The High-Speed Diesel Engine as a Competitive Power Generator 280055
HEREIN the author analyzes the Diesel oil-engine as a competitor of the steam engine and, more specifically, of the gasoline engine, in the stationary-power field and in the field of marine and land transportation.
The two bases for judging the new as against the old are, first, suitability for the purpose, and, second, the cost of performing the required service. After reviewing other fields in which the oil-engine has shown its suitability, the author considers its suitability for automotive purposes. If it is equally suitable with the gasoline engine for motor-vehicles, that type of engine which shows lower cost for power will ultimately prevail; or, if the Diesel-engine cost is sufficiently lower, this type may be adopted for certain automotive uses even though it is somewhat inferior to the gasoline engine in suitability.
The prospects of useful economic results from the automotive Diesel engine are so favorable, in the author's opinion, that almost any effort to perfect it and adapt it to the needs would be justified now. The most important reason for this conclusion is the adaptability of the engine to a great variety of liquid fuels.
No reason exists for believing there will be any substantial difference in manufacturing cost if the Diesel engine is built by the same methods and in the same quantities as the gasoline engine; hence, first cost will be in proportion to weight in pounds per horsepower. Fixed charges will be in proportion for equal life and use. Experience to date indicates that the life of the Diesel engine should be equal to or longer than that of the gasoline engine, and that service costs need be no greater.
In the matter of fuel consumption the oil-engine seems to be the more efficient, about in the ratio of 4 to 5; and this, with a cheaper fuel, means a large reduction in fuel expense per ton-mile.
Development and adoption of the oil engine have been impeded by doubt of the ability to reduce its weight sufficiently, but, after analyzing the variables that fix the weight per horsepower, the author shows that an added weight of 30 per cent, to resist the maximum cylinder pressure for its somewhat longer period, is all the weight by which this type needs to exceed that of the gasoline engine. He even intimates that it is not beyond possibility that equality of weight may be obtained in four-cycle engines and perhaps better in the two-cycle type.
Requirements as to torque, balance, flexibility and such matters are being proved by experience to be attainable, which confirms the analytical conclusion that these are only matters of engineering ingenuity and design.
There remains the difficulty of metering the fuel and properly mixing it with the necessary quantity of air for proper combustion in high-speed engines. Several solutions of this problem have been advanced and there will be others. Hence it is to be expected that there will ultimately be as many automotive Diesel engines in use as there are now successful gasoline engines.