Knock Values of Aviation Fuels

THE paper is an effort to provide a common basis for determining the relative knock-values of various aviation fuels. With this object in mind the author presents a chart showing data based on laboratory and flight tests of aviation engines with various fuels.

The author points out that, generally speaking, the better the knock rating the lower the cylinder temperature. Until more experimental evidence has been obtained, he considers that vapor pressure is of secondary importance in its relation to vapor lock.