Fuel tank dipstick measurements

[rdv]

Does anyone know the measurements I need to make a fuel tank dipstick for my 67-F?

 

Ryan

[Ned Gravel]

Ryan:

Someone on this site asked this same question a while ago.  Here is the discussion.

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=3&threadid=1070

 

[CoachTom]

Ryan,

I made my own dipstick one Saturday morning by using a wooden dowel from Lowes.  My tanks were low as I had just flown earlier in the week and was intending on this proceedure.  I drained the left tank as it was the lowest in volume into a regular yard gas can.  The yard gas can had marks on the side of it from when i filled it up for the lawnmower: one gallon at a time and used a magic marker to note the level.  Hence, I knew I had 5 gallons of fuel in that wing.

To my surprise, I did not even see a drop of fuel on the wooden dip stick in the wing as i added a gallon from the pump, check the dipstick to see if it was wet until ( i believe) it was 8 or 10 gallons ticked away on the pump.  By then, i noticed that the one gallon at a time was not making a noticable "delta" from the previous gallon entry, so i used 4 gallon increments and that created an approximately 1/4" to 1/2" mark on the dowel.

Lastly, and to my surprise, as the fuel hit the bottom of the anti siphon plate, it was approximately 35 gallons (M20K Model) and needed to add very slowly to get to the POH volume of 40 gallons in the tank.  I only got to 39.5 gallons as the fuel ran off the wing no matter how I shook it it to get those last drops in.

It took 20 minutes to accomplish and i was glad i did that exercise as i now see the corelation between the wing fuel guage, th epanel fuel guage, and my fuel stick...

Hope this helps!

[rdv]

Good plan Tom, I'll try your procedure if I cant find measurements. Thanks.

[knute]

My archive has a post I salted away from Rob Hoyle, who graciously provided the measurements and markings from the dipstick he (and the prior owner) calibrated for his 1965 C model, which turns out to work perfectly for my 52 gallon '66E model, verified every time I top up the tanks.  (It also very closely tracks my fuel computer)  I like to stick the tanks before every flight just to make sure I have exactly as much fuel as I think I do.

Hopefully email doesn't screw up the formatting too badly, but distance from the bottom of the stick is on the left (inches) and corresponding gallons is on the right.  Hope that helps or gives you a starting point!  It shouldn't be that hard to calibrate your own paint stick from Home Depot.  The measurements below obviously won't work for an F model with bigger tanks, but for any other C or E model owners with stock 52 gallon tanks, this should come pretty close.

9                 26
8 1/2           25
8                 24
7 5/8           23
7 1/4           22
6 7/8           21
6 1/2           20
6 1/16         19
5 3/4           18
5 7/16         17
5 1/16         16
4 13/16       15
4 1/2           14
4 1/8           13
3 7/8           12
3 1/2           11
2 11/16        9
2 3/8            8
2 1/8            7
1 3/4            6

Good luck!

Knute
'66 M20E - KSQL (San Carlos, CA)

[tablor]

Where do you measure?  IE at the inbd, center, or outbd edge of the fuel filler opening?  My plane had a paint stick in it, but I've always wondered how it was created.  I've always wanted to drain it and refill but I guess I've not ever gotten around to it.  I have the wing panel gauge and I always figure when the needle quits moving around at the bottom that I've got around 7 gallons remaining.  Like someone else said, I check everytime I fill up to make sure that I was in the ballpark of what I thought I had!

[rob]

Measured at the center of the fuel opening.

[Ned Gravel]

OK guys:

Can't help myself.  I am in the laboratory business.  Right now (for 2 more weeks) I am the Quality and Training Manager of an ILAC-signatory accreditation body.  That means we are completely anal about measurements. 

Are these sticks calibrated?

If so, were they calibrated by laboratories accredited to ISO/IEC 17025 for "length" (primary measurement parameter) and "volume" (derived measurement parameter)?

If so, were the calibration laboratories accredited by an ILAC signatory body?

Is the calibration traceable to the SI, through a CIPM signatory NMI, such as NIST, NRC/INMS or CENAM?

Do we have enough acronymns?  (tripple wink) 

(just to celebrate my promotion from "Senior Member" on this list to "Lives Here" as this is my 201st post.)

Fly safe.

[carusoam]

Edgar,

At which interval would you suggest we calibrate the paint stick?  and should we have a calibration decal applied to it somewhere? (insert smiley here)  Congrats on moving in....

Best regards,

-a-

[rob]

Edgar: Yes.

[knute]

Quote: rob

Measured at the center of the fuel opening.

[rob]

The center is where I measured it, so I hope it's a good place - One problem I've had with certain sticks I've made is that the soaking creeps up significantly and quickly. I got a few paint stirs from Lowes that did that, so I just switched back to an old one.

[rdav]

Does anyone have an idea for treating a dipstick that is soaking up the fuel so it can be used without contaminating fuel in the tank?  I have a handy sized dowel that I use, but it does like to draw up the fuel.  If I could stain it, or paint it, that would be ideal.

[Earl]

Quote: CoachTom

Ryan,

I made my own dipstick one Saturday morning by using a wooden dowel from Lowes.  My tanks were low as I had just flown earlier in the week and was intending on this proceedure.  I drained the left tank as it was the lowest in volume into a regular yard gas can.  The yard gas can had marks on the side of it from when i filled it up for the lawnmower: one gallon at a time and used a magic marker to note the level.  Hence, I knew I had 5 gallons of fuel in that wing.

