Van's Air Force
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Fuel Tank dip-stick markings for an RV-6?
- Thread starter Doug
- Start date
I meant to post this a while ago after working it out, but kept forgetting. Here are my dimensions:
On a 1/4" OD, 1/8" ID clear plastic dipstick, measured from the bottom end:
1.14" - 22L
2.12" - 32L
3.08" - 42L
4.06" - 52L
4.97" - 62L
6.59" - 72L (or full)
This is measured with the stick vertical when viewed from the front, and with the bottom end pushed to the bottom of the tank and then slid back to the first obstruction... I think it's an angle bracket of some kind. The tube stands about 5 degrees off vertical, tilted towards the front of the aircraft, when it's in position.
Drop the tube in, put my thumb over the top, lift it out, and read off the level.
Hope that helps!
On a 1/4" OD, 1/8" ID clear plastic dipstick, measured from the bottom end:
1.14" - 22L
2.12" - 32L
3.08" - 42L
4.06" - 52L
4.97" - 62L
6.59" - 72L (or full)
This is measured with the stick vertical when viewed from the front, and with the bottom end pushed to the bottom of the tank and then slid back to the first obstruction... I think it's an angle bracket of some kind. The tube stands about 5 degrees off vertical, tilted towards the front of the aircraft, when it's in position.
Drop the tube in, put my thumb over the top, lift it out, and read off the level.
Hope that helps!
Allan Stern
Well Known Member
Fuel Tank Dip Stick
FYI Aircraft Spruce sells a plastic dip stick and does what you are looking for. You have to start with empty tanks and then add fuel increments to the tank but it works.
FYI Aircraft Spruce sells a plastic dip stick and does what you are looking for. You have to start with empty tanks and then add fuel increments to the tank but it works.
rvmills
Well Known Member
Also meant to post this earlier. Just another data point, FWIW.
RV-Super Six on Rocket Struts, but with a Flyboys Tailwheel, so may be valid for general comparison. Std 19 gal (22 L) tanks.
I use a 5/8" diameter wood dowel, and place it straight down into the middle of the fuel cap opening to the tank bottom. My numbers are smaller than Snowflake's because I don't slide the bottom back to the first angle bracket.
I did the drill of emptying the tanks, then filling with 2 gallons at a time. My marks are in gallons, but I did the metric conversion for our decimal-based brothers and sisters.
7/8" (22mm) = 6 gal (22.7 L)
1-1/2" (38mm) = 8 gal (30.3 L)
2-5/16" (59mm) = 10 gal (37.9 L)
3-1/8" (79mm) = 12 gal (45.4 L)
3-3/4" (95mm) = 14 gal (53.0 L)
4-1/2" (114mm) = 16 gal (60.6 L)
5-3/16" (132mm) = 18 gal (68.1 L)
I didn't do a mark for full...I figured that's when it starts to run off the top of the wing!
Quick pic (very low tech!):
Cheers,
Bob
RV-Super Six on Rocket Struts, but with a Flyboys Tailwheel, so may be valid for general comparison. Std 19 gal (22 L) tanks.
I use a 5/8" diameter wood dowel, and place it straight down into the middle of the fuel cap opening to the tank bottom. My numbers are smaller than Snowflake's because I don't slide the bottom back to the first angle bracket.
I did the drill of emptying the tanks, then filling with 2 gallons at a time. My marks are in gallons, but I did the metric conversion for our decimal-based brothers and sisters.
7/8" (22mm) = 6 gal (22.7 L)
1-1/2" (38mm) = 8 gal (30.3 L)
2-5/16" (59mm) = 10 gal (37.9 L)
3-1/8" (79mm) = 12 gal (45.4 L)
3-3/4" (95mm) = 14 gal (53.0 L)
4-1/2" (114mm) = 16 gal (60.6 L)
5-3/16" (132mm) = 18 gal (68.1 L)
I didn't do a mark for full...I figured that's when it starts to run off the top of the wing!
Quick pic (very low tech!):
Cheers,
Bob
I wanted to do that, but with the slope of the tank bottom I decided I would get a more repeatable result by sliding the bottom back to the angle bracket, and the top back to the back of the opening. That way the tube sits against two hard stops, and all I have to do is align it vertically.
