Taking French and British advice, the designers targeted 400 hp as a combat requirement. Designed as a V-12, it could also be built as 4 or 6 in-line, or V-8. Design began on May 30, 1917 with the first test of a V-8 version on July 3, 1917! The Liberty powered the Curtiss NC-4 on the first trans-Atlantic flight and around the world in Douglas World Cruisers.
Specifications: Model L-12; water-cooled V-12; bore 5 in., stroke 7 in., displacement, 1649 cu. in., 400 hp at 1800 rpm., weight 786
Accession no. 1992G47