Abstract: An air cleaner assembly (10) is disclosed. The assembly (10) includes a plurality of interconnected wall members (14, 16, 18, 20) which define between them a generally ring-shaped scavenging air chamber (22). A plurality of centrifugal separators (24) are supported in the scavenging air chamber (22). Each centrifugal separator (24) includes a first tubular member (26) which has an inlet end (32) for admitting air and an outlet end (34) which is in fluid communication with the scavenging air chamber (22). Each centrifugal separator (24) also includes a mechanism (30) for swirling air passing through the first tubular member (26) and a second tubular member (28). The second tubular member (28) has an inlet end (36) adjacent the outlet end (34) of the first tubular member (26) and an outlet end (38) exterior of the scavenging air chamber (22).