Boeing B-29 Superfortress

Number 1 engine on the Boeing B-29 Superfortress "Sentimental Journey".
A veteran of World War II it flew 26 bombing missions with the 330th Bomb Group in the South Pacific.
Each of the four engines is an 18 cylinder Wright R-3350 Duplex Cyclone radial. Prop is about 14 feet in diameter.
On display at the Pima Air & Space Museum in Tucson, Arizona.