Abstract: A system for manufacturing a family of intake manifolds includes first and second intake molds. One of the first and second intake molds includes an outlet insert. A first intake manifold includes: a plenum chamber, a plenum chamber air inlet; a first number of intake runner passages; and the first number of outlets. Each of the outlets is fluidly connected to a corresponding one of the first number of intake runner passages. The second intake manifold includes: the plenum chamber; the plenum chamber air inlet; the first number of intake runner passages; and a second number of outlets. Each of the second number of outlets is fluidly connected to a corresponding one of the first number of intake runner passages. At least one of the first number of intake runner passages is not fluidly connected to any one of the second number of outlets of the second intake manifold.

Abstract: An exhaust assembly for a vehicle is disclosed, which includes a resonator including an inlet adapted for fluidly connecting to an exhaust manifold, and a closed end at an end of the resonator opposite the inlet; and a turbocharger passage extending from the resonator between the exhaust manifold and the closed end, the turbocharger passage defining an outlet. An exhaust system, a power pack, and the vehicle including the exhaust assembly are further disclosed.

Abstract: An aircraft propeller drive system has a gear to be driven by an engine and having a first plurality of teeth. A torsion bar has a first end driven by the gear and a second end rotatable relative to the first end about a torsion axis by a torsion angle. An output shaft is driven by the second end and is adapted for connection to a propeller. A clutch has a driven member rotationally fixed to the output shaft and a driving member having a second plurality of teeth. The first and second pluralities of teeth engage each other when a variation in the torsion angle from a mean torsion angle is greater than a predetermined angle. Torque is transferred between the gear and the output shaft via the clutch when the first and second pluralities of teeth engage each other.

Abstract: A pulley for a CVT has a fixed sheave, a movable sheave, a spider, a biasing member biasing the movable sheave axially away from the fixed sheave, at least one centrifugal actuator and at least one roller assembly. The at least one centrifugal actuator has an arm pivotally connected to one of the movable sheave and the spider. The arm has a thrust portion pushing against a track portion of a roller of the at least one roller assembly upon rotation of the CVT, the roller being rotationally connected to another one of the movable sheave and the spider. The roller receives the thrust portion of the arm on the track portion thereof such that the thrust portion of the arm remains in contact with the track portion of the roller. The arm and the roller thereby transfer axial and rotational forces between the spider and the movable sheave.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission operatively connected to the engine has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. A ground engaging member is operatively connected to the driven pulley. A piston is operatively connected to the driving pulley for applying a piston force thereto and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining at least one of the throttle operator and throttle valve position, detecting a parking/drive away condition indicative of one of a parking operation and a drive-away operation of the vehicle, and, responsive to the detection, actuating the piston and controlling the piston force based on the at least one of the throttle operator position and the throttle valve position.

Abstract: A drive assembly for a kart, and a kart including the assembly is disclosed. The assembly includes an electric motor including an output shaft; an assembly housing surrounding the motor, the housing defining an aperture; an intermediate shaft rotatably disposed within the assembly housing; a driving gear removably disposed on the output shaft within the housing; a reduction gear removably disposed on the intermediate shaft within the housing; and a panel removably connected to the housing for selectively covering the aperture, the driving gear and the reduction gear being removable from the motor and the housing via the aperture when the panel is removed from the housing, the panel, the driving gear, and the reduction gear being disposed above a maximum level of transmission oil contained within the housing when the motor is not operating. A method of changing a kart transmission ratio is also disclosed.

Abstract: A method of operating a vehicle having an engine, a throttle valve and a throttle operator. A continuously variable transmission is operatively connected to the engine and has a driving pulley, a driven pulley, and a belt operatively connecting therebetween. At least one ground engaging member is operatively connected to the driven pulley and includes at least one of a wheel and a track. A piston is operatively connected to the driving pulley for applying a piston force to the driving pulley when actuated and thereby changing an effective diameter of the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining an engine speed, and controlling the piston force based on the engine speed.

Abstract: A method for cleaning an exhaust valve of a two-stroke internal combustion engine is provided. The method comprises: requesting an exhaust valve cleaning cycle if at least one of a first condition or a second condition is satisfied; initiating the exhaust valve cleaning cycle if at least one of a third condition or a fourth condition is satisfied; and aborting the exhaust valve cleaning cycle if at least one of the at least one of the third or fourth conditions is no longer satisfied. The first condition is a time elapsed since a previous cleaning cycle has been completed being greater than a predetermined time. The second condition is a rate of opening of the exhaust valve being less than predetermined rate. The third condition is a throttle valve being closed. The fourth condition is an engine speed being less than a predetermined engine speed.

Abstract: A family of manifolds for a family of engines. A first and second engine respectively have a first and second number of cylinders. The second number is at least one and smaller than the first number. Each manifold has a plenum chamber and an inlet. The first and second manifolds respectively have the first and second number of outlets, each connected to one of a first number of runner passages. The first manifold is manufactured by inserting an outlet insert for forming at least one of the first number of outlets into a first or second mold, forming a first portion thereof using the first mold, forming a second portion thereof using the second mold, and connecting the portions. The second manifold is manufactured by forming a first portion thereof using the first mold, forming a second portion thereof using the second mold, and connecting the portions.

