Posted for "Al Gietzen" <alventures@email.msn.com>:

FUEL CONSUMPTION

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 max power mixture setting was approximate, and was typically with a
lambda of about 0.94, and maybe 100 - 150 degrees rich of peak EGT.  The
"leaned" run was done at about the same amount lean of peak.  The leaned run
may have no relevance in actual operation with a prop because rpm was held
as mixture was reduced by varying load while trying to maintain about 24"
MAP. Power dropped significantly, but estimated fuel economy is clearly
improved.

The BSFC values seem good; pretty much in line with expectations for a
rotary engine.  The miles/gal values were computed using the Velocity
factory values of airspeed as a reference and adjusting it by the cube root
of HP.