Doug, Pat and All,
When Tracy tested the "IVO" against his "Performance Prop" he gained a lot in takeoff and climb
performance but lost considerable top speed and coolant temp went up.............He attributed both the
speed loss and higher coolant temps to the flat hub area of the "IVO" blades which his spinner did not
cover (added drag) and essentially blocked some coolant air from his radiators................This flat area
also as has been noted sucks up hp but produces no thrust..............
I have a three blade 74 inch electric in-flight adjust "IVO" prop for my "Dyke Delta" that if I live long
enough to get in the air will have a 16 inch diameter "Mustang 2" spinner which will cover most of this
flat area of the "IVO" blade hub.............The "IVO" seems to work well in the pushers from all reports
since the flat blade hubs are mostly shielded by the engine cowl in these installations............IMHO
Kelly Troyer
"DYKE DELTA JD2" (Eventually)
"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold
"TURBONETICS"_TO4E50 Turbo
From: Pat Panzera <editor.contactmagazine@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Tuesday, August 2, 2011 8:48 PM
Subject: [FlyRotary] Re: Ross Farnham IVO testing
Jim Smith with his 150 HP, auto-fuel RV-6 is reaching speeds of 200 mph TAS using a fixed-pitch, three-blade wood Elippse propeller.
That's nearly 30 mph more than the Ivo, on the same? power.