Structure for mounting the same type of camshafts on different types of cylinder heads

A structure for mounting the same type of camshafts on two different types of cylinder heads, wherein the two types of cylinder heads have opposite intake valve/exhaust valve arrangement orders so that a transverse plane centered between an intake valve and an exhaust valve of a cylinder in one type of cylinder head is staggered longitudinally with respect to a transverse plane centered between an intake valve and an exhaust valve of a respective cylinder in the other type of cylinder head by an amount delta, cylinder bore centers of the one type of cylinder head being coincident with respective cylinder bore centers of the other type of cylinder head in locations along a line parallel to the longitudinal axis of an engine of each type, the structure comprising:

• two types of thrust bearing housings, one type of bearing housing being formed in one type of cylinder head and the other type of bearing housing being formed in the other type of cylinder head, each type of thrust bearing housing having thrust planes at opposite sides thereof, the thrust planes of the one type of thrust bearing housing formed in the one type of cylinder head being machined so as to be staggered with respect to the thrust planes of the other type of thrust bearing housing formed in the other type of cylinder head by an amount delta in the direction parallel to the engine longitudinal axes;
• a single type of thrust bearing cap adapted to be fixed to each of the two types of thrust bearing housings, the single type of thrust bearing cap having a bolt hole spaced from a transverse centerline of the thrust bearing cap by one-half the amount delta;
• and
• two types of tapped hole means, each including a tapped hole formed in the thrust bearing housing in the respective type of cylinder head, the tapped hole in the one type of thrust bearing housing being provided at a location spaced longitudinally by one-half the amount delta in one direction from a transverse plane centered between the thrust planes of the one type of thrust bearing housing formed in the one type of cylinder head and the tapped hole in the other type of thrust bearing housing being provided at a location spaced longitudinally by one-half the amount delta in a direction opposite to said one direction from a transverse plane centered between the thrust planes of the other type of thrust bearing housing formed in the other type of cylinder head, the same type of camshafts being mounted in the thrust bearing housings so that the camshaft mounted in the one type of thrust bearing housing formed in the one type of cylinder head is staggered longitudinally with respect to the camshaft mounted in the other type of thrust bearing housing formed in the other type of cylinder head by the amount delta, the single type of thrust bearing cap being mounted on each type of thrust bearing housing, with a thrust bearing cap being mounted on the one type of thrust bearing housing in reversed relation to a thrust bearing cap mounted on the other type of thrust bearing housing and the thrust bearing cap being fixed to each thrust bearing housing by a bolt which penetrates the bolt hole and is screw-coupled to the respective tapped hole.