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Valve ticking noises within a cam actuated valve train can arise mysteriously. One valve train may produce valve ticking noises, while a second, geometrically similar valve train may perform more quietly. To better understand this phenomena, we examine in detail the prototypical motion of a valve driven by a rocker arm with cylindrical rocker pad. General features of a valve's motion through its guide, induced by a rocker arm with a cylindrical pad, are derived. From these general features of valve motion, guide contact points during lift events can be inferred, and as a result, detailed forces and moments acting on the valve may be derived. From this derivation of forces acting on the valve, a metric for assessing the propensity of a valve train to tick as a result of the valve stem impacting its guide is proposed. The proposed metric indicates how the likelihood of valve tick noise can be reduced through judicious choices for valve train geometries, clearances and surface finishes.

This paper presents a process for the selection of spring rate and pre-load for an adaptively controlled pivoting vane oil pump. The pivoting vane pump has two modes: high and low speed. A spring within the pump is installed to induce a torque that causes an adaptive displacement mechanism within the pump to move toward maximum oil chamber size. In low speed mode, two feedback regions are pressurized that produce torques that counter the spring generated torque. Together, both regions being pressurized by main oil gallery pressure tend to reduce pump displacement more at lower speeds than if only a single chamber is pressurized. At higher speeds, a solenoid switch turns off pressure to one of the feedback pressure chambers, thereby reducing feedback torque that counters spring torque. This enables higher pressure calibrations in this speed mode. In this paper, we identify a process for choosing the spring rate and pre-load that calibrates the adaptive displacement mechanism.