The 1919 Curtiss C-12 was a redesigned K-12. A six-cylinder water cooled engine, it produced 427hp@2250rpm and weighed 705 lb.
The CD-12 was a C-12 with direct-drive prop, producing 325hp@1800rpm with a dry weight of 680 lb.
The Curtiss triplane specifically designed around the Curtiss C-12 engine captured both a world altitude record for a non-supercharged plane and a world speed record (piloted by Roland Rohlfs).
All Aero 