Pete was correct about how the Ivoprop works, the blades are twisted spanwise to reduce or increase the pitch of the prop. As Mark L. pointed out, this is what is required to make a really efficient prop. So in theory, the Ivoprop can be a very good option. Unfortunately, they have never solved the issue of blade creep in the hub and eventually when used on a horizontally apposed engine (VW or Corvair) in direct drive you will end up loosing a blade. I have flown behind an Ivoprop in a Kitfox with a Rotax and it was amazing to watch fuel flow go down, RPM go down and airspeed go up. As pointed out earlier, this was at much lower speed than a KR flies. Ivo has come out with Magnum blades to address the high speed issue but there is still the same hub design that requires frequent inspection to detect blade movement in the hub.
Bottom line, Ivo is not ready to be "good enough for a KR". Who wants to have a one bladed prop anyway? Regards, Bob Lee N52BL KR2 Suwanee, GA USA 92% done only 67% to go!
