This R-1830-92 Twin Wasp Pratt&Whitney
engine was essentially two nine-cylinder
radial engines packed together. It was
produced from 1932 to 1951, the 173,618
engines made were the largest production of
a single type of aviation engine ever. They
powered the B-24, C-47, DC-3, and many other
aircraft. (This example is a work of art!)