Patent ID: 8511273

Claim:
An internal combustion engine comprising in combination, a cylinder head of an internal combustion engine, the cylinder head comprising: a combustion chamber; an intake passage extending between the combustion chamber and an intake port; an exhaust passage extending between the combustion chamber and an exhaust port; an intake valve guide extending along an intake valve axis, the intake valve axis intersecting the intake passage between the combustion chamber and the intake port; an exhaust valve guide extending along an exhaust valve axis, the exhaust valve axis intersecting the exhaust passage between the combustion chamber and the exhaust port, the intake and exhaust valve axes being parallel and defining a valve plane; an intake valve rocker arm axis extending perpendicular to an intake valve rocker arm plane, the intake valve rocker arm axis being perpendicular to the intake valve axis, and the intake valve rocker arm plane being perpendicular to the valve plane; and an exhaust valve rocker arm axis extending perpendicular to an exhaust valve rocker arm plane, the exhaust valve rocker arm axis being perpendicular to the exhaust valve axis, the exhaust valve rocker arm plane being perpendicular to the valve plane, and the exhaust valve rocker arm axis is collinear with the intake valve rocker arm axis; and a crankcase connected to the cylinder head and a crankshaft operably supported in the crankcase, the crankshaft including: a first portion including a first main bearing to rotatably support the crankshaft, and a second portion including a second main bearing to rotatably support the crankshaft, the second portion being coupled to the first portion so as to define a sump; a second cylinder head; first and second banks of cylinders extending between the crankcase and respective ones of the first and second cylinder heads; a lubrication system scavenging oil from the crankcase and supplying oil to the crankshaft and to the first and second cylinder heads, the lubrication system including: a pump including a housing and a rotor, the housing being fixed to one of the first and second portions of the crankcase, and the rotor being disposed around the crankshaft axis and being rotated by the crankshaft; and a plurality of oil supply passages extending through the crankcase, at least one of the plurality of oil supply passages being cast into the crankcase.