U.S. Centennial of Flight Commission home page
Curtiss V2-3 engine

In 1916 and 1917, Curtiss produced R-3 and R-4 airplanes that were powered by the Curtiss V2-3 engine. Because this engine was heavy for the amount of horsepower it produced, it was replaced during World War I by the Liberty engine.

Credits - U.S. Air Force Museum