Practical Hand Book of Gas, Oil and Steam Engines / Stationary, Marine, Traction; Gas Burners, Oil Burners, Etc.; Farm, Traction, Automobile, Locomotive; A simple, practical and comprehensive book on the construction, operation and repair of all kinds of engines. Dealing with the various parts in detail and the various types of engines and also the use of different kinds of fuel.

by John B. Rathbun

(133) Valve Gear Arrangement.

The valve operating mechanism lay-out depends upon the cylinder and valve arrangement, and consequently varies in detail with different engines.

Overhead Valve Arrangement of the Fairbanks-Morse “R E” Engine.

Fig. F-14–15 in Chapter V, shows the valve gear of an upright engine having the inlet and the exhaust valves located in pockets placed at one side of the cylinder. The inlet valve is operated by a valve rod that is actuated by the cam. The exhaust valve stem is raised and lowered, directly, through a cam on the same shaft. The method of driving the valves in this engine is practically standard for all vertical engines having the valves located in pockets. This system is used in a greater proportion of automobile engines.

The opposed engine has the cylinders arranged on opposite side of the crank case, and makes an exceedingly well balanced and quiet running engine; as there is no point in the revolution where either the crank throws or connecting rods have an unequal angularity, or differ in velocity.

While this type of two cylinder engine is common in automobile practice, it is not often met with in stationary work, the cam-box and the cam being directly in the center of the crank case.

The opposed type of engine is particularly well adapted for aeroplane service as a steady, quiet running engine is an absolute necessity because of the frail construction of the aeroplane frame.