CYLINDER temperature is definitely one of the many important factors affecting the efficiency and life of an internal-combustion engine. Experience has indicated that cylinder temperature can be too low or too high. Each temperature extreme produces its own particular set of evils, but the high temperatures are the most destructive and the most difficult to control. Cooling-water or fin temperature is only slightly indicative of the cylinder-surface temperatures. Since we are most vitally interested in the temperature of the working surfaces, research on the subject must start on the inside. The evils of thermal distortion are well known but probably not fully appreciated. Practically every factor of engine performance is dependent upon lubrication. Excessive cylinder temperature destroys lubrication which, in turn, eventually shortens the life and decreases the efficiency of an engine.
(ABSTRACT) Dependability, economy, durability, speed, safety, appearance and riding comfort, are the factors considered by Dr. Moss in his resume of progress made in automobile development. Passing then to the problem of the effect of automobile riding on the health of passengers and drivers, he discusses air conditioning, eye strain and body posture while riding. Carbon monoxide probably is the most important of the extraneous harmful substances in relation to air conditioning and an inexpensive investigation, using a carbon-monoxide indicator, is recommended to secure its elimination. Other harmful factors are temperature, relative humidity and motion of the air. A novel suggestion is made that rats be used experimentally in studying the effects of drafts on passengers. Studies to lessen eye strain and improve body posture are also desirable.
INCREASES in horsepower, compression pressure and engine speed, which have occurred in the last five years, have imposed additional duties on the lubrication system, points out the author, who declares that bearing failure is the most serious trouble resulting on the road from the use of oil temperatures exceeding 300 deg. fahr. To reduce this temperature to a figure between 210 and 230 deg. fahr., heat must be dissipated from the oil at a rate in excess of 250 B.t.u. per min. or a heat equivalent of approximately 6 hp. Two types of oil-cooler, one using air and the other water as the cooling medium, are available at present. The former is extensively employed in connection with air-cooled engines, particularly on airplanes, but the latter is in more general use on automobiles.
Any cooling-system is, in reality, a cylinder-temperature control-system. The best operating-temperature depends upon fixed physical characteristics of metals, oils and gases. The advantages of a fixed temperature of 212 deg. fahr. under all operating and weather conditions are: Reduced piston-friction, better vaporization, elimination of crankcase-oil dilution, and prevention of rusting, thereby increasing the life of the engine. A method of determining the cylinder-wall temperatures is described and a comparison of the temperatures for water and for steam-cooling under various operating-conditions shows that, with steam-cooling, the hot-spots are no hotter and the cooler parts of the cylinder have a more nearly uniform higher-temperature. A description of the Rushmore steam cooling-system is given, together with the reason for the design of each part and a method of calculating its size.
This subject is treated in a paper in two parts. Part I, by Alex Taub, deals with laboratory tests to prove by comparative data that the higher average operating-temperatures maintained in the engine by the constant-temperature, or evaporation, system of cooling have negligible detrimental effects. Part II, by L. P. Saunders, gives the results of road-tests of cars operated under the same conditions when fitted with a standard water-cooling radiator-core and with a constant-temperature cross-flow condenser-core. Although contamination of the crankcase oil by heavy ends of the fuel is not prevented by the higher temperature of constant-temperature operation, it is asserted that this higher temperature is effective in striking an acceptable balance in such contamination and results of the tests show that the cylinder-walls are maintained at temperatures sufficiently above the vaporization point of water to reduce the condensation of water vapor to the minimum.
Classes of service already provided by the street-car and the passenger automobile influence the expectations of the motorbus passenger regarding the quality of transportation service afforded by the motorbus. If an operator persuades people to ride in his motorbuses, it will be because they offer safety, economy, convenience and comfort to a greater degree than that offered by competitive transportation media. Since the public has demonstrated that, under favorable conditions, it will patronize the motorbus to an extent that yields a profit to the operators, the future success of this means of transportation lies wholly within the control of the motorbus builders and those who operate it. Of the factors that determine the degree of success attained, motorbus-body design bulks very large. Discussion of the subject is presented from the viewpoint of the passenger, as the motorbus approaches him, as he enters it and as he judges the quality of transportation it affords.
The dimensions of automobile-body seats receive consideration with regard to the features that are conducive to comfort. A diagram is presented upon which the dimensions treated are indicated, and a tabulation of seat dimensions of 12 representative cars is included. Comments are made upon the factors influencing seat dimensions, as well as recommendations regarding the different desirable dimensions. The considerations are inclusive of cushion height, depth and slope, leg-room and head-room, upholstery shape and softness of trimming, foot-rest and other control-element locations, factors influencing entrance and egress provisions, seat widths and advisable front and rear-compartment heights. The author recommends the standardization of a range of locations for the different control elements.
The author enumerates the distinctive features of buses designed for city, for inter-city and for country service and comments upon them, presenting illustrations of these types of bus. Steam and electric motive power are discussed and the chassis components for bus service are considered in some detail. The general types of bus body are treated, together with the influences of climatic conditions and local preferences. Comfort and convenience factors are discussed at some length and the problems of heating, lighting and ventilation are given constructive attention. Fare-collection devices and methods are commented upon, and the State and local legal regulations are referred to in connection with their effect upon bus operation. Illustrations are included and a table showing condensed specifications for city buses is presented.
Two serious problems confront the automotive industry in connection with the present fuel shortage, the securing of a much higher degree of fuel economy with existing equipment and the matter of future designs. These problems are of nearly equal importance. Because its fuel bill constitutes the second greatest item of expense for the Fifth Avenue Coach Co., operating in New York City, it is constantly experimenting with devices of various kinds to improve fuel economy. Of the different devices that it has tested, the thermostatic temperature-control for the carbureter appears to afford greatest possibilities of saving, and the author presents the results of tests of this device in actual service on motor vehicles.
Progress toward a single standard type of car is not being made. Many different styles will continue to be needed to satisfy requirements of taste, ability, power and speed. Open cars, the backbone of production in the early days, are less in demand. Enclosed cars are already to be had in practically every grade. While there is a trend toward lighter weight the demand for increased luxury and greater safety makes it seemingly impossible to reduce weight in either equipment or body. Just what the result of this conflict of ideas is to be is not easy to predict. The author foresees considerable improvement in design and workmanship, a gain in economy of fuel, greater use of oil in lubricating chassis parts besides the engine, increased durability and fewer objectionable noises.