Harry Mundy designed the Lotus TwinCam engine for Colin Chapman, who needed the replacement for the Coventry Climax FWE engine used in Lotus Elite. As Keith Duckworth and Mike Costin, the co-founders of Cosworth, used to be Lotus Development Ltd employees, the initial racing adaptation of Lotus TwinCam was carried out by Cosworth, and the Kent block Cosworth SCA was designed using the basic SOHC reverse-flow cylinder head configuration of the FWE. Due to Mundy being also the co-designer of the FWE, the Kent block Lotus TwinCam initially used the cam profile of the FWE, and shared the same valve clearance adjustment shims with Coventry Climax FWA, FWB, and FWE in production.