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What may surprise some of you, is that I have a "dark
side" {:>).Hee, Hee!
One of the products I make and sell is an electronic
ignition monitor for the Emag experimental electronic ignitions of growing
popularity among the experimental crowd flying with Lycomings. One of the
problems I had in development was I (naturally) do not fly behind a Lycoming,
which mean I had to rely on my partner and a test engineer down in Texas to
check out the units - that not only required expensive 100LL but also had to
wait until they had the time avaliable.
NO LONGER. My partner lost the contest between his
engine and a lawnmotor trailer hidden in the grass of a taxiway - so he donated
the totalled engine. I took rear assessor case where the Emags are mount
(just like a magneto), cut off the rear part of the engine to have all the gear
shaft mounts and hooked up a 1/3 HP electric motor to spin them. I also
have an auto vacuum puller hooked up to simulate varying engine manifold
pressure.
Since things are a bit slow on the list I though I would
send a few photos of my Emag Spinner.
Ed
Sent: Monday, June 13, 2011 9:22 AM
Subject: Pmag Spinner
Ok, folks
Here are some photos of the new Pmag test mechanism in the
Anderson Electronic Enterprise work shop. Pretty self
explanatory.
My partner, Bill Repucci, donated his old
engine which got totaled in his encounter with an object hidden in
the grass of a taxi way while taxing up over a hill.
I took the accessory case and gears and then cut off
the back part of the engine case which retain the last journal location for the
engine's crankshaft. I then filled in that 2.5" hole with a combination of
thick wall (0.5") aluminum tubing, a bronze sleeve bearing and some
pulleys. Hooked up a 1/3 HP motor and got an inexpensive fan motor
controller (round dial on the right) to control the rpm of the motor.
Hooked motor to gear drive with a pulley and have spun it up to 3100
rpm.
I have an auto vacuum puller - you can see it lying
in front of the front panel (red handle) which permits me to simulate the
engine Manifold pressure's effect on the Pmag.
The only remaining problem is the small motor surges in
the rpm range I am most interested in 2000-2800. But, I will eliminate
that problem in the coming week. I will probably replace the bronze sleeve
bear as I just am not comfortable that it can take the loads at 3000 rpm for
long. But, it'll do for now.
The bottom line is I can now test the EIC with confidence
on a spinning "engine" without Bill or Kurt having to burn expensive 100LL -
although they still provide the acid test - using the EIC in a flying
aircraft.
Just thought you might like to see the results shown in
the attached photos. Kurt has flown and reported the following data on the
first use of the improved EIC
on his GlassAir with the fuel injected 360 (IO
360?).
MAP
"Hg RPM Ignition
Advance Displayed - Comment
29.92 0000 19.6
Static Timing Ignition advance BTDC
10.9 1140 26.6 idle
15.4 2060 33.6 Run
up
29.2 2700 28.0
WOT for take off - note how the timing has retarded approx 33.6 - 28.0 = 5.6 deg
under the heavy engine load
25.5 2550 28.0 Climb
25.0 2550 30.8 (25"
Hg and below seems to be the magic number where the MAP
causes more advance to kick in)
24.3 2550 33.6 Cruise
(here with the engine not working as hard he now has the 5.6 deg back in the
advance)
23.2`
2400 35.0 with
even lower manifold pressure he gets more advance
23.9
2400 35.0
22.7
2500 36.4 Highest
ignition advance during flight at Cruise at the lowest manifold
pressure
Ed
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