----- 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.