A two-stroke cycle rotary internal combustion engine of the Wankel type is disclosed. The engine provides a flow through intake and exhaust with intake ports on one side wall of an epitrochoidal housing and exhaust ports on the opposite side wall. Compressed air is ducted to an intake plenum which provides a source of intake air as well as bypass air which is routed around the engine for engine cooling. A particular intake and exhaust manifolding and port positioning provides centrifugal pumping for charging and scavenging. Both rotating and stationary housing engines are disclosed and a rotating housing engine having fuel charge stratification and centrifugal filtering of inlet air is also disclosed.