The two cams rotate and raise the piston with a scissor-like action to the bearings. Once at the top of the stroke the air-fuel mixture is fired. This is the power stroke during which the maximum mechanical advantage is reached after the piston has moved approximately 5% of its travel from top dead centre (approx. 10° ATDC), which makes better use of the high cylinder pressures at this point in the cycle. In comparison, a conventional engine reaches its maximum mechanical advantage after the piston has moved approximately 40% of its travel from TDC (approx. 60° ATDC). A side effect of this is a CCE can idle at much lower RPM.