----- 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.