Trying to Calibrate a Fuel dip stick

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n2801c
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Joined: Fri Oct 18, 2013 8:22 pm

Trying to Calibrate a Fuel dip stick

Post by n2801c »

Does anyone have the HxWxL dimensions of the standard and long range C170B fuel tank? I am trying to calibrate a standard over the counter clear fuel tank dip stick for a couple of C170's that I fly. Even with the slope of the tanks, I should be able to calculate the actual amount of fuel at the different marked levels. I have tried to get this information from Cessna parts dealers and others, but no one seems to have that information available. I am hoping that someone may have a tank sitting around that can give me those dimensions. Thanks.
hilltop170
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Re: Trying to Calibrate a Fuel dip stick

Post by hilltop170 »

Why don't you put the plane on a level surface, empty the tanks, and calibrate the stick by adding 5 gallons at a time to each tank?

That will give accurate and repeatable tank levels.
Richard Pulley
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1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
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n2801c
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Re: Trying to Calibrate a Fuel dip stick

Post by n2801c »

Thanks for the reply. I thought of that and still may have to do it that way, but one aircraft is a rental so it is flying all the time. I just thought if I had the dimensions I could calculate it fairly close. I just didn't realize how hard it would be to get dimensions.
swixtt
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Re: Trying to Calibrate a Fuel dip stick

Post by swixtt »

at what point will the fuel cross-drain to the other... will it happen even if the fuel selector is on one tank?
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ghostflyer
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Re: Trying to Calibrate a Fuel dip stick

Post by ghostflyer »

Cross draining of the fuel is a dark science. This is the theory for my 170A with a original fuel shut off valve . BUT what happens in flight is another mystery story .
When on the ground and selector to both ,both fuel tanks are feed to the engine and both tanks can drain one to the other . But when selected to either tank only that tank selected will supply that engine and fuel will not transfer.
When selected to off no fuel to the engine but both tanks will drain to each other .
Now when in flight and selected to both ,the engine is feed fuel from both tanks theoretically equally but we all know one tank will drain faster than the other . I have pushed it to the point where one tank showed on the overhead gauges empty.
I chicken out and then selected the fullest tank. I do not trust the overhead gauges at all and only rely on them to show that there is some fuel in the tank. At every stop or refuel I always dip my fuel tanks and check it off with hours flown and fuel burn [volume of fuel and time in air] plus check it against my fuel computer [EI] .
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Bruce Fenstermacher
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Re: Trying to Calibrate a Fuel dip stick

Post by Bruce Fenstermacher »

The only time fuel can cross fill through the fuel selector is when the selector is on BOTH AND in OFF. With the fuel selector on either right or left, there is no cross filling through the fuel selector. Of course fuel can always cross fill though the vent tubes.
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