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That's an excellent idea!
Would it be possible to make a couple of Ground test and
flight test props, that could be calibrated on aircraft with known
performance?
Like Tracy's, Ed's, Dave Leonard, and all the other guys
with known numbers.
Ground props could be optimized for better cooling on
those long ground-check runs. With known static rpm numbers from the named
airplanes this should be a good base reference, especially on static rpm
comparison. Once the airplane gets to fly there probably will be too many
different variables to maintain good comparison, but static runs eliminate about
all aerodynamic and weight influence.
Thomas Jakits
----- Original Message -----
Sent: Sunday, May 22, 2005 2:02 PM
Subject: [FlyRotary] Re: Crash
investigation
David S wrote:
Preflight and Phase One support would be an important safety tool. There
are "cheap" water brake "dynos" out there that can be used to vary loads on
the engine to break it in (AND program its ECU) properly from the safety of
the ground. Price is in the small thousands, and "leases" are available for
around $100/month. Without inferring speculation against the recent accident,
can you fathom the benefit of using such a device to determine IF and WHEN
your engine will vaporlock? Or to determine EXACTLY how much HP you are
making, so you can size the prop for it? Or so you can adequately determine
your BSFC and efficiency? Or to know how much heat you really are generating,
so you know how much you have to dissipate? Such a device could be
loaned/rented to members (or even NON-members for a premium... still cheaper
than Dyno time in a race shop)
---------------------------------------------
I believe and easier , less expensive way it to check your
installation is using Tracy or Ed A's well known performance prop and
simple do early testing with it. You will know if you are in the ballpark with
total installation, ie intake, exhaust, etc. I did this with Ed's prop and
flew off my 40 hours with it. Now have got to get my prop reduced in power
consumption and either buy Ed's or fly with mine. Hope to do so soon Ed,
thanks for your patience.
Bernie
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