An internal combustion engine includes a crankcase for rotatably supporting a crankshaft about a crankshaft longitudinal axis. The crankcase comprises a crankcase water jacket, a cylinder head which is connected to the crankcase and comprises a cylinder head water jacket, and a coolant pump for supplying the crankcase water jacket and the cylinder head water jacket with a coolant volume flow. The crankcase water jacket and the cylinder head water jacket are fluidly connected to one another in series. The crankcase water jacket is suppliable with the coolant volume flow by the coolant pump via a crankcase inlet, and the crankcase water jacket is designed such that the coolant volume flow is directed via a crankcase outlet and is transferred in the direction of the cylinder head water jacket. The crankcase inlet and the crankcase outlet are axially spaced apart. The crankcase inlet is arranged on a first longitudinal side of the crankcase.

An engine includes a block that includes a block cylinder, a block passage configured to receive a head bolt, and a block fluid passage. The engine also includes a deck extender coupled to the block, and the deck extender includes a deck cylinder configured to align with the block cylinder, a deck passage configured to align with the block passage, and a deck fluid passage configured to align with the block fluid passage. The engine further includes a cylinder liner coupled to the block and the deck extender via the block cylinder and the deck cylinder, and the cylinder liner includes a contiguous cylinder wall to form an engine cylinder. Moreover, the engine includes a cylinder head configured to couple to the deck extender.