Paul,
Here's some video data for you.
http://www.youtube.com/watch?v=dZrADAieO6w
It was taken this morning with a Flip video camera during my
takeoff run and climb to about 4k msl. OAT was 78. Initially,
the mixture was set the same as my last report as indicated by
the EM-2's mixture bar. Then I adjusted the mixture a bit richer,
toward "best power". Best I can tell, the fuel flow went to 28.6
gph. Sorry for the shaking as I was both the pilot and the
cameraman. I stopped recording when the sun blanked out the EM-2's
screen. I need to design a camera mount before I try this again.
Prop was set to 2100 rpm for initial takeoff, then to 1900, and
finally to 1700. Max engine RPM (that I can read) was 6926, but
dropped back to approx. 6350 as speed increased, prop still at
2100. You can hear engine rpm drop when I changed prop setting.
It should be noted that the primary oil and water temps are on
the EFIS, not the EM-2.
Mark S.
Good work Mark. Thanks for the data. I discovered Mike did not
install the 4 push button sw's on my EM-2 so I'll have to do that
to read that kind of data.
At a BSFC of .6 that is 286 HP. Not bad for only 6336 engine RPM.
I get 2223 prop RPM with a 2.85 gear. Why do you set the prop
RPM so low? What is the tip speed at 2223 RPM on a 76 inch prop?
What is wrong with the EM-2 display? It looks like mixture bars
are over writing the text.
Sounds like you need a set of David Clarks for your video camera :)
Paul Lamar
Glad you found that exercise of interest. I need to either, 1)
build a camera mount, 2) put some tape over the mic, and/or 3)
have someone else do the filming while I fly the airplane.
Regarding prop rpm, sometimes I use 2150, but normally I set it
at 2100 prop rpm because it works without over-revving the
engine. Tracy has the EC-2 rev-limiter set at 7500 rpm. The M/T
electric prop adjusts very slowly. When I first start feeding in
the power the rpm goes to 6900-7000rpm as seen in the video. It
doesn't come down until I'm a good ways down the runway. I may
try 2200 and feed the power slower and see how that works. Or,
start out with it set to 2100 and then re-set it once I'm rolling.
At 2100 it climbs at 1300-1500 fpm, so that works just fine for
Texas. I don't want to cause my pax any nosebleeds. BTW, I was
carrying 80 gallons of 100LL in the video.
According to my calculations, the prop tip speed at 2223 would be
about 737 fps.
Mark
It was very informative. I screen captured half a dozen at different
RPM's.
Speed of sound at sea level = 1116 feet per second
so that is only .66 Mach. Try setting the prop at 2400 RPM.
You cannot over rev a rotary with a prop connected.
It sounds like there is too much pitch at the start of the
take off roll.
The Rolex 3 rotor RX8 car's used to run 10,000 RPM for up to 24 hours
before the race organizers put a 8500 Limit on them to make
everybody else competitive.
I think if you do that you will shorten the take off roll.
80 gallons is 480 pounds of fuel. ES empty weight is supposed to
be 1900 pounds and gross weight 3200 pounds.
That is a much better ratio than a C182. Max fuel on my C182 is 88
gallons.
If I lean it very carefully I can get the fuel burn down to about
13 gallons an hour but I am only doing about 140 Kts. A used C182
is about 100K and a new one half a million :)
Paul Lamar
Paul,
Those speeds are pretty much meaningless. Vy for the Lancair ES
is 105 kts, so that was my target. Vx is 85 kts and it climbs
much better at Vx. I'll do another video once I figure out a
camera mount.
Regarding RPM limits, Tracy programmed the EC-2 for a max of 7500
rpm. So, that's my effective max rpm. Almost criminal for a p-
port engine to limit it to 7500 rpm.
Mark
As Rick Perry says "almost treasonous" :)
Paul Lamar
Mark was kind enough to take me up in his Lancair ES a few weeks ago
and I was thrilled and amazed...Mark is a great pilot, and his
airplane is the Ferrari of the air. 228 MPH casually while the
engine wasn't even doing 6K. Light responsive controls, perfectly
stable.
Gene Kahn
Gene - Thanks for the kind words. It was a nice day to fly. We
flew up over the Highland Lakes. You got some stick time. I agree,
it was a great flight!!! Glad you enjoyed it.
Paul - Actually, what I think he is saying is that I didn't hurt
anyone, I didn't break the airplane, and I didn't upset the FAA. ;-)
Mark
When you get the camera mounted Mark please select some of the
other screens from time to time so we can see all the data. I am
really interested in cruise screens at altitude. If your video
camera has a mike input you could say what altitude you are at from
time to time and other things like gross weight. The documentation
of the EM-2 could be better with more pictures of the various
screens possible.
Paul Lamar
Paul,
Honestly, I rarely use the other screens, but I'll do it if it makes
you happy. Data is split between the EM-2 and the EFIS. I may be
able to patch into the ANR for narration. First, I'll need to
fabricate a mount for the camera.
Mark
I appreciate it Mark.
Paul Lamar input input :)
Lost in Space.... it does not compute.
Dale Davies
http://www.rotaryaviation.com/eficont.html
Paul Lamar
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