People who know a lot about experimental props are airboaters:
http://www.southernairboat.com These are all pushers and lower pitch (40") , and I had no idea there were so many sensenich's out there! Looks like they rank 1., whirlwinds 2., and Ivo 3. with this crowd. Peter Hi Phil, They aren't recommended for larger direct drive engines like a Lycoming O-320 or O-360, but for 100hp and less direct drive engines they have info online. You can read more about it on their website: http://www.ivoprop.com/service-bulletins/ These props seem to be very popular with the smaller engine crowd on power parachutes and the like.
