Mailing List flyrotary@lancaironline.net Message #1807
From: Ed Anderson <eanderson@carolina.rr.com>
Sender: Marvin Kaye <marv@lancaironline.net>
Subject: Re: [FlyRotary] Re: EGT's; Fuel consumption
Date: Sat, 31 May 2003 11:57:47 -0400
To: <flyrotary>

> The fuel consumption data was very limited because of a high degree of
> scatter caused by poor flow meter performance.  The computer logged data
for
> this parameter was essentially unusable.  Some good data was measured by
> doing timed runs, i.e.; set up a steady state engine operation and take
> weight readings of a fuel supply container at one minute intervals for
five
> or more minutes.  The number of these runs was limited to 4 as these were
> the last tests we were doing and ran out of time.  The results are as
> follows:
>
> RPM Mixture MAP ("Hg)  Avg EGT (F) HP BSFC mpg
> 5,100 WOT Max pow 26.6 1,570 220 0.52 12.5
> 5,100 Leaned 23.8 1,556 155 0.49 16.9
> 5,000 Max pow 24.8 1,544 200 0.54 12.9
> 4,550 Max pow 21.8 1,488 150 0.55 15.6
>
> The target operating points were 1.) 5000 rpm WOT, 2.) 5000 rpm, 24" MAP
> about 150 lean of peak, 3.) 5000 rpm, 200 hp, and 4.) 4500 rpm, 22" MAP.
>

Hi Al,

    Here is what my spreadsheet calcuations for a 3 rotor at your rpm and
HP.
RPM,     HP,     GPH,     A/F

5100        220    19.7    13.50  WOT
5100        155    13.93    19.10 Leaned
5000        200    17.98    14.50 Max Power
4550        150    19.90    17.00 Max Power

The A/F may be off for anything but your WOT run as my program does not
factor in throttle setting, just airflow and airfuel mixture, altitude and
temperature.  (I used 0 ft altitude and 59F).  So You could have a higher
A/F but low throttle setting and get less HP than the A/F and RPM would
indicate.

Ed Anderson


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