerns

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  • kbs2244
    I think the cooling concerns are something experience will have to solve. But I would not expect a problem. As a general rule the small 2 cycle MC engines have
    Message 1 of 16 , May 7, 2013
      I think the cooling concerns are something experience will have to solve. But I would not expect a problem.

      As a general rule the small 2 cycle MC engines have large fins so they will cool while being idled on the typical clogged streets of Asian cities.

      The typical western lawnmower engine uses the flywheel as fan and is shrouded to direct the blown air over smaller fins. A completely different system for a different duty cycle.
    • HB
      Small lawnmower type engines have been extensively used for fishing boats in Southeast Asia for more than half a century without any special cooling system
      Message 2 of 16 , May 7, 2013
        Small lawnmower type engines have been extensively used for fishing boats in Southeast Asia for more than half a century without any special cooling system modifications.
        I don't see why this is now a modern concern.



        From: kbs2244 <no_reply@yahoogroups.com>
        To: multimachine@yahoogroups.com
        Sent: Tuesday, May 7, 2013 9:47 AM
        Subject: [multimachine] cooling concerns

         
        I think the cooling concerns are something experience will have to solve. But I would not expect a problem.

        As a general rule the small 2 cycle MC engines have large fins so they will cool while being idled on the typical clogged streets of Asian cities.

        The typical western lawnmower engine uses the flywheel as fan and is shrouded to direct the blown air over smaller fins. A completely different system for a different duty cycle.



      • Pat Delany
        Great point about Asian m/c traffic jams!  Not going to worry about cooling anymore. There should be a lot more air flow in even a slow moving boat than in an
        Message 3 of 16 , May 7, 2013
          Great point about Asian m/c traffic jams! 
          Not going to worry about cooling anymore. There should be a lot more air flow in even a slow moving boat than in an Asian traffic jam!

          Maybe just one big problem left, need a simple way to make a lot of copies of a 6.5" propeller. A company over here sells Thai versions for just 15 bucks but that won't help Jeremmy.

          About Jeremmy, I lost touch with him when he was in the hospital for the second time with typhoid fever. Haven't heard from him in 2 days so he may be back in the hospital.

          Pat


          From: HB <scfpigs@...>
          To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
          Sent: Tuesday, May 7, 2013 11:55 AM
          Subject: Re: [multimachine] cooling concerns

           
          Small lawnmower type engines have been extensively used for fishing boats in Southeast Asia for more than half a century without any special cooling system modifications.
          I don't see why this is now a modern concern.



          From: kbs2244 <no_reply@yahoogroups.com>
          To: multimachine@yahoogroups.com
          Sent: Tuesday, May 7, 2013 9:47 AM
          Subject: [multimachine] cooling concerns

           
          I think the cooling concerns are something experience will have to solve. But I would not expect a problem.

          As a general rule the small 2 cycle MC engines have large fins so they will cool while being idled on the typical clogged streets of Asian cities.

          The typical western lawnmower engine uses the flywheel as fan and is shrouded to direct the blown air over smaller fins. A completely different system for a different duty cycle.





        • Eggleston Lance
          ... Let s assume the prop is to be cast from 6061 or A356 Al alloy. 1000 series is too weak for this purpose. Furnace temp about 1200 -1400 F (650-760 C).
          Message 4 of 16 , May 7, 2013

            On May 7, 2013, at 1:36 PM, Pat Delany wrote:

            Maybe just one big problem left, need a simple way to make a lot of copies of a 6.5" propeller.

            Let's assume the prop is to be cast from 6061 or A356
            Al alloy. 1000 series is too weak for this purpose.

            Furnace temp about 1200 -1400 F  (650-760 C).

            Does he have a way to get that hot and contain it for
            40-60 minutes?

            Does he have a way to lift and pour 10 pounds of 760 C
            liquid material? Any error can be crippling, blinding or death.

            If yes to above, then sand cast or mold cast is the way to go.

            If he has access to local sand, clay and water, 
            he could make the bottom of the mold in the ground
            and the top from an open wooden box. He would have to make 
            a way to align the top with the bottom halves.
            Finishing the cast would be done by hand.

            Another method would be to make molds from casting plaster,
            which is NOT plaster of paris. The mold is made in two parts with sprue
            and vents built in. The melt is poured, cooled, the mold can be re-used
            a few times. The finish is much better, but the casting plaster is pricey.


          • Pat Delany
            Sadly, I don t think safety is a big concern there. Maybe someone can design safety sandals! Pat ________________________________ From: Eggleston Lance
            Message 5 of 16 , May 7, 2013
              Sadly, I don't think safety is a big concern there. Maybe someone can design safety sandals!

