Abstract: The invention relates to a two-stroke internal combustion engine with crankcase scavenging, with an exhaust passage controlled by the piston and at least two first transfer passages and at least one second transfer passage, each with a corresponding transfer window into the cylinder chamber and a window on the crankcase side for communication between the cylinder chamber and the crankcase, the transfer windows of the first transfer passages being controlled by the upper edge of the piston, and the crankcase-side window of the second transfer passage being disposed in a region of the cylinder wall that is swept by the piston skirt of the piston. The cylinder wall comprises at least one recess, which is arranged in close vicinity to the transfer window of the second transfer passage and which is in flow communication with the second transfer passage, wherein a narrow passage is arranged between the recess and the second transfer passage.

Abstract: The invention relates to a piston 1 for a four-stroke internal combustion engine, comprising a piston head 2 with a piston top 3 on the side of the combustion space, and a first groove 5 next to the piston top 3 holding a compression ring 9 and a second groove 6 further apart from the piston top 3 holding an oil scraper ring 22 being formed in the wall 4 of the piston head 2, and a piston ring land 7 being formed between the two grooves 5, 6, and further comprising a piston skirt 10 adjacent to the piston head 2, whose wall 11 includes first guide faces 12 for guiding the piston 1 in a cylinder, as well as a piston pin bore 13 carrying a piston pin 14. To reduce oil consumption and diminish frictional losses, it is provided that the ring land 7 between the two grooves 5, 6 be designed as second guide face 17 for guiding the piston 1.

Abstract: A drive unit for a motorcycle includes an internal combustion engine with at least two cylinders arranged in V-position, a clutch and a transmission, the transmission being located in the space between the cylinders.

Abstract: The invention relates to a spark ignited internal combustion engine with at least one cylinder that accommodates a reciprocating piston, with a cylinder head that receives at least one ignition device per cylinder and in which are formed one exhaust and two intake manifolds, said exhaust manifold communicating with a combustion chamber by way of one exhaust port and said intake manifolds communicating therewith by way of intake ports, said exhaust port being controlled via an exhaust valve and said intake ports via intake valves, said exhaust port on the one hand and said intake ports on the other hand being arranged to different sides of an elevated plane of the engine that passes through the axis of the cylinder and through the axis of the crankshaft, said intake manifolds being at least in sections arranged substantially in the direction of the cylinder's axis and being formed in such a manner that a reverse tumble flow is initiated in the combustion chamber, said flow being oriented from the intake ports

Abstract: The invention relates to an intake port configuration (1) for an internal combustion engine, where the swirl (D) of at least one intake flow entering the combustion chamber via an intake port controlled by an intake valve (5) can be varied, two or more flow paths being associated with at least one intake port, which paths join in the valve region (4), and the flow rate (Q) in at least one of the two flow paths being variable by means of a control element (9), and the two flow paths being constituted by two completely separate intake passages, i.e., a primary passage (2) and a secondary passage (3), said primary passage (2) having a helical form. In order to obtain a high flow rate (Q) at a high swirl level in addition to a wide range over which the swirl D may be varied, it is proposed that the intake valve axis (5a) should intersect or be tangent to the secondary passage (3) at least at one point.

Abstract: This invention relates to a drive unit for a motorcycle, comprising an internal combustion engine with at least two cylinders arranged in V-position, a clutch and a transmission. A particularly compact configuration is obtained by disposing the transmission in the space between the cylinders.

Abstract: The invention relates to an internal combustion engine comprising a cylinder block with cooling fins cast integral therewith, and a cylinder head bolted on top of the cylinder block, first coolant passages being provided in the area of at least one cylinder contained in the cylinder block, which passages are connected to second coolant passages located in the cylinder head. Cooling efficiency is increased by providing heat exchange passages in the outer region of the cooling fins, which together with the first coolant passages and the second coolant passages form a closed loop system within the engine.

