Knock Rating of Motor Fuels

EXPERIMENTS carried out in 1930 by the Knock Rating of Motor Fuels Subcommittee of the Institution of Petroleum Technologists are described in the paper which, in reality, is a continuation of one presented at the 1930 Annual Meeting of the Society. Various fuels, both straight run and blended, were tested in the Ricardo 2-liter E-35, the Delco and the Armstrong engines under three different sets of conditions and were rated in terms of blends of a high-value and a low-value straight-run gasoline, benzene and heptane and iso-octane and heptane. The last method gave a greater degree of fluctuation in knock intensity than the benzene-heptane blend, and in the future all knock ratings will be expressed in terms of the octane number, which is in agreement with knock-rating practice in the United States.