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Message
Congrats
Rusty!
Having joined the lofty ranks of those who
have buily & flown a wankel powered aircraft, the Rare & much
coveted "I Love Flying my Mazda Rotary" button is now on its way to
you.
Tracy
Thanks, but I haven't really loved it that
much yet. Maybe by the time the button gets here
:-)
OK, below is today's installment of the log. As
you'll see, climb rpm ain't what I was expecting, and likely explains the
sluggish performance. What is the "normal" spread between
static, and climb rpm for some of you guys that are
flying?
Also, you'll note that water temp is rock solid at
180 with the thermostat, but oil went as high as 240. This is
measured at the pan, and I assume (from Finn's data) that the return oil is
probably 230 or so. I'll be looking into an inline sensor so I can
measure the temp as it goes into the engine. Does anyone know what the
safe limit for oil temp would be? I'm running Mobile1 SuperSyn
10W-30, and their site doesn't exactly give a temp limit that I can
see. If the oil can (hypothetically) withstand routine use at 260
degrees, would the engine be harmed by running it that hot? I've always
figured that temp limits were for breakdown of the oil, but we do cool the
rotors with it, so I'm sure there's some limit to what the engine will be happy
with. Just sorting through my options at this
point.
Anyone know of an inline temp sensor block that's
available, and would have AN-10 or AN-12
fittings?
Cheers,
Rusty
9-1-03
/ .6 hours /
.7 total
Second, and I guess third flights
today. Still no fatalities, but I
verified that the landing gear is pretty strong. Gotta stop flaring this thing 5 ft off
the ground.
Flight notes.
This is with the prop set to 15 degrees of pitch, which gave 5400 rpm at
3 psi of boost static. It’s also
with a stock 180 degree thermostat.
First takeoff and climb was done at
0-1 psi, and 90 mph. This felt
about like the other day, but I couldn’t coax my anywhere map into giving me a
decent VSI reading .
It appeared to be about 1000 fpm. By most standards, this isn’t bad, but
it’s not what I’m hoping for. I was
also paying too much attention to the temps to notice the rpm during climb to
2000 ft. The water started out at
180 degrees, and never moved. The
oil started out at about 150 degrees, and reached about 220 by the time I got to
2000 ft. I continued flying in
circles at 5000 rpm and 120 mph, and the oil maxed out at 240 degrees. This is certainly on the edge of being
too high, but since I’m reading the oil pan, not the return oil from the cooler,
it’s not as bad as it sounds. More
power, but higher airspeed might be a wash. I need to try to rig an inline oil temp
probe for the return oil. The
aileron trim was fine today, but that’s because the fuel was balanced, the
actual trim still does nothing.
Measured the springs for replacement with stronger ones. During descent, and landing, the oil
came back down to 180 or so.
There’s also not enough up trim for landing, even with no flaps, and this
thing drops like a rock with low power.
Once on the ground, I decided to do
another run around the pattern, to see what the oil temps would do with a full
throttle takeoff. Departed at 3psi
of boost, and there was quite a difference in the feel of power. Climb was still only 1500 fpm, but the
real surprise was when I looked (finally) at the tach. During climb, at 90 mph, and 3 psi of
boost, I was only turning 4700 rpm.
Starting to make sense now.
I guess the prop was stalled during the static runs, so my 5400 rpm
(3psi) was artificially high. I bet
I was only turning 4400 or less during the 0 psi climbs. No wonder it seemed like a dog. Water of course stayed rock solid at 180
degrees, but oil climbed rapidly to about 220 degrees by 1500 ft. It’s likely that 90 mph isn’t the best
climb rate for the plane, so I’ll try a little higher airspeed next time. That will also help with the
cooling.
After the flights, I found a couple
drops of oil, from those stupid POS Earl’s swivel fittings. They’re leaking from the swivel. I’ll NEVER buy these again. I didn’t find anything else wrong, but
I’m not sure what I’ll do about the temps, so I’ll leave the cowl off for
now. I reset the prop pitch to 12
degrees, which wasn’t exactly what I meant to do. I thought I was on 14, so I went down 2 degrees. I was actually on 15, and am now down 3
degrees. Should be just fine, since
I’ve got lots of headroom on the engine rpm range to work with.
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