Mitsubishi Camshaft: 4B11 EVO X - Mechanical Kelford Cams, world leader in camshaft design and manufacture for high performance Japanese engine makes is set to release their new 4B11 camshafts. Utilising ultramodern design principles, casting techniques and state of the art CNC grinding, these camshafts will again lead the way in EVO engine development. 278/272 Duration, 11.50mm/11.00mm Lift. Stage 3 racing camshafts to suit high horsepower engine builds. Suits up to 32lb boost and 9000 RPM with Kelford valve spring.