NAMBA October 2020 Web.pub

PROPWASH October 2020 7 The problem with most model engines is that the shape of the transfer passages leading into these ports is ignored. Extensive testing by Gordon Blair identified better transfer designs. The engines all had 4 transfer ports with one boost port. He varied the transfer passage design and measured the engine power. The cylinder 12 shape, used by most model engines was the worst. The cylinder 14 design was the best. Without that style of passage, it is impossible to accurately direct the flow streams. MB 40 Transfers & Exhaust One modern model engine design is the MB 40 pylon engine. Pictures of its porting and passages are below. MB 40 Section through Boost & Exhaust MB 40 Port Layout (Continued on page 8)