Crank case scavenging of two-stroke-cycle engines
A 1929 NASA technical report on crank case scavenging in two-stroke engines, compiled from the NASA Technical Reports Server and aimed at engine engineers. The pictures are plain engineering charts: line graphs of scavenging efficiency and pressure against percent and sigma values, with a dense grid of curves and a nomogram-like chart of lambda against x-values. A designer could take from them the restrained look of technical plotting, with dashed and solid curves, labelled axes and numbered families of lines.
