Fuel Pressure Low

RW/Jeff B,

Fuel Vapourisation 

Would you expect to have some change in engine running ? 

As stated, have never had so much as a hesitation in my engine.😈

Sean Griffin wrote:

RW/Jeff B,

Fuel Vapourisation 

Would you expect to have some change in engine running ? 

As stated, have never had so much as a hesitation in my engine.😈

As long as the pump provides enough volume to keep the float levels full the engine won't know the difference. If you do get a hesitation in the future that could be an indication of the pump not keeping up. 

Where is your fuel flow sender mounted, on the pressure side of the pump? Everything on the pressure side should be less prone to vapour bubbles. I have mine mounted on the pressure side and after the return line.

"Where is your fuel flow sender mounted, on the pressure side of the pump? Everything on the pressure side should be less prone to vapour bubbles. I have mine mounted on the pressure side and after the return line."

Good point Murray.

My Red Cubes are mounted after the mechanical pump -

(1) Main Flow/Supply, before the Fuel Distribution Manifold

(2) Return Line, after Manifold.

Theory being that (1) will read Gross Fuel, (2) return line flow, which is automatically deducted from (1) giving Total Fuel used.

Seems to to work, although unnecessarily complicated, as a single Red Cube (or other) sensor can be calibrated to deliver almost as accurate readout.  😈

Tim B wrote:

The transducer is not necessarily spinning faster, although it might be. (my engineering guesses also aren't all that reliable)

I believe that the EI FT-60 fuel flow transducer ("red cube" as also supplied by Dynon and Garmin) operates on the principle of counting the vanes of a rotor interrupting a light beam. When there are vapour bubbles in the fuel stream, these can refract the light beam enough to cause false pulses to be sent to the EMS.

(from EI: "The FT-60 is compatible with gasoline, Av gas, diesel, jet A, kerosene and any other fluid with similar optical characteristics.")

Hi All,

Found this, thought it might be of interest.

Cheers.

https://youtu.be/HXJMLcpcl10?si=cLTMDquNPTdArl58

Thanks Des,

As the presenter said , always good to be able to visualise how something works, helps in failure diagnosis & installation.

One small "picky" point, probably slip of the tongue, however presenter seemed to confused pressure & flow when talking about high wing gravity feed fuel supply to a .

The Gold Cube is high flow applications: https://iflyei.com/wp-content/uploads/1030031-FT-90-Info-Rev-D.pdf

The Red Cube for low flow : https://www.iflyei.com/wp-content/uploads/FT-60-Info-Rev-F.pdf

Even the above instructions get pressure & volume mixed. Most carburettor engines operate of fuel flow/volume - not pressure per say.

😈