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Wonder what others do/thoughts on having fuel flow info.
My MGL has the ability to monitor the fuel flow but trying to figure out the value of that info?
Is it worth adding a red cube and monitoring the fuel flow?
I have a fuel pressure sensor, which I feel....gives me valuable info, but I question the aggravation/expense of adding a fuel flow reading?
What are others thoughts on this?
Hey Jerry I’m not flying yet but I was advised to get the “gold” cube for gravity feed systems. I’m using the continental engine which has no mechanical pump so I’m not sure if it makes any difference on the rotax. Just thought I’d share.
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I have had the red cube installed from the beginning, 10 years ago, and I kind of like it. It certainly is not necessary when you have direct reading sight gauges, but it gives me more accuracy than a sight gauge, which I enjoy. I never run so low where the accuracy of the last gallon or so becomes important, but its nice to know its there. Installation was quite easy and it reads out right on my Skyview panel.
You do need to know that with a Rotax with a bypass return line you must do one of two things:
1 - Use two red cubes, one in the main fuel line and one in the return line so the actual fuel flow to the carbs can be determined-this is expensive and defies the KISS principle.
2 - I used just one cube in the main fuel line and carefully calibrated the "K" factor to eliminate the return flow, which is very small anyway-on the order of 1/2 gph if you use the Rotax recommended return orifice size. This calibration takes several trial-and-error runs to get it right.
I got the Red Cube too. Just like Jim said I really like having it and being able to verify remaining fuel easily. It gives peace of mind.
Have the Red Cube and an UMA analog indicator. Just got it working so I need to find out how much return fuel is flowing. I was thinking 5-10%. We’ll see. Jim, how did you interface with the Skyview?
I have a red cube tied into my Dynon D180. Took a bit to get it calibrated, but now it works.
Is it worth it? Not really.
Is it necessary? Not really.
Do I like it? Yea, I like gages and do-dads.
Would I do it again? Probably.
Thanks all.
I found one for a good deal so I think I'll go ahead and install it.
I think it will work with the MGL calculated fuel levels so it'll give me another way to make sure I don't run out of fuel.
Just have to figure out the best way to install it.......
wvav8tr, the red cube can be one of the optional inputs to the Skyview system. The Skyview installation manual describes how to do it, and then you set it up to be one of the configurable widgets on the engine instrument monitoring page. Calibration of the "K" factor is just a number on one of the Skyview setup pages that can easily be changed, in flight if desired.
Start the calibration process by making a steady, stable, typical cruise run between two airports with fueling facilities about 100+ miles apart (farther the better), including takeoff and landing. Start the run with full topped off tanks and the red cube fuel quantity set correctly, and then top off again at the end of the run, noting exactly how much fuel was added. Compare this with what the red cube says was your fuel consumption for the run. They should agree, but if not, the % difference will tell you how much to tweak the "K" factor. I would recommend about 3 calibration runs in typical normal conditions in order to zero in on the "K" factor. This system will eliminate the inherent inaccuracy caused by the Rotax bypass/return flow when using just a single red cube in the main fuel line. I installed my red cube under the seat pan in the fuel line out of the header tank; this keeps it out of the hot, vibrating engine compartment.
Make sure to read the cube specs on installation. They have very specific requirements on how far from a fitting, pump, filter, connection ect. They are very sensitive fyi. I love having fuel flow to let me know how much fuel is remaining. Helps with power settings also.