Combustion and Design Problems of Light High-Speed Diesel Engines

MORE attention must be paid to light-weight design and to flexible combustion control if the Diesel engine is to become a serious competitor of the gasoline engine. The relative merits of existing types of combustion-chamber and injection systems used in present commercial four-cycle engines are discussed, and it is shown that the single-turbulence-chamber type offers the most promising means to high mean effective pressures at low fuel consumption. Stock high-pressure fuel-pumps and injection-valves, produced in volume by specialists, will have a great influence on the production of high-speed Diesel engines. The interrelation of combustion and injection processes in controlled-turbulence combustion-chambers is explained, and design details and test results are given of the practical application of single-chamber principles and of a stock injection system to flexible combustion control in a recently developed high-speed four-cycle engine.

Factors limiting mean effective pressure and piston speeds are discussed, as are also the mechanical problems of design, cooling and lubrication of vital parts. In comparing Diesel-engine with gasoline-engine weights, due allowance is made for the difference in maximum gas pressures.

The illustrations show examples of various combustion-chamber designs and design details and photographs of DeLaVergne high-speed engines.