This is a request for a layman's explanation for the variation of engine fluid readouts. Specifically, why do fuel pressure indications vary, sometimes inverse to what would be expected, even in cruise flight?
I have an RV-12 Rotax with the fuel return line installed per plans and the Dynon 180 pinball machine screen. Sometimes throttle application results in higher fuel pressure indication (huh?), sometimes lower--as would be expected. The sensor has been bench-tested as accurate to Dynon's current standards. Level cruise variations range from 4.4-2.75. Green arc starts at 3 PSI. Variations from normal 3.7-3.9 last from momentary to a minute or more. The Dynon downloads on Excel confirm these numbers.
I have been watching the fuel pressure because of suspected vapor problems operating in hot weather on winter grade car gas. I have been through the fuel system from tank vents to carb bowls and no anomalies found. Fuel flow numbers seem in line with power.
I have been told not to worry about variations as long as they are in the green. But I sure would like to know what's going on. TIA
Jim
RV-12 N233TX
I have an RV-12 Rotax with the fuel return line installed per plans and the Dynon 180 pinball machine screen. Sometimes throttle application results in higher fuel pressure indication (huh?), sometimes lower--as would be expected. The sensor has been bench-tested as accurate to Dynon's current standards. Level cruise variations range from 4.4-2.75. Green arc starts at 3 PSI. Variations from normal 3.7-3.9 last from momentary to a minute or more. The Dynon downloads on Excel confirm these numbers.
I have been watching the fuel pressure because of suspected vapor problems operating in hot weather on winter grade car gas. I have been through the fuel system from tank vents to carb bowls and no anomalies found. Fuel flow numbers seem in line with power.
I have been told not to worry about variations as long as they are in the green. But I sure would like to know what's going on. TIA
Jim
RV-12 N233TX