Short-Stroke Engine

an internal combustion engine whose stroke-bore ratio is less than one. The theory of the short-stroke engine was developed by the Soviet scientist N. R. Briling. The stroke-bore ratio determines the overall dimensions and weight of the engine. The use of the short-stroke engine makes it possible to increase the speed of rotation without increasing the mean piston velocity, that is, without reducing mechanical efficiency; lengthen the service life of the piston assembly for moderate mean piston velocities; increase the coefficient of admission because of larger clear opening of valves; and reduce heat losses because of the decrease in the ratio of the cylinder face to the volume. Short-stroke engines have come into wide use.