ABNORMAL COMBUSTION EFFECTS ON ECONOMY.

Abstract

The fact that the efficiency of the spark ignition (SI) engine depends on the usable value of compression ratio is well known. Typical gains to be obtained in high-compression engines are shown for representative cool-running modern units of overhead-valve design. Gains in power output are also obtained and with low-cost fuel this was a potent incentive for raising compression ratio, but with the energy crisis this has changed.