Use of ‘Free’ Scavenge Air in the Development of Two-Stroke Loop-Scavenged Engines for Turbocharging

Abstract

A brief historical description of the special characteristics of Crossley two-stroke c.i. engines is employed to justify the use of an independently driven and controlled source of compressed scavenge air in an extensive series of engine tests, from the analysis of which novel techniques were evolved for assessing: (1) scavenge air pressure drop and flow, using static engine flow tests; (2) i.h.p. from brake test results; (3) b.h.p. using a special turbocharger performance factor chart. These techniques may well be of use on other types of engine.