n2ryd

I am going to use a OS 160 twin for power in a 1/4 scale Balsa USA Pup and I am concerned with the fuel tank location. With the tank as low as possible within the fuselage the connection point on the 160's carb is lower than the bottom of the tank.

Will I experience a problem with flooding or the tank syphoning, when the engine is not running?

Will the engine run rich because the carburator is located below the fuel tank?

Is there a valve I can get that could be operated by a mini servo to shut off the fuel line when the plane is on the ground and the tank is full?

The tank will not be pressurized because of the lack of a pressure tap on the 160's exhaust system.

Any help or advice with this application would be greatly appreciated. I am at the installation point for the fuel system and need any advice as soon as possible.

Thanks

Bob.

Bax

My Feedback: (11)

The gravity feed will work, but your engine will tend to drip at low throttle settings, and will likely experience a noticeable change in the mixture as the fuel tank drains. It will allow fuel to drip out of the carburetor when the engine's not running because of the higher fuel level. Of course, you'd get this with any engine where the fuel level's higher than the needle.

There isn't a specific fuel valve, but you can use one of the valves people use for smoke systems. Another way is to simply use a clamp on the fuel line when you have the model in the pits. Drain the tank at the end of the day to prevent fuel running out in the car and while the model's in storage.

n2ryd

Thanks for the help.

To expand on yoursuggestions! Would it be wise to use a pump to maintain the same fuel pressure during the run? I have a Perry pump that I may be able to put in the line and have it work to supply the same pressure for the entire run.
I also like your idea of using a clamp to crimp the line when not in use. I can reach thru the cowl and crimp it very easlly.

Bob

Bax

My Feedback: (11)

You'd need a pump only if your engine has fuel draw issues.