ZIESENHEIM, F., "DEVELOPING A HIGH-COMPRESSION AUTOMOTIVE ENGINE," SAE Technical Paper 210049, 1921, doi:10.4271/210049.
The paper is divided into three parts; the fuel problem, the selection of the most economical internal-combustion engine for adaptation to automotive purposes and the details of the development work undertaken.After stating the fuel problem, inclusive of production, volatility and price charts, the methods of increasing the engine-fuel supply, the characteristics of present engine fuels and general considerations regarding the selection and adaptation of the most economical engine are discussed. Classifying internal-combustion engines as being of low, medium or high compression, the essential factors, advantages and disadvantages of each class are commented upon in detail.High-compression engines are classified, as to their method of injecting the fuel into the combustion-chamber, into the three general classes of air, gas-pressure and mechanical injection. These are described and analyzed at length, numerous charts and diagrams being included, and a lengthy summary of all the essential factors thus far considered follows.The development work on mechanical injection that was done in the laboratory of the Carnegie Institute of Technology, Pittsburgh, is illustrated and described in detail. The two methods, variable-pressure and constant-pressure, are discussed separately at length.