Paul wrote:

Will your ducted fan 13B achieve 5000 RPM now Perry?
Good work on the mount Perry.

Perry Mick wrote:

Thanks,
sure it does, I've had over 5000 RPM since I found the
restrictive air filter and went to the carbon fiber prop.
Static is about 4800, climbout is 5100, cruise full throttle
it goes to 5400, but I always throttle back to 4800
because it's smoother.

Attached is a guesstimate of stock engine HP.  Shows
that the '89 Turbo II should produce about 140 HP at
4000 RPM, so in that case perhaps the duct could go.
But I'm going to try ducted first with a prop pitch of
50 inches (at the tip) vs. 38 that I have now.

The second plot shows the repitched prop with more
HP will still run in about the same RPM range I am
now, 4800-5400, and avoid supersonics.  Supposed
to do about 160 knots with that pitch, and 175 HP.
So there's your inefficiency factor, assuming a normal
Long-EZ can go 160 knots on 120-150 HP.
--
Perry J. Mick
Duckt N7XR
http://www.ductedfan.com

 
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