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Hi Folks,
Finally back on the List after I lost my
harddisk last week. Have not had a chance to read through all the
backlog, so if anyone addressed anything to me personally, would
appreciate it if you would resend the message.
Monday got first flight in with new prop,
was probably not the best day, but had waited for over a week as remanats of
IVAN went through. Wind was from the NE gusting to 18Kts.
"P" Factor
I did find out on the first take off what the
"P" factor really stood for - and it isn''t "propeller"{:>). Wind
was from the right quarant on take- off, but knowing what to expect (I
thought) based on my taxi test, I proceeded down the runway. It was
taking quite a bit of right rudder to keep the nose pointed straight ahead -
but with the nose wheel all was managable - until I lifted off.
The moment the tires left the ashaflt, the
aircraft jumped to the left side of the runway (hangars on that side).
Full right rudder and then some was required {:>). Wind from
the right quardrant was probably a major factor.
The good news was ROC was over 1500 fpm which
for my lead sled was about 400-500 fpm greater than normally with a full
load of fuel. So I was up and high above the trees very quickly. I was
climbing out at the IAS (120 mph) that best suited my old installation - so
it may prove that a different airspeed will provide an even better rate of
climb.
Top Speed
Climbed up to 7000 MSL for a high speed
run. Eventually got up to 6300 rpm (perhaps a bit more) and 175 mph
indicated with OAT of 71F (actually 5 deg warmer at 7000 than on
surface). Calculations put this at 201 MPH with a fuel burn of 11.28
GPH. At WOT at 7000 msl I would normally burn 12 gph with the old set
up. So the big prop has not hurt and may have even helped top
end speed. Although I did not time the climb to 7000 msl, it certainly
seemed to come by quicker than with the old prop and gear
box.
Inlet Area
Also, this was the first flight with my 2 GM
cores inlet area reduced to a total of 28 sq inches, temperatures were
what I would excect on climb-out on a 65F OAT day. Oil was approaching
200F and coolant 210F when leveled off at 3000MSL and soon dropped down to
165 Oil and 170 coolant at 5200 rpm at 6 GPH fuel burn.
One thing I learned was that the 28 sq inch
inlet is fine for cruise HP with temps around 165-170F on oil and coolant at
engine rpms of 5000-5600 burning around 7 gph. But, by the end of my
high speed run the temps of both had pushed up to 200F where they
stabilzed. So I will probably open up the left hand inlet ( that I
had reduced to 10 sq inches) to the same area (18 sq inches) of the right
hand inlet giving me a total of 36 sq inches of inlet area for the
radiators.
Landed at an airfield with 100 wide runway to
refine my take off technique - but it turns out the wind was 90Deg across
that runway and the take off was not much different than the first (but with
less of a personal "P" factor having more runway to play with {:>).
Once the wheels left the ground the aircraft want to go left. So
decided to get back and set it down before the wind got worst. I guess
the good news is that even with a cross wind gusting to 18kts the "P" factor
was managable, if a bit hairy.
On approach found that I will need to reduce my
idle rpm, that big prop even turning slowly was at my old idle (2000 rpm)
simply still turning too fast and it was difficult to keep the approach
speed down. .
But, landed safely and decided to wait for a
better day.
Injector
Diffusers
One other thing to report. I had stopped
using the injector diffusers (those little plastic inserts that are designed
to break up the injected fuel spray more) in my last two
manifolds. After I had removed them, I had noticed that I could
not lean the engine much beyond 6 -7 gph without the engine
starting to stumble a bit. So this time I stuck them back in front on
the injectors and could lean the engine down to 4.5-5 gph before it started
to stumble. So don't know for certain but it appears that the
diffusers do help. Wonder if anyone else had attempted flying with and
without and noticed any difference?
So hopefully the computer is finished with its
problems and I will report more from next flight. So all in all I am
very pleased with the first flight. My intially impression is I may
need to have the prop trimmed an inch or so as I would like a bit more rpm
for take off and climbout. But, will conduct a bunch more flights
before deciding
Best Regards
Ed Anderson