Big HP Twin Engine Airboat!!! 

I think they are from sensenich.com and they can custom build blades to the size you want.

This was just a test to see if it can handle a load. He mounted a large crane on deck and wanted to make sure it would still run dry land

Beer holder is right or left hand! We don't put them down! Lol

Nice. Post a vid when u water test. I'd like to see that

That's the engine speed. I think he is running 2:1 gear reduction

Hola qué tal por fa que dimensiones tiene el bote y que motores tiene gracias

Yes

??? Maybe but may cause leaks. I've seen some with mufflers and different style blades that quiets them down

That would create too much back pressure and reduce the power.

I agree

+jrichard73 The boat is running twin 540ci Chevy Big Blocks and I imagine he is trying to turn the props more with torque than hp. Reduction is 2:1

+Antrigen UM, you do know that without torque there is no such thing as horsepower right? I am very familiar with airboats and have custom built several big prop monsters and know what I am talking about. With that being said a gear reduction is a torque multiplier.

+Turbo Chevelle I have no doubt that you know what you are talking about. My comment is that this is a workboat and as such requires a lot of very precise small moves to position it often with very heavy loads and that is best accomplished with lower rpm's so that the boat does not suddenly jump. Along with the multiplication of torque, there is a decrease in rotational speed of the output shaft compared to the input shaft when using a reduction gear so the engine would to turn higher rpm's to get the same prop speed taking him out of the torque range of the engine. Torque gets you moving and hp gives you the top end.

I am very aware of the work boats as well quad engine and so on. A friend of mine builds them and I also have worked my boats from survey to pipeline and environmental. The engine like a bigger gear reduction because it takes the load off of the engine resulting in better longevity. Also with the higher reduction ratio equaling lower tip speed you have a huge reduction in noise which is also a plus. My last boat swung an 84" Diameter 5 blade Sensenich Superwide and at wide open throttle at 50 foot the boat registered 89 decibels. The boat was quiet and an absolute bulldozer. At 5200 rpm my prop speed was 1,666 rpm. Everyone said it wouldn't work and it proved everyone wrong. The funny thing is that I did it with a custom built 397ci SBC built with 5.850" rod and custom pin height pistons.