Fuel metering options

[gauvins]

I'd like to get relatively accurate measures of fuel consumption. (Old Perkins 4.154)

I can't find a reasonably priced gauge. Could be the simplest device.

Where should I look?

[model 10]

Homebuilt aircraft stuff is about $500 @ Chief Aircraft etc.

[a64pilot]

However with a Diesel you most measure two fuel flows, fuel going to the engine and subtract the fuel coming from.
Most of us decide it’s not worth it and write down engine hours, motor somewhere distant, fuel her up and of course divide fuel by hours and get consumption. Cause meters are not cheap
That is not going to tell you what 1kt cost you fuel wise though unless you do it a few times at different RPM settings.

I assume your talking engine running consumption? Not fuel tank gauge?
Cheapest one of those is a wooden dowel assuming you have access and an opening to your tank, most have an unused fuel port.

[model 10]

It would be easy on a common rail I suppose. No way around needing 2 transducers on an engine with a return line.

[a64pilot]

Even common rails have return fuel, however the ECU knowing lots of variables like air temp and density altitude, injector pulse width etc can give a quite accurate calculation of fuel used, that is how all modern cars give you fuel consumed, fuel mileage etc. those are calculated, not measured.

[Ding Duck]

Found this website Futurlec, The Electronic Components and Semiconductor Superstore and they have the following Part listed at US$32.90
Part Code: GASFLOWMETER

Flow Rate 2.0 - 30.0 liter/hr
Fitting for 3/8" Barb
Suitable for both Diesel and Gasoline
Displays Both Flow Rate and Total Number of Liters/Gallons
Unit Can be Switched to Display Readings in Gallons
Ideal for Tractors, Generators, Go-Karts
Low Battery Power Alert
Fluid Temperature: 0 to 60°C
Fluid Pressure: up to 85 psi
Supply Voltage: Uses 2 x AA Batteries

As A64Pilot stated, you will need 2 units, one for Supply and Return lines each.
Will the flow rate of your Engine being sufficient for these meters?
They also don't state the accuracy, but may be a place to start?
Cheers

[sy_gilana]

You don't HAVE to have two. As long as the engine does not need fuel cooling like my early version of common rail engine, a Detroit 2 stroke.


If you put a T in the line, and send the return straight back to the suction line, with a pickup line fitted with the flow meter to make-up the burned fuel, you will get an accurate reading.


I have done that on a few boats.

[J Clark H356]

Only problem I see with this unit is 2 l/hr is .52 gal/hr. My generator only burns about .25 and my Yanmar .4 to .5 gph for total around .75 net with both running. What happens if the flow is less than that? Will it still totalize the fuel? This would be by far less than anything I have seen. Last time I looked for something like this it was around $1000.

[Ding Duck]

I guess this flowmeter would not be suitable for your installation as it is below the specs quoted.
the units you say may employ a different technology to sense the low flow rate.
I would suggest that at min or low flow rates this particular type of unit may not be that accurate, but what that is I don't know. You could always fill the tank, run engine at a constant RPM for a period of time, top the tank back up and determine the difference between the meter and the actual fuel used?