An engine block, an engine subassembly, and method for providing and manufacturing an engine block. The engine block includes a plurality of cylinder barrels positioned in the engine block, at least one oil jacket channel formed in the engine block, and an oil inlet port positioned in a peripheral wall of the engine block and connected to the at least one oil jacket channel. The at least one oil jacket channel includes a plurality of curved channel sections. Each curved channel section in the plurality of curved channel sections extends about at least a portion of a circumferential portion of a respective cylinder barrel in the plurality of cylinder barrels. The at least one oil jacket channel extends between adjacent cylinder barrels of the plurality of cylinder barrels in the engine block.

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 block assembly for a V-engine is provided. In one example, the cylinder block assembly includes a cylinder block including a plurality of cylinders divided into a first cylinder bank and a second cylinder bank, a valley positioned between the first and second cylinder banks, and a plurality of crankshaft supports. The cylinder block assembly further includes a structural frame including an interior surface coupled to the plurality of crankshaft supports and two top surfaces arranged above the interior surface and on opposing sides of the assembly, where each top surface is coupled to the cylinder block above a top of the plurality of crankshaft supports.

An engine includes a cylinder block defining at least one main bearing bulkhead adjacent to a cylinder, and a crankshaft rotatably housed within the block by a main bearing. A bulkhead insert has a cap portion, and an insert portion provided within the bulkhead. The insert portion has having first and second end regions connected by first and second straps. Each strap having a flanged beam cross section. The first and second ends of the insert portion are configured to connect a main bearing cap column to a cylinder head column. Each of the first and second end regions define at least one protrusion having a surface substantially normal to engine combustion and reactive loads. The cap portion is configured to mate with the first end region at the main bearing cap column and support the main bearing.

A cylinder block includes a first bank, a second bank, and a press-fitting portion. The first bank and the second bank are arranged in positions offset from each other in a cylinder arrangement direction. The press-fitting portion is provided straddling a first end surface of the first bank and a second end surface of the second bank. The press-fitting portion has a hole. The first end surface protrudes in a direction in which the press-fitting portion protrudes in the cylinder arrangement direction, with respect to the second end surface. A thickness of the press-fitting portion in a radial direction of the hole at a first portion that is connected to the first end surface is thinner than a thickness of the press-fitting portion in the radial direction of the hole at a second portion that is connected to the second end surface.

An outboard motor includes a crankshaft, a first bank including a plurality of first cylinders, a second bank including a plurality of second cylinders, a plurality of first injectors, a plurality of first spark plugs, a plurality of second injectors, and a plurality of second spark plugs. Each of the first and second cylinders includes a combustion chamber, an intake port, and an exhaust port. The first injectors and the first spark plugs are alternately disposed in a vertical direction. The second injectors and the second spark plugs are alternately disposed in the vertical direction in a reverse order to that of the first injectors and the first spark plugs. When the crankshaft is seen from a horizontal direction, the first cylinders and the second cylinders are disposed symmetrically about a point of symmetry arranged on an axis of the crankshaft.

A cylinder block is provided. The cylinder block includes a cylinder, two crankshaft supports at a bottom of the cylinder block, a cylinder head engaging surface at a top of the cylinder block, and first and second exterior sidewalls, the first exterior sidewall extending from the cylinder head engaging surface to a first structural frame engaging surface positioned above a centerline of the two crankshaft supports.

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.

Provided is a head cover structure of an engine, which is capable of increasing supporting rigidity of a head cover. The engine includes a driving force transmission mechanism for transmitting a driving force of a crankshaft to a valve train, in which on one end side in a cylinder row direction of the head cover, a bulging portion for covering an upper side of the driving force transmission mechanism is provided, and an engine mounting portion is attached to the bulging portion. The bulging portion is provided with an inclined surface portion having an inclined surface inclined downwardly toward the other end side in the cylinder row direction, and the inclined surface is formed to rise upwardly from an intermediate position in the cylinder row direction so as to be continuous with a top surface of the bulging portion on the one end side in the cylinder row direction.

A structural frame is provided. The structural frame includes a bottom surface, first and second cylinder block sidewall engaging surfaces, the first and second cylinder block sidewall engaging surfaces positioned above the bottom surface at a height that is above a centerline of a crankshaft support included in a cylinder block when the structural frame is coupled to the cylinder block.