Abstract
This review of Diesel engine development is based on the work carried out at the Diesel Research Laboratory of Caterpillar Tractor Co. under the sponsorship of the author as Director of Research.
For many years intensive effort has been made to understand the combustion process in this type of engine by a better knowledge of the fundamentals of ignition and the mechanism of the combustion process, and this study has been developed in the laboratory on a competitive basis. Originally six combustion systems were put to trial and a modified precombustion-chamber engine won the palm of victory on the basis of its ability to maintain uniformity over extended periods of operation.
Briefly, the character of the comparative combustion studies followed two general classifications: (1) visual combustion studies; (2) study of combustion-chamber deposits.
In order to make extended studies of the combustion phenomena by visual means, a quartz window was designed to achieve maximum cleanliness without the distraction of soot condensation on the cold windows.
The author describes the precombustion-chamber process, and deals with the composition of combustion gases, flame duration, temperature distribution, the mechanism of ignition, and combustion-chamber deposits. He also discusses the development of fuel-injection equipment, pretiming, precalibrating, and the evolution of the fuel pump; he describes the characteristics of several types of check valve and fuel valve, and the fuel-pump control of engine torque characteristics. Spray characteristics and the flow through the fuel-valve orifice are also examined. Comments are made upon materials for cylinder liners and piston rings, and the effect of fuel inclusions on cylinder wear; lubrication is also considered.
It is believed that excellent performance has been achieved in the precombustion-chamber engine with a minimum of complication in the fuel-injection equipment, and that the development of this principle of combustion has not yet reached its limit of progress.
Get full access to this article
View all access options for this article.