Abstract: In an internal combustion engine, a piston/cylinder arrangement includes a hemispherical combustion chamber formed either in a piston crown secured to a top of the piston or in the piston head itself. This hemispherical combustion chamber occupies substantially an entirety of the surface area of the upper face of the piston crown or piston. A cylinder head extension member extends downwardly into the hemispherical combustion chamber so as to occupy a volume thereof as necessary to increase the compression ratio to a desired value. When the hemispherical combustion chamber is formed in the piston crown, the piston crown is secured to but spaced apart from the piston head so as to insulate the piston crown from the piston head. This enables the piston crown to be formed of superior grade metal relative to the piston head.

Abstract: For a hypocycloidal crank transmission for piston engines, particularly internal-combustion engines, having a lift/guide shaft rotatably arranged in crank webs of a main crankshaft which are rotatably connected in a synchronous manner and having lift eccentrics for an oscillatingly driven piston connecting rod controlled by way of an orthogonal straight-motion mechanism, it is suggested for achieving a one-piece lift/guide shaft that this lift/guide shaft have, as a shaft-side guiding element of the hypocycloidal straight-motion mechanism, a guide eccentric or an eccentric guide pin.

Abstract: An internal combustion engine having a direct cylinder injection and including a variable valve timing mechanism for at least changing the time of closing of the intake valve. The fuel injection timing and intake valve closing timing are controlled so that under low and mid-range engine speeds, but high loads, the intake valve is closed before the piston reaches bottom dead center position on its intake stroke so as to reduce the effective compression ratio. Fuel injection timing is begun before the piston has reached its bottom dead center position during the intake stroke under high-speed, high-load conditions and is not initiated until after the piston has reached its bottom dead center position and begun its compression stroke under other engine running conditions. The engine is provided with an injector location and piston with a bowl in its head that improves fuel stratification under at least some running conditions so as to permit lean burn operation.

Abstract: An improved piston-cylinder internal combustion engine alters the volume of the combustion chamber without relying on movement of the piston to change the volume of the combustion chamber.

Abstract: This invention provides a porous thermal barrier layer for protecting parts of an internal-combustion engine having parts which are acted upon by combustion, and particularly by heat, and to a process for applying such a thermal barrier layer to these parts. The thermal barrier layer, which is formed of grains and/or fibers connected with one another on the exterior side, and is produced at least partially from a heat-resistant, temperature-shock-stable and abrasion-proof barrier material, has a heat penetration number defined by the following formulab=.sqroot.p.cndot.C.cndot..lambda.withb: the heat penetration number of the thermal barrier layerin ?J.cndot.(Kcm.sup.2 .sqroot.s).sup.-1 !,p: the density of the thermal barrier layer in ?g/cm.sup.3 !,.lambda.: the thermal conductivity of the barrier material in ?W/cmK!, andC: the specific heat of the barrier material in ?J/gK!which heat penetration number is smaller than 0.25 ?J.cndot.(Kcm.sup.2 .sqroot.s).sup.-1 !, particularly smaller than 0.1 ?J.cndot.(Kcm.

Abstract: An air diffuser (20) and method of operation for an air intake system of an internal combustion engine. The air intake system includes a throttle body (22) up stream from an intake manifold (24), with the air diffuser (20) mounted between them. The air diffuser (20) includes vanes (62,64) extending into its main bore (52) in order to diffuse and redirect the air flowing from the throttle body (22) into the intake manifold (24). The diffusion and redirection of the air reduces the noise emanating from the intake manifold (24) for particular engine operating conditions.

Abstract: A twin-piston engine (1), i.e., a crankcase scavenged two-stroke internal combustion engine comprising two pistons (2,3) travelling in essentially the same direction, and wherein one (4) of the cylinder bores, the exhaust bore (4), contains all exhaust ports (6), and the other cylinder bore (5), the scavenging cylinder bore, contains a number of scavenging ports (7,8,9).

Abstract: A cylinder block of a vertically oriented multicylinder engine includes a cylinder block structure which is configured to support a crankshaft in a vertical orientation. The cylinder block includes a cylinder head mounting surface thereupon, and a plurality of cylinders therein. The plurality of cylinders are configured along horizontal axes. A reinforcing rib or wall is included, with an inclined surface which is inclined with respect to the axes of the cylinders, to ensure that oil which may contact the reinforcing rib flows downward into the crankcase of the engine.

Abstract: An intake pipe for an internal combustion engine has an intake assembly to which the air supplied from an air cleaner flows in accordance with the opening of a throttle valve, and independent intake pipes receive the air in the intake assembly and distribute the air into each cylinder of the internal combustion engine. The intake passage between the air cleaner and the throttle valve assembly is arranged next to and separated by a partition wall from at least one of a negative pressure part of the intake passage downstream of the throttle vale, the intake assembly provided in the negative pressure part and the independent intake pipes, whereby two independent intake spaces are formed on either side of the partition wall.

Abstract: A combustion air intake system for an internal combustion engine has an intake manifold which supplies intake air to the engine through pairs of differing length intake runners. A valve assembly is disposed between the intake runners and the engine and includes a molded composite housing having pairs of combustion air through passages which are in flow communication with associate pairs of intake manifold runners. An axially extending valve bore defines an axis through the valve housing and bisects the through passages. Molded integrally within the valve housing is a molded composite valve member having an axial valve shaft, disposed in the valve bore, and integral valve plates, disposed in predetermined through bores. The valve member is rotatable in the valve bore to open and close the valve plates for regulation of air flow through the predetermined through bores and associated intake runners.

