The work presented here seeks to compare different means of providing uniflow scavenging for a 2-stroke engine suitable to power a US light-duty truck. The three different configurations which could utilize this type of scavenging system that were investigated are (1) the opposed-piston engine, which has been applied to aircraft propulsion as well as engines for power generation and rail traction, (2) the poppet-valve uniflow configuration, as exemplified by the Detroit Diesel 2-stroke engine, and (3) the sleeve-valve uniflow engine, the unusual arrangement of which was used in the Rolls-Royce Crecy, intended for high-speed interceptor aircraft application. All of these concepts were compared in terms of indicated fuel consumption for the same cylinder swept volume, and a new methodology for optimization was developed using a one-dimensional engine simulation package which also took into account charging system work.
As a result of this work it was found that the opposed-piston configuration provides the best attributes since it allows maximum expansion and minimum heat transfer. It was found that existing experiential guidelines for port angle-area specification for loop-scavenged, piston ported engines using crankcase compression could also be applied to all of the other scavenging types. This has not been demonstrated before.