GB338872A - Improvements in the exhaust and scavenging arrangements of internal combustion engines - Google Patents

Abstract

338,872. Kjaer, V. A. Aug. 26, 1929. Drawings to Specification. Four-stroke-cycle engines; cylinders, pipes for. -In multi-cylinder engines which are scavenged by air from a blower during the last parts of the exhaust periods, the cylinders are connected in groups to exhaust manifolds so that the high pressure exhaust period in any one cylinder will not cause such a back pressure in another cylinder as to hinder the scavenging action therein. In an eight cylinder engine two exhaust manifolds are used; the cranks are at 90‹ and the cylinders I, IV, V and VIII are connected to one manifold and the remaining cylinders to another. The exhaust periods of cylinders I and IV are 90‹ apart and a similar time interval exists between V and VIII; the two pairs are separated by an interval of 270‹. The exhaust period in any one cylinder extends over a period of crank movement of 255‹, the high pressure position being about 35‹ on each side of bottom dead centre. The scavenging period extends over a portion of the intake stroke. As a consequence of the described connections the high pressure exhaust period in any one of the four cylinders connected to one manifold is over before scavenging commences in any other cylinder of the group. In a seven cylinder engine two groups of three cylinders exhaust to two manifolds the remaining cylinder having a separate exhaust pipe.