Both of the co-founders were former employees of Lotus Engineering Ltd., and Cosworth initially maintained a strong relationship with Colin Chapman; and initial revenues of the company came almost exclusively from Lotus. When the company was founded in 1958, Duckworth left Lotus, leaving Costin (who had signed a term-employment contract with Chapman) at the company. Until 1962, Costin worked on Cosworth projects in his private time, while being active as a key Lotus engineer on the development of Lotus 15 through 26 (Elan), as well as leading the Team Lotus contingent at foreign races, as evidenced by the 1962 Le Mans Lotus scandal.