Abstract: An internal combustion engine including a belt tension adjusting device and a belt tensioner damping arrangement.

Abstract: A valve operating device for an internal combustion engine in which a selective coupling mechanism is operable to control the lift and opening interval of the valve includes a hydraulically operated phase adjusting mechanism disposed between the timing wheel and the camshaft to effect relative angular movement therebetween for timing control of valve operation.

Abstract: A variable valve-timing device for an intake or exhaust valve in a cylinder head of an internal combustion engine operated directly from a camshaft includes a low speed rocker arm mounted on a low speed rocker arm shaft and a high speed rocker arm mounted on a high speed rocker arm shaft. The low speed rocker arm and the high speed rocker arm are interconnected by a pin. A low speed cam is provided on the camshaft corresponding with the low speed rocker arm. A high speed cam is provided on the camshaft corresponding with the high speed rocker arm. The low speed rocker arm shaft and the high speed rocker arm shaft have a common fluted shaft. An outer circular hollow shaft is provided on the common fluted shaft and the low speed rocker arm is mounted on the outer circular hollow shaft.

Abstract: A hydraulic tappet for an internal combustion engine has a collar located axially on a valve stem, the outer periphery of the collar slidably engaging a cylindrical bore which is coaxial with the valve stem. A cap having a central tubular formation which slidingly engages over the end of the valve stem and an outer periphery which engages the cylindrical bore, is separated axially of the collar, to define a first chamber between the cap and collar and a second chamber between the cap and the end of valve stem. An inlet for hydraulic fluid is provided to the first chamber and the first and second chambers one interconnected by a non-return valve which prevents flow from the second chamber. A controlled leakage path is provided from the second chamber and a spring biases the cap into engagement with a cam formation.

Abstract: An intake- and/or exhaust-valve timing control system for internal combustion engines in which a ring gear mechanism is provided between a timing pulley and a cam shaft for adjusting the phase angle between the pulley and the cam shaft. A drive mechanism is also provided for driving the ring gear mechanism depending upon the operating state of the engine. The drive mechanism includes a hydraulic circuit having oil supply and exhaust passages, a flow control valve having a spool valve for controlling the amount of working fluid flowing through the hydraulic circuit, a controller for monitoring the operating state of the engine, and an electromagnetic actuator having a plunger rod for actuating the flow control valve in response to the control signal from the controller. The flow control valve and the actuator are integrally mounted in the cylinder head. Therefore, relative friction between the facing ends of the spool valve and the plunger rod is avoided.

Abstract: A rocker arm is formed from a unitary sheet metal material with a unitary journal and pad with selective welds to provide rigidity.

Abstract: A hydraulic valve lifter for use in an internal combustion engine, comprises an inverted cup-like body, an inverted cup-like plunger housed within the body, a high pressure chamber defined between the body and the plunger, and an oil passage through which an oil is fed to the high pressure chamber. At least one oil discharge hole is defined in the plunger and extends from the oil passage to open to a valve stem so as to lubricate between the valve stem and a valve guide.

Abstract: An extended circumference intake poppet valve system for use with a single charge carrying intake duct/port to an engine cylinder in a four cycle internal combustion engine to include three or more annular intake poppet valves (secondary valves), annular valve seats (mini ports), disposed within a primary valve head which spans said single duct/port (valve system), said valve system in fluid communication with said duct and said cylinder for opening and sealing said duct/port at said duct seat, intake valve lifting and closing means, wherein the area of the duct/port, and the matched area of the open valves are substantially equal for an extended optimum charge flow period, and in addition, valve open areas at all valve lift points during the inlet event that occur, initially and throughout extended duration through closure, are enlarged when compared with a single poppet valve servicing the same duct/port, resulting in greatly enhanced charge volume into the cylinder during the intake event.

Abstract: In a valve operating system for an internal combustion engine that includes a valve operation mode changing mechanism capable of changing at least one of either the lift amount of opening of an engine valve openably and closably carried in an engine body or the opening or closing timing in accordance with a variation in hydraulic pressure supplied to the changing mechanism. A selector valve is provided and includes a valve element slidably received in a housing attached to the engine body to change the supply of hydraulic pressure to the valve operation mode changing mechanism. The housing of the selector valve is provided with a working oil chamber which receives an oil pressure for driving, toward a position to supply a higher hydraulic pressure to the valve operation mode changing mechanism, a valve element biased toward a position to supply a lower hydraulic pressure to the valve operation mode changing mechanism.

Abstract: An electronically controllable pneumatically powered valve actuating mechanism for use in an internal combustion engine is disclosed. The engine is of the type having engine intake and exhaust valves with elongated valve stems. The actuator has a power piston reciprocable along an axis and adapted to be coupled to an engine valve and a pneumatic arrangement for moving the piston. A pneumatic damping arrangement imparts a first decelerating force to the piston when the engine valve reaches a first separation from one of said valve-open and valve-closed positions to begin reducing engine valve velocity as the engine valve approaches said one position, and imparts a second lesser decelerating force to the piston when the engine valve reaches a second lesser separation from that one position.

Abstract: A valve tappet and control system is provided including expansible and collapsible hydraulic link; wherein the control system causes expansion of the hydraulic link and determines the timing of the collapse and thus the closing of an intake valve of an internal combustion engine. The timing is variable depending on engine operating conditions, such as output power and turbo charger boost pressure. In one embodiment, a rotary valve and fluid gating device is used to connect a pressure line used to expand the hydraulic link to a dump line at one instance during each cam shaft rotation to provide the early closing of the valve. In a second embodiment, a rotary cam follower with an oblique surface is used, wherein the orientations of the oblique surface is the determinative feature that is controlled to change early closing time as well as a delayed opening.

