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. If you are serious about one of these props, I'd recommend contacting the company and asking for contact information for customers that are actually using one in the same application that you will be using. Better to hear from people with direct experience if at all possible to dispel any potential misunderstandings. I have one of the Magnum models for my Subaru setup, but since I am not flying yet I can't offer you any sort of PIREP, and since my application is different than yours it probably would not help you anyways. All I can offer you is that my research a couple of years ago showed this to be a reasonably priced prop that has a good following. It is not the fastest or absolute best in climb, but is a decent compromise given the significantly cheaper price compared to other in-flight adjustable pitch props. -Dj -- Dj Merrill - N1JOV Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/ Glastar Flyer N866RH - http://deej.net/glastar/