              Pat


              From: Eggleston Lance <wheezer606@...>
              To: multimachine@yahoogroups.com
              Sent: Tuesday, May 7, 2013 3:43 PM
              Subject: Re: [multimachine] cooling concerns

               

              On May 7, 2013, at 1:36 PM, Pat Delany wrote:

              Maybe just one big problem left, need a simple way to make a lot of copies of a 6.5" propeller.

              Let's assume the prop is to be cast from 6061 or A356
              Al alloy. 1000 series is too weak for this purpose.

              Furnace temp about 1200 -1400 F  (650-760 C).

              Does he have a way to get that hot and contain it for
              40-60 minutes?

              Does he have a way to lift and pour 10 pounds of 760 C
              liquid material? Any error can be crippling, blinding or death.

              If yes to above, then sand cast or mold cast is the way to go.

              If he has access to local sand, clay and water, 
              he could make the bottom of the mold in the ground
              and the top from an open wooden box. He would have to make 
              a way to align the top with the bottom halves.
              Finishing the cast would be done by hand.

              Another method would be to make molds from casting plaster,
              which is NOT plaster of paris. The mold is made in two parts with sprue
              and vents built in. The melt is poured, cooled, the mold can be re-used
              a few times. The finish is much better, but the casting plaster is pricey.




            • greg123452003
              ... Because modern engines use much tighter clearances.
              Message 6 of 16 , May 7, 2013
                --- In multimachine@yahoogroups.com, HB <scfpigs@...> wrote:
                >
                > Small lawnmower type engines have been extensively used for fishing boats in Southeast Asia for more than half a century without any special cooling system modifications.
                > I don't see why this is now a modern concern.
                >
                Because modern engines use much tighter clearances.
              • greg123452003
                ... It s going to be scrap alloy, NOT ingots! THINK third world NOT Kalifornia!
                Message 7 of 16 , May 7, 2013
                  --- In multimachine@yahoogroups.com, Eggleston Lance <wheezer606@...> wrote:
                  >
                  >
                  > On May 7, 2013, at 1:36 PM, Pat Delany wrote:
                  >
                  > > Maybe just one big problem left, need a simple way to make a lot of copies of a 6.5" propeller.
                  >
                  > Let's assume the prop is to be cast from 6061 or A356
                  > Al alloy. 1000 series is too weak for this purpose.

                  It's going to be scrap alloy, NOT ingots! THINK third world NOT Kalifornia!
                • greg123452003
                  ... Because modern engines use much tighter clearances.
                  Message 8 of 16 , May 7, 2013
                    --- In multimachine@yahoogroups.com, HB <scfpigs@...> wrote:
                    >
                    > Small lawnmower type engines have been extensively used for fishing boats in Southeast Asia for more than half a century without any special cooling system modifications.
                    > I don't see why this is now a modern concern.
                    >
                    Because modern engines use much tighter clearances.
                  • HB
                    I don t see that making any difference in the use of old or newer air-cooled small engines They are also using modern small engines NOW without any extra
                    Message 9 of 16 , May 8, 2013
                      I don't see that making any difference in the use of old or newer air-cooled small engines
                      They are also using modern small engines NOW without any extra cooling modifications just like the way they did with the older engines.



                      From: greg123452003 <greg123452003@...>
                      To: multimachine@yahoogroups.com
                      Sent: Tuesday, May 7, 2013 10:47 PM
                      Subject: [multimachine] Re: cooling concerns

                       


                      --- In multimachine@yahoogroups.com, HB <scfpigs@...> wrote:
                      >
                      > Small lawnmower type engines have been extensively used for fishing boats in Southeast Asia for more than half a century without any special cooling system modifications.
                      > I don't see why this is now a modern concern.
                      >
                      Because modern engines use much tighter clearances.



                    • Eggleston Lance
                      yes, I assumed scrap alloy. I am suggesting that extruded aluminum window frames, lawn chair frames, cola cans etal would not be strong enuff for
                      Message 10 of 16 , May 8, 2013
                        yes, I assumed scrap alloy.

                        I am suggesting that extruded aluminum window frames,
                        lawn chair frames, cola cans etal <series 1000> would not be strong
                        enuff for this purpose.

                        Therefore use previously cast alloy wheels, small engines,
                        BBQ, etal to make the props. 
                        lance
                        ++++
                         
                        On May 8, 2013, at 1:50 AM, greg123452003 wrote:

                         cast from 6061 or A356
                        > Al alloy. 1000 series is too weak for this purpose.

                        It's going to be scrap alloy, NOT ingots! THINK third world NOT Kalifornia!