Abstract: In an overhead cam internal combustion engine, an adjustable thickness shim assembly is interposed between the end of a valve stem and the underside of a conventional inverted cup follower engaged by the cam shaft. A body component of the shim assembly forms a ramp for a tapered wedge component which is slidable along the ramp to adjust the effective thickness of the shim. The body component has an inclined threaded bore adjacent to the wedge component receiving a screw which when turned advances along the ramp to butt against the wedge component. The body component is formed of a material having a higher coefficient of thermal expansion than the screw such that when the engine is cold the screw is pinched in its bore and will not turn. When the engine is warmed to normal operating temperature, the body component expands to a greater degree than the screw and the screw is free to turn.

Abstract: Modified cams and cam followers are designed to remove lash arising from clearances and compliance in valve train components. The cam followers have a crowned cam contacting surface having a crest, and the cams have a relief formed in a part of the base circle opposite the lift profile. The relief extends across the area opposed to the crest so that the region of the relief, the cam engages the follower in a path offset from and lower than the crest. The cam regions remote from the relief contact the follower on the crest. When the cam moves from the offset contact to the crest contact the valve train will be compressed just enough to remove the compliance prior to lift profile engagement. If any lash is present, it is also removed by the same action.

Abstract: A two-stroke internal combustion engine comprising an engine block including a first exterior surface portion, a second exterior surface portion spaced from the first portion and having therein a crankcase-defining cavity, and a combustion air passage extending from the first exterior surface portion to the crankcase-defining cavity, an intake manifold fixed to the first exterior surface portion of the engine block and including therein a combustion air passage in alignment with the combustion air passage in the engine block, and a carburetor fixed to the intake manifold and having therein a combustion air passage in alignment with the intake manifold combustion air passage.

Abstract: A valve driving mechanism includes a pair of cam shafts for driving either an intake valve or an exhaust valve, and a power transmitting device provided on said first cam shaft for driving the cam shafts. A phase varying device of annular configuration is provided between the cam shaft and the power transmitting device for varying a relative rotation phase between the cam shaft and the power transmitting device so that a compact valve timing control can be provided.

Abstract: A sealing device is provided on the outer circumference of an oil pressure unit of the oil pressure rush adjuster, or on the partitioning wall of a sub-reservoir surrounding the oil pressure unit, or therebetween so as to provide a sealing between said partitioning wall and said outer circumference of the oil pressure unit while the engine in which the rush adjuster is mounted is stopped and so as to allow a portion of the oil to leak therebetween while the engine operates. Since the oil is perfectly prevented, while the engine stops, from leaking between the outer circumference of the oil pressure unit and the partitioning wall of the sub-reservoir, the oil amount residing in the reservoirs is enough even though not supplied from the cylinder head, and the air cannot be drawn into the high pressure chamber.

Abstract: A lubricating arrangement for the overhead camshafts of an internal combustion engine. The cylinder head assembly is formed with wells in which lubricant can accumulate during the running of the engine and which surround at least in part the camshafts. When the engine stops running, the wells will retain lubricant so that the camshaft will be lubricated immediately upon start up. The wells associated with at least one of the camshafts are formed at least in part by the bearing caps that journal the camshafts. One camshaft is supported by a greater number of bearings than the other camshaft and the fastening means associated with the camshaft bearings of the camshaft having the greater number of bearings are smaller than those associated with the other camshaft so as to insure equal torque down.

Abstract: A pneumatically powered valve actuator is disclosed including a valve actuator housing, a main piston reciprocable within the housing along an axis and a pair of auxiliary pistons fixed to and movable with the main piston. The main piston has a pair of oppositely facing primary working surfaces. A pair of air control valves reciprocable along said axis relative to both the housing and the main piston between open and closed positions control air flow from a pressurized source causing the main piston and the pair of auxiliary pistons to move. Each auxiliary piston forms, in conjunction with a surface of the corresponding air control valve, a variable volume annular chamber. The variable volume chamber function during the early portion of piston movement to apply a reclosing force to the air control valve and during a latter portion of the piston movement to vent air compressed by the piston during damping. This venting of the residual air is in an axial rather than a radial direction.

Abstract: A valve spring retainer for a valve operating mechanism for an internal combustion engine comprises a matrix formed from a quenched and solidified aluminum alloy powder, and a hard grain dispersed in said matrix. The hard grain is at least one selected from the group consisting of grains of Al.sub.2 O.sub.3, SiC, Si.sub.3 N.sub.4, ZrO.sub.2, SiO.sub.2, TiO.sub.2, Al.sub.2 O.sub.3 -SiO.sub.2 and metal Si. The amount of hard grain added is in a range of 0.5% to 20% by weight, and the area rate of said hard grain is in a range of from 1% to 6%.

Abstract: A variable lift valve train mechanism for an internal combustion engine. The valve train varies valve lift depending on engine RPM, providing a relatively lower valve lift at lower engine RPMs for increased bottom-end torque and a relatively higher valve lift at higher engine RPMs for increased overall top-end performance. The valve train includes a rocker arm at one end engaging a valve and at its other end engaging a cam such that upward movement of the cam causes downward opening movement of the valve. The rocker arm has a convex fulcrum-engaging upper surface extending between the rocker arm ends. A variable-position fulcrum assembly includes a pivot arm, the lower end of which is pivotally mounted to a pivot point, and the upper end of which carries a fulcrum roller element engaging the fulcrum-engaging upper surface of the rocker arm to define a variable fulcrum point.