Abstract: A variable-capacity intake system for a vehicle internal combustion engine, and of the type presenting: a first and second reservoir connected to common air supply means; at least a first intake conduit connecting the first reservoir to a respective cylinder of a corresponding first block; at least a second intake conduit connecting the second reservoir to a respective cylinder of a corresponding second block; respective branches connecting the first intake conduit to the second reservoir and the second intake conduit to the first reservoir; and valve means for selectively connecting each reservoir to one of the intake conduits.

Abstract: A combustion powered tool having a self-contained internal combustion power source constructed and arranged for creating a combustion for driving a driver blade to impact a fastener and drive it into a workpiece includes a housing having a main chamber enclosing the power source, a combustion chamber defined within the main chamber, an air flow enhancing device disposed in the combustion chamber for enhancing the flow of air therein, and a supplemental air flow enhancing device disposed externally of the combustion chamber and within the housing for forcing air past the combustion chamber as a cooling mechanism.

Abstract: An integrated air/fuel induction system for a multicylinder internal combustion engine includes an intake manifold assembly having an airbox for providing a source of intake air for consumption by the engine. The intake manifold assembly also includes an air plenum communicating with the airbox. A plurality of intake runners is integrally formed, at least partially, within the airbox, for directing intake air flowing from the plenum into each cylinder of the engine. The airbox thereby encapsulates and utilizes the volume of space surrounding the intake runners. The integrated air/fuel induction system also includes a fuel rail removably latched to the manifold assembly. A biasing member is provided to compensate for any slack between the fuel rail and the manifold assembly. In addition, rotational and axial locators are provided so as to position the fuel rail relative to the engine.

Abstract: An internal combustion engine (1) comprising at least two cylinders (4,8) meeting to form a combustion space (12) therebetween, a first piston (3) adapted to reciprocate within the first cylinder (4) and a second piston (7) adapted to reciprocate within the second cylinder (8). The two pistons are drivably coupled via a chain drive connecting their respective crankshafts and synchronously move one with respect to the other such that the second piston moves at a frequency haft of that of the first piston. An air/fuel mixture inlet aperture (14) as well as an exhaust aperture (15) are located in the wall of the second cylinder (8) and are opened or closed by the movement of the second piston (7).

Abstract: An inlet manifold system particularly adapted for a "V-8" to "V-16" Type internal combustion engine. Such an engine has a first and a second bank of cylinders.First and second elongated secondary manifolds disposed substantially parallel to and above the respective bank of cylinders;A plurality of substantially parallel, spaced apart, demand runners joined to each respective secondary manifold along its length, each demand runner extending from the secondary manifold to a cylinder in the opposite bank of cylinders and in fluid connection with the secondary manifold and the cylinder.A plurality of substantially parallel, spaced apart, supply runners joined to each respective secondary manifold along its length and in fluid connection therewith.The demand runners and the supply runners are connected to the secondary manifolds such that each pair of adjacent spaced apart demand runners has an supply runner therebetween.

Abstract: An improved engine output shaft includes a crankpin assembly for operatively connecting the shaft to each reciprocating piston for translating the reciprocating motion of each piston to rotary motion of the shaft through a leverage arm between the axis of rotation of the shaft and the point of operative connection between each piston and the shaft. The crankpin assembly is fixed to rotate with the shaft and defines a plurality of fixed crankpin offsets and transition offsets which sequentially vary the moment arm in a predetermined manner during the rotation of the shaft to produce a substantially constant total engine torque output during each increment of rotational movement.

Abstract: An air intake device with individual suction pipes having a variable effective length includes entry ports which are provided between a region of each of the suction pipes and a manifold. The entry ports can be closed by a closing device. The closing device is disposed outside a range of influence of the intake air flowing through the suction pipes, so that as a result no force which could move the closing device out of place is exerted on the latter. Air guide elements and air guide walls are provided in order to prevent the intake air from breaking away. The air intake device can be used in the intake pipe of an internal combustion engine.

Abstract: In an axial-piston engine of the type known as a "wabbler" engine, in which the motion of the pistons is transferred to a straight main shaft by means of a non-rotating element (referred to as the "wabbler") which nutates as the shaft rotates and transfers the motion to the pistons via arms at its periphery, a design of the wabbler in which the wabbler is made in two or more parts so as to enclose a swashplate on the shaft, with thrust bearings between the wabbler and the swashplate (which latter is fixed to the shaft). The parts of the wabbler are rigidly connected together, so as to maximise the bending strength of the assembly in resisting the thrust loads from the pistons, and to facilitate the transfer of the loads to the bearing surfaces so as to avoid excessive localized loading of the bearings.

Abstract: A cooling air system for an internal combustion engine has an engine enclosure and a plenum connected to the engine enclosure. A radial flow fan disposed in the plenum has blades which are spaced from the side wall a preselected distance. An inlet duct in the engine enclosure directs drawn outside ambient air toward a radiator located within the engine enclosure. A shroud extending into the plenum directs air flow passing through the radiator axially toward the radial flow fan. An outlet opening at the top end of the plenum exhausts radially directed heated air flow elevationally to the atmosphere.

Abstract: According to the present invention, a system for controlling a runner system in an internal combustion engine is provided which optimizes the available torque output over a broad range of engine speeds. The system generally includes opening or closing a short runner bypass valve system according to changes in engine speed. More particularly, the method comprises sensing a speed of an engine, determining a current open/closed mode of a short runner bypass valve system, calculating a time to a short runner bypass valve system switch point, including compensating for a time period required to switch between open and closed modes, and switching the short runner bypass valve open/closed mode at a given time if the current open/closed mode is not equal to a desired mode.