An apparatus includes a bearing assembly of a first camshaft and a second camshaft on a cylinder head of an internal combustion engine. The first camshaft has a first recess where a tool is insertable into the first recess and the second camshaft has a second recess where the tool is insertable into the second recess. A cylinder head hood is attached to the cylinder head where the cylinder head hood has a first through-opening matched with the first recess and a second through-opening matched with the second recess. A first wall area of the cylinder head hood that at least partially delimits the first through-opening and a second wall area of the cylinder head hood that at least partially delimits the second through-opening are disposed at different heights.

A continuous variable valve duration apparatus includes: a camshaft, a front cam unit and a rear cam unit of which the phase relative to the camshaft can be varied, a front inner wheel and a rear inner wheel, a front guide bracket and a rear guide bracket, a front wheel housing and a rear wheel housing, a front control shaft, a rear control shaft, a phase controller selectively changing the relative phase of the front control shaft and the rear control shaft, a main driving unit for driving the rear control shaft, vibration sensors that measure the vibration of each cylinder corresponding to the front cam unit and the rear cam unit and output a corresponding signal, and a controller for controlling the operation of the main driving unit and the phase controller according to the output signals of the respective vibration sensors.

Methods and systems are provided for a cylinder head with an exterior wall including a removable camshaft carrier. In one example, a cylinder head includes a camshaft carrier removably couplable to a mount surface of the cylinder head and adapted to form a portion of an exterior wall of the cylinder head while coupled to the mount surface. The camshaft carrier may include a first section removably couplable to the cylinder head and a second section removably couplable to the first section, with the first section and the second section together shaped to receive a camshaft journal.

A radial engine-generator includes an electric power generator and a radial engine. The radial engine-generator can be a mobile and portable unit, and is employable as a primary or back-up source of electric power at data centers, manufacturing facilities, electric vehicle charging stations, medical facilities, telecommunications, and residential neighborhoods, among many other applications. The electric power generator and radial engine are coupled together. The radial engine includes, among other components, multiple cylinders, multiple cylinder heads, and multiple overhead camshaft assemblies. The overhead camshaft assemblies are located at the cylinder heads and each include one or more camshafts. The camshaft(s) receive rotational drive input from a crankshaft of the radial engine. In certain implementations, camshaft carrier assemblies can be provided to support components of the overhead camshaft assemblies.

A cylinder head cover of plastic for covering a cylinder head of an internal combustion engine is disclosed. The cylinder head cover includes a bearing track including at least two bearing points each having a bearing opening for supporting a camshaft. A bearing ring is provided in at least one of at least one bearing point and a bearing opening. The bearing ring is injected into the plastic of the cylinder head cover. An oil duct that leads to at least one of the two bearing points and serves for bearing lubrication is arranged in the cylinder head cover.

An internal combustion engine is provided, which includes an engine body provided with a cylinder having openings for intake and exhaust, and valve bodies that open and close the openings, cam shafts, each provided with a cam lobe that depress the corresponding valve body to open the openings, and bearing members pivotally supporting the cam shaft via lubricating oil. The cam shaft includes cam journals pivotally supported by the bearing members, and a recess formed at a position of the cam journal, opposing the cam lobe in the circumferential direction, and depressed radially inwardly of the cam journal, the recess being deeper in an axial end part of the cam journal than an axial center part.

An internal combustion engine includes an engine body provided with a cylinder having openings for intake and exhaust, and valve bodies that open and close the openings, cam shafts provided with cam lobes that depress the valve bodies so as to open the openings, and bearing members that pivotally supports the cam shaft via lubricating oil. Each cam shaft includes cam journals pivotally supported by the bearing members, and a hollow bore extending in the axial direction of the cam shaft. When an area of the cam journal around the hollow bore is seen in a cross-sectional view perpendicular to the axial direction, a thickness on a projecting side of the cam lobe is X1, and a thickness on the opposite side to the cam lobe in the circumferential direction is X2, a relationship of X1>X2 is satisfied in at least a part of the cam journal.

A control method can be used for securing continuously variable valve duration (CVVD) startability when a CVVD error is recognized by a CVVD controller during an operation of a CVVD system. The control method includes performing engine startability securing control for solving the CVVD error by applying a starting air volume to starting of an engine through at least one of a valve position fixing value, a valve position threshold, or an immediately previous valve position value.

An internal combustion engine includes an engine body provided with a cylinder having openings for intake and exhaust, and valve bodies that open and close the openings, cam shafts provided with cam lobes that depress the valve bodies so as to open the openings, and bearing members that pivotally supports the cam shaft via lubricating oil. Each cam shaft includes cam journals pivotally supported by the bearing members, and a hollow bore extending in the axial direction of the cam shaft. When an area of the cam journal around the hollow bore is seen in a cross-sectional view perpendicular to the axial direction, a thickness on a projecting side of the cam lobe is X1, and a thickness on the opposite side to the cam lobe in the circumferential direction is X2, a relationship of X1>X2 is satisfied in at least a part of the cam journal.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, valves of a cylinder are deactivated in a closed state in response to an indication of degradation of a valve of the cylinder. Further, fuel flow to the cylinder may be stopped via ceasing to inject fuel to the cylinder.