An compression-release engine brake opens an exhaust valve at an end of a compression stroke for performing braking function. The compression-release engine brake includes: an exhaust cam including a main cam lobe and a brake cam lobe, an exhaust rocker arm including a roller mounted on one end of the exhaust rocker arm contacting or not contacting the exhaust cam and rotating around a rocker arm shaft by rotation of the exhaust cam, a valve bridge disposed at the other end of the exhaust rocker arm and connected with a pair of exhaust valves, and a reset module disposed between the exhaust rocker arm and valve bridge, contacting the roller with the brake cam lobe according to being suppled of engine brake oil, and exhausting the engine brake oil after opening the exhaust valve by rotation of the exhaust cam.

An engine oil passage structure for an engine contributing to downsizing the engine and achieving protection of an oil passage against external forces is provided. Provided is an oil passage structure for an engine installed in a small vehicle, the engine including an engine body formed of a crankcase and a cylinder block and a cylinder head stacked inclined vehicle frontward on the crankcase, the crankcase, the cylinder block, and the cylinder head being integrally fastened. The oil passage structure includes, near a bent part formed by a case front wall of the crankcase and a cylinder front wall of the cylinder block forming a valley part by an obtuse angle, a right-left direction oil passage extending in a right-left direction along the valley part.

A valvetrain assembly configured to selectively perform a bleeder brake operation includes a rocker arm configured to rotate about a rocker shaft, a camshaft having a lobe configured to impart motion to the rocker arm through a pushrod, and a valve bridge assembly operably associated with the rocker arm and configured to be selectively engaged by the rocker arm to open at least one of a first and second engine valve. An engine brake capsule is operably associated with the valve bridge assembly and configured to operate in a drive mode where the engine brake capsule does not cause the valve bridge assembly to open the first or second engine valves, and a brake mode where the engine brake capsule engages the valve bridge assembly to partially open the first engine valve to perform the bleeder brake operation.

An actuation transmission apparatus for actuating a latching arrangement for latching and unlatching a first body and a second body of a switchable valve train component of an internal combustion engine, the latching arrangement being biased from an unlatched position where the first body and the second body are unlatched towards a latched position where the latching arrangement latches the first body and the second body together, the actuation transmission apparatus including: a shaft rotatable by an actuation source; a contacting element for contacting the latching arrangement; and a biasing device for biasing the contacting element rotationally with respect to the shaft. In use, the biasing device becomes biased by the shaft when the actuation source rotates the shaft when the actuation source attempts to actuate the latching arrangement to the unlatched position, via the contacting element, when the latching arrangement is in an un-actuatable state.

A latch assembly (500) can comprise a main latch pin assembly (531, 532) comprising a first diameter (D1) on a first main pin face (512, 522), and a secondary latch piston (541, 561) comprising a second diameter (D2) on a secondary piston face (543, 563). The secondary latch piston can be configured to selectively act on the main latching pin assembly. The main latch pin assembly can be biased to oppose the secondary latch piston. The first diameter can be greater than the second diameter. A rocker arm assembly (10) can comprise the latch assembly. A primary arm (100) can be configured to receive the main latch pin assembly. A secondary arm (300) can be configured to receive the secondary latch piston.

A center pivot roller rocker arm assembly can comprise a main roller rocker arm, a second roller rocker arm, and a latching assembly. The main roller rocker arm can comprise a rocker shaft bore, a valve end, a cam end, and a main cam surface on the cam end. The second roller rocker arm can comprise a second rocker shaft bore, a second cam end, and a second cam surface on the second cam end. The latching assembly can be coupled to the rocker shaft bore and configured to latch and unlatch the main roller rocker arm to the second roller rocker arm. A lost motion assembly can be configured with the main and second roller rocker arms. A main cam surface can have a different extent for receiving cam actuation than a second cam surface.

In an exemplary embodiment, an internal combustion engine, in which a valve is opened and closed when a piston reciprocates in a cylinder, has a configuration to perform repeatedly the following combined strokes: an intake stroke.fwdarw.a compression stroke.fwdarw.a combustion stroke.fwdarw.an exhaust stroke in a four-cycle internal combustion engine are combined with an intake and compression stroke.fwdarw.a combustion and exhaust stroke in a two-cycle internal combustion engine. The internal combustion engine can reduce pumping loss in a six-cycle internal combustion engine and increase the output.

An actuation apparatus for actuating a component of a switchable valve train device of an internal combustion engine includes: a support body for mounting on a cylinder head cover of the internal combustion engine; an actuation lever mounted to the support body for pivotal movement of the actuation lever between a first position for actuation of the component and a second position for allowing de-actuation of the component; and a biasing means for urging the actuation lever from the second position towards the first position. In use, the biasing means becomes biased when an actuation source causes the actuation lever to pivot to the second position. When the actuation source attempts to actuate the component when the component is non-actuatable, the biasing means causes the actuation lever to pivot from the second position to the first position, thereby to actuate the component when the component becomes actuatable again.

A rocker arm assembly operable in a first mode and a second mode, the rocker arm assembly selectively opening first and second engine valves based on rotation of a cam shaft having a first cam lobe and a second cam lobe, includes: a rocker shaft; a first rocker arm assembly having a first rocker arm that receives the rocker shaft and rotates around the rocker shaft in the first mode based on engagement with the first cam lobe; a second rocker arm assembly having a second rocker arm that receives the rocker shaft and rotates around the rocker shaft and selectively act on one of the first and second engine valves in the second mode based on selective engagement with the second cam lobe; and a biasing assembly that cooperates with the second rocker arm to bias the second rocker arm to a neutral position.

Systems and methods for determining operation of a cylinder deactivating/reactivating device are disclosed. In one example, a direction of engine rotation is selected to maximize air flow through the engine while the engine is rotated without combusting air and fuel. Operation of one or more cylinder valve deactivating mechanisms is assessed while the engine is rotated without combusting air and fuel.