The present invention relates to a piston (10) for an internal combustion engine, which has a piston skirt (14) as well as a piston head (13) having a circumferential ring belt (21) and having a circumferential cooling channel (24) closed off with a closure element (26), wherein a circumferential recess (23) is formed between the piston head (13) and the piston skirt (14). According to the invention, it is provided that the closure element (26) consists of at least two subcomponents (27, 28), that each subcomponent (27, 28) has a radially oriented base plate (29) and at least one circumferential collar (31) oriented axially on the outer edge (29a) of the base plate (29), which collar is accommodated in at least one outer fold (34) that runs underneath the ring belt (21).

Aspects of the disclosure are directed to a crank. In accordance with one aspect, the crank includes a first web, wherein the first web includes a first plurality of protrusions, and wherein one of the first plurality of protrusions includes a first midline radial axis and is non-symmetric with respect to the first midline radial axis; and a second web coupled to the first web, wherein the second web includes a second plurality of protrusions, and wherein one of the second plurality of protrusions includes a second midline radial axis and is non-symmetric with respect to the second midline radial axis.

Aspects of the disclosure are directed to an engine crank. In accordance with one aspect, the engine crank includes a first web, wherein the first web includes a first plurality of air channels, and a second web coupled to the first web, wherein the second web includes a second plurality of air channels.

A two-stroke engine piston (1) is disclosed comprising a piston top (3), a mantle surface (5), a stratified scavenging channel (7) in the mantle surface (5), and a weight reduction space (9) arranged between the piston top (3) and the stratified scavenging channel (7). The weight reduction space (9) has a largest first axial extent (a1) at the mantle surface (5) and a second axial extent (a2) radially inside the mantle surface (5), and wherein the second axial extent (a2) is greater than the largest first axial extent (a1). The present disclosure further relates to an engine (30), a hand-held tool (40), and a method of manufacturing an engine piston (1).

A method includes operating an air boosting apparatus of a two-stroke, opposed piston engine as a function of one or more factors including a first engine speed, a first torque, demand, a first altitude, a first transient rate, and one or more first ambient conditions to provide a first pressure S ratio (PR} of pre-turbine pressure (PTP) versus turbocharger compressor discharge pressure (CDP} and a first air-to-fuel ratio (AFR).

A piston crown for a piston of a pair of pistons in a two-stroke, opposed-piston, compression ignition combustion engine has a barrier layer and a conductive layer. The barrier layer at least partially surrounds a combustion chamber formed by the piston crown and an end surface of an opposing piston. The conductive layer connects the crown to the rest of the piston body. The barrier layer and the conductive layer are joined either through welding or through the fabrication process. Optionally, the piston crown includes an insulating layer between the barrier and conductive layers.

The present disclosure relates to a system for controlling ignition of an air/fuel mixture intake charge directed into an internal combustion engine. The system may have a longitudinally movable inner cylinder liner configured to fit within a cylinder wall portion of an internal combustion engine, and able to receive a piston of the engine therein. A portion of the inner cylinder liner defines an internal volume forming a combustion chamber, and the internal volume controls a compression ratio of the cylinder. The system also has a cylinder head assembly operatively associated with the inner cylinder liner and able to move linearly to cause longitudinal displacement of the inner cylinder liner relative to the cylinder wall portion. This enables the volume of the combustion chamber to be further varied, to thus further vary the compression ratio.

A non-polluting, zero hazardous gas emission electricity generating hybrid system is provided with a hydraulic pressure drive cylinder. To one end of the linear movement drive cylinder is connected with a fluid reservoir containing the fluid to be supplied to the drive cylinder. The fluid from the reservoir is pressured through the inlet pipes by the mechanical pump electrically connected to the motor positioned on top of the said fluid reservoir. To the other end of the linear movement drive cylinder is provided an outlet means for collecting the said fluid into the fluid reservoir enabling the linear movement for the hydraulic cylinder.

An air-leading type, stratified scavenging two-stroke engine. The engine including a cylinder member and a crankcase joined therewith has an intake passage, an exhaust passage, first and second scavenging passages, a communicating portion and an air passage. The intake passage, the exhaust passage and the air passage are formed in the cylinder member. The first and the second scavenging passages each has a cylinder member-side passage and a crankcase-side passage. The cylinder member-side passages of both of the first and the second scavenging passages communicate with each other via the communicating portion. The air passage is connected to the cylinder member-side passage of the first scavenging passage. In the engine, air for pre-scavenging is introduced from the air passage through a check valve into the cylinder member-side passage of the first scavenging passage, and a part of the introduced air flows into the second scavenging passage through the communicating portion.

A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.