Typical Radiators. (B) Front Type.
Hunsaker finds that 0.83 square feet of actual cooling surface per horsepower is correct at 60 M. P. H., while others give a value of about 100 square foot under similar conditions. The front or projected area varies with the thickness of the radiator, the thicknesses varying from 2 to 5 inches. The Livingston radiator gives a cooling surface of 50 square inches per square inch of front surface. The total cooling effect depends upon the speed, the location in regard to the slipstream, and the position on the body. A radiator maker should always be consulted when making the final calculations. See Chapter XVI.
Fuel Tanks and Piping. The fuel tanks may be of copper, aluminum or tin-coated steel, and all joints should be welded or riveted. Never depend upon solder, as such joints soon open through the vibration of the engine. Gasoline should not come into contact with steel, nor the zinc used on galvanized iron. Splash plates are provided to keep the fluid from surging back and forth while in flight. All gas should be supplied to the engine through a filter or strainer placed in the main gas line. The valves in the fuel lines should be provided with stopcocks, so arranged that they can be closed from the pilot's seat.
In general, the carbureters should be fed by gravity from an overhead service tank, this tank being supplied from the main reservoir by air pressure or a gasoline pump. The air can be compressed by a pump on the engine or by a paddle driven pump operated by the airstream, and as a rule the latter is preferable, as it can be operated with the aeroplane gliding and with the engine dead. Air pressure systems are likely to fail through leaks, while with a good gasoline pump conditions are much more positive. The gravity service tank should be located so that it will feed correctly with the aeroplane tilted at least 30 degrees from the horizontal.
Two Views of the "Monosoupape" Gnome Rotary Cylinder Motor. This Motor Has 9 Cylinders Arranged Radially Around the Crankshaft and Develops 100 Horsepower. The Cylinders Are Air Cooled.
The gasoline piping should be at least 5/16 inch inside diameter, and should be most securely connected and supported against vibration. To guard against crystallization at the point of attachment, special flexible rubber hose is generally used. This must be hose made specially for this purpose, as ordinary rubber hose is soon dissolved or rotted by gasoline and oil. Air pockets must be avoided at every point in the fuel and oil system.
Hall-Scott "Big Six" Aeronautical Motor of the Vertical Water-cooled Type. 125 Horsepower.