A piston includes: a piston head; and a piston skirt connected to the piston head, wherein the piston skirt includes wall portions protruding outward from a surface of the piston skirt, the wall portions adjacent to each other in a circumferential direction of the piston skirt are inclined in directions opposite to each other with respect to a direction of movement of the piston in a bore for the piston, and define a tapered portion, and the tapered portions are spaced away from each other in the circumferential direction of the piston skirt.

A piston for a high temperature internal combustion engine is provided. The piston includes an upper wall, base wall, outer rib, and inner rib defining a cooling chamber therebetween, and a plurality of ring grooves formed in the outer rib. Only the second ring groove is formed with the keystone cross-section, and all of the other ring grooves are formed with the conventional rectangular cross-section. Thus, the piston can be formed with low manufacturing costs and can also provide exceptional performance when used in high temperature combustion engines, wherein the temperature at the first ring groove is greater than 280° C., and thus prevents carbon from depositing or burns off any carbon deposits, but the temperature at the second ring groove is between 200° C. and 280° C., in which case carbon deposits can form and cause the piston ring to stick.

Operating an internal combustion engine includes conveying fuel of spray plumes of directly injected fuel out of a swirl pocket in a combustion bowl in a piston, and impinging the fuel upon an anti-sooting ramp transitioning between a radially inner shelf surface of the combustion bowl and a radially outer squish surface of the piston. The shelf surface is spaced an axial distance (FA) from a plane defined by the squish surface that is from 1% to 2% of an outer diameter (OD) dimension of the piston. Impinging the fuel upon the anti-sooting ramp directs the fuel upwardly from the squish surface to limit wall-wetting in the combustion cylinder.

A sensor device system for detection of a liquid adjacent to the sensor having a glass fiber laminate substrate, at least one pair of comb electrodes formed on the glass fiber laminate substrate, a first of the pair of comb electrodes being interdigitated with a second of the pair of comb electrodes, the pair of comb electrodes defining geometric parameters; and a passivation coating covering the pair of comb electrodes.

A piston includes: a piston head; and a piston skirt connected to the piston head, wherein the piston skirt includes wall portions protruding outward from a surface of the piston skirt, the wall portions adjacent to each other in a circumferential direction of the piston skirt are inclined in directions opposite to each other with respect to a direction of movement of the piston in a bore for the piston, and define a tapered portion, and the tapered portions are spaced away from each other in the circumferential direction of the piston skirt.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The piston may be configured to move in the cylinder in a first stroke from one end to another. The first stroke may include an expansion stroke portion and a non-expansion stroke portion. The non-expansion stroke portion may include a momentum stroke portion. The non-expansion stroke portion may include a scavenging phase. The engine may further include first and second piston rod portions extending from opposite faces of the piston. Passageways in the piston rod portions may be configured to communicate gases between a combustion chamber and other locations.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted within the cylinder. The piston may be configured to move in the cylinder in a work stroke from one end to another. The work stroke may include an expansion stroke portion, a momentum stroke portion, and a compression stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. Passageways in the piston rod portions may be configured to communicate gases between a combustion chamber and a location outside the cylinder.

A method of manufacturing an engine piston may include performing upper-body formation for forming an upper body as an upper portion of a piston body by pressing a powder-type sintered material, performing lower-body formation for forming a lower body as a lower portion of the piston body by pressing a powder-type sintered material, performing bonding for forming the piston body by providing a brazing material between the upper body and the lower body and brazing the upper body and the lower body to each other while sintering a sintered material, performing machining for removing pores from the surface of the piston body by machining the surface, and performing heat treatment for forming a passive film by performing at least one of nitriding heat treatment or oxidation heat treatment on the surface of the piston body.

An engine piston having a piston upper part, a piston lower part connected to the piston upper part, a piston pin mounted in the piston lower part connects the piston to a connecting rod, and a first cooling space between the piston upper and lower parts for cooling oil. The first cooling space is connected to a second cooling space formed between the piston upper part and a piston lower part via at least one transfer bore, a cooling oil conduction sleeve for conducting cooling oil through a bore in the connecting rod towards the first cooling space. A guiding surface of the cooling oil conduction sleeve adjoins a support face of the piston lower part. At least one groove circulating in the circumferential direction is introduced into the guiding surface of the cooling oil conduction sleeve and/or into the support face of the piston lower part.

A piston is provided with a gapless ring positioned in a subport position. Specifically, the gapless ring is positioned between the air ports and the crankcase of the engine. The gapless ring includes a rail and an annular ring received within the rail. The ring includes a ring gap and the rail includes a rail gap. When the rail receives the annular ring, the ring gap and rail gap are spaced apart in a circumferential direction such that the gaps do not overlap. In certain embodiments, the rail includes a notch. When the annular ring is received within the notch, the annular ring and rail are biased against rotating with respect to each other. In certain other embodiments, the gapless ring includes an oil scraping surface.