Bizzarrini P538 drivers Edgar Berney and Andre Wicky, but records indicate both retired after three hours with a cooling problem. A second team in a production-based Bizzarrini A3/C, driven by Sam Posey and Massimo Natili, was disqualified after a pit lane violation, possibly while returning with serious frame damage. American Ferrari driver Mike Gammino then commissioned a Lamborghini 4.0-liter V12 powered car, which he raced once. Bizzarrini attempted to build a second, 3.5-litre V12 car for Le Mans, but was unable to complete it before bankruptcy. Beginning in the mid-1970s and continuing at least through the 1990s, former Bizzarrini engineer Salvatore Diomante
V12 engine the advantages of lower centers of gravity and improved pilot visibility for single-engined designs. Only the pre-war origin BMW VI V12 of Germany was an "upright" engine. The United States had the experimental Continental IV-1430 inverted V12 engine under development, with a higher power-to-weight ratio than any of the initial versions of the German WW II inverted V12s, but was never developed to production status, with only 23 examples of the Continental inverted V12 ever being built. 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,