The first opening part penetrates the first partition wall that separates the crank chamber and the oil sump chamber. The lubricating device of the engine includes an oil mist generation control part. The oil mist generation control part disperses gas injected from the crank chamber into the oil sump chamber through the first opening part when the crank chamber has a positive pressure or restricts the flow of oil with which the injected gas collides, thereby controlling an amount of oil mist generated in the oil sump chamber.

An engine case includes bearings, an oil pump, lubricating oil passages, and a relief device. The bearings rotatably support a crankshaft and a camshaft. The oil pump and the lubricating oil passages are configured to pressure-feed lubricating oil to the bearings. The relief device is configured to adjust a pressure of the lubricating oil. The lubricating oil passages include main lubricating oil passages. The main lubricating oil passages include communication portions linearly formed with extending portions. The communication portions communicate between the respective bearings of the crankshaft and the camshaft from outside the engine case. The extending portions extend from outside the engine case to the bearing of the camshaft. The relief device is disposed having a relief valve and a relief hole at the extending portions.

An internal combustion engine includes a cam chain chamber accommodating a cam chain and a chain guide guiding the cam chain. The engine also includes a chain tensioner including a case main body, a plunger sliding in the case main body, a coil spring biasing the chain guide against the cam chain via the plunger, interlocking teeth located on a surface of the plunger, and an engaging portion engaged with the interlocking teeth and configured to inhibit the plunger from moving in a direction away from the chain guide. The engine also includes oil supply passages in an inner wall of the cylinder head and an inner wall of the cylinder body and configured to supply oil to the chain tensioner.

A fluid delivery system is provided including a reservoir including oil, a hydraulic pump in fluid communication with the reservoir, and a heat exchanger system. The heat exchanger system is in fluid communication with the hydraulic pump, a generator, and an engine gearbox. The hydraulic pump is configured to deliver the oil to the heat exchanger system. The heat exchanger system is configured to provide the oil according to first temperature criteria to the generator and provide the oil according to second temperature criteria to the engine gearbox.

A fluid delivery system is provided including a reservoir including oil, a hydraulic pump in fluid communication with the reservoir, and a heat exchanger system. The heat exchanger system is in fluid communication with the hydraulic pump, a generator, and an engine gearbox. The hydraulic pump is configured to deliver the oil to the heat exchanger system. The heat exchanger system is configured to provide the oil according to first temperature criteria to the generator and provide the oil according to second temperature criteria to the engine gearbox.

The present disclosure relates to an engine assembly for a vehicle. The engine assembly comprises an engine including a cylinder head and an engine block. The engine block comprises a cylinder block and a crankcase having a crankshaft. The engine may be used in different models of the vehicle having different characteristics by interchanging or replacing the cylinder head from a plurality of cylinder heads and/or a cylinder block from a plurality of cylinder blocks, while keeping one or more engine components such as the crankcase, a timing chain, or a valve cover the same. Accordingly, the engine is adaptable to different vehicles.