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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
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