Need trans for small diesel

Discussion in 'Diesel Engines' started by PAR, Nov 3, 2013.

  1. michael pierzga
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    michael pierzga Senior Member

    Whoa ! Its rxcomposite...

    You ok, your family ok ?

    Been worried about the terrible disaster in the philipines
     
  2. rxcomposite
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    Location: Philippines

    rxcomposite Senior Member

    Thanks for the concern Michael. I am well so is my family. We live in the Norther part of the Philippines and it was the central part that was hardest hit by the super typhoon Haiyan and flattened everything in its path. Several Visayan provinces were devastated. Just a month ago, there was an earthquake, same region, and toppled most of the massive 17th century structures.

    Although we are far away, we were also affected by the wrath of the typhoon. Some felled trees and fences. Still repairing the damage. Other than that, we are ok.
     
  3. oldfurr
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    oldfurr New Member

    A real F-N-R marine tranny, rated to over 80 HP & 5000 RPM input so should be long lasting in your application but almost 41 lbs. & nearly 10"x8"x12" w/o any clutch.
    http://ntlongfar.en.alibaba.com/pro...igh_Speed_Marine_Gearbox_Transmission_MG.html
    There are a lot of other such items to be found on international trade lead boards this is just one I remembered off the top of my head from an earlier search for small marine diesel sets.
     
  4. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Yeah, just what I need an overly heavy, without clutch, China made trans, that will not have a warranty and will prove it's price and value, the first time I load it up hard . . . pleeease.
     
  5. oldfurr
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    oldfurr New Member

    You're welcome.
     
  6. WestVanHan
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    WestVanHan Not a Senior Member

    Rototiller trans...the type that uses a belt as a clutch and also to reverse the drive?
     
  7. parkland
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    parkland Senior Member

    I think most use an aluminum wheel, cause aluminum has better friction to rubber, and a wheel with rubber rim, and it slides along 90* from the drive wheel to provide an infinate gear ratio.

    Just don't stay in low ratio too long, or rubber wears away.

    Very smart and simple reliable invention.
     
  8. WestVanHan
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    WestVanHan Not a Senior Member

    Dunno about those being in rototillers...IIRC an antique car in the early 1920's had that.

    It's a belt tensioner for forwards,and pulling back engages another idler to get reverse. Saw one in a boat when I was a kid.
     
  9. nimblemotors
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    nimblemotors Senior Member

    I have a transmission from a Geo Metro, also have one from a Geo Tracker,
    they are about 40-50lbs without the flywheel. If you have some mechanical skills, you can find an old powerglide, convert it to a 'shorty', and run it without a torque converter, 1.7:1 first gear I think, about 50lbs too.
     
  10. FishStretcher
    Joined: Oct 2011
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    FishStretcher Junior Member

    Honda goldwings have reverse gear. Some modern snowmobiles do as well. But I think a late 1990s goldwing trans might be worth a look.
     
  11. Marco1
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    Marco1 Senior Member

    If you are still after a gearbox, you have a few choices.
    You can modify a car transmission from whatever mini car is available in your local wrecking yard. Get rid of second and first gear and leave direct (3) and reverse.
    otherwise, buy a marine gearbox. Technodrive make one that is 9 Kilos, ZF 10k or even PRM80 at 12 Kilos
    http://www.lancingmarine.com/databook5pages/mechanical.pdf

    Or you can try your luck on e-bay

    http://www.ebay.co.uk/itm/ARONA-INB...005&prg=9063&rk=2&rkt=6&sd=141226649497&rt=nc

    http://www.ebay.co.uk/itm/Hurth-marine-boat-gearbox-HBW10-2R-/331154225040


    My favorite
    http://www.ebay.co.uk/itm/stuart-turner-gear-box-marine-/261425543533
    http://www.ebay.co.uk/itm/Vintage-S...versing-Boat-Gearbox-To-Restore-/291107757423
     
  12. parkland
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    parkland Senior Member

  13. Marco1
    Joined: Oct 2009
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    Marco1 Senior Member

    I read that thread in the wood boats forum and I was surprised that no one came up with any real solution.

    I know the OP said he did not want to make a gearbox, but I think that converting one would be just as much work.

    Considering the engine in question is rather small, I can think of a very simple way to transfer power from a small engine to the prop shaft via a contraption that would be easy to make.

    Forward would be via two pulleys and a V belt, ratio 2:1, the use of a pulley will provide a drop down. The "forward" pulley and belt will be loose and a tensioner would make it engage forward.

    For reverse, there is an aluminium wheel driven by a chain off a sproket on the same shaft the primary pulley is. This reverse pulley turns on a separate shaft, welded to the bracket it pivots on.
    The reverse wheel bracket if pushed sideways, will touch a secondary rubber wheel on the secondary shaft, the one that goes to the prop.
    The reverse wheel bracket and the tensioner bracket are one, so that if a leaver is attached to this bracket, pulling one way tensiones the forward belt, pushing the other releases the forward belt and at the same time presses the reverse wheel against the secondary wheel and produces reverse.
    The whole thing does not need to be big at all and contained in a steel plate box.
    Hard to describe without a sketch but it is rather simple.

    Of course making this for only forward and neutral would be even simpler. Just a V belt and a tensioner on a leaver.

    A PRM80 is about 380 pounds some $700 plus shipping. Forget the ZF/Hurth M10 they are dearer and rather bad.
     
  14. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    How about a toothed belt and pulley? Or a motorcycle chain and sprocket (noisy)? Drive engage will be through a magnetic clutch from a used auto aircon clutch. Most auto aircon starts at 5 Hp so maybe you can get something bigger. No reverse though.
     

  15. Marco1
    Joined: Oct 2009
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    Marco1 Senior Member

    There are many ways to achieve a reverse gearbox for marine use if the power to transmit is small. It is all a matter of how much work you want to put into it.
    Even a hydraulic pump would provide forward and reverse rather neatly but at a much higher cost.
    if I had to make "my" contraption I may even try a different ratio for reverse so that the rubber wheel on the prop shaft side is bigger and the aluminium wheel smaller and you get better grip and less of a bang going in reverse if the shaft is still spinning.

    i may even try to do this for fun and attach it to a Honda 5HP for my tinnie. I hate the 25HP mercury hanging from the back of it.
     
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