fan boat

Moreover, it was the Wrights that discovered the errors in Lillianthath's work, which drove them nuts until they decided to generate their own data. The biggest gift of the Wrights, other than being the first to have coordinated all axis control, was the prop. Early "adventures" had some control, but not full command, but it was their work on a reasonable prop, that really was their big offering. To this day, you can't get a whole lot more efficient with a wooden prop.

 

If you are really serous about building an airboat check www.airboatfun.com. They have plans for a single person airboat for $12.50. They claim you can power it with an 8 to 10 HP lawn mower motor. However this would take building a very light weight boat. Watch the video, it really looks like fun. If I could find the time I'd build one myself. I don't think you would be able to do it with an aluminum boat and a 6.5 HP motor too much weight and not enough power.

 

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Well, I guess I was wrong about sharp chines, at least as far as this airboat. For 12' aluminum jonboats though, the bottom width is 32-32" and I still think that might be too skinny with the motor up high like it is.
40-50 mpg sounds pretty nice.

As far as the shallower, deeper water thing, I had a small sternwheeler that could go in a few inches of water. When I would go from deeper water into shallower, when it got to around a foot deep, you could feel the boat slow down and the engine would work harder. Canoes were the same way. I think I read something about an underwater pressure wave bouncing back. I'm kind of surprised it seems to be the opposite with this airboat. I guess this being a planing boat and the others being displacement boats must be the difference.


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Hoyt was describing to me, a weedeater engine turning about an18 inch model airplane prop, that he powered a small skiff with, and it ran at a few miles per hour.
The about 18 inch diameter prop, was about the distance he was holding his hands apart when he was telling me about it.
Maybe invite him.

Some of the small leaf blowers produce 80 mph exhaust. Small diameter.

 

In the early days of ultralight aircraft we used 8hp two stroke engines and 36" to 48" props. Mostly 48". This gave about 75lbs of thrust w a good wood prop. Some high performance units w go cart engines about the same size made over 100lbs od thrust.

Later 30hp belt drive ultralight engines w 2-1 belt drive made 200lbs of thrust w a 54" wood prop. These were twin cylinder snowmobile engines.

You might search UL engine parts and find a gold mine.

 

http://www.boatdesign.net/forums/diy-marinizing/weed-eater-engine-conversion-1681-42.html

I used 25cc engine. You really need at least 50cc.

https://www.youtube.com/watch?v=C0cRF7ZdsqE

https://www.youtube.com/watch?v=18g3AJPag9Y

 

Like the canoe.

 

Hoyt, your fan canoe is really cool!

 

Thanks.

http://www.boatdesign.net/forums/diy-marinizing/weed-eater-engine-conversion-1681-41.html

See movie in post #604 for a close up.