Abstract: Lead-in of a valve seat member being pressed into a valve body bore has larger angle initial lead-in portion followed by smaller angle transition lead-in portion leading to press-fit outside diameter. This prevents a maximally misaligned valve seat member from shaving a silver as the lead-in passes across the shoulder of a counterbore at the entrance of the press-fit inside diameter of the bore.

Abstract: A saw-tooth shaped groove around the outside of a valve seat cooperates with the wall of a bore into which the valve seat is pressed to capture material displaced from the wall of the bore during the step of pressing the valve seat into the bore.

Abstract: A valve damping piston and a cam follower piston have telescopic sliding fits in opposite ends of a through-bore in the lifter housing. A pressure chamber is cooperatively defined within the housing between the two pistons, and is communicated to the engine oil supply. A lash adjusting piston has a telescopical sliding fit with the exterior axial end of the damping piston, and the two cooperatively define between themselves a lash adjusting chamber. The lash adjusting chamber is communicated to the pressure chamber by an axial segment of the telescopic sliding fit of the damping piston to the housing. The clearance provided by this axial segment creates a flow restriction that results in the pressure in the lash adjusting chamber being appreciably lower, 50% for example, than the pressure in the pressure chamber. The damping piston contains a circumferential groove that is directly communicated to the termination of the axial segment.

Abstract: A system for accomplishing solenoid control of engine valves places a soldnoid valve between an oil gallery and the lost-motion actuator for each valve. Although the basic phasing for the valves is established by a camshaft, the actual phasing is accomplished by causing the valve actuators to execute lost-motion. The amount of lost-motion establishes the actual opening and closing phase angles for the valves. The amount of lost-motion of each actuator is established by the timing of the opening and closing of the corresponding solenoid valve. Oil that is pumped from the actuators can be stored in an accumulator that is connected to the gallery for subsequent use in replenishing the actuators.

Abstract: An especially adapted engine valve includes structure which damps motion of the valve during its final closure to seat. A spool portion of the valve establishes, with its associated guideway, a damping chamber into which oil under pressure may be admitted via a feed passageway. Oil is discharged through a flow-restricted bleed passageway during closure of the valve so as to create beneficial pressure buildup within the damping chamber and thus reduce the valve's closing velocity. Since the damping functions occur passively (i.e. dependent only upon the relative location of the valve within its guideway), gentle closing of the valve can occur at any point on the cam lobe thereby making it especially well suited for use in "lost motion" valve control systems. The valve is preferably sealed against oil leakage by a pair of axially spaced-apart seal members, and a drain port having an end located between the seal members at all times during the valve's displacements between its opened and seated positions.

Abstract: Hydraulic engine valve lifter includes a pair of pistons defining a pressure chamber therebetween and a separate lash adjusting piston which defines a lash adjustment chamber with one of the pistons in the pair. One-way valve structures permit fluid to flow from the pressure chamber into the lash adjustment chamber thereby displacing the lash adjusting piston to, in turn, adjust valve lash. Motion damping functions during a downstroke of the lifter pistons are also provided by a valve damper chamber and fluid passageways between the pressure and damper chambers. Structure is provided which opens communication between the pressure and damper chambers during upstroke of the lifter pistons (thereby precluding motion damping) and then closes communication at a predetermined location during downstroke (thereby providing motion damping).