Abstract: The invention relates to a piston 1 for a four-stroke internal combustion engine, comprising a piston head 2 with a piston top 3 on the side of the combustion space, and a first groove 5 next to the piston top 3 holding a compression ring 9 and a second groove 6 further apart from the piston top 3 holding an oil scraper ring 22 being formed in the wall 4 of the piston head 2, and a piston ring land 7 being formed between the two grooves 5, 6, and further comprising a piston skirt 10 adjacent to the piston head 2, whose wall 11 includes first guide faces 12 for guiding the piston 1 in a cylinder, as well as a piston pin bore 13 carrying a piston pin 14. To reduce oil consumption and diminish frictional losses, it is provided that the ring land 7 between the two grooves 5, 6 be designed as second guide face 17 for guiding the piston 1.

Abstract: The invention relates to a four cycle outboard internal combustion engine for driving a watercraft with a cylinder housing having cylinders arranged in at least two rows, wherein a piston is reciprocating in each cylinder, said pistons driving an approximately horizontally accommodated propeller drive shaft by way of an approximately vertically arranged crankshaft, each cylinder bank being provided with cylinder head sealing surfaces for a cylinder head housing receiving gas shuttle valves and wherein the cylinder head sealing surfaces of all of the cylinders are arranged in one single cylinder head sealing plane and an exhaust main manifold for all of the cylinders is arranged approximately parallel to the crankshaft in the cylinder head housing in the area of a central plane of the motor which is configured parallel to the crankshaft.

Abstract: The invention relates to internal combustion engine, with an engine block with at least one cylinder, with a cylinder head which is fastened to the cylinder, with cooling ribs which are disposed on the outside of the cylinder and the cylinder head in order to discharge the heat produced during the operation of the internal combustion engine, and with an oil pump for conveying the engine oil through oil lines to the parts to be lubricated of the internal combustion engine and to an oil cooler for cooling the engine oil. An effective and even cooling of the internal combustion engine is ensured in such a way that the oil cooler is integrated in the cooling ribs of the internal combustion engine and two mutually separated oil conduit systems are provided in the cylinder head, namely a lubricating oil system and a cooling oil system.

Abstract: The invention relates to a single-track motor vehicle with an internal combustion engine with at least one cylinder which is arranged in an inclined manner approximately horizontally against the driving direction, with at least one intake valve being arranged above at least one exhaust valve. In order to achieve the most compact possible design it is provided that the exhaust valve is triggered by way of a rocker lever.

Abstract: An exhaust system for internal combustion engines, in particular two-cycle internal combustion engines, includes a resonance-type exhaust part having at least one diffuser-cone unit formed with a diffuser, a countercone, and a connecting part with a preferably constant cross section extending between the diffuser outlet cross section and cone inlet cross section. In order to provide the resonance-type exhaust part as compact as possible by employing a simple production method, the connecting part is formed as a first deflection arc, preferably with an angle of deflection of about 180°±30°.

Abstract: The invention relates to a two-stroke internal combustion engine with crankcase avenging, with an exhaust passage controlled by the piston and at least two first transfer passages and at least one second transfer passage, each with a corresponding transfer port into the cylinder chamber and a port on the crankcase side for communication between the cylinder chamber and the crankcase, the transfer ports of the first transfer passages being controlled by the upper edge of the piston, and the crankcase-side port of the second transfer passage being disposed in a region of the cylinder wall that is swept by the piston skirt of the piston. For control of the second transfer passage the proposal is put forward that the piston skirt of the piston be provided with a control opening in the area of the crankcase-side port of the second transfer passage.

Abstract: The invention relates to a four-stroke internal combustion engine with at least two inlet valves and an inlet flow path with at least two inlet ports per cylinder which branch off from a common inlet pipe and are guided separately up to the inlet valves and of which at least one inlet port is designed as a charge loading port and at least one inlet port as a volumetric port, with a throttle device for volumetric control being provided in the inlet flow path and the inlet flow path being connected with a fuel supply device. In order to achieve in the simplest possible way an improvement of the exhaust gas quality at low fuel consumption it is provided that the fuel supply device is formed by a joint carburettor for both inlet ports, with preferably the carburettor being arranged in the zone of the branching of the inlet ports from the inlet pipe.

