A cylindrical part capable of supporting an ignition-coil-integrated plug cap is formed on a head cover so as to correspond to a plug hole of a cylinder head. The cylindrical part is formed by fitting and fixing a pipe material to a mounting hole part formed in the head cover, the mounting hole part facing the plug hole.

An air monitoring system measures tan amount of pollutant in the air. The system includes a plurality of air quality sensor devices arranged within a selected area. Each of the air quality sensor devices is configured to measure air pollutant levels in the selected area, and includes at least one sensor operatively coupled to a controller, wherein the controller is configured to receive a measured input from the at least one sensor. A wireless communication device is coupled to the controller, and is configured to communicate with a central server device.

An installation tool installs a camshaft to a lower supporting portion. A cylinder head of an internal combustion engine includes the lower supporting portion, a cam holder, and a half-thrust washer. The camshaft is sandwiched between the cam holder and the lower supporting portion via a bearing. The half-thrust washer is inserted into respective annular groove disposed in an outer peripheral surface of the bearing and half annular groove disposed in the cam holder. The installation tool includes a bearing holder that holds the bearing, a head abutting portion abutted against a reference surface of the lower supporting portion with the bearing held, and an opposed concave knock portion into which a knock collar disposed in the cam holder is inserted to adjust a position of the half annular groove with respect to the half-thrust washer.

A plastic molded article includes a base having a main surface, a first tubular portion protruding from the main surface, a second tubular portion protruding from the main surface and having an inner diameter smaller than that of the first tubular portion, and a pair of ribs that protrudes from the main surface and connects an outer circumferential surface of the first tubular portion and an outer circumferential surface of the second tubular portion to each other. The base, the first tubular portion, the second tubular portion, and the ribs are integrally molded of plastic. The ribs are located on opposite sides of an imaginary plane that includes a central axis of the first tubular portion and a central axis of the second tubular portion.

A camshaft cover, a camshaft assembly, and a double-cylinder engine are provided. The camshaft cover has an integral structure, and includes a first shaft cover portion, a second shaft cover portion, a first connecting portion and a second connecting portion. The first connecting portion and the second connecting portion are connected between the first shaft cover portion and the second shaft cover portion, and spaced apart axially.

A head cover structure (45) for an internal combustion engine (1) comprises a head cover (4) connected to a cylinder head (3), and an auxiliary cover (44) connected to the head cover and defining a gas-liquid separation passage (74) jointly with the head cover, the gas-liquid separation passage being communicated with a crankcase chamber (11) of the internal combustion engine, and configured to separate lubricating oil from a crankcase gas drawn from the crankcase chamber, wherein the auxiliary cover is integrally formed with an intake pipe (49) internally defining a part of an intake passage (20) of the internal combustion engine, and the auxiliary cover internally defines a crankcase gas introduction passage (63) communicating the gas-liquid separation passage with an interior of the intake pipe.

An internal combustion engine having at least one cylinder bank comprising multiple cylinders, each cylinder comprises a rocker arm box for accommodating rocker arms of a valve train, and each cylinder comprises a rocker arm cover pivotable relative to the rocker arm box. The rocker arm cover carries an ignition coil contactable with a spark plug via an extension extending through a protective tube between the cylinder head and the rocker arm box or the rocker arm cover. The rocker arm cover comprises a first portion with a first introduction aid, into which the protective tube is threaded during closure of the rocker arm cover and a second portion with a second introduction aid, into which the spark plug extension is threaded during closure of the rocker arm cover to automatically and self-centringly form an electrical contact between the spark plug extension and the ignition coil.

A novel cylinder head arrangement for an in-line four cylinder or eight cylinder engine. A modified arrangement allows additional space for installation of wider rocker arm assemblies used for variable valve lift (VVL), cylinder deactivation (CDA) and other types of variable valve actuation (VVA). In one embodiment, cam towers adjacent the end two cylinders are not used. At least one end support is used, which may be an outboard bearing on a camshaft for each end. The wider rocker assemblies may then be installed. In another embodiment, cam towers adjacent the inner two cylinders are eliminated and a single camshaft support piece with a support bearing is installed between the inner cylinders to provide support for the camshafts. The wider rocker assemblies may then be installed on at least one of the middle cylinders. A novel oil control valve operates latches in switching rocker arm assemblies.

A device for monitoring the function of an engine is powered by heat from the engine or other sources other than a conventional, external direct electrical power supply, which may create sparks and/or be unavailable. The device monitors one or more of heat, vibration, or other parameters and can detect certain problems with engine function. The device is particularly suited for remote engine monitoring, and can store and/or display data concerning monitored engine characteristics, and/or directly or indirectly send such data to a location removed from the engine.

The head cover for an engine includes a gas passage in the head cover, a gas outlet formed on a head cover wall at a terminal end portion of the gas passage in the head cover, a gas intermediate outlet portion formed in the head cover wall so as to face space inside the head cover except the gas passage in the head cover, and a gas intermediate inlet portion formed in the head cover wall so as to face the gas passage in the head cover, in which an opening specification in which through holes penetrating the head cover wall are formed and a closing specification in which the through holes are not formed can be selected for the gas intermediate outlet portion and the gas intermediate inlet portion.