Search Results

TENDENCY to detonate is probably the most important factor in determining the usefulness of fuels for internal-combustion engines. Although it is possible, by various means, to measure more or less accurately the relative knocking-characteristics of fuels, no way has heretofore been found of rating fuels that does not depend upon some arbitrary non-reproducible conditions and measurements. The general methods adopted have consisted in comparing one fuel with another, but no absolute standard has been available. Knocking is a function of several variables, the knocking characteristics of which have been found by keeping a certain number of them constant while certain others are varied, thus rating them in terms of load, the spark-advance necessary to produce knocking, the position of the throttle at which knocking begins, and the like.