Why a Gasoline Engine Goes
As you know, gasoline is a very inflammable fluid, and will explode if placed too close to fire.
This explosive quality is the basic principle of the gasoline engine. By admitting a small quantity of gasoline vapor into an enclosed cylinder, and exploding it by means of an electric spark, repeating this operation continuously, the engine is given a regular rotary motion.
Look at Fig. 1. Starting from the gasoline tank, the fluid is fed into the ‘carburetor’, which is a sort of atomizer. Here the gasoline is mixed with air, and broken up into a very fine spray, in which condition it will explode readily.
The engine will not start of itself. Its fly-wheel must first be turned by hand, or by some other outside force, until the first explosion takes place. After this its action is automatic.
As shown in Fig. 1, the fly-wheel is being turned, and is drawing the piston down the cylinder, which in turn sucks gasoline vapor, (shown by little arrows) through the ‘intake valve’. This ‘intake valve’, and the ‘exhaust valve’ on the opposite side of the cylinder, are opened and closed at the proper time through the action of the gears shown in the illustration.
Passing to Fig. 2, the fly-wheel in turning has drawn the piston to its lowest point, and is now shown forcing it up the cylinder. This compresses the gasoline vapor in the cylinder to a density at which its explosion produces the greatest amount of power. The intake and exhaust valves are both closed.
WHAT CAUSES THE EXPLOSION IN A GAS ENGINE
Fig. 3 shows the explosion. The cylinder has been filled with compressed gas, and the piston has again started on its downward travel. The spark plug, set in the top of the cylinder, makes a spark every time an electrical current passes through it. A switch on the engine permits the current to pass to the spark plug only when the engine is at this position in its action. (Fig. 3.) The consequent explosion drives the piston downward with great force, turning the fly-wheel, which by its weight continues the rotary motion after the downward impulse of the piston has been expended.
Fig. 4 shows the fly-wheel, still turning, forcing the piston up and thus expelling the burned gases from the cylinder through the exhaust valve, held open for this purpose. From this position the engine goes again to that of Fig. 1, and through 2, 3, and 4, continuously, exploding every second revolution, and giving a regular rotary motion to the fly-wheel.
The illustrations show a one-cylinder motor, but these engines can be built with two or more cylinders, arranged to explode at different times, thus giving very smooth action to the fly-wheel and main shaft.
Aeroplanes, almost all automobiles, various pumps and other machinery are driven by gasoline engines. The rotary motion can readily be transmitted by chains or gears to the propellor of an aeroplane or motor boat, or the wheels of an automobile. It is only in the past few years that the gasoline engine has reached its present high state of perfection.
THE BEGINNING OF AN AUTOMOBILE
CRANKCASE SHOWING BEARINGS.
The heart of the automobile is the engine. It is built around the crankcase, which is its foundation or base.
CRANKCASE WITH CRANKSHAFT AND FLY-WHEEL ADDED.
The crankshaft serves the same purpose in an automobile as the pedals do on a bicycle.
The fly-wheel on the end helps it to keep turning at an even speed.
Gasoline vapor is exploded in the cylinders. This pushes the piston down, and as the piston is connected to the crankshaft it starts the crankshaft turning.
The piston and the rod that connect it to the crankshaft are just like the feet and limbs of any one riding a bicycle.
Cylinders showing piston in place and connected to crankshaft.
The gears or “cog-wheels” are for running the fan, the pump and other parts.
THE HEART OF THE AUTOMOBILE
Cylinder added to crankcase.
The cylinders are next bolted down to the crankcase, the pistons and crankshaft having been connected, as shown in Fig. 3. A cover is placed over the gears to keep them clean.
An oil pan or reservoir is attached to the bottom of the crankcase to hold oil for the engine.
The carburetor furnishes the gasoline vapor for the cylinders. It is connected to the engine by a crooked pipe called the intake manifold.
After the gasoline has been exploded a valve opens and allows the burned gases to escape through another pipe, called the exhaust manifold.
Oil is poured in the spout which is at the left of the carburetor. It runs down into the reservoir and is pumped up through the engine a little at a time.
Oil pump and filler added to motor.
