Gas tanks

[roadkingh1]

I have a 370 DA 97' model. I am in the process of redoing my gas gauges and sending unit to make them more precise. In order to do that I have to find out the true dimensions of my tanks. I have measured them on the out side and took account of the wall thickness. The one thing I do not know is what the nonusable capacity of my tanks( Ex. how far my pickup tube goes into the tank. I have been told that it was about 1" from the bottom. Both tanks have a capacity of 140 gallons ( stamped on the tanks). If you read searay's literature, it descripes as having capacity of 275 gallons, but only a usable capacity of 261 gallons. After my calculations I came out with 270 gallons between the two, which is 9 gallons to much according to searay. The only thing I can think of is the length of the pickup tube. I may have to call skyline industries and see if they still have some drawings for those models.

 

[Lazy Daze]

Here's an idea, although it might not be the easiest thing. Run tank #1 empty. Fill tank #2 completely. Siphon Tank #2, taking accurate measurements of what you take out. It would take a while, but you could fill a 5-gallon gas can, empty it into tank #1, fill it, empty it, fill it, empty it.... you get the picture.

I suppose you could, using a stopwatch, accurately time how long it takes to siphon the gas into the 5-gallon can (I think you could use your fuel pump as the siphon). Once you know exactly how long it takes to fill the can, run the siphon directly into tank #1 and start your watch. Although, I think the first way would, in reality, be more accurate.

 

[tobnpr]

What would you do with this piece of information if you had it?
Plan on running on fumes into the fuel dock?
Not trying to be sarcastic- but I can't see a practical use in knowing exactly how many gallons of fuel I can pull out of a tank before sucking air because I'm never going to let it even get close to that level.