reverse-flow scavenging

Definition

Cars & Driving

  • noun a scavenging system for two-stroke engines in which a cylinder has two pairs of transfer ports, at the front and rear respectively, with two exhaust ports located on either side of the two pairs of transfer ports; the incoming streams of mixture spread out like a fan, are deflected downward and expel the spent gases
http://www.dictionarycentral.com/definition/reverse-flow-scavenging.html