A view of a representative single-cylinder engine is shown at [Fig. 225]. The cam shaft is located at a and is driven by the gears which are shown just in the rear of the fly-wheel. At c are the cam and the roller, which actuates the exhaust valve. The cam consists of a collar with a flat projection or toe upon its surface; the roller rests just above the surface of the collar, and is forced upward when struck by the projection. The roller is inserted to lessen the friction by rolling instead of rubbing. The valve stem extends upward into the valve chamber, and is encircled by the coiled spring e; the stem is guided by the guide at g. The exhaust is at E; I is the pipe leading from the vaporizer V to the inlet port in the valve chest. The inlet valve is directly below the spring S and is inverted, being held in place by the spring. The dome-shaped cap containing the inlet valve is removable for access to both valves. The complete cover is also removable. It will be observed that this engine has an open frame very similar to that of a steam engine, giving free access to the crank-pin and main bearings; the latter are shown fitted with oil boxes b instead of the grease cups, as there is no pressure tending to force the oil out along the shaft as in the two-cycle type. This open base not only makes the bearings more accessible, but renders it easier to lubricate them and keep them cool. At H is the ignition gear. P is the cooling water pump, run by the eccentric e. The suction is piped to d and the pump discharges through the pipe k into the cylinder. The outlet for the cooling water is at O; N is the cylinder oil cup for oiling the bore of the cylinder. The compression cock R is for relieving the compression at starting. The coupling at X is for attaching the propeller shaft.
In this engine, the cylinder, base and bolting flange are one casting, the upper half of the main bearing being removable for the insertion of the shaft. The cover is bolted on separately.
AUTOMOBILE FRAMES
The chassis for the single-cylinder, eight horse-power motor machine shown herewith is built on the principle of most frames, of any make and is typical of the majority of light motor car chassis at present in use.
Fig. 226. Eight horse-power single cylinder chassis
A diagrammatic plan of the eight horse-power, single-cylinder chassis is shown in the accompanying illustration ([Fig. 226]) in which, A indicates parts enclosed, taking the mixture of gasolene and air from the float-feed spray carburetor B, which has an automatic air regulator. The purpose of this last device is to dilute the mixture when the engine has a light load and is inclined to race; generally speaking, this regulator serves to proportion the ingredients of the explosive mixture to the requirements of the engine. Current O for the ignition of the explosive mixture (ignition occurs once for every two revolutions of the fly-wheel), is supplied by an accumulator and intensified by a high-tension coil. The products of combustion pass through the exhaust pipe C to the muffler D, from which they pass to the atmosphere through a series of fine holes. The starting handle E makes a simple connection with the end of the motor shaft F when required. G is the fly-wheel. The drive from the engine is through a universal joint H to the change-speed gear J, the latter consisting of two trains of toothed wheels, a big wheel on the primary shaft gearing with a small one on the secondary shaft to give a high speed, and vice versa. From the change-speed gear, the drive is through a shaft K, having a universal joint L at each end, to the bevel gearing above the differential gear of the live rear axle. Bevel gears and the differential gear are all contained in the casings M. Three brakes are fitted, one operated by pedal, working on a drum N secured to the propeller shaft, the others operated by the side lever and working on drums O O, secured to the rear wheels. The change-speed gear gives three speeds forward and a reverse; the frame is of pressed steel; the rod and wheels are of the artillery type and carry 700 mm. by 85 mm. pneumatic tires. The gasolene tank holds 41⁄2 gallons, sufficient for 200 miles, and the lubricating oil tank holds 1 gallon, sufficient for 350 miles. Any beginner in motoring matters, who studies the diagram, will obtain a fair idea of the mechanism of the customary type of light car chassis.
