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In this paper the data of film-lubrication theory have been adapted to the purposes of bearing design for reciprocating engines, particularly for the case of the high-speed internal-combustion engine. Suitable corrections for end leakage in short bearings have been incorporated and the results are presented in the form of design charts. Some published experimental data have been correlated with reference to the theory. The flow of oil in pressure-fed engine bearings has also been treated, the oil being considered as a coolant as well as a lubricant. The paper includes a brief discussion of the application of the data in design, with remarks on some detail features and practices.

The resistance of air flow through poppet valves has been tested experimentally by the authors. The experiments which they carried out and describe include flow in both inlet and exhaust directions, and the ranges of valve opening and of pressure head extend to or beyond the limits which normally may be utilized in practice. Individual valves were tested variously mounted, and pairs of valves were tested as grouped in an actual design. The experiments have been extended in an effort to improve the flow characteristics of the poppet valve by modification of its shape and that of the valve approaches.

A theory is developed for the supercharging effect produced in an engine cylinder when a long suction pipe is attached. As a preliminary to this theory, equations are given for suction and exhaust flow where no inertia effects are present. Results of the theory are compared with experiment, and some data are given on engine performance when supercharged in this manner.