For what it's worth, I started with the fuel not visible, and filled until it just touched the bottom of the tube. From there, I added 10L at a time and made marks until it was full. Once full, I went back and interpolated to get the marks I use now. I was surprised how close to linear the fill was... 10L was about 1" of depth, right up to about the 55-60L point.
woodmanrog
Well Known Member
For RV6A on level surface
Here are measurements I made on a paint stick for fuel. I place the stick vertically at the rear of the filler hole to the bottom of the tank.
1"=5 gal.
2 3/4 "=10 gal.
3 5/16"=12 gal
4 1/4"= 15 gal
Full at bottom of filler neck ring.
Here are measurements I made on a paint stick for fuel. I place the stick vertically at the rear of the filler hole to the bottom of the tank.
1"=5 gal.
2 3/4 "=10 gal.
3 5/16"=12 gal
4 1/4"= 15 gal
Full at bottom of filler neck ring.
rvmills
Well Known Member
Rob,
I thought your checking method was a pretty good way of making measurements consistent. Neat trick. I doubt I'll go back and re-measure though, 'cause the only time I really use less than full tanks is for mod testing and racing, and aerobatics. Even then, I add a little "for the wife and kids and dog". Close (plus a smidge) is OK.
Ours pencil out pretty closely, except for the first one...but that's probably because you measure at the back of the fill opening...another good trick (edit...just saw you are an A as well).
Our 5 and 6 gal measurements are probably really for reference...I'm not normally gonna blast off with six a side, unless its to fly next door for cheap gas!
Cheers,
Bob
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Here is one for the 6A....................FYI
http://www.vansairforce.com/community/showpost.php?p=119559&postcount=7
http://www.vansairforce.com/community/showpost.php?p=119559&postcount=7
I was thinking that over-analyzing it was probably not worth the effort... I rarely take off without full tanks at the start of the day too, and i'm light enough that solo full tanks aren't really a problem for aerobatics, even at Van's limit. It's just handy for guessing how much farther I can fly when i'm enroute.the only time I really use less than full tanks is for mod testing and racing, and aerobatics. Even then, I add a little "for the wife and kids and dog". Close (plus a smidge) is OK.
One of the local RV pilots marks his dip-stick in "hours remaining," not Gal or L. Saves doing the math.
rvmills
Well Known Member
I was thinking that over-analyzing it was probably not worth the effort... I rarely take off without full tanks at the start of the day too, and i'm light enough that solo full tanks aren't really a problem for aerobatics, even at Van's limit. It's just handy for guessing how much farther I can fly when i'm enroute.
One of the local RV pilots marks his dip-stick in "hours remaining," not Gal or L. Saves doing the math.
Agreed on all points...its just a good tool in the kit at times.
And with tongue-in-cheek...the hours remaining marks would be quite variable on mine, depending on how greedy I am with the black knob. However, my bladder has fairly consisitent time and range marks, though come to think of it, that's variable too (by how many preflight cups of joe or sodas or waters are consumed!)
One of our local pilots here recently said in a discussion of running out of gas, "if you never want to run out of gas, just drink two cups of coffee before you take off"
(He's a much older gentleman...ahem...but I can sorta relate )OT, but all in fun!
Cheers,
Bob
Currently the best solution for me not running out of gas is to have uncomfortable seats. Mine were carved from single-density foam, and have no bolstering. After about two hours it feels like you're sitting on a basketball that wants to roll towards the flap handle. Maybe it's just me.
Was going to replace them with Classic Aero or Flightline seats this year, but unfortunately my transponder crapped out and I had to replace it with a Garmin 327. That ate my budget for new seats this year. Maybe next year.
Was going to replace them with Classic Aero or Flightline seats this year, but unfortunately my transponder crapped out and I had to replace it with a Garmin 327. That ate my budget for new seats this year. Maybe next year.
