Fuel flow sender/sensor options

[trailer]

Are there any fuel flow senders available for a homebuild project which aren't $100s. Even prices for marine applications are eye watering. Any suggestions???

[cherk]

52 minutes ago, trailer said:

Are there any fuel flow senders available for a homebuild project which aren't $100s. Even prices for marine applications are eye watering. Any suggestions???

Futurlec  ;:https://www.futurlec.com/sensor/flowfuel30l0.shtml

[trailer]

 

7 hours ago, cherk said:

Futurlec  ;:https://www.futurlec.com/sensor/flowfuel30l0.shtml

Thanks Churk, tried them recently, the website doesn't work for orders and then I found the email contact for orders very slow and suss, were keen for payment but vague detailing shipment and supply. Found reviews dating back 7 years to recent warning about dealing with them.

 

https://www.resellerratings.com/store/Futurlec

[RFguy]

There are quite a few like this, but I am not sure I like having a couple of $1 cogs in my aircraft fuel flow. - not sure if the cog stops it blocks flow???
or is there a minimum pressure to get flow ?.  The OF05ZAT-AR  series  look OK. - you could use two in parallel, that's probably safe enough. (and you'd need some indication that one got stuck so you knew one was down) 

 

Now, also the common Red Cube sender is not immune from failure, either.

 

https://www.supercub.org/forum/showthread.php?60571-Inside-your-Red-Cube-fuel-transducer-(mine-failed)

 

post #29 is interest. worth while reading through the forum thread.

 

the chink one :

 

https://www.aliexpress.com/item/32814415226.html?spm=a2g0o.productlist.main.81.bc6c91fdfaX391&algo_pvid=f9b1cb7c-92d2-482e-b80c-7282caccc20f&algo_exp_id=f9b1cb7c-92d2-482e-b80c-7282caccc20f-40&pdp_ext_f={"sku_id"%3A"64598145468"}&pdp_npi=2%40dis!AUD!32.89!16.44!!!!!%402102111816733838903893115d0688!64598145468!sea&curPageLogUid=qyCzyEZ9FMjR

 

and : 

 

https://www.aliexpress.com/item/1005004429310822.html?spm=a2g0o.productlist.main.107.bc6c91fdfaX391&algo_pvid=f9b1cb7c-92d2-482e-b80c-7282caccc20f&algo_exp_id=f9b1cb7c-92d2-482e-b80c-7282caccc20f-53&pdp_ext_f={"sku_id"%3A"12000029156016190"}&pdp_npi=2%40dis!AUD!19.28!16.39!!!!!%402102111816733838903893115d0688!12000029156016190!sea&curPageLogUid=WUWYIauRLTLI

 

 

 

 

 

Edited January 10, 2023 by RFguy

[skippydiesel]

What is the specific benefit(s) in having a flow rate available to the pilot?

Edited January 10, 2023 by skippydiesel

[RFguy]

It's a check to understand / know  the engine output / workload, along with MAP. RPM and throttle position might mean nothing without MAP and fuel flow. 

[skippydiesel]

I understand however we (that is us in little sport aircraft) fly simple planes. Fuel usage ie keeping a fuel log) will give you, albeit historic, fuel consumption ,which can, at a pinch, be related to flow. The way I see it, go the KISS rout when ever practical. Practical, in this context, - cost/effective (accuracy) and piloting efficiency (does this devise enhance your ability to manage the aircraft/engine better).

At the end of the day, personal preference is the determining factor - I had one in my last aircraft. It was great until its accuracy started to diminish. Got one in the new aircraft - yet to decide if it is an aid or just information overload.

I do think some form of flow/no flow information is good but knowing the (reliable/accurate?) flow rate???

[facthunter]

Good ones give you totals used also. Fuel gauges are not that accurate. If your system returns some fuel that complicates your figures.  Nev

[facthunter]

If any indication is not very reliable, having it is questionable without a test function or a backup.  Where you are flying supercharged and at higher altitudes, fuel flow requires close monitoring on piston engines for engine management and multiple fuel tank switching..   Nev

[rgmwa]

I have a red cube in my plane to measure fuel flow to the engine.  It was included in the kit. However the Rotax has a fuel return line so I’ve never understood what value there is in having it.

