A steel piston with an engineered coating is provided. A high thermal conductivity material, for example copper, is disposed on first regions of a combustion bowl to reduce hot spots in the piston. A low thermal conductivity material, for example a ceramic, is disposed on second regions of the combustion bowl to reduce loss of heat through the piston. The high thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 5 μm to help reflect IR radiation and promote fuel flow. The low thermal conductivity material disposed on the combustion bowl has a surface roughness (R.sub.a) of less than 3 μm to promote fuel flow. The low thermal conductivity material is also disposed on the bowl rim and top ring land, and has a surface roughness (R.sub.a) of greater than 8 μm on the bowl rim and top ring land to retard gas flow.

A neat-fuel direct-injected compression ignition engine having a thermal barrier coated combustion chamber, an injection port injects fuel that satisfies a stoichiometric condition with respect to the intake air, a mechanical exhaust regenerator transfers energy from exhaust gas to intake compression stages, an exhaust O.sub.2 sensor inputs to a feedback control to deliver quantified fuel, a variable valve actuation (VVA) controls valve positions, an exhaust gas temperature sensor controls exhaust feedback by closing the exhaust valve early according to the VVA, or recirculated to the chamber with an exhaust-gas-recirculation (EGR), heat exchanger, and flow path connecting an air intake, a load command input, and a computer operates the EGR from sensors to input exhaust gas according exhaust temperature signals and changes VVA timing, the load control is by chamber exhaust gas, the computer operates a fuel injector to deliver fuel independent of exhaust gas by the O.sub.2 signals.

A piston for an internal combustion engine includes a piston bowl. The piston bowl has a half section profile that includes a bowl entry extending radially from the longitudinal piston center axis, a first bowl recess extending radially from the bowl entry and defining a bowl depth and a first radius of curvature, a second bowl recess extending radially from a first bowl recess to an end perimeter surface and defining a second radius of curvature, a bowl lip defined by the first bowl recess and the second bowl recess, and a bowl edge defined by the second bowl recess and the end perimeter surface. The first bowl recess further defines a first bowl recess exit angle at the bowl lip. The second bowl recess further defines a second bowl recess exit angle at the bowl edge.

Systems, devices, and methods described herein provide one or more radical chemicals generators (RCGs) and/or mini-chambers (M-Cs) that can be used to provide enhanced radical ignition (ERI) in an internal combustion engine. RCGs as described herein can include quenching systems (QSs) that can be configured to quench a flame of combustion products to produce a jet of partial combustion products containing radical species (RS). The jet of partial combustion products can be injected to a main combustion chamber (MCC) of an engine to induce ERI. ERI can proceed under leaner fuel conditions and lower temperatures compared to those needed for conventional thermally induced, fuel oxidation chain initiation reaction processes.

A piston for an internal combustion engine includes a piston bowl. The piston bowl has a half section profile that includes a bowl entry extending radially from the longitudinal piston center axis, a first bowl recess extending radially from the bowl entry and defining a bowl depth and a first radius of curvature, a second bowl recess extending radially from a first bowl recess to an end perimeter surface and defining a second radius of curvature, a bowl lip defined by the first bowl recess and the second bowl recess, and a bowl edge defined by the second bowl recess and the end perimeter surface. The first bowl recess further defines a first bowl recess exit angle at the bowl lip. The second bowl recess further defines a second bowl recess exit angle at the bowl edge.

This piston for a diesel engine includes: a bottom portion that has a deepest combustion chamber bottom in the combustion chamber; a circumferential protrusion that is provided around an entire circumference of a circumferential wall between the bottom portion and a top surface of the piston and protrudes toward an intersection (P0) of a center line of the piston and the top surface in a cross-sectional view that includes the center line; an inclination portion that inclines closer to the top surface toward an outer side in a radial direction from the circumferential protrusion; and a rising portion that rises from the inclination portion toward the top surface.

A fuel injector includes an injector housing having a fuel connector, and an outer housing surface extending around a longitudinal axis of the injector housing. The outer housing surface includes a cylindrical upper section, a cylindrical lower section, and a middle section. The fuel connector defines a connector axis oriented normal to a longitudinal axis of the injector housing and extending between a first connector end attached to the middle section, and a terminal connector end radially outward of the outer housing surface and having therein a fuel inlet. The fuel connector includes an outer connector surface having an unthreaded base section, and an externally threaded end section adjacent to the terminal connector end.

An engine management system and method may include a control system and method for controlling an internal combustion engine. The internal combustion engine may be a direct-injection engine using a Sonex Controlled Auto-Ignition (“SCAI”) combustion path. The control system and method may utilize fuel injection pressure, timing of start and end of injection, management of turbo airflow, fuel supplied, and other factors to provide reduced emissions and improved performance.

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.