An engine control device controls control amounts of a variable valve mechanism and a spark plug, the control amounts in a homogeneous lean operation region set in a first load region are different from that in a non-lean operation region which is a stoichiometric or rich operation region set in a second load region higher than the first load region. The control device performs control, in other operation region set in a third load region between the first and second load region, so that an air-fuel ratio of the internal combustion engine is equal to that of non-lean operation region, the control amount of the variable valve mechanism is equal to that of homogeneous lean operation region and the control amount of the spark plug is equal to that of the non-lean operation region in accordance with an operation amount of an accelerator pedal.

An internal combustion engine is configured to operate in a homogeneous-charge compression-ignition combustion mode and a spark-ignition combustion mode employing late intake valve closing. A method for operating the internal combustion engine includes determining an amount of residual gas re-inducted into a combustion chamber from a previous engine cycle and determining an amount of fresh air trapped in the combustion chamber for the present engine cycle based upon the amount of residual gas re-inducted into the combustion chamber from the previous engine cycle. Engine fueling to the cylinder for the present engine cycle is controlled based upon the amount of fresh air trapped in the combustion chamber for the present engine cycle.

A method and apparatus for reducing at least one of HC, CO, and NO.sub.x emissions from an operating internal combustion engine fueled by hydrocarbon or similar fuels, such as alcohols, wherein a portion of the internal combustion chamber has aluminum and/or titanium containing surfaces coated with a titanium dioxide coating further comprising a dopant in and/or on the adherent titanium dioxide coating.

A cylinder head includes: a cylinder head body; multiple fuel ports extending to cylinders from a sidewall surface of the cylinder head body, the sidewall surface being located on one side of a longitudinal axis, on which intake ports are disposed; multiple injection valve attachment bosses projecting from the sidewall surface, surrounding openings of the fuel ports, and adapted to attach cylinder fuel injection valves to the fuel ports; and multiple projections projecting from the sidewall surface and disposed adjacent to the corresponding injection valve attachment bosses. A cylinder block includes: a cylinder block body; and a sensor attachment boss projecting from a sidewall surface of the cylinder block body, the sidewall surface being located on the one side of the longitudinal axis, on which the sidewall surface of the cylinder head body is located. The sensor attachment boss is adapted to attach a knock sensor to the cylinder block.

A method and apparatus for reducing at least one of HC, CO, and NO.sub.x, emissions from an operating internal combustion engine fueled by hydrocarbon or similar fuels, such as alcohols, wherein a portion of the internal combustion chamber has aluminum and/or titanium containing surfaces coated with a titanium dioxide coating further comprising a dopant in and/or on the adherent titanium dioxide coating.

Various systems and methods for controlling a turbocharger of an engine via a wastegate are described. In one example, the wastegate is adjusted according to a difference between the boost pressure and the atmospheric pressure. In this manner, the interdependency between controlling the boost pressure and using the boost pressure to actuate the wastegate in a boost-based wastegate configuration may be reduced.

A piston is used for an engine including: an ignition plug disposed in the vicinity of a central axis of a cylinder; intake and exhaust ports disposed at positions where the ignition plug is interposed therebetween; and an injector disposed at a position offset from the ignition plug toward the intake port to inject fuel sprays toward a crown surface of the piston. The piston includes: a recess formed by recessing the crown surface of the piston with respect to other portions of the crown surface, in which the recess includes a step on an outer peripheral edge over the entire circumference thereof with respect to the other portions, and a pair of lateral sides formed straightly so as to extend substantially in parallel to a straight line connecting the injector and the ignition plug when seen in a direction of the cylinder axis.

A fuel injection apparatus includes: an injector disposed at a position offset from an ignition plug toward an intake port and injecting a fuel spray toward a crown surface of a piston, and an injection controller causing the injector to perform injection in accordance with an amount and timing of fuel injection preset in accordance with an operating state of an engine. The piston includes: a first recess formed by recessing a central portion of the crown surface and a second recess formed by recessing part of the first recess on an injector side further than the first recess. The injector injects 50% or more of fuel to be injected for the last fuel injection toward the second recess during a compression stroke, and injects part of the fuel to be injected for the last fuel injection toward an area of the first recess other than the second recess.

An in-cylinder pressure detecting device of a direct injection type internal combustion engine is provided in which a ring-shaped pressure detection element (34) surrounding a fuel injection hole (33b) is provided in the vicinity of an extremity of an injector (20) that injects fuel into a combustion chamber. Since the pressure detection element is provided on the injector, not only is it unnecessary to change the shape or structure of the cylinder head or the combustion chamber in order to provide the pressure detection element, but it is also possible to cool the pressure detection element (34) by fuel passing through the inside of the injector to thus enhance the precision of pressure detection and the durability. Further, since the ring-shaped pressure detection element (34) surrounds the periphery of the fuel injection hole (33b), it is possible to maximize the dimensions of the pressure detection element (34) to thus further enhance the precision of pressure detection while avoiding interference between the pressure detection element (34) and fuel injected via the fuel injection hole (33b).

In the present invention, an internal combustion engine is provided with an in-cylinder fuel injection valve and a secondary air supply device and is formed so as to make possible first catalyst warming control and second catalyst warming control that promote the raising of the temperature of an exhaust gas purification catalyst. The first catalyst warming control comprises control to inject fuel from the in-cylinder fuel injection valve during the compression stroke to form a stratified state, and control to greatly delay ignition timing. The second catalyst warming control comprises control to supply secondary air to an engine exhaust gas passage. The internal combustion engine executes the first catalyst warming control after startup and, after the first catalyst warming control is executed, carries out control (third catalyst warming control) to execute the first catalyst warming control and the second catalyst warming control simultaneously.