Cosworth founders Keith Duckworth and Mike Costin were both former employees of Lotus. Their new company developed the Twin Cam for competition use under Cosworth Project Code TA, with specific versions designated with an 'Mk.' prefix. One of the initial batch became the experimental Cosworth Mk.X in 1962. This was followed in 1963 by the dry-sump Mk.XII with racing camshafts designated the 'CPL2' (26/66/66/26) and high compression Cosworth pistons, used actively by Team Lotus in Lotus 20B, 22, 23 and 23B.