[IBob]

rgmwa it's not something I would fit, but then we do not have the distances that you have in Australia: it may be a different matter if I was over there.
As for making some use of your red cube: with many instruments, I think it is change that you are interested in. So even where there is an offset, as with the Rotax fuel return, you will still have a reading that it normally sits at in, say cruise, or climb. With that in mind (or marked) you can then be looking for change.
Aside from that, if you are able to access the return line easily (it is accessible in the Savannah) you could establish the return rate at a set pressure, so arriving at an actual  fuel burn rate.
 

Edited January 11, 2023 by IBob

[trailer]

4 hours ago, RFguy said:

https://www.aliexpress.com/item/32814415226.html?spm=a2g0o.productlist.main.81.bc6c91fdfaX391&algo_pvid=f9b1cb7c-92d2-482e-b80c-7282caccc20f&algo_exp_id=f9b1cb7c-92d2-482e-b80c-7282caccc20f-40&pdp_ext_f={"sku_id"%3A"64598145468"}&pdp_npi=2%40dis!AUD!32.89!16.44!!!!!%402102111816733838903893115d0688!64598145468!sea&curPageLogUid=qyCzyEZ9FMjR

 

 

Thanks for the reply RF guy, those budget units say they are for honey, milk oil etc, unable to find any which reference petrol. 

[rgmwa]

Thanks iBob. It's a standard item in the RV12 kit, and as you say it's probably the change in typical reading that's important rather then the absolute value in most cases. 

[turboplanner]

Fuel flow sensors are not good for measuring fuel consumption because of all the variables which change the readings.

Fuel float gauges in the thin wings of RA aircraft which might be flying slightly off exactly level are also difficult to manage while you are flying.

Fuel burn at cruise rpm is a much more accurate assessment of how much you have left, and much easier to manage, and you can back it up with gauge readings because you will know what they should be reading.

 

Because all GA aircraft are expected to do cross country trips, the manufacturers provide fuel burn figures for taxy, take off, climb, cruise, descent. In RA you might have to calibrate your own.

 

Aircraft specifications usually quote Total Fuel and Useable Fuel. Total fuel is the first fill after the build where fuel fills all the lines, filters, sumps, carb bowl and everything blow the pickup pipe.

 

Useable fuel is everything the pickup pipe can get and can be surprisingly less than total fuel in some aircraft. Useable fuel is what we use for fuel burn calculations.

 

The attached spreadsheet is Performance & Operation Fuel Burn calculations for a 200 Nm trip in an aircraft with 25.91 litres/hour at five thousand feet and 99 kts TAS cruise with take off from a busy airport.

 

Before take off we can ensure we have a minimum reserve of fuel.

 

After take off at the regular checkpoints we note our fuel endurance in minutes.

If an emergency crops up and you call ATC usually, they will ask for endurance, and its easier to start from the last checkpoint than scratch your head.

 

If the fuel gauges are showing a lot less than your checkpoint calculation, you could have a bad fuel leak, and this gives you more time to confirm it and manage it.

[Markdun]

I use fuel flow data for three main purposes: first, as a power setting...I find  rpm pretty hopeless as an indicator of power as it’s too dependent on vertical speed (noting that fuel flow will increase a tad when you put the nose down & rpm increases with no change in throttle position; second, for calculating fuel remaining (which is cross checked to fuel level, either visual sight or fuel level sender); third, as a check on full power fuel flow at WOT during climb out.

I find that once you have calibrated the fuel flow sender they are very accurate, even on Rotax with a fuel return line. But that’s the issue... calibration is a RPIA & can take a while.
On my Corby I have an old ‘Navman’ sensor connected to an MGL XTREME EFIS/EMS.  This was a dream to calibrate as the Corby’s fuel tank is 40l and easily measured with a dip stick. Fuel remaining cross check is to a resistive float fuel level sensor. Cost of the sensor was zero as I liberated it from a yacht. It has an axial turbine which allows fuel to flow even if the turbine seizes. Most accurate when mounted vertically with fuel flowing upwards. Sensor is plastic, but I had it for 700 hours in the Cygnet without any issues. It is still working well.
On the Cygnet I have a Red Cube. I did have the Navman but when I converted from Vw to Jabiru the Navman couldn’t deal with the electrical voltage spikes from the Jab voltage regulator. But then neither did the Red Cube which I purchased on eBay for a good price. Problem was fixed by installing a Powermate VR. The Red Cube works... cant say It’s really any better than the old Navman. Again it feeds data to an MGL XTREME. Fuel remaining is cross checked with a visual fuel level.

