High rpm jet drive

Any advice on a jet drive to use with a rotary engine at rpm range up to 8500?

 

Search for Jet Drive info

I might suggest you type in "jet drive" in the "search" function above. You will get a lot of info,

....including this one
http://www.boatdesign.net/forums/showthread.php?t=11254

 

high rpm

scott jet is a high rpm jet. They are in new zealand. There is a company called adkins rotory that marinizes the rotory and they suggest a gearbox bofore a kodiak jet pump to fall in line with the 3-4k rpm range. I think this would give it some torque. The yamaha jet i would think would be a high rpm jet but i am not sure.

 

Jet units for high rev engines

Having built jet unit powered boats, we would suggest you fit a F.N.R . gearbox straight on the engine. Thay are not that expensive and not too heavy, but they give you the option of proper rev matching, and the safety of a true neutral and the chance to backflush the jet pump when you get it all clogged up with weed - which happens all too often.
The jet units we use are the world leaders - Hamilton Jets see : www.hamjet.co.nz for details and powrer speed calculations etc.

Good boating
Hugh Mattos
www.explorermarine.co.uk

 

What kind of rotary are you thinking about using? I was under the impression that Rotaries like those from Mazda have a reduction between the rotor and the shaft on the order of 3 to 1? So with an engine speed of 8500RPM that would be a shaft speed of approx. 2800 RPM? Just thinking out loud.

 

It all depends on whether you use a gear box or not

 

I think you were missing my point. We all remember that in a rotary engine, the rotor travels in an eccentric motion around the case and around the shaft. The shaft and the rotor are geared together. At that point there can be a gear reduction not requiring a gear box. When I think gear box I think of something that is attached to the output shaft of the engine.