                      • Adam Simmons
                        I doubt it would make any difference, but the critical tolerance for heat is piston to cylinder wall -- especially since the aluminum piston expands at a
                        Message 11 of 16 , May 8, 2013
                          I doubt it would make any difference, but the critical tolerance for heat is piston to cylinder wall -- especially since the aluminum piston expands at a faster rate than the surrounding steel cylinder. Older engines left a lot of space between the piston and cylinder wall, and in search for more efficient, cleaner and quieter engines they've shrunk up that tolerance over the years. 

                          So, let's say they had .008" before, you probably have .005" now, and that's a big difference when it comes to overheating a motor. Now, cylinders today are much straighter, and the pistons should be designed to limit growth, but the rough idea is that smaller gap, less room to expand.

                          Lets' not forget this is air directly above water, which will have a high humidity and fantastic thermal transmission capabilities, not to mention be cooler than air over land.  I don't forsee a problem.

                           - Adam


                          On Wed, May 8, 2013 at 1:17 AM, HB <scfpigs@...> wrote:
                           

                          I don't see that making any difference in the use of old or newer air-cooled small engines
                          They are also using modern small engines NOW without any extra cooling modifications just like the way they did with the older engines.



                          From: greg123452003 <greg123452003@...>
                          To: multimachine@yahoogroups.com
                          Sent: Tuesday, May 7, 2013 10:47 PM
                          Subject: [multimachine] Re: cooling concerns

                           


                          --- In multimachine@yahoogroups.com, HB <scfpigs@...> wrote:
                          >
                          > Small lawnmower type engines have been extensively used for fishing boats in Southeast Asia for more than half a century without any special cooling system modifications.
                          > I don't see why this is now a modern concern.
                          >
                          Because modern engines use much tighter clearances.




                        • greg123452003
                          ... I doubt that aluminum window frames, lawn chair frames or even BBQs are going to be lying around in an African village just waiting to be melted down into
                          Message 12 of 16 , May 9, 2013
                            --- In multimachine@yahoogroups.com, Eggleston Lance <wheezer606@...> wrote:
                            >
                            > yes, I assumed scrap alloy.
                            >
                            > I am suggesting that extruded aluminum window frames,
                            > lawn chair frames, cola cans etal <series 1000> would not be strong
                            > enuff for this purpose.
                            >
                            > Therefore use previously cast alloy wheels, small engines,
                            > BBQ, etal to make the props.
                            > lance
                            > ++++

                            I doubt that aluminum window frames, lawn chair frames or even BBQs are going to be lying around in an African village just waiting to be melted down into propellers. And even if that was the only source of aluminum, it's not that hard to add scrap copper to make a very hard wearing alloy.
                          • greg123452003
                            ... However these are air-cooled motorcycle engines NOT fan-force cooled engines like lawnmowers. These motorcycle engines WILL nip up and seize if there is
                            Message 13 of 16 , May 9, 2013
                              --- In multimachine@yahoogroups.com, HB <scfpigs@...> wrote:
                              >
                              > I don't see that making any difference in the use of old or newer air-cooled small engines
                              > They are also using modern small engines NOW without any extra cooling modifications just like the way they did with the older engines.
                              >

                              However these are air-cooled motorcycle engines NOT fan-force cooled engines like lawnmowers. These motorcycle engines WILL nip up and seize if there is not a sufficient flow of air over them. Sure a fan and shroud can be added if needed, but it would be very useful to know what is being designed. Without knowing the parameters of the most likely boat and the intended usage this is all wild speculation.

                              Is the need for a high speed boat to get to more distant fishing grounds and return in a day? Is the boat going to be trawling or even pair trawling? Is the engine needed to help push the boat through the vast expanses of introduced water weeds that are choking large parts of Lake Victoria? Without knowing what the needs are you cannot design a successful solution. And remember an unsuccessful solution wipes out the purchaser's financial viability.

                              Design something that's half-baked and it will be like the tens of thousands examples of previous aid lying around Africa, Asia, the Pacific and South America, scrapped and unused.

                              To provide a solution, you first need to know what to problem to be solved is.
                            • michael broadbent
                              While I agree with some of your remarks about knowing what one  as in mind for the end product I believe earlier posts  talked of a small motorbike engine I
                              Message 14 of 16 , May 9, 2013
                                While I agree with some of your remarks about knowing what one  as in mind for the end product
                                I believe earlier posts  talked of a small motorbike engine I presumed rightly or wrongly 100 to 125cc.
                                With that in mind limitations are  already in place as to size of vessel and the type of journeys and use.
                                         The problem you mention of weeds is already solved. I live in a 55foot narrow boat on part of the UK
                                canal system .Prop fouling occurs both with weeds and rubbish and even discarded shopping trolleys.
                                To free the prop there is a weed hatch which allows one to reach the prop from inside the boat.
                                      With the long tail the unit if fouled can be spun through 180 degree and the prop worked on from inside the
                                boat or if the unit is small the whole unit can be lifted out to work on.
                                       My own thoughts are more to the materials available ,if I  require a bearing ,pipe and steel they are all within
                                a 10 minute walk not so in other countries .Next is fabrication methods no good saying wield A to B if no wielding is available  or turn pipe to suit if a lathe is several days journey away. Having travelled a fair bit of the world I am intrigued to see how
                                different people solve problems in different ways long may it continue.
                                 
