Research in Exhaust Manifolds

Over a period of four years, with the aid of the Office of Naval Research, the author has investigated the effect of the exhaust manifold on engine performance, particularly in two-stroke-cycle multicylinder engines. Some aspirator-type manifolds create suction rather than back pressure and result in scavenging-air flows that are greater than obtainable not only with conventional manifolds but even with no manifolds at all.