Q. How about cleaning the radiator?
A. The entire circulation system should be flushed out occasionally. To do this properly, the radiator inlet and outlet hose should be disconnected, and the radiator flushed out by allowing the water to enter the filler neck at ordinary pressure, from whence it will flow down through the tubes and out at the drain cock and hose. The water jackets can be flushed out in the same manner. Simply allow the water to enter into the cylinder head connections and to flow through the water jackets and out at the side inlet connection.
Q. Will the radiator freeze in winter?
A. Yes; unless an anti-freezing solution is used in the circulating system you are bound to experience trouble. As the circulation does not commence until the water becomes heated, it is apt to freeze at low temperature before it commences to circulate. In case any of the radiator tubes happen to be plugged or jammed they are bound to freeze and burst open if the driver undertakes to get along without using a non-freezing solution. Wood or denatured alcohol can be used to good advantage. The following table gives the freezing points of solutions containing different percentages of alcohol: 20% solution freezes at 15 degrees above zero. 30% solution freezes at 8 degrees below zero. 50% solution freezes at 34 degrees below zero. A solution composed of 60% water, 10% glycerine and 30% alcohol is commonly used, its freezing point being about 8 degrees below zero. On account of evaporation fresh alcohol must be added frequently in order to maintain the proper solution.
Q. How are leaks and jams in the radiator repaired?
A. A small leak may be temporarily repaired by applying brown soap or white lead, but the repair should be made permanent with solder as soon as possible. A jammed radiator tube is a more serious affair. While the stopping of one tube does not seriously interfere with the circulation, it is bound to cause trouble sooner or later, and the tube will freeze in cold weather. Cut the tube an inch above and below the jam and insert a new piece, soldering the connections. If the entire radiator is badly jammed or broken it would probably be advisable to install a new one.
IV
THE GASOLINE SYSTEM
Q. How does the carburetor work?
A. The carburetor is of the automatic float feed type, having but one adjustment, the gasoline needle valve. The cross-section diagram of carburetor ([Fig. 149]) shows how the gasoline enters the carburetor, is vaporized by a current of air and passes through the inlet pipe to the engine in the form of an explosive mixture. The gasoline, entering the bowl of the carburetor, gradually raises the float to a point where the inlet needle is forced upwards into its seat, thus cutting off the flow of gasoline. As the gasoline in the bowl recedes, the float lowers, allowing the needle to drop from its seat and the flow of gasoline is resumed. It is plain to see that a constant level of gasoline is maintained in the carburetor by the automatic action of float and needle. The quantity of gasoline entering into the mixture is governed by the needle valve (see [following page]). The volume of gas mixture entering the inlet pipe is controlled by opening and closing the throttle, according to the speed desired by the driver.
