----- Original Message -----
Sent: Thursday, September 09, 2004
2:07 PM
Subject: [FlyRotary] First engine
run with Monster Prop
Ok, got out today and fired up the engine
with the new prop and gear box. This is the 76x88 inch prop that
is 2" longer than the one Tracy and Rusty have on their birds. The
static was 5400 rpm at 28.75" with ambient manifold pressure reading
29.75" (as best I interpolated). OAT was 87F. Idle was
considerably smoother whether due to increased mass of larger prop, new
gear box or both. I did notice the 2.85 has considerably less gear
lash than the 2.17.
I took it for a quick taxi up and
down our 35' wide runway and notice that the "P" effect was considerable
at full power. It felt like someone was taking the nose of the
aircraft and forcefully shoving it to the left. Rudder with Nose
wheel helping kept things under control without any problem, but I think
my first full power takeoffs will be where they have those 100 -150'
wide runways - just to be safe.{:>). Subjectively seemed to
have considerable more acceleration but will not do any definitive
test on this runway.
Temperatures were normal. After
extended runup the oil temps approached 190F and coolant temp got up to
210F this is what I would normally see. Considering that the
static rpm was the same as my old gearbox and prop, it likely I was
producing the same HP and therefore would not expect major
difference. The larger prop did not seem to interfere with the
cooling airflow - at least on the ground.
The RPM is a bit less than I had hoped for
- but may just indicate that the 2" increased diameter over the
ones flying now (74x88) is a bit more prop than is optimum. I will
fly with it and record the data so that Performance Propellers will know
how much to trim when I ship it back.
Hope to get the spinner painted over the
weekend and go flying early next week.
Ed
Ed Anderson
RV-6A N494BW Rotary
Powered
Matthews, NC
Hi, Ed...in the military I was fortunate
enough to have the opportunity to fly a few aircraft that are, as the
military feels a need to do to their aircraft, overpowered.
In New Mexico, I had a brief flight in a P-51. A definate torque
machine. The accepted method for takeoff was to apply power
gently, until enough airspeed is achieved that the rudder has more
authority. (Of course ailerons and other controls will also slowly gain
more authority). Once the tailwheel was up and flying speed was
attained, only then was more power added. I also flew the U-6
(Beaver) in Viet Nam.....we were also limited on takeoff power. Once
flying speed was attained, more power could be added. Probably
will work for the RVs with "the club" as well. Wouldn't hurt to
try it. Congrats on getting your engine, prop/redrive
assembled. Thanks for keeping us informed with your progress and
test results. Paul Conner, 13b powered SQ2000 at the airport and
ready for taxi
testing.