Long Tail ..a question of balance

Discussion in 'DIY Marinizing' started by pistnbroke, Feb 8, 2009.

  1. pistnbroke
    Joined: Jan 2009
    Posts: 1,405
    Likes: 33, Points: 48, Legacy Rep: 404
    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    I am putting together a long tail powered by a 6.5 hp Honda and my question is how do I deteriming the piviot point ...Logic would say point should be forward of the balance centre so the prop sinks but how much and am I right ??
     
  2. TerryKing
    Joined: Feb 2007
    Posts: 595
    Likes: 25, Points: 0, Legacy Rep: 289
    Location: Topsham, Vermont

    TerryKing On The Water SOON

    A few photos.. from Bangkok

    Here are a few photos from Bangkok of LongTails I saw recently.. It certainly seems that the balance puts the prop into the water, the drivers hand is on top of the handle. The drivers seem to easily move the prop up and down.

    Balancing a Turbocharged 6 cylinder diesel (the largest I saw) is not child's play!! These are amazing boats..

    Small LongTail:
    http://www.terryking.us/photoalbum/v/travel/bangkok08/P1010766.JPG.html

    Pivot Points and drivers: 4 Cylinder diesels:
    http://www.terryking.us/photoalbum/v/travel/bangkok08/?g2_page=11

    A closer-up of the pivot. SEEMS adjustable!
    http://www.terryking.us/photoalbum/v/travel/bangkok08/P1160548.JPG.html?g2_imageViewsIndex=1

    Other weight-distribution example:
    http://www.terryking.us/photoalbum/v/travel/bangkok08/P1160047.JPG.html

    The whole album here:
    http://www.terryking.us/photoalbum/v/travel/bangkok08/

    I'd love to build one of these some time with an aluminum-block V8 :)

    HEY! Show us a photo of yours when you're done!
     
  3. pistnbroke
    Joined: Jan 2009
    Posts: 1,405
    Likes: 33, Points: 48, Legacy Rep: 404
    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    Thanks for that Terry ....I deduce
    Limit on downward movement of tailshaft even if it only hits the boat transom.
    seem to retain gearbox and control of the lever ...anyone seen one go in reverse ??
    Uses the clutch
    the mounts would indicate slightly tail heavy but not much..

    Well I have the centrifugal clutch and got the tail pipe/shaft and bearings yesterday . Have engineered the prop end with a taper roller bearing and oil seal so the job is moving...My shaft goes under the engine with a 2.11 chain drive so I can have a right hand prop ...
     

    Attached Files:

  4. TerryKing
    Joined: Feb 2007
    Posts: 595
    Likes: 25, Points: 0, Legacy Rep: 289
    Location: Topsham, Vermont

    TerryKing On The Water SOON

    Small Aircooled Engines "Marinizing"

    While we're at this: Can anyone ID this engine I recently saw used in small boats on Mabul Island off the East coast of Borneo?? They seem to work pretty well in these small (12 foot or so planing boats).

    The Engine:
    http://terryking.us/photoalbum/v/travel/borneo2009/boats/Borneo2009-Boats-34.JPG.html

    A boat on plane:
    http://terryking.us/photoalbum/v/travel/borneo2009/boats/Borneo2009-Boats-40.JPG.html

    More boats:
    http://terryking.us/photoalbum/v/travel/borneo2009/boats/?g2_page=7

    The whole album:
    http://terryking.us/photoalbum/v/travel/borneo2009/

    (Click on any photo for larger; click again for even bigger)

    These guys spend most of their time building, fixing and running boats, and fishing. I think I could live there!
     
  5. pistnbroke
    Joined: Jan 2009
    Posts: 1,405
    Likes: 33, Points: 48, Legacy Rep: 404
    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    Looks like the 13 hp copy of the honda ..I think its Lupin or similar brand
    I have the 6.5 hp version
    dond see the point of extending the shaft so far behind the boat as you would only draw more water..better under the boat ...like the offset rudder

    anyone out there built and balanced a longtail
     
  6. Mark Wo
    Joined: Dec 2007
    Posts: 143
    Likes: 5, Points: 0, Legacy Rep: 56
    Location: Minnesota

    Mark Wo Senior Member

    yep

    You certainly want to ensure that the longtail, when unattended, sits with the prop in the water. How much force is erquired to lift it out of the water is a personal preference. I've seen first hand what happens when the motor is balanced with the prop out of the water when unattended (my first mud motor build). I did not have a clutch on this motor either. Combination of the two was a horrible mistake.

