The cam-within-a-cam consists of a solid intake camshaft within a hollow exhaust camshaft. The solid shaft has holes for cylindrical pins, located at five points that align with axial slots in the hollow outer shaft.
Camshaft-within-a-camshaft design (Mahle's CamInCam)
Assembled steel articulating camshaft to allow controlled phasing of the exhaust valve event.
With conventional wastegated turbochargers or fixed geometry turbochargers (FGT), a turbine flow area cannot be adjusted during operation.
Knocking is abnormal combustion in which the air-fuel mixture ignites prematurely due to exposure to high temperature and pressure, creating an unwanted high-frequency noise. When the compression ratio is increased, the temperature at compression top dead center (TDC) also rises, increasing the probability of knocking.