has anyone heard anything about Vari-Prop?  http://www.variprop.com   I spoke with Larry Morgan the other day after a stop at van's.  he is a retired engineer and has been working on this project for 20 years, sinking over a million dollars into development (hey Tracy, sound familiar?...how to turn a big fortune into a small one....:-)  he showed me the ellipse blade for the RV which he hopes to fly in the next month.  the prop tip must have a chord length of perhaps 3/4" !  the wood blade is very stout, maybe 4" chord midway and 2" thick(from memory).  I was thinking I could install one on my O-320 and later use it on my renesis.  he offers 2,3,4 blade combos, tho most are buying the 3 and 4 bladed models for their high-perf planes. his system is all electric with a small stepper motor driving a remote hydraulic master piston that produces pressure for a piston in the hub. feedback of rpm lets it keep a constant speed.  hub and blades weigh about 58lbs, pump maybe 3?