A two cycle engine having a block defining an exhaust port and a cylinder, a head, and a piston defining a combustion chamber is disclosed. The exhaust port has a resonant frequency that causes a portion of the combusted and uncombusted exhaust gasses to flow from the exhaust system and back into the combustion chamber. At a speed above the predetermined speed, a majority of the portion of the combusted and uncombusted exhaust gasses flows from the exhaust system and back into the combustion chamber without engaging the skirt of the piston.

A two cycle engine having a block defining an exhaust port and a cylinder, a head, and a piston defining a combustion chamber is disclosed. The exhaust port has a resonant frequency that causes a portion of the combusted and uncombusted exhaust gasses to flow from the exhaust system and back into the combustion chamber. At a speed above the predetermined speed, a majority of the portion of the combusted and uncombusted exhaust gasses flows from the exhaust system and back into the combustion chamber without engaging the skirt of the piston.

The invention relates to a two-stroke internal combustion engine, in particular for a motor vehicle, with direct fuel injection, comprising at least one working cylinder (1) which comprises a bushing and in which a piston (6) can be moved in an oscillating manner; at least one outlet channel (2) which opens into the working cylinder (1) above the upper dead center of the piston (6); at least two inlet openings (5) which are distributed over the circumference of the bushing and which open into the working cylinder (1) above the lower dead center of the piston (6) such that a uniflow scavenging process of the working cylinder (1) is produced during the operation of the two-stroke internal combustion engine; and a slider which releases and closes the inlet openings (5), whereby the slider is designed as a tube slider (4) which surrounds the bushing of the working cylinder (1) and which comprises a closed casing. The slider releases or closes the inlet openings (5) in an oscillating manner in the longitudinal direction of the bushing during the charge cycle.

The invention relates to a two-stroke internal combustion engine, in particular for a motor vehicle, with direct fuel injection, comprising at least one working cylinder (1) which comprises a bushing and in which a piston (6) can be moved in an oscillating manner; at least one outlet channel (2) which opens into the working cylinder (1) above the upper dead center of the piston (6); at least two inlet openings (5) which are distributed over the circumference of the bushing and which open into the working cylinder (1) above the lower dead center of the piston (6) such that a uniflow scavenging process of the working cylinder (1) is produced during the operation of the two-stroke internal combustion engine; and a slider which releases and closes the inlet openings (5), whereby the slider is designed as a tube slider (4) which surrounds the bushing of the working cylinder (1) and which comprises a closed casing. The slider releases or closes the inlet openings (5) in an oscillating manner in the longitudinal direction of the bushing during the charge cycle.

A dual fuel carburetor includes a carburetor body, a main jet pipe and a float chamber housing to form a float chamber, the needle valve device includes a pushing needle and a needle valve base, the pushing needle is movably inserted in the float chamber housing, and a window is formed at a bottom of the float chamber housing, the needle valve device further includes a sealed corrugated sleeve positioned around the pushing needle, which has a first end hermetically connected with the pushing needle and a second end hermetically connected with the float chamber housing, a driving spring is positioned around the pushing needle, and the pushing needle has a driving end extended out from the float chamber housing and opposite to that end cooperated with the valve base hole. The needle valve device is in a reasonable design to obtain mechanical controls or other automated drive controls.

Provided is an air leading type stratified scavenging two-stroke internal combustion engine including an air passage configured to allow supply of air to a scavenging passage configured to allow communication between a crank chamber and a combustion chamber, at least one sensor configured to detect an operating condition of an engine, and a fuel valve configured to control fuel supply to the air passage based on detection performed by the at least one sensor. The fuel supply to the air passage is controlled by the fuel valve at times other than start and idling of the engine or at needed times in addition to the start or the idling of the engine.

Provided is an air leading type stratified scavenging two-stroke internal combustion engine including an air passage configured to allow supply of air to a scavenging passage configured to allow communication between a crank chamber and a combustion chamber, at least one sensor configured to detect an operating condition of an engine, and a fuel valve configured to control fuel supply to the air passage based on detection performed by the at least one sensor. The fuel supply to the air passage is controlled by the fuel valve at times other than start and idling of the engine or at needed times in addition to the start or the idling of the engine.

Cooperatively shaped piston and cylinder head arrangements for internal combustion engines are disclosed. The piston may have a domed head with one or more curved exhaust channels and inlet channels formed therein. The piston cylinder may have curved surfaces that are exact or close inverse or negative counterparts to the curved surfaces of all or part of the domed head, including the exhaust channels, and/or inlet channels formed on the piston.

A two-stroke internal combustion engine includes: a piston-cylinder group defining a combustion and a pumping chamber, the piston mobile in the cylinder between a bottom dead center where the combustion chamber's volume is maximum and the pumping chamber's volume is minimum, and a top dead center, where the combustion chamber's volume is minimum and the pumping chamber's volume is maximum. The engine also includes an intake conduit communicating with the pumping chamber, an exhaust conduit communicating with the combustion chamber, at least a pair of transfer conduits allowing communication between the pumping and combustion chambers, and at least two primary channels in the piston, individually provided with an inlet facing onto the exhaust conduit and an outlet facing on a respective transfer conduit at least when the piston is at the top dead center. A lateral surface of the piston includes a lowering where the primary channels inlets are located.

A two-stroke internal combustion engine includes: a piston-cylinder group defining a combustion and a pumping chamber, the piston mobile in the cylinder between a bottom dead center where the combustion chamber's volume is maximum and the pumping chamber's volume is minimum, and a top dead center, where the combustion chamber's volume is minimum and the pumping chamber's volume is maximum. The engine also includes an intake conduit communicating with the pumping chamber, an exhaust conduit communicating with the combustion chamber, at least a pair of transfer conduits allowing communication between the pumping and combustion chambers, and at least two primary channels in the piston, individually provided with an inlet facing onto the exhaust conduit and an outlet facing on a respective transfer conduit at least when the piston is at the top dead center. A lateral surface of the piston includes a lowering where the primary channels inlets are located.