Fig. 73a.-Diagram Showing Method of Connecting the G. C. Kerosene Vaporizer to Conventional Four- Power Plant parts of G. C. kersoene vapor izer is illustrated at Fig. 73-a. This device has been in use in England for nearly two years and has been applied with success on com mercial vehicles, motor boats and stationary en gines. An advantage is that this type of kerosene vaporizer does not interfere in any way with the design or construction of the motor which retains the usual gasoline carburetor. This is employed for starting purposes, and the engine is run on gasoline until sufficient heat is obtained to va porize the heavy fuel. The desired temperature for vaporizing the kerosene may be attained after motor operates five or six minutes. As the heavy fuel mixture is conveyed to the intake manifold above the regular form of carburetor, it is possible to use either fuel independently and run the motor on one fuel should the supply of the other become exhausted. The G. C. vaporizer replaces the conventional muffler, and the exhaust gases are led to it from the motor, so the heat usually wasted is utilized for aiding in vaporizing the heavy fuels. The exhaust gases pass through the central portion of the vaporizer and during their passage they heat up a triple layer of small fragments of cast iron through which a horizontal pipe extends containing the fuel to be vaporized. Atmospheric air is drawn through the vaporizer at the same time from another opening, and as this mixes with the kerosene vapor, the cylinders are fed with a homogeneous gas. The amount of kerosene entering the vaporizer is automatically regulated by the motor suction and the supply increases in proportion to the motor speed because the degree of vacuum in the cylinders depends on the amount of throttle opening. The kerosene supply pipe goes to a float chamber communicating with the vaporizer by an independent p pe. The mixture from the vaporizer goes to the intake manifold, through a long fuel supply pipe, the motor end of which is fitted with an auxiliary air mixing valve and a throttle for regulating the amount of gas going to the cylinder. The adjustments are very simple, and once the vaporizer is installed it is claimed that it requires no further attention. If the motor shows evidence of smoking, the adjustment A of the auxiliary air valve is moved in the direction of the arrow D. If the engine back-fires because the mixture is too thin, the adjusting screw A is screwed in the direction of C. The low speed adjustment is obtained by the screw B, which is moved in the direction a if the motor smokes and toward b for back-firing. The amount of kerosene entering the vaporizer-silencer may be regulated by moving the screw E on the float chamber in the direction e for smoking, and in direction f if the motor back-fires. It is claimed that this device permits the use of other fuels besides kerosene, as it has operated successfully on alcohol, heavy petro Fig. 74.-Defining Method of Utilizing Kerosene in Two-Cycle Motors by Direct Injection in Cylinder. leum, and very low grade kerosene, commonly called "distillate." When properly adjusted, it is advanced that the consumption of kerosene is about 20% less than gasoline needed for the same power output. To start a motor employing this system it is necessary to close the kerosene throttle entirely and to start the motor on the gasoline carburetor and regulate its speed for five to ten minutes by the gasoline throttle at the lower portion of the intake manifold. When it is desired to operate on kerosene, the gasoline throttle is gradually closed and the kerosene gas controlling throttle is gradually opened until the motor is running on the kerosene mixture. Q. What else may be done to use kerosene? A. Some forms of two-cycle motors use kerosene by the method outlined at Fig. 74. When the air is transferred from the engine base where it has been compressed, a portion of the air stream is deflected through a by-pass to the top of the float bowl so that the liquid contained therein is placed under pressure. This pressure causes a certain amount of the fuel to spray through the spray pipe or nozzle placed at the top of the cylinder by-pass passage and a stream of kerosene is injected into the entering air stream and vaporized. With either of these systems it is not possible to start directly on kerosene; it is necessary to run the engine on gasoline until it becomes hot enough to evaporate the less volatile liquid fuel. With the carburetor shown at Fig. 73, it is a relatively simple matter to change from one fuel to the other. With the injection system shown at Fig. 74, the float bowl may be filled with gasoline directly from the gasoline tank with the valve handle in the position shown by the dotted line, and when the valve handle is straight up the gasoline inlet is shut off and the fuel supply is through the kerosene inlet. Q. What becomes of the burnt gases when they are discharged from the engine? A. After the burnt gases pass out of the cylinder, they pass through the exhaust manifold and exhaust pipe to the muffler. Q. What is a muffler? A. A muffler is a simple device designed to silence the gases as they issue from the engine before they pass to the outer air with as little loss of power due to back pressure as possible. Q. Why is it imperative that as little back pressure exist in muffler and exhaust piping as possible? A. When the gases are discharged through the open exhaust valve, their pressure is approximately 40 pounds per square inch, and if the muffler and exhaust piping offers a decided resistance to their passage to the outer air, there will be a negative pressure equivalent to that exerted by the exhaust gases that will tend to prevent the piston coming to the top of its scavenging stroke. This would mean that considerable force or power would be utilized in expelling the exhaust gases that could be employed to much better advantage in propelling the car. Q. What is a muffler cut-out valve? A. The muffler cut-out valve is a fitting interposed between the exhaust manifold and the muffler in such a way that it can be operated to allow the exhaust gases to escape directly to the air from the manifold without passing through the muffler. Q. How is a muffler cut-out valve operated and what advantage does it offer? A. The muffler cut-out valve is usually operated by a simple pedal that can be pressed down by the toe or heel of the foot and locked in the open position. A muffler cut-out offers several advantages, the most important being that it permits the motorist to listen to the explosions to see that they follow in regular sequence and also to relieve any back pressure due to the muffler when all the engine power is needed as in high speed work and hill climbing. Q. Can a muffler be both silent and efficient? A. Mufflers of modern construction offer but little back pressure and are silent enough so that nothing but a barely perceptible hissing noise is heard when the engine is running. Q. Describe method of silencing the exhaust in a muffler. A. A muffler consists of a series of compartments in which the gases are allowed to expand and as they increase in volume their pressure is reduced. The exhaust passes from one compartment of the muffler to the neighboring one through a series of holes which break up the main stream into a number of smaller streams, this cooling the gases and reducing the pressure until it is but slightly greater than that of the air. The ideal muffler would be one that would discharge the gases only when their pressure had been reduced to such a low point that there would only be difference enough between the exhaust gas and atmospheric pressure to insure clearing out the muffler. |