                                Cheers Mike
                                        
                                      
                                        

                                 
                                From: greg123452003 <greg123452003@...>
                                To: multimachine@yahoogroups.com
                                Sent: Thursday, 9 May 2013, 9:20
                                Subject: [multimachine] Re: cooling concerns



                                --- In multimachine@yahoogroups.com, HB <scfpigs@...> wrote:
                                >
                                > I don't see that making any difference in the use of old or newer air-cooled small engines
                                > They are also using modern small engines NOW without any extra cooling modifications just like the way they did with the older engines.
                                >

                                However these are air-cooled motorcycle engines NOT fan-force cooled engines like lawnmowers. These motorcycle engines WILL nip up and seize if there is not a sufficient flow of air over them. Sure a fan and shroud can be added if needed, but it would be very useful to know what is being designed. Without knowing the parameters of the most likely boat and the intended usage this is all wild speculation.

                                Is the need for a high speed boat to get to more distant fishing grounds and return in a day? Is the boat going to be trawling or even pair trawling? Is the engine needed to help push the boat through the vast expanses of introduced water weeds that are choking large parts of Lake Victoria? Without knowing what the needs are you cannot design a successful solution. And remember an unsuccessful solution wipes out the purchaser's financial viability.

                                Design something that's half-baked and it will be like the tens of thousands examples of previous aid lying around Africa, Asia, the Pacific and South America, scrapped and unused.

                                To provide a solution, you first need to know what to problem to be solved is.



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                              • David G. LeVine
                                ... Air cooled motor cycle engines idle at low load, at high speed there is lots of airflow, at low speed, not much. A boat will almost always be slow to
                                Message 15 of 16 , May 9, 2013
                                  On 05/09/2013 04:20 AM, greg123452003 wrote:
                                  > However these are air-cooled motorcycle engines NOT fan-force cooled engines like lawnmowers. These motorcycle engines WILL nip up and seize if there is not a sufficient flow of air over them. Sure a fan and shroud can be added if needed, but it would be very useful to know what is being designed. Without knowing the parameters of the most likely boat and the intended usage this is all wild speculation.

                                  Air cooled motor cycle engines idle at low load, at high speed there is
                                  lots of airflow, at low speed, not much. A boat will almost always be
                                  slow to speed up, hence my concern for additional cooling since the
                                  amount of time at slow speed will affect the engine temperature.

                                  Dave 8{)
                                  --

                                  "A word to the wise ain't necessary - it's the stupid ones that need the
                                  advice."

                                  Bill Cosby
                                • Adam Simmons
                                  I doubt it ll be an issue. Most engines can take heat abuse for quite a while before there are issues. I ve ran a junkyard assembled Chevy 350 (different
                                  Message 16 of 16 , May 9, 2013
                                    I doubt it'll be an issue.  Most engines can take heat abuse for quite a while before there are issues.

                                    I've ran a junkyard assembled Chevy 350 (different pistons, different heads, different compression ratios) on a run stand with no load, and no coolant. WOT was controlled by a string with a spare piston on it. After 10 minutes, we started wondering how long it would run.  The RPM was controlled by valve float - roughly 6500.  After another 5, it started to have heating issues,  at around 20 it finally stopped.  

                                    An engine designed to be air cooled would last much longer, even sitting still.  


                                    On Thu, May 9, 2013 at 11:03 AM, David G. LeVine <dlevine@...> wrote:
                                     

                                    On 05/09/2013 04:20 AM, greg123452003 wrote:
                                    > However these are air-cooled motorcycle engines NOT fan-force cooled engines like lawnmowers. These motorcycle engines WILL nip up and seize if there is not a sufficient flow of air over them. Sure a fan and shroud can be added if needed, but it would be very useful to know what is being designed. Without knowing the parameters of the most likely boat and the intended usage this is all wild speculation.

                                    Air cooled motor cycle engines idle at low load, at high speed there is
                                    lots of airflow, at low speed, not much. A boat will almost always be
                                    slow to speed up, hence my concern for additional cooling since the
                                    amount of time at slow speed will affect the engine temperature.

                                    Dave 8{)
                                    --

                                    "A word to the wise ain't necessary - it's the stupid ones that need the
                                    advice."

                                    Bill Cosby


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