Any Lycoming IO-540 Drivers With A FLOSCAN 201B Out There???

[Dynon101]

I have a Lycoming IO-540 and I am running a FLOSCAN 201B without any kind of return line/port to the fuel tank and I was hoping that someone can please give me your pulses/gallon number you are using so that I have something to start with.

My fuel flow is showing 0.0 GPH at idle and it should be reading more like about 1.6 GPH at 1000 RPM.

Hopefully there is someone out there who can let me read off of their homework and give me a ball park number to plug in and work off from there.

Thanks I will buy you a free $100 pancake at the next fyl in breakfast!!!

 

[jakej]

Try 29,000 as the initial K factor - Dang, guess I’ll have to pass on the pancakes.

 

[kellym]

I have a Lycoming IO-540 and I am running a FLOSCAN 201B without any kind of return line/port to the fuel tank and I was hoping that someone can please give me your pulses/gallon number you are using so that I have something to start with.

My fuel flow is showing 0.0 GPH at idle and it should be reading more like about 1.6 GPH at 1000 RPM.

Hopefully there is someone out there who can let me read off of their homework and give me a ball park number to plug in and work off from there.

Thanks I will buy you a free $100 pancake at the next fyl in breakfast!!!

I don't know the default pulse count for the Floscan, as I have the now stock EI red cube. However, the fuel flow at 1000 rpm idle is a bit higher, more like 2.6, with it being in the 2.5-3.5 range for taxi. With all fuel flow sensors the wiring connections are critical, and faston blade connectors are not always sufficiently tight.

 

[DBRV10]

Ours started life at 30350, I think it is now in the high 29XXX range.

As jake suggested start around there and do the maths later.

 

[Dynon101]

Thanks Ya"all!!!

What is the response from the red cube...is it pretty accurate right out of the box or do you need to fiddle with it???

All this talk of pancakes I am getting hungry...

 

[jakej]

Most likely needs a fiddle, not all fuel system setups are equal - that why you need to go through the calibration process IF you want accurate fuel flow computation.

 

[preid]

Start at 29k do a fill up and fly 50 gallons than match what the computer says to what you actually need. Do the math and adjust it to.
do it again and slowly it will get to where you will get it accurate. 0gph at idle sounds like a general issue, what is it a WOT? Should be around 22-23gph and 3gah or so leaned at 1000 rpm taxi- once warmed up. However that isn’t the basis for fuel flow but a general ballpark that you’re getting it closer to accurate. I needed to do 3-4 fillups before I got my red cube rock solid and accurate to .01 difference.

 

[kellym]

Thanks Ya"all!!!

What is the response from the red cube...is it pretty accurate right out of the box or do you need to fiddle with it???

All this talk of pancakes I am getting hungry...

It wasn't bad, but after I replaced the spade connectors with the overlap connectors I had to adjust the K factor down, IIRC from default 68000 down to maybe 66500. It is routinely within a few tenths now.

 

[kellym]

Start at 29k do a fill up and fly 50 gallons than match what the computer says to what you actually need. Do the math and adjust it to.
do it again and slowly it will get to where you will get it accurate. 0gph at idle sounds like a general issue, what is it a WOT? Should be around 22-23gph and 3gah or so leaned at 1000 rpm taxi- once warmed up. However that isn’t the basis for fuel flow but a general ballpark that you’re getting it closer to accurate. I needed to do 3-4 fillups before I got my red cube rock solid and accurate to .01 difference.

The 260 hp IO-540 should be at or a little over 24 gph at sea level takeoff. Perhaps 23 at say 3000 DA. The real measure of whether TO fuel flow is correct is showing EGTs all below or very close to 1300 for the first few hundred feet of climb.
The manual gives the equation for adjusting the K factor.
I agree, it will take 3-4 fillups to get accurate, but no gas pump is going to have the identical accuracy as the last one, much less identically level ground, so you will always have a few tenths difference between calculated and pump results.

 

[Dynon101]

So I did a 3.3 HR flight and the fuel counter calculated 3.3 gallons less than what was actually burned so it is off by minus 1 gallon per hour.

I am not at the airplane to look at the pulses per gallon that it is currently set to but lets say it is currently 29000, what would you all suggest that I start with (I don't know if I should add or subtract pulses)

THANKS for your suggestions

 

[skysailor]

Calculated fuel burned divided by actual fuel burned. This number will be somewhat less than 1. Multiply your K factor (29000 in your example) by this number. The result will be the new K factor to put in the Skyview.

 

[thibault]

Calculated fuel burned divided by actual fuel burned. This number will be somewhat less than 1. Multiply your K factor (29000 in your example) by this number. The result will be the new K factor to put in the Skyview.

Everyone should calibrate this way before you fly, because it will be accurate the first time and you waste no fuel (assuming you have one flow measurement device and you are an injected engine with the device mounted after the metering of fuel (ie. just before it goes to the "spider":

1. Go to your aviation fuel pump and put exactly five gallons in a gas container that is transparent enough that you can put a line on the outside at the 5 gallon mark with a Sharpie.

2. Back to the hangar. Empty that fuel in another container.

3. Disconnect the output of the flow measurement device.

4. Install a long enough line to the output to reach the marked empty container and place it where you can watch it fill from the cockpit.

5. Get in the cockpit, turn on the EFIS, zero out any indication of fuel used, set the mixture to full rich and use the electric boost pump to fill the external container to exactly the 5 gal mark.

6. Write down exactly what the EFIS measured for fuel consumed. If not exactly 5 gal, change the k-factor accordingly and dump that fuel into the tank. Goto step 7.

7. If they were different values, repeat 5 and 6 until the EFIS says exactly 5 when the can has 5 at this high flow rate. If they were the same already, go to 8.

8. Now check at a cruise flow setting to see if the measurement is linear. This time, with the catch container empty, zero out any indication of fuel used, set the mixture off and the boost pump turned on. Then push in the mixture control to your typical cruise fuel flow.

9. If things are wonderful, the catch container will again have 5 gal exactly when the EFIS says five gal. If that happens, you are done calibrating. If not you will have to guess at a k-factor that will approximate fuel flow for the overall condition, knowing that it will not be exact for full power and cruise at the same time. It makes sense then to lean towards the k-factor that best measures cruise flow. Just keep in mind that the full power flow is wrong by a little depending on what you actually measured.

10. Put the 5 gal in the A/C, reconnect to the spider and go fly.