Quincy David Epperly (March 3, 1913 – January 7, 2001) was an American race car builder.
After completing a correspondence course in "Theory of Aircraft Construction", Epperly moved to Southern California in 1940 to work for Lockheed and Pacific Airmotive.
During the mid-1950s Epperly opened his own shop in Lawndale, California, and in 1957 he assisted chassis designer George Salih in the construction of a radical approach in racing car design which placed a four-cylinder Offenhauser engine on its side, rather than in the upright position, as was the usual custom for the Indianapolis roadsters of that era.
[2] Epperly also built the body for the first Spirit of America land speed racer,[citation needed] out of his shop in Gardena, California.
It later traveled to the Festival of Speed at Goodwood in 1993, to Australia in 1995 for the CART Surfer's Paradise race, to Michigan International Raceway in 1996 for the U.S. 500 (where demonstration laps at around 140 mph were made), and to the California Speedway in 1997 for the Marlboro 500.