A valve actuation system comprising a valve actuation motion source configured to provide a main event valve actuation motion to at least one engine valve via a main motion load path that comprises at least one valve train component. The valve actuation system further includes a lost motion component arranged within a first valve train component in the main motion load path, the lost motion component being controllable to operate in a motion conveying state or a motion absorbing state. The valve actuation system also comprises a high lift transfer component arranged in the main motion load path, with the high lift transfer component being configured to permit the main motion load path to convey at least a high lift portion of the main event valve actuation motion when the lost motion component is in the motion absorbing state.

A method of determining a condition of a component (e.g., valves) of an engine having a manifold air pressure sensor during a cold test includes providing pressurized air to an intake of the engine. The method includes rotating a crankshaft of the engine. The method includes measuring pressures with the manifold air pressure sensor as a function of crankshaft rotational position. The method includes comparing the pressures with a predetermined baseline. The method includes indicating a condition of the component based on the comparison of the pressures with the baseline.

A drive circuit (203) of an actuator (2) calculates an actual working angle from an actual operation quantity with reference to a reference table used to calculate a target operation quantity, and transmits the actual working angle and the actual operation quantity to a command unit (4). The command unit (4) determines whether or not the received values of the actual working angle and the operation quantity correspond to the valve working angle and the operation quantity of the reference table stored in the command unit (4), to detect a discrepancy between the operation modes of the actuator (2) and the command unit (4).

A valve drive device for an internal combustion engine is disclosed. The valve drive device has an axially displaceable cam element and an adjusting device with a first engagement element which displaces the cam element axially into a first switching position and a second engagement element which displaces the cam element axially into a second switching position. The adjusting device has a first slotted guide track in which the first engagement element is guided in the first switching position and a second slotted guide track in which the second engagement element is guided in the second switching position. The first engagement element is positively coupled to the second engagement element. The adjusting device includes a triggering device which holds the first engagement element fixedly in the second switching position counter to a restoring force. A method for axial displacement of a rotating cam element is also disclosed.

A valve train may include a camshaft, a cam follower, and first and second cams mounted axially adjacent in a torque-proof manner on the camshaft. The valve train may also include an adjustment arrangement having adjustable first and second mechanical engagement elements, which may each cooperate with at least one slide guide arranged on the camshaft. The valve train may further include a control shaft or control slide forming a stop for the first and second engagement elements and adjusting the first and second engagement elements into respective switching positions. The cam follower may be drivingly connected with the first and second cams in first and second positions, respectively. The first and second engagement elements may each be adjustable between respective basic positions, in which no contact exists with the associated slide guide, and the respective switching positions, in which the respective engagement element cooperates with the associated slide guide.

A valve train may include a camshaft having first and second slide guides, first and second cams mounted axially adjacent in torque-proof manners on the camshaft, and a cam follower adjustable between a first position, in which the cam follower is drivingly connected with the first cam, and a second position, in which the cam follower is drivingly connected with the second cam. The valve train may also include an adjustment arrangement having adjustable mechanical first and second engagement elements for axially adjusting the cam follower between first and second positions. Each engagement element may be adjustable between basic positions, in which no contact exists with a respective one of the slide guides, and switching positions, in which the respective engagement element cooperates with the slide guide. Each engagement element may have a spring that prestresses it into the switching position. The valve train may further include an arresting device and an actuator for each engagement element, wherein the arresting device, when in a locked position, holds the associated engagement element in the basic position, and the actuator releases the arresting device

A control system of a continuously variable valve duration (CVVD) is provided. A system for controlling a CVVD by adjusting an actuator for controlling the CVVD includes an electronic control unit (ECU) configured to output a command for adjusting the actuator based on a vehicle state and a cam position sensor is configured to measure a cam revolutions per minute (RPM). A controller is configured to calculate a crank RPM from the cam RPM when a failure occurs during communication with the ECU. A target phase angle is extracted based on the calculated crank RPM, and an electric current is output that corresponds to the extracted target phase angle to the actuator.

A control system of a continuously variable valve duration (CVVD) is provided. A system for controlling a CVVD by adjusting an actuator for controlling the CVVD includes an electronic control unit (ECU) configured to output a command for adjusting the actuator based on a vehicle state and a cam position sensor is configured to measure a cam revolutions per minute (RPM). A controller is configured to calculate a crank RPM from the cam RPM when a failure occurs during communication with the ECU. A target phase angle is extracted based on the calculated crank RPM, and an electric current is output that corresponds to the extracted target phase angle to the actuator.

A valve actuation system for an internal combustion engine is disclosed. The engine has a first set of cylinders having a first set of exhaust valves and a second set of cylinders having a second set of exhaust valves. The valve actuation system for the exhaust valves includes one or more first cams having a compression-release lobe and a main exhaust lobe adapted to transfer valve actuation motion to the first set of exhaust valves, and one or more second cams having an early exhaust valve opening (EEVO) lobe and a main exhaust lobe adapted to transfer valve actuation motion to the second set of exhaust valves. The valve actuation system may provide any combination of (i) main exhaust valve actuation with or without compression release actuation with (ii) main exhaust valve actuation with or without EEVO for the two sets of cylinders.

An internal combustion engine includes cylinders that are divided into a first cylinder group and a second cylinder group, a cylinder reduction mechanism that holds intake valves and exhaust valves of the first cylinder group in closed states so as to establish a reduced-cylinder state. When the engine is stopped in the reduced-cylinder state, the electronic control unit provided in the engine starts the engine by ignition, by executing fuel injection and ignition in an expansion-stroke cylinder. When the first cylinder group includes an exhaust-stroke cylinder, the engine is started by ignition through fuel injection and ignition in the expansion-stroke cylinder, after a piston is moved in a reverse direction through fuel injection and ignition in the exhaust-stroke cylinder. When the first cylinder group does not include the exhaust-stroke cylinder, the engine is started by ignition, through fuel injection and ignition in the expansion-stroke cylinder and an intake-stroke cylinder.