Aston Martin DB3
The Aston Martin DB3 and later DB3S were racing cars built in the 1950s. Although they used some DB2 parts, they were quite different, being designed especially for racing. The original modifications were done by ex-Auto Union engineer, Eberan von Eberhorst, though others handled the later DB3S work.
The DB3 was introduced in 1951 with a 133 hp (99 kW) 2.6 L Lagonda straight-6 engine from the DB2 Vantage. The car was unsuccessful, so a larger 2.9 L engine, producing 163 hp (122 kW), was introduced in June 1952.
Source: Wikipedia, 2011