The Wright R-3350 was a critical development for the success of the Boeing B-29, its major airframe application. Early versions of the R-3350 encountered lubrication and cooling problems, and a fuel-air mixture problem that led to some backfires and destructive engine fires. Engineers later solved the problem by replacing the carburetors with a fuel-injection system.
Twin turbo-superchargers were installed in each engine to compress the thin air at high altitudes. The long nose case of the engine contained a gear reduction drive, which permitted the propeller to turn at slower speeds than the engine, producing greater efficiency.
A total of 6,958 Wright Cyclone R-3350-57 engines were built between January 1944 and November 1945, and powered the Boeing B-29/A/B, XB-29E, RB-29/A, TB-29/A/B, TRB-29A, C-97, YC-97, Lockheed C-121A, VC-121B, and Consolidated Vultee B-32. Other models of the R-3350 powered the Martin PB2M Mars flying boat, and continued to serve commercial aviation long after the war.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.