Variable pitch propellors?

[Cody Townsend]

Just had a thought. Would a variable pitch impellor be possible? Or does it change the circumference of the impellor making it impossible for a ski such as ours. I have no idea, just a thought. These things are awesome for boats as long as you keep em' out of the sand.

http://www.land-and-sea.com/marine/t...rque-shift.htm

Check it out.

[01xdime]

Cody that woud be sweet man i've often wondered what if we had something like that. It looks as if it's possible. The video of that one boat almost jumping out of the water is pretty impressive.

[PAINKILLER]

i dont think it can work on our application. you need to have a very tight fit that is what the wear ring is for, and when this prop moves like that you lose the tight fit on the wear ring. now if the wear ring would expand with the prop then it could work.

[Cody Townsend]

I figured that much but it would be sweet dad had one on our 27' Crownline w/ a 496 HO. We had a 21 pitch prop on it then switched to the variable pitch prop, it went from 72mph to almost 78mph, came out of the water like a bass boat.

[way2fast]

The impellers used in PWC are already variable pitch...that is the pitch changes in different areas of the blades. The blades do not actually "shift" or change position as they do in the Land & Sea Torque Shift Prop.
I'm actually amazed that that company is still in business. They had a fancy catalog containing a large assortment of unproven and badly designed parts for performance outboards. From what I have heard about that prop, it would break, loose parts and blades if it were run on a fast boat set up for a surfacing propeller. (prop run mostly out of the water due to high transom height)
A similiar "shifting" prop could actually work better in a PWC pump than it would on a boat, but only if the pump were always loaded, if allowed to run dry and rev up, the prop would probably fly apart. If the angle of the blades could change and the diameter stay the same, it might work... perhaps for calm water drags.

Richard