Abstract: In a reciprocating engine with at least two cylinders, with at least one primary connecting rod and at least one secondary connecting rod, whose small ends are connected to a piston each, the crankshaft ends of the connecting rods, i.e., the ends opposite of the small ends, are mounted on a common crank pin of a crankshaft. The crankshaft end of the primary connecting rod has a shoulder whose inner surface is rotatably connected to the crank pin via a first bearing, the outer surface of the shoulder defining a bearing surface for at least one secondary connecting rod. The inner and outer surfaces constituting the bearing surfaces of the essentially tubular shoulder extend around the full periphery and are configured as cylindrical surfaces preferably. The at least one secondary connecting rod has a crankshaft end with a non-divided divided big eye surrounding the shoulder of the primary connecting rod, the inner surface of which eye is supported on the outer surface of the shoulder via a second bearing.

Abstract: This invention relates to an internal combustion engine for a motorcycle, with two or more single cylinders arranged in a plane approximately normal to a crankshaft, each cylinder accommodating a reciprocating piston and the pistons acting via connecting rods on the same crank of the crankshaft supported in a crankcase. To reduce manufacturing expense, the engine is to be provided with modular components for universal use with at least two different cylinder arrangements (V-type, W-type).

Abstract: A four-stroke cycle internal combustion engine comprises at least two inlet valves and a correspondingly branched intake line. In order to ensure that a high power and a more favorable specific fuel combustion will be achieved at high speeds and a reduced fuel consumption and a lower emission of exhaust gas will be achieved particularly at low speeds and under partial loads. A rotary valve, which has at least two passages, which are associated with respective intake branch lines and are as straight as possible and lead to respective inlet valves, is provided downstream of the junction where the intake line is branched. The internal combustion engine also comprises at least one additional pipe section, which in one position of the rotary valve is connected by the rotary valve between one intake branch line and one of the passages which is then open whereas the rotary valve then shuts off the other passage or passages.

Abstract: A liquid-cooled internal combustion engine having a piston-controlled exhaust, particularly a two-stroke cycle internal combustion engine, is provided with a generator or a magneto-generator unit and with a lubricating oil pump. The cylinder head is provided with a cap, which defines a space for cooling liquid and extends over the cylinder approximately as far as to the exhaust port and at its end that is adjacent to the crankshaft has a sealing surface. In order to minimize the transmission of solid-borne sound and the radiation of sound, the cap and the cover for the oil pump are secured by means of collar screws, which have been tightened against a stop, and a washer provided with a vulcanization-bonded rubber layer is disposed between the head of each of said screws and the cap or the cover.

Abstract: A two-stroke-cycle internal combustion engine designed for crankcase scavenging has an exhaust passage, which extends from an exhaust window in the cylinder wall and which contains a control member, which is adjustable in the direction of travel of the piston to adjust the flow area of the exhaust window in dependence on one or more operational parameters of the internal combustion engine, in particular, in dependence on its speed. In order to minimize the scavenging losses and to permit the engine to combust even very lean mixtures while having a good drivability, the control member conforms to the flow lines in the exhaust passage and constitutes that edge of the exhaust window which is nearer to the crankshaft and said control member is movable to adjust said edge.

Abstract: In an exhaust system, particularly for two-stroke cycle internal combustion engines, at least that portion which adjoins the internal combustion engine consists of two joined shell sections made of sheet metal and contains a catalytic converter. In order to simplify the manufacture and to ensure that the gas dynamics will not adversely be affected, the catalytic converter is constituted by a central partition, which extends between the sheet metal shell sections in the direction of flow of the exhaust gases and is provided with a catalytic coating and is optionally apertured.