THE POWER PLANT OF AN AUTOMOBILE
The electric generator makes electricity to be used for starting the engine and lighting the car.
The magneto gives an electric spark, which explodes the gasoline in the cylinders.
The water pump keeps water flowing around the cylinders to prevent them from getting too hot. This water comes back to the pump through the radiator at the front of the car. Wind blows through the radiator and cools off the water. The tire pump on up-to-date cars is run by the engine. It does not pump except when the gears, which are shown in the picture, are pulled together.
An electric motor starts the engine by turning the fly-wheel. This makes it unnecessary to get out and crank the car by hand.
SECOND STAGE OF CONSTRUCTION
The transmission is added.
The transmission makes it possible to reverse the car. It also enables the driver to go into high-speed gear when on level roads and low-speed gear for starting and for pulling hills.
Double-drop pressed steel frame.
The frame on which the car is built.
Addition of semi-elliptic and three-fourths-elliptic springs to frame.
Large springs are placed at the front and rear of the frame. They make the car ride smoothly.
Adding the front axle.
READY FOR THE WHEELS
Showing addition of full-floating rear axle.
Completed engine and transmission is next fastened to the frame and connected to the rear axle by the drive shaft.
Showing addition of gasoline tank and gas lead to carburetor.
Showing how steering gear is connected.
WHAT THE COMPLETED CHASSIS LOOKS LIKE
Wheels are next added to chassis.
Completed chassis with radiator added.
The water which keeps the engine from getting too hot is pumped around the cylinders and then through the radiator. The wind blows through the little openings in the radiator, and cools off the water. Then the water is pumped around the cylinders again.
The steps and fenders are next attached.
THE MARVELLOUS GROWTH OF TWENTY YEARS
The finished car.
GASOLINE AUTOMOBILE.
The first American-built automobile, now in Smithsonian Institute, Washington, D. C., where this photograph was taken. The rude carriage that was a curiosity twenty years ago and less—the vehicle that vied with the two-headed calf and the wild man of Borneo at the county fairs—was the beginning of the greatest transportation aid since the birth of civilization. Because of it our standards of living have become higher. It has broadened the horizon of all of us.
Built by Elwood Haynes, in Kokomo, Indiana, 1893-1894. Equipped with one-horse-power engine. Successful trial trip made at speed of six or seven miles an hour, July 4, 1894. Gift of Elwood Haynes, 1910. 262,135.
Cartoon: panicking people and animals in street when antique car passes by When an automobile passed you twenty years ago.
HOW AUTOMOBILES HAVE IMPROVED
Haynes engine
LEFT SIDE VIEW
Haynes engine
RIGHT SIDE VIEW
A new exhibit in the Smithsonian Institute, officially known as “Exhibit Number 56,860,” is attracting a great deal of attention from visitors to the National Museum. It consists of a complete Haynes six-cylinder unit power plant, and has been given a position at the side of the original Haynes “horseless carriage,” where the striking contrast shows the remarkable improvement that has been made in motor design and construction during the past twenty-two years.
The most important features of the power plant are shown clearly and comprehensively by having sections cut away from the various parts, so that the visitors to the Institute are enabled to see the mechanical construction, and the relation of the component devices.
On the right side of the engine, the intake and exhaust manifolds are shown in their natural position. A full vertical section of the Stromberg carburetor gives a good idea of how the gasoline is mixed with the air and supplied to the cylinders. The Leece-Neville generator has its casing cut away to give a view of the windings and cores. Numerous windows have been cut into the crankcase to disclose the crankshaft construction and the oil reservoir. The transmission gears are also shown in this manner.
Most of the electrical equipment is shown clearly on the left side of the motor. Here an interesting feature is the full vertical section of the American Simms high-tension dual magneto. A half section has been removed from the rear cylinder, and the piston as well, to give a glimpse of the interior construction. A large portion of the Leece-Neville starting motor casing has been cut away. The cover-plate on the switch controlling the starting motor has been replaced with a glass cover to display the method of completing the circuit from the battery to the motor. A skeleton selector switch is mounted at the rear of the transmission case, instead of its usual position on the steering wheel. The electric gear-shifting mechanism is made visible by using a glass plate for the top cover-plate on the transmission.