From: "James R. Osborn" <flyrotary@lancaironline.net>
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Subject: Re: [FlyRotary] 20B with RD-1C Prop Options
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Date: Fri, 30 Oct 2015 14:50:11 -0700
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>

Hey Steve,

I had not thought about that problem.  Ear muffs?  I=92d love to see =
some photos of your test stand.  You can send them to me offline if =
that=92s more appropriate.  Thanks.

-- James Osborn
rxcited@gmail.com


> On Oct 30, 2015, at 2:08 PM, Steven W. Boese =
<flyrotary@lancaironline.net> wrote:
>=20
> James,
>=20
> I have an engine test stand that was used to develop a NA 3B =
installation and is presently used in development of a turbo Renesis =
installation.  If a prop suitable for flight is used on the test stand, =
operation at high power causes the prop to cavitate.  When this happens, =
the sound is deafening and the vibration is also felt through the =
ground.  It is worth considering that extended operation of the =
cavitated prop may be detrimental to the longevity of the prop and =
possibly the operator.  I don't know exactly what "extended" means and =
it is something I hope not to find out.=20
>=20
> FWIW
>=20
> Steve Boese
> RV6A, 1986 13B NA, RD1A, EC2 =20
>=20
> ________________________________________
> From: Rotary motors in aircraft <flyrotary@lancaironline.net> on =
behalf of James R. Osborn <flyrotary@lancaironline.net>
> Sent: Friday, October 30, 2015 9:12 AM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: 20B with RD-1C Prop Options
>=20
> Hi Bill,
>=20
> Yeah after I sent that I realized slip was a much smaller difference.  =
The difference between top speed and standing still is 100% slip!
>=20
> I don=92t really know what to expect for HP.  I threw those numbers =
out there for feedback.  So what numbers say for unported site port, =
medium street port side port, and peripheral port on a 20B can we =
reasonably achieve?
>=20
> Thanks for more input and numbers.  It will be interesting to try to =
work it out on the ground and the more I think about it, adjustability =
will be a real big help.  I did recall correctly that a friend has an =
old dyno I can borrow.  So I guess I will move in that direction first =
and set the prop selection aside for now.
>=20
>=20
>=20
> --
> Homepage:  http://www.flyrotary.com/
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