There will have to be a line that fills and a line that overflows. If you run the lines as alfredbmor described, the overflow goes into the muffler. Depending on the muffler and where it is, that overflow can be hard to spot. If you go with that layout and want it to work well, there needs to be a fairly straight downhill run from where the pressure tap is in the muffler to the muffler exhaust pipe. A buddy has one airplane where the muffler takes maybe an ounce of fuel before it starts to pour out the exhaust.

My P47 tank has 3 lines. I've got a T in one of the three lines. Two of the lines are shown in the picture. I have had those lines rigged with Uniflow and without. Whenever you have all the hoses enclosed in a cowl, you're going to have to have a T or something like a fuel dot. Fuel dots have never been dependable for me.


I've used the OS91FX's OEM muffler in the P47. It does not leak overflow fuel quickly. So I've got a T in that line.

I use a hemostat to clamp that line between the muffler and the T. It works well. I don't mind dealing with the hemostat. It's cheaper than a fuel dot and 100% dependable.

I pull both lines you see in the picture out and pull their plugs to fuel. Fill into one line, look for instant overflow from the other that says the tank is full. With slightly different routing to not have uniflow, those two hoses do exactly the same. And the hemostat is still needed. I think the long one I have cost $5.

When you've got all the lines behind a cowl, you have to be lucky for them to work without needing to pinch one of the lines. And you will need a T or a special Fuel Dot.