Four valves per cylinder engine head

Abstract

An improved head assembly replacement for the Harley Davidson Motorcycle engine 20 adapted to utilize four valves per cylinder using push rods 50 without modification to the engine block, and maintaining the existing location and configuration for the mounting of the normal intake and exhaust systems. The standard rocker arms actuate the new dual intake and exhaust valves through a yoke 54 bridging each pair of valves. The exhaust valve and intake valve pairs are inclined at an included angle of 50 to 70 degrees in the plane of the engine crankshaft. The pushrods 50 remain in the standard position and the self-adjusting hydraulic tappets are retained.

1 . An improved head assembly for Harley Davidson engine having an integral camshaft and push rod system comprising: 
 a head having a pair of exhaust valve ports with seats and a pair of intake valve ports with seats for each cylinder, also a plurality of push rod passages in linear alignment with the engine camshaft, and a threaded spark plug hole centrally located between the ports, the general area around the ports with the threaded hole recessed with the areas underneath and between the engine forming a combustion chamber.    a pair of exhaust valves disposed transversely parallel and having angularity with each cylinder centerline in said engine and contiguous with the appropriate port for relieving the combustion gases on an exhaust stroke.    a pair of inlet valves disposed angularly with respect to each cylinder in said engine contiguous with the appropriate port for introducing a combustible mixture of fuel and air into the engine on a suction stroke.    a plurality of rocker arms and valve springs, the arms causing said valve and the springs surrounding the valve stem for lifting the valve and returning them into contact with the valve seats under the influence of the springs at the appropriate timing.    a pair of rocker arm shafts unitedly retaining the rocker arms in rotatable linear containment allowing each set of valves to react in sequence for operation of the engine.    a plurality of push rods drivingly communicating between the engine camshaft and said rocker arms such that each pair of valve are lifted from the head in a sequence producing a cyclic action allowing the engine to operate.    a yoke disposed between the rocker arm and bridging a pair of valves to provide the latter of equal lifting from the head and equal returning to the head.    
   
   
       2 . An improved head assembly for an internal combustion gasoline engine having an integral camshaft and plush rod system comprising: 
 a head having a pair of exhaust valve ports with seats and a pair of intake valve ports with seats for each cylinder, also a plurality of push rod passages in linear alignment with the engine camshaft, and a threaded spark plug hole centrally located between the ports, the general area around the ports with the threaded hole recessed with the areas underneath and between the engine forming a combustion chamber.    a pair of exhaust valves disposed transversely parallel and having angularity with each cylinder centerline in said engine and contiguous with the appropriate port for relieving the combustion gases on an exhaust stroke.    a pair of inlet valves disposed angularly with respect to each cylinder in said engine contiguous with the appropriate port for introducing a combustible mixture of fuel and air into the engine on a suction stroke.    a plurality of rocker arms and valve springs, the arms causing said valve and the springs surrounding the valve stem for lifting the valve and returning them into contact with the valve sets under the influence of the springs at the appropriate timing.    a pair of rocker arm shafts unitedly retaining the rocker arms in rotatable linear containment allowing each set of valves to react in sequence for operation of the engine.    a plurality of push rods drivingly communicating between the engine camshaft and said rocker arms such that each pair of valves are lifted from the head in a sequence producing a cyclic action allowing the engine to operate.    the utilization of the standard Harley Davidson rocker arm disposed in the same position and location as the standard heads.    
   
   
       3 . An improved head assembly for an internal combustion gasoline engine having an integral camshaft and push rod system comprising: 
 a head having a pair of exhaust valve ports with seats and a pair of intake valve ports with seats for each cylinder, also a plurality of push rod passages in linear alignment with the engine camshaft, and a threaded spark plug hole centrally located between the ports, the general area around the ports with the threaded hole recessed with the areas underneath and between the engine forming a combustion chamber.    a pair of exhaust valves disposed transversely parallel and having angularity with each cylinder centerline in said engine and contiguous with the appropriate port for relieving the combustion gases on an exhaust stroke.    a pair of inlet valves disposed angularly with respect to each cylinder in said engine contiguous with the appropriate port for introducing a combustible mixture of fuel and air into the engine on a suction stroke.    a plurality of rocker arms and valve springs, the arms causing said valve and springs surrounding the valve stem for lifting the valve and returning them into contact with the valve seats under the influence of the springs at the appropriate timing.    a pair of rocker arm shafts unitedly retaining the rocker arms in rotatable linear containment allowing each set of valves to react in sequence for operation of the engine.    a plurality of push rods drivingly communicating between the engine camshaft and said rocker arms such that each pair of valves are lifted from the head in a sequence producing a cyclic action allowing the engine to operate.    an exterior face of the exhaust ports and an exterior face of the intake ports disposing the configuration and location of the standard Harley Davidson.    
   
   
       4 . An improved head assembly for an internal combustion gasoline engine having an integral camshaft and push rod system comprising: 
 a head having a pair of exhaust valve ports with seats and a pair of intake valve ports with seats and a pair of intake valve ports with seats for each cylinder, also a plurality of push rod passages linear alignment with the engine camshaft, and a threaded spark plug hole centrally located between the ports, the general area around the ports with the threaded hole recessed with the areas underneath and between the engine forming a combustion chamber.    a pair of exhaust valves disposed transversely parallel and having angularity with each cylinder centerline in said engine and contiguous with the appropriate port for relieving the combustion gases on the exhaust stroke.    a pair of inlet valves disposed angularly with respect to each cylinder in said engine contiguous with the appropriate port for introducing a combustible mixture of fuel and air into the engine on a suction stroke.    a plurality of rocker arms and valve springs, the arms causing said valve and the springs surrounding the valve stem for lifting the valve and returning them into contact with the valve seats under the influence of the springs at the appropriate timing.    a pair of rocker arm shafts unitedly retaining the rocker arms in rotatable linear containment allowing each set of valves to react in sequence for operation of the engine.    a plurality of push rods drivingly communicating between the engine camshaft and said rocker arms such that each pair of valve are lifted from the head in a sequence producing a cyclic action allowing the engine to operate.    a standard hydraulic valve lifter disposed in the standard engine location communicating the engine camshaft and each pushrod for the automatic adjustment for zero clearance between the rocker arm and the newly paired valves.