Hi Jos
"For checking the fuel system i added fuel flow sensors in both feed and
return line, and the matronix controller to see fuel flow on the Dynon (or
any other fuel flow meter). Extra is a switch that takes the return flow
sensor out of the equation. The result on the fuel flow meter is the netto
throughput of the system. Part of the checklist is to check that switch
and see that the fuel exceeds 120 liters per minute on each pump, and
increases with 2 pumps. Any malfunction or blockage will show up, taking
the guessing out before flight."
Boy with 120 liter per minute flow (7,200 liters per hour), you could
shoot some fuel out the back for jet assisted take offs ;-)
I have not tested flow with fuel pressure regulator attached, but did put
restriction on outlet and with 2 pumps running, series with bypass, there
was only perhaps a small increase in flow, but there was an increase in
pressure (thumb on outlet was the instrument used).
What sort of % increase in flow are you seeing with 2 pumps running
compared to 1 running on your system??
Did you actually put diaphragm of fuel pressure regulator under pressure
as described in Rotax manual to simulate boost in airbox and lower
atmospheric pressure and measure that differential pressure (carb fuel
pressure above airbox pressure by approx. 2 to 5 PSI) and found that a
flow on ground of at least 120 liters per hour will satisfy?
If not what is significance to 120 liters per hour on 914??
Ron Parigoris
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