The Merlin is considered one of the most successful aircraft engines of the World War 2. It first entered service in the Fairey Battle in March, 1936 and is most closely associated with the Avro Lancaster, Hawker Hurricane, Supermarine Spitfire, North American P-51D Mustang, and de Havilland Mosquito.
Packard
Merlin 224
This is a Packard built Rolls-Royce Merlin engine manufactured in the U.S. It is based on the Rolls-Royce Merlin 24. Packard built engines were given a "2" prefix so this is a Merlin 224. Over 54,000 Packard Merlins were manufactured.