MV Aviation

Fuel tank calibration and dip stick production

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Hi Folks,

a friend of mine is about to launch an online shop for fuel tank dip sticks. It is just a hobby-side-endeavor for him, so I'm trying to support him with data. The shop is not yet online, but production will start soon. And he will ship worldwide ;-). The dipsticks will be in the 15-20$ range.

 He has collected Data for some PA28, C172, and Aquila models. I sent him the data of my 65E's fuel tanks. In order to offer more models and confirm the existing data, I'd like to ask you to send me your measurements if you have some. Text files, Excel sheets, ... doesn't matter, as long as you're confident with the data :-)

Your support is much appreciated!

Thanks a lot!

Marco

 

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Somebody send this guy a good M20J/64gal tank calibration!   I'd definitely buy one.

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2 hours ago, EricJ said:

Somebody send this guy a good M20J/64gal tank calibration!   I'd definitely buy one.

Why not just make your own?  Use a paint stirring stick and a ball-point pen.  Lowes or Home Depot will give you one for free, and you probably have a pen lying around.  I made mine that way 5 years ago and it hasn't yet discolored or faded.

Run a tank empty, then add 2 gallons at a time.  At least then you'll be 100% sure it's correct.

Or look around MooneySpace, someone might have already posted the measurements like they did for the M20C/E.  The M20F with 64 gallon tanks should be identical to the J.

 

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4 minutes ago, Andy95W said:

Why not just make your own?  Use a paint stirring stick and a ball-point pen.  Lowes or Home Depot will give you one for free, and you probably have a pen lying around.  I made mine that way 5 years ago and it hasn't yet discolored or faded.

Run a tank empty, then add 2 gallons at a time.  At least then you'll be 100% sure it's correct.

Or look around MooneySpace, someone might have already posted the measurements like they did for the M20C/E.  The M20F with 64 gallon tanks should be identical to the J.

 

There is so much variation in fuel tank capacity of same model Mooney's reported by different owners I would never trust anyone else data. The whole point of the exercise that Andy refers to above is to find out what your tank capacity is. Don't you want to know what your tanks really holds?

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29 minutes ago, kortopates said:

...Don't you want to know what your tanks really holds?

Naw, I'd rather worry the the gauges are all wrong and I better be on the ground with at least 15 gallons indicated remaining. :rolleyes:

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The variation on make your own.   Free paint stirrer.  The thicker ones from Sherwin Williams are the best.  When refueling Stick the tank draw the line. Fuel it up..   Do the math.  Write the gallons on the line.   Sharpies work well too.   Takes several fuel ups, but will be really accurate.   I use the middle of the filler neck most inner point.

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I suspect the variations are due to how people are taking data rather than actual tank dimensions or capacities.   Or did Mooney actually change the tank shape significantly over production runs for similar models?   

If I were to make my own stick I think I'd use the "mark it before you fill it and see what it took" method until I had a decent calibration, but if I could buy one I'd rather save myself the effort.

 

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There are so many ways to place the stick in the tank its difficult to use someone else's numbers without a video describing how they place the stick.

 

-Robert

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Yep... I'd not trust anyone's stick but my own.

  1. Too many different ways to place the stick.
  2. Have the tanks been resealed... and what was the quality of the stripping/resealing.
  3. Bladders or no bladders
  4. Between the neck in the filler and the holes between sections of tank in my K, the speed of the fuel filling operation also makes a difference.
  5. etc, etc, etc...

I'll run a tank dry and work it out myself, thanks.

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I bought a FuelHawk gauge and did mine manually. Its accurate to 0.2 +/- gal. Averaging 8.7gph block to block when I dip before and after flights. I've even been down into the mid 7-gph range on some slow <145kt flights

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I made a sick for my C from someone's numbers, I think from here on Mooneyspace.  I verified it's accuracy by always sticking the tank before I topped off.  It was spot on. 

If anyone has numbers for a K I would love to try them out.  I'm still waiting for a convenient time to run my tank dry and meter the fill up. 

