REPETITION of the 1923 and 1924 Cooperative Fuel Research Steering Committee's motor-car tests, using modern cars and gasolines ranging in end points from 312 to 432 deg. fahr., provided the data on which this paper is based.
Supplementary runs were made also on a variable-compression engine to learn the optimum performances of these gasolines if an engine were designed around them. The experimental work covered is divided into three groups.
Experiments conducted under Group 3 are particularly interesting because the single-cylinder C.F.R. engine used made operation possible with optimum compression ratios and mixture temperatures, which result in maximum thermal and volumetric efficiencies, respectively. This group comprised four major steps, and data for each one are presented.
Design of engines must follow the gasoline which the oil companies find they can market most economically, Mr. MacCoull thinks.