To my surprise, I did not even see a drop of fuel on the wooden dip stick in the wing as i added a gallon from the pump, check the dipstick to see if it was wet until ( i believe) it was 8 or 10 gallons ticked away on the pump.  By then, i noticed that the one gallon at a time was not making a noticable "delta" from the previous gallon entry, so i used 4 gallon increments and that created an approximately 1/4" to 1/2" mark on the dowel.

Lastly, and to my surprise, as the fuel hit the bottom of the anti siphon plate, it was approximately 35 gallons (M20K Model) and needed to add very slowly to get to the POH volume of 40 gallons in the tank.  I only got to 39.5 gallons as the fuel ran off the wing no matter how I shook it it to get those last drops in.

It took 20 minutes to accomplish and i was glad i did that exercise as i now see the corelation between the wing fuel guage, th epanel fuel guage, and my fuel stick...

Hope this helps!

[danb35]

You could probably spray it with a clear lacquer.

[Hank]

Make your measurements [mine are at 2-gallon intervals] using the paint stir-stick and a marker. Then buy either a plastic tube or a "real" fuel dipstick and transfer the marks with an engraver, Dremel tool or the like. They won't ever fade away . . .

[sleepingsquirrel]

Quote: knute

My archive has a post I salted away from Rob Hoyle, who graciously provided the measurements and markings from the dipstick he (and the prior owner) calibrated for his 1965 C model, which turns out to work perfectly for my 52 gallon '66E model, verified every time I top up the tanks.  (It also very closely tracks my fuel computer)  I like to stick the tanks before every flight just to make sure I have exactly as much fuel as I think I do.

Hopefully email doesn't screw up the formatting too badly, but distance from the bottom of the stick is on the left (inches) and corresponding gallons is on the right.  Hope that helps or gives you a starting point!  It shouldn't be that hard to calibrate your own paint stick from Home Depot.  The measurements below obviously won't work for an F model with bigger tanks, but for any other C or E model owners with stock 52 gallon tanks, this should come pretty close.

9                 26

8 1/2           25

8                 24

7 5/8           23

7 1/4           22

6 7/8           21

6 1/2           20

6 1/16         19

5 3/4           18

5 7/16         17

5 1/16         16

4 13/16       15

4 1/2           14

4 1/8           13

3 7/8           12

3 1/2           11

2 11/16        9

2 3/8            8

2 1/8            7

1 3/4            6

Good luck!

Knute

'66 M20E - KSQL (San Carlos, CA)

[sleepingsquirrel]

Quote: sleepingsquirrel

 This was the start for my M20B dip tube. I check it on a fuel fill and find it close enough .

[Jerry 5TJ]

I use a clear hard plastic tube to "dip" the tank.  Stick it in, cover the open top end with your thumb, remove and read the level. 

Here is the inches to gallons chart (not traceable to NIST) for the 26 gallon (per side) tank in a short-body antique Mooney.

 

[DrBill]

I have verified these numbers with my 65 E.

Mooney Tank Dipstick
9                 26
8 1/2           25
8                 24
7 5/8           23
7 1/4           22
6 7/8           21
6 1/2           20
6 1/16         19
5 3/4           18
5 7/16         17
5 1/16         16
4 13/16       15
4 1/2           14
4 1/8           13
3 7/8           12
3 1/2           11
2 11/16        9
2 3/8            8
2 1/8            7
1 3/4            6

BILL

 

[mooneygirl]

It's is embarrassing to Mitch but I still use the re-formatted paint stirrer from my father's C model.  Can't bring myself to get a new one though mine has duct tape on it and all.  Memories of Maggie 1

[M20F-1968]

Does anyone have fuel dipstick measurements for an F, G or J model with Monroy long range tanks?

I agree that the dipstick can best be made from a plastic tube and markings transfered by marking the plastic tube with a file. 

The level can be easily seen if the tube is inserted, then withdrawn with a finger occluding the upper open end.  The fluid level can be directly visualized. 

John Breda

[jkb458]

For my 66 M20E, I used a "universal fuel gauge", a black Sharpie, and the aforementioned measurements for the short bodies.  I've been using this setup for about 3 years with no discernable wear on my Sharpie markings.

Universal Fuel Gauge

http://www.sportys.com/PilotShop/product/9324#

 

[tlandrum]

I have now been flying my 67' m20F for a few months now... love her.

The fuel measurements are quite different than in m20C I had a few years ago, most notably when it gets to the bottom of the fuel range.

I think most of this group has found the same thing I have, but I want to make sure. When I have less than about 10 or 12 gallons of fuel in a tank I don't get any on my dipstick. So I am not able to accurately measure anytime I have less than 20 gallons?!?!!? I know this is true with any tank, but this sure seems to be a lot of variability where it counts the most. It is 1/3 of a tank!

Any thoughts on this... or can everyone at least confirm that there is no fuel below the fuel cap when you are down to a third of a tank.

[jetdriven]

I would not use an dipstick that was not calibrated on level ground using my own aircraft. I did just that by draining the plane with the fuel strainer drain until it was empty. I then put two gallons in at a time while measuring with a universal fuel hawk and marking the supplied chart. No guessing, it's verified and calibrated within one gallon per side. I cring at the thought of guessing how much fuel is on board in a plane with crappy furl gauges and no totalizer.