Direct fuel injection, two-valve per cylinder pushrod valvetrain combustion system for an internal combustion engine

A direct fuel injection, two-valve pushrod valvetrain internal combustion engine, comprising:

• an engine block having a plurality of engine cylinders;
• a cylinder head mounted on the engine block and comprising a plurality of cylinder tops each aligned with a different one of the engine cylinders, each engine cylinder and associated cylinder top together at least partially defining a combustion chamber of the internal combustion engine, wherein each of the cylinder tops includes a single intake port such that the cylinder tops each have only one intake opening, a single exhaust port such that the cylinder top has only one exhaust opening, a spark plug bore, and a fuel injector bore;
• a plurality of spark plugs, each having a spark plug central axis and being mounted within a different one of the spark plug bores so as to provide spark energy within its associated combustion chamber when in use;
• a plurality of fuel injectors, each having a fuel injector central axis and being mounted within a different one of the fuel injector bores so as to provide a spray of fuel within its associated combustion chamber when in use;
• a crankshaft mounted within the engine block and having a crankshaft axis about which the crankshaft rotates;
• a plurality of pistons, each positioned in a different one of the engine cylinders and connected to the crankshaft by a piston rod;
• a pushrod valvetrain system that includes a camshaft and a plurality of two-valve pushrod assemblies, each of the pushrod assemblies being positioned at least partially within the cylinder head adjacent a different one of the combustion chambers, wherein the camshaft is mounted beside the engine cylinders and wherein each of the two-valve pushrod assemblies comprise:
• first and second pushrods each having a lifter configured to be driven by cams on the camshaft;
• first and second rocker arms that are mounted above the cylinder top and that are driven by the first and second pushrods, respectively;
• an intake valve positioned in the intake port and having a valve stem driven by the first rocker arm;
• and
• an exhaust valve positioned in the exhaust port and having a valve stem driven by the second rocker arm;
• wherein the intake port and exhaust port of each cylinder top are positioned adjacent each other and are positioned along an axis that intersects a center point of each of the ports;
• and
• wherein the spark plug bore and fuel injector bore of each cylinder top are both located in the cylinder top on a same side of the axis intersecting the center points of the intake and exhaust ports.