 On the J200 I have a Flowscan sensor which came with the aircraft and which was submerged in floodwater for several weeks. It too works well but I’m struggling with calibration.... again mainly due to electrical interference from the Jabiru voltage regulator. It is cross checked to the Jabiru ‘fuel level’ sensors (sight gauge, mech gauge & electrical level), which in my limited experience are all total crap.  This also makes calibration really difficult.  I’m thinking it’s going to take quite a lot of flying to get the fuel flow sensor in this aircraft calibrated accurately.  With less than 10 hours in this aircraft it’s still ‘work in progress’.

I also have a non-turbine FF sensor in my boat...it a Lowrance.  I’m not a big fan.  The range of fuel flow is from zero to 8lph? but mostly around 2.5-3.5lph...it just doesn’t like that...& it cost heaps, often reads zero until you give it as tap. It connects via Ethernet.

 

 If I was looking for a sensor I’d be scanning eBay. For new .I would probably give the MGL plastic one a try, but that would be an experiment.

 

[biggles]

I too installed a Navman Fuel Flow monitor in my Jabiru, which has performed without fault for 14 years now. I was so impressed with its reliability and accuracy that I purchased another ,” just in case “, when I heard that the manufacture was being discontinued. It is still in its sealed container in the garage. The only minor issue is that it tends to give unreliable  readings when the electric pump is operating, and takes about 5 minutes to “recalibrate” after the pump is shut down…. Bob 

[Markdun]

Biggles that’s the averaging or smoothing algorithm the display uses. In my Corby I have both the MGL and the old Navman wired up to the same old Navman FF sensor.  Both displays get the wobbles, but different wobbles, when the electric Facet pump is on & neither give info on the averaging methodology they use. There is also fluctuation with the carb float bowl needle and seat opening and closing, most significantly at idle. In a lot of respects the display of FF to+/- 0.05 lph ie to 0.1lph is a misleading distraction.

[facthunter]

The needle is modulating and will have little variations in normal operations. Bottom feed bowls are worse. Vibrations can help flow and are generally not desired. The unseating pressure and reseating are unlikely to be the same. To seat it will take a bit more.  Nev.

[Old Koreelah]

On 11/1/2023 at 9:56 PM, Markdun said:

I use fuel flow data for three main purposes: first, as a power setting...

Me too, Mark. It’s useful to have alternative sources of info if you lose an instrument.

My Tacho has gone crazy a couple of times, but the Mizer (bought second hand from Maj Millard) always tells me how much load I’m putting on the engine.

 

After dipping the tanks and setting the fuel quantity on the Mizer, it’s my only fuel gauge and has never let me down. Swapping tanks every thirty minutes is a good way to be ahead of a potential fuel problem.

[facthunter]

I'd prefer to keep the better feeding one with more fuel for the approach.  I don't like ever having less than I hour.   Nev

[Markdun]

Me too. With fuel I’m ultra-conservative; none of this laissez faire lefty progressive nonsense. On a delivery flight from Northam WA to the ‘East’ with the aircraft picked up from one of the worst LAME in the country who only fixed the reported fuel leak after I got the Avgas shower from the leaking fuel pooling in the wing and then emerging from the wing root when you opened the cockpit door.  With that fixed we then flew to Kalgoorwhere I spent full day to redo numerous other non-fixes including reconnecting one wing tanks fuel level sensor... connector corroded off. Next leg was a long one to Forrest following the railway.  Every 20 minutes I recalculated fuel used and remaining from fuel tank level gauges, fuel flow meter (JPI) which we hadn’t calibrated, and estimated from engine performance data in the POH; each confirming each other...a tight cocked hat if you like and understand old fashioned navigation.  The owner in the right seat was amused.  This helped me in deciding whether to land at one of the railway landing strips every 80nm, head south to the coast and highway, or continue on to Forrest. We departed full at 100litres, I’d planned on landing with 20 (or 15 if headwinds arrived); my 3 calcs at the last railway emergency landing strip estimated 25l would remain, and the bowser at Forrest confirmed 30 was remaining.  BTW the JPI was quite accurate despite the unmetered Rotax return fuel line to one of the wing tanks.