Abstract: A method for changing a gear driving configuration of a discrete gear transmission (DGT) in a powertrain including an engine operatively connected to a continuously variable transmission (CVT). The DGT has a DGT input shaft operatively connected to a CVT driven pulley, a plurality of gears having a plurality of gear driving configurations and a DGT output shaft selectively operatively connected to the DGT input shaft based on the gear driving configuration. Responsive to a gear shift request, a target driven pulley speed is determined for synchronizing the DGT input shaft with the DGT output shaft for the desired gear driving configuration. The engine is controlled to change an engine speed to the target engine speed corresponding to the determined target driven pulley speed. Responsive to the DGT input shaft being synchronized with the DGT output shaft, the current gear driving configuration is changed to the desired gear driving configuration.

Abstract: An exhaust valve assembly for a two-stroke internal combustion engine has a valve actuator, and a two-part valve having a primary and secondary valves defining first and second decompression passages respectively. The primary valve is operatively connected to the valve actuator. The primary valve is in first, second and third primary valve positions when the valve actuator is in first, second and third actuator positions respectively. The secondary valve is in a first secondary valve position when the valve actuator is in the first or the second actuator position and in a second secondary valve position when the valve actuator is in the third actuator position. The first and second valve decompression passages fluidly communicate with each other when the valve actuator is in the second actuator position, and are fluidly separate from each other when the valve actuator is the first or the third actuator position.

Abstract: A fracture-separated engine component and a method for manufacturing same is described. The engine component includes first and second parts each having a fracture surface extending along a fracture plane. Prior to fracture separation, the engine component is case-hardened by nitriding and has a nitriding hardness depth of 0.4 to 0.7 mm. After the nitriding, the engine component is cooled such that each one of the subsequent fracture surfaces reaches a temperature below ?100° C. The fracture separation is then performed. After, the engine component has two fracture surfaces along a fracture plane, the fracture surfaces having hardened peripheral areas and unhardened core sections. No point of the unhardened core sections located in the fracture plane is located at a distance greater than 1.1 mm from a nearest hardened peripheral area. Each one of the fracture surfaces includes elongated partial fracture surfaces with a width of less than 3.2 mm.

Abstract: An internal combustion engine has a cooling jacket defined in the cylinder block for cooling at least an exhaust side of the cylinder. The cooling jacket at least partially surrounds the cylinder and includes a first cooling passage positioned between the exhaust passage and the first auxiliary exhaust passage, and a second cooling passage positioned between the exhaust passage and the second auxiliary exhaust passage. The cooling jacket on at least the exhaust side of the cylinder comprises an upper portion and a lower portion which are in fluid communication with each other via at least one of the first cooling passage and the second cooling passage.

Abstract: A method of operating a vehicle at different altitudes. The vehicle has an engine, a throttle valve and a throttle operator. A continuously variable transmission has a driving pulley connected to the engine, a driven pulley, and a belt operatively connecting therebetween. A ground engaging member is operatively connected to the driven pulley. A piston is connected to the driving pulley. A control unit controls actuation of the piston and the piston force. The method includes determining an altitude and/or an atmospheric pressure, a driven pulley speed, and at least one of the throttle operator position and the throttle valve position. The piston is selectively actuated based on the altitude and/or the atmospheric pressure. The piston force is controlled based on the driven pulley speed, and at least one of: the throttle operator position and the throttle valve position. Vehicles and other methods of operation thereof are also disclosed.

Abstract: An exhaust valve assembly has a valve actuator, a first valve part (FVP) operatively connected to the actuator, a second valve part (SVP), and at least one auxiliary valve operatively connected to the second valve part. When the actuator is in a first position, the FVP is in a fourth position, the SVP is in a seventh position and the at least one auxiliary valve is in a ninth position. When the actuator is in a second position, the FVP is in a fifth position, the SVP is in the seventh position and the at least one auxiliary valve is in the ninth position. When the actuator is in a third position, the FVP is in a sixth position, the SVP is in an eighth position and the at least one auxiliary valve is in a tenth position. The second position is intermediate the first and third positions.

Abstract: A supercharged internal combustion engine is disclosed which includes a supercharger operatively connected to the crankshaft via a clutch supported by an intermediate shaft such that torque variations are partially absorbed by the clutch.

Abstract: A piston for an internal combustion engine is disclosed. The piston body has two pin bores for receiving a piston pin. At least one rib is disposed on the second side and extends outwardly therefrom. The at least one rib is aligned laterally between the two pin bores in a direction along the piston pin axis. The at least one rib has a longitudinal axis extending generally perpendicular to both the reciprocation axis of the piston and the piston pin axis. A piston having a boss extending approximately within the piston pin radius of the piston pin axis, and a piston having a boss generally following the contour of the piston pin are also disclosed. An engine having the piston is also disclosed.

Abstract: A multiple-disk clutch used in the power train of a motor vehicle for transmitting power from the crankshaft of an engine to a transmission input shaft is disclosed. The multiple-disk clutch comprises an actuation system supported at least in part by one of the inner and outer clutch member, and connected to a pressure member. The multiple-disk clutch is positioned within the multiple-disk clutch. The actuation system is adapted to overcome the biasing force of a spring or springs and release the compression force exerted by the pressure member on the driving and the driven friction disks such that the friction disks are spaced apart and power transmission through the multiple-disk clutch is interrupted.

Abstract: A transmission for a vehicle is disclosed. The transmission has a reverse gear locking device that includes a rotating shaft having a longitudinal axis, the rotating shaft adapted for rotational movement about its longitudinal axis, and a lock connected to the rotating shaft and positioned in alignment with a stopper extending from the shift drum of the transmission. The initial position of the lock prevents the shift drum from engaging the reverse gear. A rotational movement of the rotating shaft tilts the lock out of alignment with the stopper and allows the shift drum to engage the reverse gear.