2 hours ago, gsxrpilot said:

Between the neck in the filler and the holes between sections of tank in my K, the speed of the fuel filling operation also makes a difference.

The difference in filling fast vs slow can be up to 3gal a side.  I have been finding if I'm not present or don't personally fuel the plane I'm always 3-6gals short.  Drives me crazy.

Cheers,

Dan

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1 hour ago, DanM20C said:

If anyone has numbers for a K I would love to try them out.  I'm still waiting for a convenient time to run my tank dry and meter the fill up. 

The difference in filling fast vs slow can be up to 3gal a side.  I have been finding if I'm not present or don't personally fuel the plane I'm always 3-6gals short.  Drives me crazy.

I've done my K but just used the wing mounted gauges instead of making a stick.  I ran each of the tanks dry on different flights. After landing I filled each tank in 5 gal increments and noted how that was displayed on the wing mounted gauges. I also noted how it was displayed on the EDM-900 digital gauges as well. Between both of those very accurate gauges, I decided I didn't need a stick. I keep the diagram and notes tucked into the front cover of my POH for easy reference.

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Unfortunately I don’t have wing mounted gauges.  If I did I would forgo the stick too.  EDM 900 is going in on the 1st of the year.:)

Cheers,

Dan

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4 minutes ago, DanM20C said:

Unfortunately I don’t have wing mounted gauges.  If I did I would forgo the stick too.  EDM 900 is going in on the 1st of the year.:)

Cheers,

Dan

I'd recommend the CiES senders to go with the EDM-900. 

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I've done my K but just used the wing mounted gauges instead of making a stick.  I ran each of the tanks dry on different flights. After landing I filled each tank in 5 gal increments and noted how that was displayed on the wing mounted gauges.

Are the wing mounted gauges certified for use to fulfill Tomato Flames requirement?

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I love the wing mounted gauges. One of mine has a cloudy lens that I'd like to either replace or figure out how to clean. 

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Might get away with headlight polish for that, Paul... But, I think the cracking may go deeper than the surface... get a price from Lasar, they probably aren't measured in AMUs...

Tomato flames is not very specific about what is used for a fuel level... but...

the MEL in the POH is pretty specific on what needs to be working.

Pp thoughts only, not a CFI...

Best regards,

-a-

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34 minutes ago, gsxrpilot said:

I love the wing mounted gauges. One of mine has a cloudy lens that I'd like to either replace or figure out how to clean. 

If you don't mind paying $50 each, they are very easy to change.

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17 minutes ago, DonMuncy said:

If you don't mind paying $50 each, they are very easy to change.

Is it the gauge or the gauge and whole assembly?

I, too, have a cloudy one but not enough that I want to mess up my paint to replace.

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Just now, Bryan said:

Is it the gauge or the gauge and whole assembly?

I, too, have a cloudy one but not enough that I want to mess up my paint to replace.

You won't mess up the paint. The gauge is a simple dial with a metal bottom and a clear plastic top. It is fed magnetically from a sender in the wing plate. The gauge is held in with silicone glue. You pry out the old one with a thin screwdriver or some such. Clean out the remaining silicone, then put a glob of silicone in the recess, push the gauge in place and tape it down until the silicone sets up. Done. The gauge even has a little bump on it so it only sits in place one way, so you won't put I in wrong. 

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7 hours ago, Raptor05121 said:

I bought a FuelHawk gauge and did mine manually. Its accurate to 0.2 +/- gal. Averaging 8.7gph block to block when I dip before and after flights. I've even been down into the mid 7-gph range on some slow <145kt flights

Same thing I did. I did the paint stirrer for awhile but really like the FuelHawk and reading it. Just be sure if you use one that after you put it in let it sit for a couple seconds before putting your finger over the top. If not then the fuel level inside it may not be at the same level as the tank if you don't let it settle. 

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8 hours ago, DanM20C said:

I'm still waiting for a convenient time to run my tank dry and meter the fill up

just dont run one dry like you did the last time, Dan :)

 

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