    I started the motor and pushed the boat off the shore. As I got into the boat, the motor swung around and the spinning prop almost hit me in the head. I've been told I have a hard head and all but I think the prop would hitting my head would have made short order out of me..

    for what it is worth.

    Mark
     
  7. Paraprop
    Joined: Oct 2009
    Posts: 15
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Thailand

    Paraprop Junior Member

    Latest Thai Long tail boats

    Hi,

    I am living in Thailand and my hobby is to build long tail boats and tune Honda engines.

    I would like to share the long tail setups presently available here.
    The engine shown, is a new model of the 6.5hp engine from Honda with Digital ignition and "Marine" compatible parts. The governor is removed and the ignition has a limiter at 4500 RPM. the idle can go down to about 800 RPM with the special carb setup and the camshaft used.

    the complete setup costs here about $400.- so no need to have headache with home R&D.

    The equivalent setup with a 13hp engine is around $650.-
     

    Attached Files:

  8. SPS TH Longtail
    Joined: Mar 2010
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Thailand

    SPS TH Longtail SPS

    Hi, Please visit our website of Thai Manufacturing of Long tail propeller. We can support your requirement in some part. Our website is www.longtailboatsps.com
     
  9. Landlubber
    Joined: Jun 2007
    Posts: 2,640
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    Location: Brisbane

    Landlubber Senior Member

    Hey, just buy one and have it sent home, thanks for the info.
     
  10. Frosty

    Frosty Previous Member

    The true longtail was the Yanmar industrial deisel chug chug chug with black smoke and plenty of noise.

    The bigger 6 cylinders are the Hino E700 a lovely engine resembling a Ford Lehman in red as well.

    Some of them are dressed in chrome injector pipes pulleys etc etc I have some photos taken through the rail way lines of the Bridge on the River Kwai

    When on the plane there appears to be no effort required, there fore the upward thrust of the surface prop would suggest that some considerable force is allowed to counter act that.
    The weight used to push the engine down and the prop up --looks--- to be about --say--6 to 8 kilo looking at the effort required by the small figure of a Thai.

    Some one asked reverse?? they don't -you swing the thing all the way round till the prop is a beam. Very versatile really.
     
  11. tom kane
    Joined: Nov 2003
    Posts: 1,766
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Because the drive shaft is on an angle the decending prop blades should pull the drive down into the water even at speed that is what happened on my trimmable drive which was free to move up or down.
     
  12. foilcats
    Joined: Mar 2007
    Posts: 56
    Likes: 1, Points: 0, Legacy Rep: 16
    Location: Auckland

    foilcats Stephen Snedden

    Longtail engines from Thailand

    Tom I was wanting to call you and have a chat, you remeber me Stephen Snedden i was making allooy barges before folding type,
     
  13. tom kane
    Joined: Nov 2003
    Posts: 1,766
    Likes: 45, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    Hi Stephen, I often think about you and MYARK and often when I need a quiet pick-me-up I watch the video I have of the trip to Waikeremoana Lake as it gets me back to my boating and camping trips. I still live same address in Hillcrest Hamilton. You can get e-mail contact to me through this website. It would be great to have a chat.
     

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  14. SCHWIMMWANNEN
    Joined: May 2013
    Posts: 28
    Likes: 4, Points: 0, Legacy Rep: 59
    Location: Poland

    SCHWIMMWANNEN Junior Member

    Hi all.I'm Polish and poorly know English-very sorry.
    I am building a wood strip canoe boat with a long tail and a 6.5 hp.
    This is a little unusual technical solution because of the long tail is docked on a permanent basis and has a chance to move only up and down.
    Here is a link to a video of the design and construction of kanu.
    and here's a link to a Forum where all construction stages showed Kanu.
    http://forum.kanu.pl/viewtopic.php?t=836


    First try ditching-kanu with an internal combustion engine




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    Logo CANOE
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    Last edited: May 27, 2013
    1 person likes this.

  15. SCHWIMMWANNEN
    Joined: May 2013
    Posts: 28
    Likes: 4, Points: 0, Legacy Rep: 59
    Location: Poland

    SCHWIMMWANNEN Junior Member

    Other boats which builds my friend.
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    Last edited: May 27, 2013
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