lml@lancaironline.net Mailing List Archive

Mike,

Anybody have comments either way on fuel flow transducers?

You bet. Early in my testing I had at least a 10% accuracy error in the FF readings. The reason was that I had used 2 different "reducers" at each end of the transducer. One was the hollow type used with a properly sized nipple

and the other was a nipple with a size change at the pip thread (drilled out type).

Well, wouldn't you know it, I used the size change nipple on the input side and the turbulence caused by the small hole being near the transducer wheel led to false readings. When I swapped the fittings on the input and output, the transducer became as accurate as the readout on the self serve fuel pumps used to fill the tanks. Glory be! Uh, because I am using the more understandable Lycoming set up, the transducer is between the throttle body and the spider without fuel being returned to a tank.

Grayhawk

PS My tank levels back up FF and those pumps where Gallons spin the dollar indicator much faster. So do the time calculations.

In a message dated 1/4/2010 5:49:12 P.M. Central Standard Time, mikeeasley@aol.com writes:

I mentioned earlier about the "mental math" I do to confirm that the time, fuel flow, fuel level numbers match up. I pulled up some of my JPI flight files and compared the fuel level changes to the fuel flow number and they matched up very well. So my mental math and data confirm the current accuracy of my fuel gages. My experience is the fuel flow transducer is a more accurate tool than the fuel level in determining how much fuel has been used out of a full tank.

Anybody have comments either way on fuel flow transducers?

Mike Easley

Colorado Springs