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Just for info, and maybe this is so obvious that it goes without saying (except that was not the case me) but when I did mine for my 6a I just leveled the plane and added fuel to the left tank in 2 gal increments and marked the stick. It never seemed correct and so I again drained the tank and leveled the plane and this time put a 2x4s upright (cut to the exact length) under each wing to hold level. Then I repeated the process and came up with an entirely different and appearently more accurate set of marks). Anyway, I have since lost the stick and was going to repeat the process, however if I knew that the above listed marks for the 6a were obtained in a manner that held the plane level during the process I'd feel comfortable using them and avoiding the whole ordeal. Anyone know?
Since you will use the dip stick to determine how much fuel is in each tank during pre-flight, I would think that leveling the plane would be counterproductive. Wouldn't it be better to pu the plane on level ground in normal resting attitude, and put fuel in and mark the stick accordingly?
Look back at post 10...... The stick that I marked for my 6A is within 3/10 of a gallon any place on the stick during fill up. No magic here. I parked at the pump and filled one tank, a gallon at a time and marked the stick. The stick works perfect for both tanks. And it does not matter if one tank has 4 gallons in it and the other tank has 15 gallons in it.
Just curious if anyone with a 6 has an idea of roughly how much fuel is left in a tank when it can just be barely see when looking into the tank. Am thinking about making up a dipstick and was just curious.
It'd be easy to figure based on filling it from this point, buy I'm laying in bed and not topping off tanks, ATM.
It'd be easy to figure based on filling it from this point, buy I'm laying in bed and not topping off tanks, ATM.
az_gila
Well Known Member
Be careful copying other peoples stick dimensions if you have a -6.
Vans plans have had different dimensions for the location of the fuel filler hole for the -6 and -6A tanks, and then settled on a mid dimension when he went pre-punched. The fore-aft filler hole position will affect your numbers.
A look at the top view and the side view of the tank on page 18 of the latest plans sheet will show one of the differences.
Best you calibrate it yourself using the 2 gallons at a time method with the plane sitting on a flat surface.
GeneL
Well Known Member
Dipstick calibration
Tram, At the gas pump with your tank level out of sight fill 'till the level is just at the bottom of the stick, then add 1 gallon at a time and mark each on the stick. When you get to the top of your filler (full) you know what your capacity is (rv7=21 gallons, rv6=19 gallons) just mark the gallons down from there. Note this is not as accurate on "A" models since due to pitch at rest you can not fill the tanks unless someone is pushing down the tail (filler holes are cut for tail dragger stance??? Gene
Tram, At the gas pump with your tank level out of sight fill 'till the level is just at the bottom of the stick, then add 1 gallon at a time and mark each on the stick. When you get to the top of your filler (full) you know what your capacity is (rv7=21 gallons, rv6=19 gallons) just mark the gallons down from there. Note this is not as accurate on "A" models since due to pitch at rest you can not fill the tanks unless someone is pushing down the tail (filler holes are cut for tail dragger stance??? Gene
Frank Smidler
Well Known Member
6 fuel level by eye
I have checked this many times. I look at were the fuel is relative to the front bottom angle just under the filler. If the fuel is even with the top of the angle it is at 7 gal. If it is just at the bottom of the angle it is 5 gal. I have checked this by looking at were the fuel is relative to the angle, fill it full and subtract the amount pumped from 19 gal. Yes I have checked the total capacity of my tanks and they are both exactly 19 gal. Further I have intentionally ran each dry and the usable in level flight is the total 19 gal.
Just curious if anyone with a 6 has an idea of roughly how much fuel is left in a tank when it can just be barely see when looking into the tank. Am thinking about making up a dipstick and was just curious.
It'd be easy to figure based on filling it from this point, buy I'm laying in bed and not topping off tanks, ATM.
I have checked this many times. I look at were the fuel is relative to the front bottom angle just under the filler. If the fuel is even with the top of the angle it is at 7 gal. If it is just at the bottom of the angle it is 5 gal. I have checked this by looking at were the fuel is relative to the angle, fill it full and subtract the amount pumped from 19 gal. Yes I have checked the total capacity of my tanks and they are both exactly 19 gal. Further I have intentionally ran each dry and the usable in level flight is the total 19 gal.
az_gila
Well Known Member
Only on the pre-punched skins. The drill it yourself filler hole had two possible locations, one for a -A and one for a taildragger. I believe the pre-punched location may be a mid way compromise.
It depends on your -6 kit age....
