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Ernest,
based on your 400 x 5 msec = 15 ml, gives you an injector
flow rate of 450 cc/min which is about right for the stock 13B N/A
injector
Ed
Sent: Sunday, May 08, 2011 1:49 AM
Subject: [FlyRotary] Re: I've got fuel pressure
On 05/07/2011 05:57 AM, Lehanover@aol.com wrote:
Good job on the trouble shooting.
Lynn E. Hanover
I'll
probably start rambling, but I've spent the past two days covered
in
gasoline, so I have an excuse. Jumping in and out of the plane to
turn fuel valves, try to bleed lines, or switch on pumps has me beat
down.
What I
lack in intelligence, I make up for with stubborness.
Today, Lee,
my younger son, helped me set the fuel pressure to 45psi. I couldn't watch
the pressure gauge while fiddling with the regulator, so he called out the
numbers while I adjusted. The regulator is back in a hole. I don't
believe he has any idea how grateful I am, or how much work he saved me by
turning a 2-hour job into a 3 minute task.
The next thing on the agenda
was "characterizing" (my term) the injectors. The Megasquirt has an
injector test function. You tell it how long to fire the injectors, and
how many time. Set it to fire ten times or so for a few milliseconds to
verify clickety-click from the injectors, or set up a fixture to capture and
measure the sprayed fuel, and you should be able to tell exactly how the
injectors are behaving. I'm not the type to pass up that sort of useless
information.
s = milliseconds sprayed
f = nominal flow
m = missed flow due to turn-on/off time
c =
cycles sprayed
c(sh-m) = measured volume
The two unknowns
are m and h. Do it for several s values and you have a series of equations
that you can solve for m and h.
That was my goal. I got several
good runs, but when I set s to 80, the program bailed on me. Said 65 was
the highest I could set it to. Unfortunately, from that point on whenever
I turn the MS on, I would get full fuel flow. I wasn't able to turn off
the test mode, change it to something else, or switch it to normal.
Today was going to be my first run of the engine. Unfortunately, I
ended up having to reflash the firmware, and reconfigure all the computer
settings. It is back up and running now, and I did just a basic test of
the secondary injectors. I haven't even had time to boil the numbers down
to see if they make sense. The injectors all measured out very close
together, so I'm confident they are going to service me well.
The raw
numbers from the primary injectors (only one test on the secondaries, and
they looked the same).
400 5ms squirts gave 15ml.
400 20ms squirts
gave 60ml.
1600 5ms squirts gave 48ml on one injector and 49ml on the
other.
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