Can i use a motorcycle engine?

Discussion in 'Boat Design' started by 65chill, Dec 3, 2008.

  1. Frosty

    Frosty Previous Member

    10 degrees is not a problem, after that that I would e checking to see if the pump is at the front or the back just to be on the safe side. 20 is pushing it a bit and would need modification to be sure.
  2. Chris Bretter
    Joined: Nov 2008
    Posts: 45
    Likes: 1, Points: 0, Legacy Rep: 55
    Location: Durban

    Chris Bretter Zaphod

    Do you think there would be mechanical issues at 20-25 degrees.Assuming the oiling was all ok.The thrust bearing would be loading up a bit more.The motor i was hoping to use is a Datsan SD22 old but solid was used by Chrysler marine at one time also as a generator system by Datsun.Some trand have a 10 deg drop so that might make the angle smaller.
  3. Frosty

    Frosty Previous Member

    If the engine is lubricated I see no problems at 25degrees, except that you are nearly pushing the boat up in the air. You will be needing a 10-12 foot shaft inside a tube.

    I have seen Thai long tail system on a Wharram ( the one that broke up on the beach) and others.

    What thrust bearing? what are you using for transmission. To be honest I dont know what the Thai long tails use as a thrust bearing. I assume they must modify the tail shaft bearing to a tapered roller, but Im not sure.

    One thing is for sure is you need one.

    What do you mean a generator system, a 12 v alternator or 240V
  4. Bruce Woodburn
    Joined: Nov 2008
    Posts: 12
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Vancouver BC

    Bruce Woodburn Junior Member

    I don't think you can take the clutch and transmission off the cb450. Most Japanese motorcycle engines (the 4 cylinder ones anyway) are unit construction with oil shared between engine and transmission. If you tried to cut the transmission off, you'd have a big hole in the crankcase to deal with and no output shaft. An antiquated pushrod twin, say a vintage British twin or a new Harley, would be a better choice if you really want to do this. They have the output sprocket on the left side.

    On the other, all this is making an outboard a very appealing option.

  5. Bruce Woodburn
    Joined: Nov 2008
    Posts: 12
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Vancouver BC

    Bruce Woodburn Junior Member

    message deleted
  6. johng
    Joined: May 2009
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: London

    johng New Member

    hi all sorry to dig up this old thread.. but I have been thinking along the same lines :rolleyes:

    I have a torquey V4 honda engine sitting unused and unloved in my shed.... I was wondering what Icould do with it... its powerful I would say!

    Weight in the region of 80kgs..

    Reading back to an earliler posting, of course mouting it transversaly will cause a bad torque reaction, after all a motorbike will lift itself around the back sprocket under power...

    Anyway, if anyone ever did try something like this , I would be pleased to hear there thoughts, or anyone else .

    By the way I am John, from London..
    I am quite sure we dont have restrictions on boats as much over here, but will obviously check this..
    I have found a boat, that used to have a 400cc outboard on the back.. its cheap and as an experiment, could be a good starting block.. It looks to be around 14' and is just a shell - which may make a build a bit easier..

  7. luppyrasi
    Joined: Jun 2009
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Luxembourg

    luppyrasi New Member

    Hi its Pascal from Luxembourg, before years I have put truck-engines in haverster to race, then motorcyle-engines (like XR500 and Gpz1100) on lawnmowers to race. This year im will start to put a Ducati916 engine on a albatross aluminium boat. (Frosty knews that kind of boat).The original Ford 100e works very well, also for waterskiing, but there are faster boats know. A Yamaha Vmax would also be a good stabil engine, but a bit havy, in luxembourg there is not a long time when the sun shines, more time to work on it. At the moment I am calculating what gear the propellor must be designed. I think the gear difference will be too big to use more gears on the water? The gravity problem I did not spent time for...the boat has a large seat to work against. Is there anybody who has experience with?
  8. apex1

    apex1 Guest

    Put it in a Bike!
  9. Rangerspeedboat
    Joined: Apr 2009
    Posts: 120
    Likes: 3, Points: 0, Legacy Rep: 17
    Location: Texas

    Rangerspeedboat Senior Member

    Will someone just put a motorcycle engine that they have laying around in a boat. So what if the engine quits after a while, what were you going to do with it anyays? Find all the parts to make it a bike again.

    I would say the best boat to put it in would be a hydroplane, short but fast trips. Its not like your going to run a hydroplane for hours on end, at top speed.
  10. luppyrasi
    Joined: Jun 2009
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Luxembourg

    luppyrasi New Member

    When the engine is damaged we put another in. There also exists already fast hydropanes, but the looks not very classic. Looking for the guy with experiance.
    Joined: Oct 2002
    Posts: 4,519
    Likes: 110, Points: 63, Legacy Rep: 1009
    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    There are a lot of air cooled 10-20 hp industrial engines , lawn tractor , roto tiller and similar that could be pod mounted on a cat.

    The tiller units have reduction gears .

    Honda has a great reputation .

  12. luppyrasi
    Joined: Jun 2009
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Luxembourg

    luppyrasi New Member

    Sorry but the only thing what has to be in the water is the propeller.
  13. mark775

    mark775 Guest

    Subaru's are great, low profile and,, properly (expensively) done, are very pretty. Goldwing motors are MADE for ersatzclassic runabouts - shaft drive, reversing gearbox, beautiful.
  14. Village_Idiot
    Joined: Oct 2007
    Posts: 382
    Likes: 14, Points: 18, Legacy Rep: 138
    Location: USA

    Village_Idiot Senior Member

    Methinks it would be better to use the motorcycle engine to drive an air prop to propel the boat.

    Lotsa folks using 13hp Honda engines with small aero props to push around jon boats - this is generally for secondary propulsion, mostly for shallow water, not the primary propulsion as found in larger airboats that use large I/C engines to drive a large, loud prop. I think you would need at least 150hp engine for a primary air drive to achieve any kind of good performance. Check bowfishing forums for a plethora of information regarding secondary air drives.

  15. mudman
    Joined: Mar 2007
    Posts: 88
    Likes: 5, Points: 0, Legacy Rep: 72
    Location: Madisonville, LA

    mudman Junior Member

    A guy I hunted with tried to put one in a mudboat. A 14 foot aluminum boat with a kawisaki 440 in it. We rigged it in high gear. The boat never ran right, even in high gear it wouldn't do what we thought it would. We tried all kinds of stuff, different props, switching gears, etc. It just wouldn't move very well. Problems getting on plane and such. Seems like it would work right? We later switched it out to a Subaru EA 81 with a 1:1 ratio, and that baby ran after that.

    That was the only motorcycle engine that I've seen in a boat, and it did not work. My experience tells me that a motorcycle engine belongs on a motorcycle.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.