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.

Improvements in a mechanism that determines top dead center of an internal combustion engine where detecting the top of the stroke can be difficult to determine as the crank is being rotated. The gauge set mounts into a spark plug or fuel injector hole. These holes are usually a tapped hole where the piston position gauge can be threaded into, to provide a stable and concentric mount where the measurement pin passes through the exterior threaded shaft of the mount. A pin extends into the cylinder to determine when the piston is approaching and at the top of the cylinder. The mount is an elongated stalk that allows for additional cam gauges where the cam gauges can be mounted and linearly adjustable on the single stalk. The measurement is with dial indicators so a user can measure three varying engine parts to determine the top-dead-center.

A control device for controlling an internal combustion engine equipped with an engine body, a variable compression ratio mechanism A configured to be able to change a mechanical compression ratio of the engine body, and an intake system configured to be able to make exhaust discharged from combustion chambers of the engine body be recirculated to an intake passage of the engine body. The control device is provided with a compression ratio control part controlling the variable compression ratio mechanism A so that the mechanical compression ratio becomes the target compression ratio. The compression ratio control part sets the target compression ratio at a lower value when exhaust is being recirculated at a predetermined operating region at an engine low load side than when exhaust is not being recirculated.

An upper oil pan assembly is attached to the lower portion of a cylinder block. An opening is formed on a side wall of the upper oil pan assembly. The variable compression ratio mechanism changes a top dead center position of a piston in accordance with the rotational position of a control shaft to thereby change the compression ratio. The control shaft is rotationally driven by an actuator. At least a portion of the actuator is fixed to a main bearing cap in a state in which at least a portion thereof is positioned on the outer side of an upper oil pan assembly.

An upper oil pan assembly is attached to the lower portion of a cylinder block. An opening is formed on a side wall of the upper oil pan assembly. The variable compression ratio mechanism changes a top dead center position of a piston in accordance with the rotational position of a control shaft to thereby change the compression ratio. The control shaft is rotationally driven by an actuator. At least a portion of the actuator is fixed to a main bearing cap in a state in which at least a portion thereof is positioned on the outer side of an upper oil pan assembly.

A saddled vehicle includes: a fuel injection valve mounted in a cylinder head from one side surface of the cylinder head and injecting fuel toward a combustion chamber; and a fuel pump that supplies fuel to the fuel injection valve in response to a generated pump pressure. The fuel pump is disposed in a space between main frames and a down frame and in the one side surface of the cylinder head. Accordingly, there is provided a layout of the fuel pump capable of sufficiently protecting the fuel pump without a need to restrict a position of an internal combustion engine.

An internal combustion engine includes an auxiliary chamber bulkhead, the auxiliary chamber bulkhead including: a peripheral wall portion that is inserted in a vertical hole extending from a combustion chamber along a reference axis and that is in contact with an inner wall of the vertical hole about the reference axis; and a bottom wall portion that is continuous from the peripheral wall portion and that bulges from the vertical hole toward the combustion chamber, the peripheral wall portion and the bottom wall portion defining an auxiliary chamber that communicates with the combustion chamber. An ignition plug is disposed above the peripheral wall portion along the reference axis. A fuel injection valve is disposed in a position inclined with respect to the reference axis toward an opening formed in an inner surface of the peripheral wall portion.

An endless band drive system having a variable center distance between the drive pulley and the driven pulley also has a rotatable control shaft and an endless band guide, where the guide is positioned by the rotatable control shaft for maintaining a slackless endless band with change of pulley center distance. Rotation of the control shaft pivots the endless band guide thereby maintaining a slackless endless band with change of the pulley center distance. Preferably, the rotatable control shaft also provides means for adjusting the center distance between the drive pulley and the driven pulley. The present invention provides a slackless endless band system for a variable compression ratio engine having a variable center distance between the drive pulley mounted on the crankshaft and the driven pulley mounted on the camshaft. The system provides slackless operation of the endless band at two or more compression ratio values.

A reciprocating piston and cylinder apparatus with adjustable stroke volume. The apparatus comprises an axially displaceable traveling cylinder, a stationary piston, and an optional sleeve secured to the traveling cylinder in a detachable manner. The traveling cylinder is displaced along its axis by a thrust component and acts cooperatively with the stationary piston to create a pressure change within the housing.

An internal combustion engine includes an auxiliary chamber bulkhead, the auxiliary chamber bulkhead including: a peripheral wall portion that is inserted in a vertical hole extending from a combustion chamber along a reference axis and that is in contact with an inner wall of the vertical hole about the reference axis; and a bottom wall portion that is continuous from the peripheral wall portion and that bulges from the vertical hole toward the combustion chamber, the peripheral wall portion and the bottom wall portion defining an auxiliary chamber that communicates with the combustion chamber. An ignition plug is disposed above the peripheral wall portion along the reference axis. A fuel injection valve is disposed in a position inclined with respect to the reference axis toward an opening formed in an inner surface of the peripheral wall portion.