The Pratt & Whitney R-1830 Twin Wasp is an American air-cooled radial aircraft engine.

It was selected as the power plant for both the four-engined Consolidated B-24 Liberator heavy bomber and the twin-engined Douglas DC-3 transport, two of the most-produced aircraft.

The production run of 173,618 R-1830 examples[1] makes it the most-produced aviation engine in history.

Mostly retired today, the R-1830 is still used on Douglas DC-3 and various museum aircraft and warbirds seen at airshows.

It is not manufactured anymore, but spares are still available and there is still a market for second-hand engines and parts.