Thai racing longtail

Discussion in 'Powerboats' started by joeu3, Sep 26, 2012.

  1. pistoninthewind
    Joined: Dec 2013
    Posts: 1
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    Location: Sapulpa Ok

    pistoninthewind New Member

    I race drag boats, they have gotten sooo far out of hand , that they are too fast to be safe at the lake. Some friends of mine were talking about these. We could race them on big ponds ect and have a blast. Could you e-mail me a phone # I would love to bend your ear. Thanks Craig
  2. Jason1977
    Joined: Mar 2018
    Posts: 1
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    Location: Michigan

    Jason1977 New Member

    Hey man
    nice boat looks awesome. Any construction design tips you can pass on Joeu3? Did you construct yours from a set of drawings? Did you make any drawings? Is your longtail engine mount and drive shaft a one off custom piece? I talked to mud motors and they stated there shafts are only rated up 3800PRM, in most of the videos the Thai racers are running two stroke motors that max out at about 6800rpm. How did you resolve this?
  3. joeu3
    Joined: Sep 2012
    Posts: 30
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    Location: Summerland Key

    joeu3 Junior Member

    Hello Jason,
    I haven't been to this page is a very long time and I will pass what I remember I did on this boat. To design the boat I took a ton of screen shots of youtube videos showing longtails, using educated guesses on sizes, I started to write the numbers down. After a lot of images and numbers I came to a pretty good general idea of the length, width, height and step placement. Now I also wrote to a lot of Thai builders and they all basically said the same thing, they're homemade and there are no plans. I'm sure there are plans but probably well guarded secrets on the top hulls/designers. The plywood is very thin 1/16" birch, I used fiberglass and kevlar to reinforce the hull. Along with epoxy and modern additives to glue and fillet it all together. The motor mount, drive shaft, and all the metal work is all one off custom welded in my garage. When I asked about the drive shafts they said it is a shaft in a tube supported by lubricated something, like leather or I don't remember. What I ended up doing was 3/4 or 1" steel hollow shaft in side a larger tube with bearings pounded in every so many inches. I also used o rings and filled the outer tube with oil. The props have a tapered fit onto the shaft, I believe I pounded in a solid shaft into the hollow drive shaft, drilled and hammered in two pins. I hope this answers some of your questions. I will check and see if I have any pics of that area.
  4. joeu3
    Joined: Sep 2012
    Posts: 30
    Likes: 10, Points: 8, Legacy Rep: 52
    Location: Summerland Key

    joeu3 Junior Member


    shock absorbing motor mount and pivots

    jet ski shaft bearing from motor to shaft with home made adapter


    Shaft mount
  5. sutluc
    Joined: Aug 2018
    Posts: 1
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    Location: Canada

    sutluc New Member

  6. tom kane
    Joined: Nov 2003
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    The Thai long tail propulsion was originally a French invention 1900 La Motogodille, National Motor Museum,the first racing engine available to the public. And spread through the French Colonies. And it has changed little over the years. The link shows a DIY model (experimental) from the 1950`s.
  7. Leksmol
    Joined: Oct 2018
    Posts: 1
    Likes: 0, Points: 1
    Location: Thailand,Bankok

    Leksmol New Member



    Hello my friend. This boat is so beautiful.Thus I want to this boat's drawing scale that you have.Please;

  8. Qmaster 1
    Joined: Jul 2021
    Posts: 1
    Likes: 0, Points: 1
    Location: North Eastern North Carolina

    Qmaster 1 New Member

    joeu3 Interesting thread. I've been wanting to build one of these for several years now. But kept striking out on Plans. Im now convinced they dont exist. You have done a amazing job on your build. If you could Id love to know more details on this build. Length, Width, Step, Curve etc. I have a Motor and have found the correct Long Tail Kit for my Motor Kawasaki 650SX jet ski engine as well as the Tulip design race props. I know its been Two years sence youve posted and as a new member I cant figure out how to PM you. My direct email is

    Thanks Bud

    Last edited: Jul 21, 2021
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