Is that dyno data Jon or in the boat data. If in the boat
     you have the
     fixed pitch prop situation most of the time. Of course
     when you
     accelerate
     the engine is loaded down temporarily. I also assume this
     is not your
     supercharged engine. Do you have any inlet air temp data
     for your
     test?

     BTW what BSFC are you seeing with your new supercharged
     rotary boat
     engine?

     Paul Lamar

Dyno data. We use only the low compression ratio rotors (for both NA
and supercharged engines). The last dyno testing we did was for a
special supercharged application -- customer wanted more power and a
"fatter" torque curve than the NA engine provides, and did not want
to run premium gas. So we reduced the boost pressure a bit, aimed
for (and got) about 210hp at 6500 rpm. Don't recall all the data
offhand (I'm home now), will look in the next couple of days and
post. With this setup, on regular gas and relatively cool ambient
temperatures I could advance the timing way beyond MBT with NO HINT
of detonation, at high or low speed. Haven't tried it with the
distrubutor ignition on the NA engines... hopefully soon. When I was
developing our 240Si (240hp @ 6500 rpm), I was able to induce
detonation (with bad results) at high speed. Did not have any
problem at lower speed.

Regarding boat prop load... you can load the engine above the
"theoretical" prop curve pretty easily by weighing down the boat
with excessive gear and people, or by towing water skiers, or by
running into the wind or into heavy seas.

Jon

 
The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.