Differential Fuel Burn question...

[hharney]

Gord

Here is what I have used to set my fuel flows. When I performed this test it changed my OEM indicator reading from the high green arc to the red line on take off. I only adjusted the front engine and then test flew the aircraft.

During the test we had difficulty reaching the 2800 rpm value that the chart suggests. There is a factor to use if you cannot reach this value. Problem was (and I am going by memory here) is that we could only achieve 2500 rpm on the ramp. The equation to use for lower rpm tests did not go that low. We had to graph the line out further to find the intersection and set the pressure at that point. When I perform a take off the rpm achieve the full 2800 rpm and my fuel flow (based on pressure) goes just beyond the red line on the front engine.

I have just installed a JPI engine analyzer with fuel flow and before I adjust the rear I will fly the aircraft to see the difference in fuel flow with the original settings. Should everything go right tomorrow I should be able to test the JPI for the first flight tomorrow.

See attached procedure

[hharney]

The test on the new JPI EDM 760 was flawless. I flew again today to record some numbers for the warranty card. Amazingly the fuel flows were very consistent with my factory fuel flow gauge. I have flown in other aircraft including Skymasters were the numbers were miles apart. Mine seem to be fairly close. Have others out there had similar results? The amount of information that this unit provides was rather intimidating while reading the handbook but once I started using it I could see that it was very simple to use. I haven't mastered the fuel quantity and usage yet but that will come.

Hope to get in a good cross country next week and have a chance to really see it work and to be able to dial it in at cruise. Should be a trip to Dayton to scout the hotel accommodations for SOAPA meeting. I'll post my results.

[Walter Atkinson]

Congratulations on your new monitor.

Engine monitors are so valuable that I consider them a "Go--No-go" item for an IMC flight and I would prefer not to fly VMC without them.

The challenge is to learn how to interpret the data that they display. Gaining that understanding will save you a lot of money on maintenance and could, one day, save your life.

(some of the info in the manual concerning the interpretation of the data is factually incorrect--like what happens to the EGT and CHT during pre-ignition. Use the manual to learn how to operate the instrument. It is quite good for that. Be cautious of the materials related to interpreting the data.)