A small air-cooled internal combustion engine includes an aluminum engine block including a cylinder, a crankcase reservoir, and an outer surface, a piston positioned within the cylinder and configured to reciprocate within the cylinder, and a crankshaft coupled to the piston and configured to rotate about a crankshaft axis, wherein a portion of the crankshaft is located in the crankcase reservoir, where the outer surface of the engine block has an edge located a radial distance from the crankshaft axis and the radial distance is less than less than a standard minimum distance between the crankshaft axis and a horizontal mounting surface for a standard garden mounting flange for a horizontally-shafted engine.

A small air-cooled internal combustion engine includes an aluminum cylinder block, an aluminum cylinder head welded to the aluminum cylinder block, and a weld securing the aluminum cylinder block to the aluminum cylinder head, wherein a joint having a first length is formed between the aluminum cylinder block and the aluminum cylinder head and wherein the weld extends for a second length that is at least 25% of the first length.

A small air-cooled internal combustion engine includes an aluminum cylinder block, an aluminum cylinder head welded to the aluminum cylinder block, and a weld securing the aluminum cylinder block to the aluminum cylinder head, wherein a joint having a first length is formed between the aluminum cylinder block and the aluminum cylinder head and wherein the weld extends for a second length that is at least 25% of the first length.

A cylinder is configured for use with a piston that moves through compression and combustion strokes between top and bottom positions in an internal combustion engine. The cylinder defines a bore in which the piston moves between the top and bottom positions. The bore has a transfer port and an exhaust port. The cylinder can have interconnected parts that together define the bore. Those parts can include a first part that reaches along the bore upward from the transfer port beside the top position of the piston, and a second part that reaches along the bore downward from the transfer port beside the bottom position of the piston. The sectional lengths of the first and second parts provide greater access for manufacturing at the bore, the transfer port, and the exhaust port.

An internal combustion engine-includes at least one cylinder crankcase, at least one cylinder head (2) including at least one valve cover (1), charge-cycle valves, a valve train-assembly, injectors (3), an injector cable harness, injection lines (4), a fuel rail (5) and a pre-separator for separating the oil aerosols present in the blow-by volume flow being situated in the cylinder head (2).