The Allied forces used V12 engines with an "upright" design, while many German engines (aside from the BMW VI, which was designed prior to World War II), used an inverted engine design, which had a lower centre of gravity and improved pilot visibility for single-engined designs. The only American-design inverted V12 engine of any type to see even limited service in World War II was the air-cooled Ranger V-770, which was used in aircraft that were only used for training purposes within the United States, such as the Fairchild AT-21 Gunner.
the allied forces used v12 engines with an "upright" design while many german engines (aside from the bmw vi which was designed prior to world war ii) used an inverted engine design which had a lower centre of gravity and improved pilot visibility for single-engined designs the only american-design inverted v12 engine of any type to see even limited service in world war ii was the air-cooled ranger v-770 which was used in aircraft that were only used for training purposes within the united states such as the fairchild at-21 gunner