Abstract: An internal combustion engine having: a cylinder block defining a cylinder; a cylinder head defining a seat; a piston; a crankshaft, the piston, cylinder, and cylinder head defining a variable volume combustion chamber therebetween; an air intake passage; an exhaust passage; a fuel injector; and a combustion pre-chamber housing connected to the cylinder head and extending in part into the combustion chamber. The housing has: a tapering portion; and a tip connected to the tapering portion. The tapering portion abuts the seat. The tapering portion tapers toward the tip. The seat and the tapering portion of the housing have corresponding shapes. The housing defines: a combustion pre-chamber; and at least one orifice fluidly communicating the combustion pre-chamber with the combustion chamber. A spring biases the tapering portion of the housing against the seat of the cylinder head. A spark plug is connected to the combustion pre-chamber housing.

Abstract: An engine assembly for a vehicle includes an internal combustion engine and an exhaust system. The exhaust system includes a catalytic converter, a main muffler, a hydrocarbon trap, a pre-muffler disposed upstream from the main muffler and the hydrocarbon trap, and an exhaust path valve. The exhaust path valve is movable between first and second exhaust path positions. The exhaust path valve obstructs a second exhaust path in the first exhaust path position such that exhaust gas flows from an exhaust port of an engine cylinder to the catalytic converter to the main muffler and to the atmosphere. The exhaust path valve obstructs a first exhaust path in the second exhaust path position such that exhaust gas flows from the exhaust port of the engine cylinder to the catalytic converter to the hydrocarbon trap and to the atmosphere.

Abstract: A gearing assembly for a vehicle drivetrain. The assembly includes a first shaft rotating about a first shaft axis; a second shaft with a second shaft axis parallel to the first shaft axis; a first freewheel clutch gear mounted to the first shaft; a second gear mounted to the first shaft; a third freewheel clutch gear mounted to the second shaft and engaged with the second gear; and a fourth gear mounted to the second shaft and engaged with the first gear. When the first shaft rotational speed is greater than the second shaft rotational speed, the first shaft drives the second shaft via the second and third gear, the first gear being overrun; and when the second shaft rotational speed is greater than the first shaft rotational speed, the second shaft drives the first shaft via the fourth and first gear, the third gear being overrun.

Abstract: A power pack for a vehicle selected from a group of different vehicles is disclosed. The power pack includes an internal combustion engine and a continuously variable transmission (CVT) operatively connected to the engine. The CVT includes: a drive pulley operatively connected to a crankshaft of the engine, the drive pulley being rotatable about a drive pulley axis; a driven pulley rotatable about a driven pulley axis; a belt connecting the drive pulley to the driven pulley; and a housing at least partly enclosing the drive pulley, the driven pulley and the belt. The power pack also includes a sub-transmission selected from a group of different sub-transmissions depending on the selected vehicle. The selected sub-transmission is mounted to the housing of the CVT. The housing of the CVT is configured to mount any sub-transmission of the group of different sub-transmissions. A method for assembling a power pack is also provided.

Abstract: An engine assembly for a vehicle includes an internal combustion engine and an exhaust system. The exhaust system includes a catalytic converter, a main muffler, a hydrocarbon trap, a pre-muffler disposed upstream from the main muffler and the hydrocarbon trap, and an exhaust path valve. The exhaust path valve is movable between first and second exhaust path positions. The exhaust path valve obstructs a second exhaust path in the first exhaust path position such that exhaust gas flows from an exhaust port of an engine cylinder to the catalytic converter to the main muffler and to the atmosphere. The exhaust path valve obstructs a first exhaust path in the second exhaust path position such that exhaust gas flows from the exhaust port of the engine cylinder to the catalytic converter to the hydrocarbon trap and to the atmosphere.

Abstract: An engine assembly for a vehicle includes an internal combustion engine operating on a two-stroke engine cycle. A compressor is in fluid communication with an intake port of at least one cylinder of the engine to pump air into the engine. An exhaust pipe is in fluid communication with an exhaust port of the at least one cylinder. The exhaust pipe has an inlet and an outlet defining a length of the exhaust pipe therebetween. A diameter of the exhaust pipe increases along a portion of the length of the exhaust pipe in a flow direction of the exhaust pipe. The diameter of the exhaust pipe does not decrease along the length of the exhaust pipe in the flow direction of the exhaust pipe.

Abstract: A power pack for a vehicle selected from a group of different vehicles is disclosed. The power pack includes an internal combustion engine and a continuously variable transmission (CVT) operatively connected to the engine. The CVT includes: a drive pulley operatively connected to a crankshaft of the engine, the drive pulley being rotatable about a drive pulley axis; a driven pulley rotatable about a driven pulley axis; a belt connecting the drive pulley to the driven pulley; and a housing at least partly enclosing the drive pulley, the driven pulley and the belt. The power pack also includes a sub-transmission selected from a group of different sub-transmissions depending on the selected vehicle. The selected sub-transmission is mounted to the housing of the CVT. The housing of the CVT is configured to mount any sub-transmission of the group of different sub-transmissions. A method for assembling a power pack is also provided.

Abstract: An engine assembly for a vehicle includes an internal combustion engine operating on a two-stroke engine cycle. A compressor is in fluid communication with an intake port of at least one cylinder of the engine to pump air into the engine. An exhaust pipe is in fluid communication with an exhaust port of the at least one cylinder. The exhaust pipe has an inlet and an outlet defining a length of the exhaust pipe therebetween. A diameter of the exhaust pipe increases along a portion of the length of the exhaust pipe in a flow direction of the exhaust pipe. The diameter of the exhaust pipe does not decrease along the length of the exhaust pipe in the flow direction of the exhaust pipe.

Abstract: A turbocharger for an engine includes a housing, a shaft, a turbine wheel mounted to the shaft for rotation therewith, a compressor wheel mounted to the shaft for rotation therewith, and a bearing cartridge rotatably supporting the shaft relative to the housing. The housing is positioned axially between the turbine and compressor wheels. The bearing cartridge includes an inner ring mounted to the shaft, an outer ring disposed between the inner ring and the housing and movable relative to the housing, and a first and a second plurality of roller elements axially spaced apart from one another and disposed radially between the inner and outer rings to rotatably support the inner ring relative to the outer ring. A radial gap (RD) is defined between the outer ring (134) and the housing (126). Lubricant flows into the radial gap and radially separates the outer ring from the housing during operation of the turbocharger.

Abstract: A turbocharger for an engine includes a housing, a shaft, a turbine wheel mounted to the shaft for rotation therewith, a compressor wheel mounted to the shaft for rotation therewith, and a bearing cartridge rotatably supporting the shaft relative to the housing. The housing is positioned axially between the turbine and compressor wheels. The bearing cartridge includes an inner ring mounted to the shaft, an outer ring disposed between the inner ring and the housing and movable relative to the housing, and a first and a second plurality of roller elements axially spaced apart from one another and disposed radially between the inner and outer rings to rotatably support the inner ring relative to the outer ring. A radial gap (RD) is defined between the outer ring (134) and the housing (126). Lubricant flows into the radial gap and radially separates the outer ring from the housing during operation of the turbocharger.