Abstract: A four-cycle engine includes a cylinder block defining a cylinder bore. A piston is reciprocally disposed within the cylinder bore. A cylinder head member closes an end of the cylinder bore to define a combustion chamber together with the cylinder bore and the piston. The cylinder head member defines an inner passage having a first end communicating with the combustion chamber and a second end terminating at an outer surface of the cylinder head. A valve assembly having a valve section and an actuateable section is provided. The valve section is selectively placed at an open position and a closed position to connect and disconnect the inner passage with the combustion chamber, respectively. The actuateable section is formed oppositely from the valve section. A valve actuation mechanism is arranged to actuate the actuateable section to move the valve section between the open position and the closed position.

Abstract: A four-cycle engine includes a cylinder block defining a cylinder bore. A piston is reciprocally disposed within the cylinder bore. A cylinder head member closes an end of the cylinder bore to define a combustion chamber together with the cylinder bore and the piston. The cylinder head member defines an inner passage having a first end communicating with the combustion chamber and a second end terminating at an outer surface of the cylinder head. A valve assembly having a valve section and an actuateable section is provided. The valve section is selectively placed at an open position and a closed position to connect and disconnect the inner passage with the combustion chamber, respectively. The actuateable section is formed oppositely from the valve section. A valve actuation mechanism is arranged to actuate the actuateable section to move the valve section between the open position and the closed position.

Abstract: An improved induction system for an internal combustion engine that improves power throughout the entire speed and load ranges by including two plenum chambers, having separate intake passage that serve the cylinders of the engine. One plenum chamber and its intake passages is designed to improve low and midrange performance while the other plenum chamber and its intake passage is tuned for high speed performance. An atmospheric air inlet is provided only for the latter plenum chamber and the first mentioned plenum chamber receives its atmospheric air from this plenum chamber through a connecting passageway.

Abstract: An improved induction system for an internal combustion engine that improves power throughout the entire speed and load ranges by including two plenum chambers, having separate intake passage that serve the cylinders of the engine. One plenum chamber and its intake passages is designed to improve low and midrange performance while the other plenum chamber and its intake passage is tuned for high speed performance. An atmospheric air inlet is provided only for the latter plenum chamber and the first mentioned plenum chamber receives its atmospheric air from this plenum chamber through a connecting passageway.

Abstract: Several embodiments of engine and induction systems wherein the engine is positioned transversely in the engine compartment and the intake ports of the engine face rearwardly and are served by individual runners that extend across the top of the engine in the opposite direction from the way the intake ports face. The engine is inclined forwardly from the vertical so as to provide adequate height between the cylinder head and the runners and a plenum tank associated with it so as to prevent heating of the induction system.

Abstract: An induction system for an internal combustion engine that is disposed transversely in an engine compartment. The induction system comprises a plurality of manifold runners that emanate from one side of the cylinder head, extend over the top of the cylinder head and terminate at a plenum chamber positioned on the other side of the cylinder head. For sound deadening purposes, a sound deadening baffle plate is affixed to the manifold runners. In some embodiments, this is done on the top of the manifold and in other embodiments, it is done on the underside of the manifold runners.

Abstract: A number of embodiments of internal combustion engine constructions having intake manifold passages that extend from the intake ports back over the top of the engine and above the cylinder head assembly to provide a long intake passage for good low speed running. In all embodiments, an oil separator is formed in the cam cover and the engine is inclined from the vertical so as to permit clearance for the oil separator beneath the intake manifold without increasing the overall height of the engine.