First Gas engine

I'm putting together my first warbird and gas engine combo. I have a Hangar

9 P47 60 size and a Zenoah G20. My question involves installing the fuel tank. I have the necessary fuel line and stopper for gasoline. The G20 has a fuel pump on the Walbro carb. Since I don't need an exhaust tap for fuel tank pressure I want to use the second line (the upper hose in the tank) for filling with a fuel dot on the side of the fuse. The gas feed line on the carb will of course be under the cowl so it is not useable as a fill hose. I would think I need a vent, correct? Is there an easy way to hook up fuel line or do I need to use a third line in to the tank through the stopper? Where do I put the vent hose? Does it overflow when the tank gets filled? Thanks for the help! Howard
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If running a third line is a hassle, and it usually is, put the fuel fill into the feed to the carb. You can use one of those fill things that you stick a probe into, and it shuts off the flow on one side, that should go to the carb. Otherwise, you can put a T into the line and plug it after filling. Flooding the carb is not usually a problem with a walburo type carb.

The overflow/vent opens to the bottom of the plane, with enough line to plug an overflow can into, to keep from loosing gas. Just make sure the vent inside the tank is in the highest part of the tank.

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A gas carb(Walbro) has a valve in it so you will not pump gas into it if your tank is vented. You can just tee into the line from the tank to the carb to fuel and defuel.

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Ralph Henrichs

"Howard" wrote

LHS will have a good chance of having one in stock. One brand is this:

Note that is automaticaly shuts off the fuel line going to the carb.

Not a problem for the above item - no flow to the carb is possible. If you were to use a fuel line T with a stopper in the fill line while flying, it is still about impossible to get the fuel flowing past the carb. The Walburo type carb has a pulse fuel pump that uses pressure pulses from the crank case to pump fuel. It has a check valve as part of it, and will not tend to allow much, or any, fuel to pass.

Even if it did flood a little, all you have to do is turn the exhaust port to the center of the earth, and turn the prop though compression a couple times, but make sure the ignition switch is off. Of course, you know that it is pretty much manditory to use a grounding switch for the ignition, right? After that, turn the ignition switch back on (un ground the ignition) and crank it. Gas engines love to be very wet, anyway, since most do not have chokes.

Go with the refueling valve. Makes life easy, pretty cheap, and also a neat way to refuel with the least hastle, and all with the cowl still on.

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If you will be using the DuBro Kwik-Fill valve, make sure to check that the valve closes completely after you remove the refueling probe. Even a slight air leak here will cause the carburetor to suck air (since air is less dense than fuel) and your engine will quit. Also, watch the condition of the O-ring seals as they age.

Ask me how I know...

D. Anderson

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Quick note about fuel lines and the G20.

In case you did not know, there is a proper way to run your vent lin in order to keep gasoline from escaping when the plane is nose down o inverted. Because the G20 does not have a pressure tap exhaust, th tank is free vented to the atmosphere.

Heres what you do. Its really simple.

Vent the inside of the tank as normal with an upturned brass tube, the run the vent line from the outside of the tank UP Above the tank an make a loop around the top of the tank, then run the vent line down th back of the tank to exit out the bottom of the airplane. This allow the vent line to be free to atmosphere but keeps the gasoline withi the tubing and tank

-- Matt Cheste

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