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Very few data seem to be available on the frictional losses in automobile engines caused by the failure of the oil to perform its function as a lubricant. The researches of the Lubrication Inquiry Committee in England indicate that the friction of a flooded bearing is proportional to the speed of the engine, the area of the bearing and the viscosity of the lubricant and is independent of the pressure and of the materials of which the opposing surfaces are composed. The principal sources of friction in an engine are the crankshaft, the camshaft and the connecting-rod bearings, which rotate; the pistons and the valves, which slide; and the auxiliaries, such as the generator, the pump and the distributor.

IN the discussion of automatic devices in motor cars presented in this paper, special emphasis is placed on fully automatic and semi-automatic clutches, drives, and transmissions. Two methods of attack are being used to eliminate the clutch pedal: power operation of the mechanical clutch and the fluid coupling. Three fundamental types of control for vacuum-operated clutches are discussed: 1. Position or follow-up type valving. 2. Balanced or pressure-sensitive type. 3. Balanced cushion with variable bleed. In a review of the merits and demerits of the fluid coupling, fuel economy and the shock loads on the driving mechanism are stressed. An appraisal of the operating principles and characteristics of various fully and semi-automatic transmissions compares the following: overdrive; four-speed semi-automatic transmission with fluid coupling; three-speed fully automatic transmission; and four-speed fully automatic transmission with fluid coupling.

THE most serious problem arising from higher degrees of supercharging is the increase in exhaust temperatures and the amount of additional heat to be handled. This conclusion is expressed following a theoretical exploration into the possibilities of supercharging and the ultimate limit to which it is possible to go. Efficiencies which may be expected with increasing degrees of supercharging, with and without compressor intercooling, are predicted. Some of the present-day superchargers are discussed, including the Roots, vane, centrifugal, and exhaust turbo-type blowers, and the advantages and disadvantages of each are given. Before closing his paper, Mr. Knudsen emphasizes the need for more compact and efficient accessories.

The paper opens with a number of quotations from publications issued by the Army War College and showing the bearing of motor transport on a proper military policy for the United States. The author then describes two experimental trips recently made by motor-truck owners near New York in an effort to determine proper motor-transport operating conditions. A statistical summary is given for these two experimental trips. The Army War College has issued in compliance with instructions of the Secretary of War a “Statement of a Proper Military Policy for the United States,” supplemented by a number of pamphlets dealing with particular features of this military policy in considerable detail. In many of these supplementary pamphlets there appears a considerable amount of material bearing upon the subject of motor transport and from them the brief quotations in the following paragraphs are taken.

This paper presents the results of studies on the mechanism of intake valve underside deposit formation in recent model passenger car engines. The effect of fuel and lubricant composition on deposit formation, as well as the influence of engine design and operating conditions, are described. High-speed motion pictures have been made showing the phenomena occurring in the intake underside area during various types of engine operation, and the conclusions reached from this study are also presented. Techniques for automatically operating laboratory engines in a manner giving intake valve deposits representative of those obtained in field test vehicles have been developed and are described.