Operating an engine includes moving a piston in a combustion chamber between a bottom dead center position and a top dead center position in an engine cycle. A fuel is injected into the combustion chamber through a plurality of sets of nozzle outlets varied set-to-set with respect to outlet size and spray angle. Spray jets of the injected fuel are propagated in an impingement-limiting fuel spray pattern that is based on the set-to-set variation in outlet size and spray angle so as to limit dissipation of heat from combustion of the injected fuel to material of the engine by way of a thermal barrier coating (TBC) upon a surface of the combustion chamber.

A liquid injector atomizer for direct injection in to the cylinder of an internal combustion engine is provided, with a supply of pressurized liquid a supply of pressurized gas, a body, and a nozzle with two or more orifices each for the liquid and the gas. Each orifice directs a jet of metered pressurized liquid or gas out of the injector body. At least two of the liquid jets are aimed at one or more collision points, where at least two gas jet streams collide at a same collision point or another collision point, thereby creating a finely atomized liquid.

A piston includes a crown having a deck, a spark recess, an exhaust valve recess, and an intake valve recess. The piston also includes a wedge disposed on the crown extending from the exhaust valve recess and the intake valve recess toward the spark recess above the deck. The wedge is a planar wedge disposed at an angle substantially parallel to an associated exhaust valve received by the exhaust valve recess. The crown is symmetrical about a piston center line.

Systems are provided for cooling combustion chamber gasses and increasing an amount of air entrained in an injected fuel spray. In one example, a cooling passage may be included in an internal combustion engine, the cooling passage positioned exterior to a cylinder bore of the engine and coupled to the cylinder bore at a first opening and a second opening. The cooling passage may receive gasses from the cylinder bore via the first opening, and may cool the gasses as they travel through the cooling passage before returning the gasses to the cylinder bore via the second opening.

An internal-combustion engine includes a cylinder, a piston, a spark plug, and a fuel injection valve. The piston includes a top surface and a cavity provided in the top surface. The cavity includes a bottom surface, a vertical wall, a first sidewall, and a second sidewall. The fuel injection valve includes a plurality of injection ports from which a plurality of fuel mists are to be obliquely injected toward the top surface of the piston in respectively different directions at a predetermined crank angle in a compression stroke. The cavity extends from a position close to a center of the piston toward the fuel injection valve when viewed from above the top surface of the piston. The first and second sidewalls extend toward the fuel injection valve when viewed from above the top surface of the piston.

A piston for use in 4 Cycle reciprocating Internal Combustion Engines. The one embodiment includes a multifunctional Engraving or Imprint that is machined into the crown of the piston. This “Imprint” consists of concentric circles of metal removed in a machining process resulting in the compartments of the functional areas within the crown of the piston connected by either the height and or cross drillings within the Imprint. The functional result is to create low and high pressure zones within the crown of the piston as it proceeds upward on the compression stroke facilitating the creation of an active moving rotational swirl in the outer 25% on the top surface area of the piston circumference. The active swirl pattern results in ultimate homogenization of the air fuel mixture leaving no area of the combustion chamber with weak or separated air and fuel molecules resulting in enhanced power and complete combustion.

A ducted combustion system is disclosed. The ducted combustion system includes a combustion chamber bound by a flame deck surface of a cylinder head of an internal combustion engine and by a piston top surface of a piston disposed within the internal combustion engine. The system includes a fuel injector including a plurality of orifices, the plurality of orifices injecting fuel into the combustion chamber as a plurality of fuel jets. The system includes a duct structure defining a plurality of ducts and disposed within the combustion chamber between the flame deck surface and the piston top surface, the plurality of ducts being disposed such that each of the plurality of fuel jets at least partially enters one of the plurality of ducts upon being injected into the combustion chamber.

An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

A thermal insulation film is formed on a bottom surface of a cylinder head facing a top surface of a piston. The thermal insulation film in a region (a circumferential region) of a bottom surface of the cylinder head configuring a squish area in a circumferential edge of a cavity region is formed to be thinner than the thermal insulation film in a region (a cavity region) of the bottom surface of the cylinder head facing a cavity. The thermal insulation film in the circumferential region is polished, and surface roughness thereof is equal to or lower than 3 μm. The thermal insulation film in the cavity region is not polished, and surface roughness thereof is 3 to 8 μm on average.

Combustion chamber of a diesel engine, the combustion chamber comprising: a piston having a piston bottom surface and a cylinder head having a cylinder head surface the combustion chamber having a combustion chamber axis, wherein one of said piston bottom surface and said cylinder head surface includes at least one depression and an ignition element is disposed in said combustion chamber and extends along said combustion chamber axis, said ignition element is configured to cause ignition along a longitudinal route of said combustion chamber axis.