Abstract: A piston for an internal combustion engine includes a compound piston body having a crown piece joined to a skirt piece by a circumferential weld. The skirt piece is formed of a lower temperature-capable steel such as a low alloy steel, and the crown piece is formed of a higher temperature-capable steel having a martensitic microstructure and containing about 10% wt. or greater of chromium. Related methodology for making a piston is also disclosed.

Abstract: A valve actuation system is disclosed for use with an internal combustion engine. The valve actuation system may have a rocker shaft, a rocker arm pivotally mounted on the rocker shaft, at least one cam follower and a pushrod connecting the at least one cam follower to the rocker arm. The valve actuation system may also have a plurality of gas exchange valves, and a bridge connecting the rocker arm to the valves. The valve actuation system may further have at least one spring disposed around each of the valves and configured to bias each of the valves toward closed positions, and a rotocoil configured to rotatably connect the at least one spring to each of the valves. The rotocoil may have an internal chamfer at a bridge end with an angle of about 26-28°. The at least one spring may have an assembled load of about 750-850 N.

Abstract: A piston for an internal combustion engine includes a compound piston body having a crown piece joined to a skirt piece by a circumferential weld. The skirt piece is formed of a lower temperature-capable steel such as a low alloy steel, and the crown piece is formed of a higher temperature-capable steel having a martensitic microstructure and containing about 10% wt. or greater of chromium. Related methodology for making a piston is also disclosed.

Abstract: A rocker base is disclosed for use with a valve actuation system. The rocker base may have a housing with a top, a bottom, side walls connecting the top to the bottom, and end walls disposed between the side walls. The rocker base may also have rocker arm supports located inside the housing and integrally formed with the side walls, and an injector spring pad extending from one of the end walls toward a center of the housing. The rocker base may further have a rib connecting the injector spring pad to one of the rocker arm supports.

Abstract: A washer member disposed in a valve housing of an engine is disclosed. The washer member resiliently supports an injector push member via an elastic member and receives a pair of hydraulic lash adjusters for operating an inlet valve and an outlet valve of a cylinder of the engine. The washer member includes a base portion adapted to abut a support member disposed within the valve housing. The support member defines a clearance with the valve housing to movably dispose the pair of hydraulic lash adjusters within the valve housing. The washer member further includes a side portion extending from the base portion. The side portion is configured to define a lateral movement of the elastic member within a tolerance limit. The side portion is further configured to define a rotational movement of the washer member within a tolerance limit.

Abstract: A valve actuation system is disclosed for use with an internal combustion engine. The valve actuation system may have a rocker shaft, a rocker arm pivotally mounted on the rocker shaft, at least one cam follower and a pushrod connecting the at least one cam follower to the rocker arm. The valve actuation system may also have a plurality of gas exchange valves, and a bridge connecting the rocker arm to the valves. The valve actuation system may further have at least one spring disposed around each of the valves and configured to bias each of the valves toward closed positions, and a rotocoil configured to rotatably connect the at least one spring to each of the valves. The rotocoil may have an internal chamfer at a bridge end with an angle of about 26-28°. The at least one spring may have an assembled load of about 750-850 N.

Abstract: A rocker base is disclosed for use with a valve actuation system. The rocker base may have a housing with a top, a bottom, side walls connecting the top to the bottom, and end walls disposed between the side walls. The rocker base may also have rocker arm supports located inside the housing and integrally formed with the side walls, and an injector spring pad extending from one of the end walls toward a center of the housing. The rocker base may further have a rib connecting the injector spring pad to one of the rocker arm supports.

Abstract: A washer member disposed in a valve housing of an engine is disclosed. The washer member resiliently supports an injector push member via an elastic member and receives a pair of hydraulic lash adjusters for operating an inlet valve and an outlet valve of a cylinder of the engine. The washer member includes a base portion adapted to abut a support member disposed within the valve housing. The support member defines a clearance with the valve housing to movably dispose the pair of hydraulic lash adjusters within the valve housing. The washer member further includes a side portion extending from the base portion. The side portion is configured to define a lateral movement of the elastic member within a tolerance limit. The side portion is further configured to define a rotational movement of the washer member within a tolerance limit.

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: A single-piece piston body for an internal combustion engine includes a crown portion having a circumferential ring belt including an oil ring groove configured to accommodate an oil control ring and a skirt portion having a first skirt wall disposed on the major thrust side and a second skirt wall disposed on the minor thrust side of the piston, and two box walls that connect the skirt walls and which are set back with respect to the ring belt. A first plurality and a second plurality of axial drain passages extend from the oil ring groove to the bottom of the crown portion, the first and second pluralities of axial drain passages being substantially centered at opposite box sides of the piston and each plurality of axial drain passages spanning an arcuate portion of about 45-75 degrees.

Abstract: A single-piece piston body for an internal combustion engine includes a crown portion having a circumferential ring belt including an oil ring groove configured to accommodate an oil control ring and a skirt portion having a first skirt wall disposed on the major thrust side and a second skirt wall disposed on the minor thrust side of the piston, and two box walls that connect the skirt walls and which are set back with respect to the ring belt. A first plurality and a second plurality of axial drain passages extend from the oil ring groove to the bottom of the crown portion, the first and second pluralities of axial drain passages being substantially centered at opposite box sides of the piston and each plurality of axial drain passages spanning an arcuate portion of about 45-75 degrees.