In an oil pan, an outer surface of an oil pan body is covered with urethane foam material. The outer surface of the oil pan body is cation treated to be a surface-treated layer, and the urethane foam material is adhered to the outer surface of the oil pan body by the surface-treated layer without any gaps therebetween. The oil pan further includes an undulating portion formed on the outer surface of the oil pan body and undulating in an inward and outward direction. The surface-treated layer is formed on the undulating portion and the urethane foam material is adhered to the undulating portion without any gaps therebetween. The undulating portion includes a bowl-shaped recess recessed into a bowl shape toward an inner side of the oil pan body and the urethane foam material is adhered to an entire inner surface of the bowl-shaped recess without any gaps therebetween.

A head cover structured and arranged to cover at least part of a face of a cylinder head of an internal combustion engine is described. The head cover includes a chamber formation part structured and arranged to provide a chamber to restrain sound propagating through air from the cylinder head. The chamber formation part includes a partition part for partitioning the chamber from a space on a cylinder head side. The partition part has a convex part projecting into the chamber, and a through hole may be provided in the convex part that penetrates from the space on the cylinder head side to the chamber.

An engine cover member mounting structure, including: an engine body; a peripheral member arranged on an outer wall of the engine body; a cover member arranged between the outer wall and the peripheral member; and a harness routed between the outer wall and the peripheral member, wherein the harness is held on a surface of the cover member.

A chain cover is configured to cover a timing chain that transmits rotation of a crankshaft of an internal combustion engine to a camshaft. The chain cover includes a crankshaft-side opening forming portion that defines a crankshaft-side opening into which the crankshaft is inserted, and a general portion that is a section different from the crankshaft-side opening forming portion. The crankshaft-side opening forming portion is made of a first material. The general portion is made of a second material. The first material and the second material are different from each other.

A crank cap assembly including a single crank cap rotatably supporting a crankshaft includes: a fastening member fastened to the crank cap, a mass member; and an elastic rubber member elastically attaching the mass member to the crank cap. The elastic rubber member includes a first rubber part arranged between the fastening member and the mass member and a second rubber part arranged between the crank cap and the mass member. The first rubber part and the second rubber part are arranged to be aligned in the mounting direction when attaching the crank cap to an engine body, and the elastic rubber member is formed so that a length in the mounting direction is longer than a maximum length in a cross-section of the elastic rubber member perpendicular to the mounting direction.

A camshaft housing includes two longitudinal frame bars and lateral frame bars. The longitudinal frame bars extend in the axial direction of a camshaft. The lateral frame bars extend between the longitudinal frame bars. A bearing portion is arranged in each of the lateral frame bars to rotationally support the camshaft. Each lateral frame bar has a bolt hole to receive a bolt that is inserted through the bolt hole to fix the camshaft housing to a cylinder head body. The bolt hole extends through the lateral frame bar and is arranged on the outer side of the bearing portion in the longitudinal direction of the lateral frame bar. Each longitudinal frame bar has a vibration reducing portion. The cross-sectional area of the longitudinal frame bar gradually changes in the longitudinal direction of the longitudinal frame bar.

A head cover structured and arranged to cover at least part of a face of a cylinder head of an internal combustion engine is described. The head cover includes a chamber formation part structured and arranged to provide a chamber to restrain sound propagating through air from the cylinder head. The chamber formation part includes a partition part for partitioning the chamber from a space on a cylinder head side. The partition part has a convex part projecting into the chamber, and a through hole may be provided in the convex part that penetrates from the space on the cylinder head side to the chamber.

To provide an engine side cover structure of a saddle type vehicle that can also cover the back side of a crankcase. An engine side cover structure of a saddle type vehicle includes a vehicle body frame arranged between a front wheel and a rear wheel; an engine including a crankcase, and a cylinder extending upward from the crankcase, the engine being supported by the vehicle body frame; and a side cover covering a side of the crankcase; where the side cover includes a cover main body that covers the side of the crankcase, and an extended portion that extends backward from the cover main body; and the cover main body is fixed to the crankcase, and the extended portion is fixed to the vehicle body frame.

A sound reducing device (30) for an internal combustion engine (1, 101) comprises a chamber forming member (33) defining a sound reducing chamber (32) having a prescribed column length jointly with a belt cover, and the sound reducing chamber communicates with the belt chamber via an opening (31), and the opening opposes a part of a timing belt passed around the cam pulley.

Methods and systems are provided for a vehicle component cover. In one example, a vehicle component cover may be adapted to conceal vehicle components within an engine compartment, and the cover may include an embedded support structure having a plurality of lock orifices positioned to align with a plurality of openings of a solid encasement. The plurality of lock orifices are adapted to couple in locking engagement with a plurality of extensions of an emblem of the cover.