Abstract: A valve actuation system is disclosed for an internal combustion engine. The system may have a gas exchange valve, a rocker arm pivotally connected to a shaft, a pushrod, a lash adjuster disposed in the pushrod. The system may also have an adjusting screw disposed in the rocker arm and configured to engage and fluidly supply the lash adjuster. The adjusting screw may include a shaft having a threaded outer annular surface, and a head connected to the shaft and having a rounded outer surface and a flat end face. The adjusting screw may also include an axial passage passing through the flat end face, a radial passage formed in the shaft and extending from the threaded bore of the rocker arm to the axial passage, and at least one radial groove formed in the rounded outer surface of the head and passing through the axial passage.

Abstract: An intake valve actuation (IVA) system for a dual fuel engine is disclosed. The IVA system is retrofittable between the dual fuel engine and a diesel fuel engine and includes a cam lobe with a cam-profile, a rocker arm, and an IVA piston. The rocker arm has a pad surface, which includes a plane that passes through a central axis of a rocker shaft. The rocker arm is operably connected with the cam lobe and intake valves. A rotational movement of the cam lobe corresponds to switch between the open and closed positions of intake valves. The IVA piston has a face portion, which selectively abuts against the pad surface, to temporarily lock the intake valves in open position. The IVA system defines a hand-off when the face portion abuts against the pad surface. The cam-profile facilitates constant velocity of the intake valves at the hand-off.

Abstract: An intake valve actuation (IVA) system for a dual fuel engine is disclosed. The IVA system is retrofittable between the dual fuel engine and a diesel fuel engine and includes a cam lobe with a cam-profile, a rocker arm, and an IVA piston. The rocker arm has a pad surface, which includes a plane that passes through a central axis of a rocker shaft. The rocker arm is operably connected with the cam lobe and intake valves. A rotational movement of the cam lobe corresponds to switch between the open and closed positions of intake valves. The IVA piston has a face portion, which selectively abuts against the pad surface, to temporarily lock the intake valves in open position. The IVA system defines a hand-off when the face portion abuts against the pad surface. The cam-profile facilitates constant velocity of the intake valves at the hand-off.