Let us know what radial engines you know about , flying on the DC-3/C-47
Gravity always wins!
Here is some information I have found mostly on Wikipedia, I am sure there were other engine types used, if you know let us know.
A variety of engines were fitted to the DC-3 throughout the course of its development. The original civilian aircraft used Wright R-1820 Cyclone 9s, but later aircraft (and the majority of military ships) used the Pratt & Whitney R-1830 Twin Wasp radial which offered better high-altitude and single engine performance. A few Pratt & Whitney R-2000 radials saw use.
The R-1820 Cyclone 9 represented a further development of the Wright P-2 engine dating back to 1925. Featuring a greater displacement and a host of improvements, the R-1820 entered production in 1931. The engine remained in production well into the 1950s. The R-1820 was built under license by Lycoming, Pratt & Whitney Canada and also, during World War II, by the Studebaker Corporation. The Soviet Union had purchased a license for the design, and the Shvetsov OKB was formed to produce the engine as the M-25.
The R-1820 was at the heart of many famous aircraft including the early Douglas airliners (prototype DC-1, the DC-2, earliest civilian versions of the DC-3, and the limited-production DC-5), B-17 Flying Fortress and SBD Dauntless bombers, the early versions of the Polikarpov I-16 fighter (as M-25), and the Piasecki H-21 helicopter.