Abstract: A modular intake manifold for a V-style motor cycle engine is configured to interface with manifold ports on cylinder heads of a first engine and with manifold ports on cylinder heads of a second engine. The first engine has cylinders of a first length, and the second engine has cylinders of a second length larger than the first length. The manifold port of each cylinder head of the first engine is offset from the centerline of the respective cylinder bore by a first offset distance. The manifold port of each cylinder head of the second engine is offset from the centerline of the respective cylinder bore by a second offset distance that is greater than the first offset distance. A method includes manufacturing the first cylinder and second cylinders, the first and second cylinder heads, and the intake manifold with the respective same considerations.

Abstract: An air cooled V-twin engine comprises first and second cylinders, first and second cylinder heads, first and second fuel injectors, a fuel tank, and first and second fuel pumps. The cylinders and the cylinder heads comprise cooling fins and define first and second combustion chambers. Each of the fuel injectors is attached to a respective one of the cylinder heads in a manner such that they can discharge fuel directly into said combustion chamber. The first fuel pump is operatively connected to the fuel tank and to the second fuel pump in a manner such that the first fuel pump can pump fuel from the fuel tank to the second fuel pump. The second fuel pump is operatively connected to the fuel injectors in a manner such that the second fuel pump can pump fuel to the fuel injectors.

Abstract: An EGR gas passageway member is removably attached to a motorcycle cylinder assembly between the cylinder head and the cylinder of said motorcycle cylinder assembly in manner such that presence of the EGR gas passageway member is partially concealed. The EGR gas passageway member allows motorcycles to be provided with EGR systems without significantly impacting the aesthetic appearance of the engines of such motorcycles.

Abstract: A modular intake manifold for a V-style motor cycle engine is configured to interface with manifold ports on cylinder heads of a first engine and with manifold ports on cylinder heads of a second engine. The first engine has cylinders of a first length, and the second engine has cylinders of a second length larger than the first length. The manifold port of each cylinder head of the first engine is offset from the centerline of the respective cylinder bore by a first offset distance. The manifold port of each cylinder head of the second engine is offset from the centerline of the respective cylinder bore by a second offset distance that is greater than the first offset distance. A method includes manufacturing the first cylinder and second cylinders, the first and second cylinder heads, and the intake manifold with the respective same considerations.

Abstract: A motorcycle engine case comprises crankshaft support portions that are configured and adapted to support a crankshaft in a manner such that the crankshaft is rotatable about a crankshaft axis relative to the engine case. The engine case also comprises an internal cavity that is configured and adapted to house at least one flywheel in a manner such that the flywheel is rotatable about the crankshaft axis with the crankshaft relative to the engine case. The engine case further comprises an adjustable oil scraper that is movable toward and away from the crankshaft axis and that can be locked in position relative to the crankshaft axis. The oil scraper is adapted and configured to remove oil clinging to the flywheel as the flywheel rotates about the crankshaft axis.

Abstract: A motorcycle engine case comprises crankshaft support portions that are configured and adapted to support a crankshaft in a manner such that the crankshaft is rotatable about a crankshaft axis relative to the engine case. The engine case also comprises an internal cavity that is configured and adapted to house at least one flywheel in a manner such that the flywheel is rotatable about the crankshaft axis with the crankshaft relative to the engine case. The engine case further comprises an adjustable oil scraper that is movable toward and away from the crankshaft axis and that can be locked in position relative to the crankshaft axis. The oil scraper is adapted and configured to remove oil clinging to the flywheel as the flywheel rotates about the crankshaft axis.

Abstract: A motorcycle crankcase is configured to support a crankshaft in a manner such that the crankshaft is rotatable about a crankshaft axis. The motorcycle crankcase comprises a pair of piston cylinder mounts, first and second horizontally oriented downward facing mounting surfaces, a generally semi-cylindrical bottom surface, and a plurality of crankcase bolt lugs. The pair of piston cylinder mounts are configured and adapted to rigidly connect to a pair of piston cylinders oriented in an upright V-twin style manner. The first and second mounting surfaces are configured and adapted to secure the motorcycle crankcase to a motorcycle frame. The crankcase bolt lugs are spaced about the crankshaft axis and each of the crankcase bolt lugs partially protrudes radially outward from the bottom surface. The motorcycle crankcase is devoid of any portion positioned directly beneath the first mounting surface.