Pulsed pressure lubrication system for an overhead valve engine

An internal combustion engine comprising:

• a crankcase having an oil sump therein;
• a cylinder head secured to said crankcase;
• a camshaft disposed in said crankcase and being journalled in a bearing in said crankcase for rotational movement therein, said camshaft including main oil lubricating passage means extending axially therethrough in flow communication with said oil sump and further including auxiliary lubricating passage means extending from said main passage means to a sidewall outer surface of said camshaft disposed in said bearing;
• an oil pump for delivering oil under pressure from said oil sump to said main lubricating passage means;
• an intake valve and an exhaust valve;
• a valve rocker mechanism disposed on said cylinder head and being operatively connected to said intake and exhaust valves;
• a rocker box housing said valve rocker mechanism;
• secondary lubricating passage means extending from said camshaft bearing to an upper portion of said rocker box and being aligned with said auxiliary passage means such that said secondary lubricating passage means is in momentary flow communication with said auxiliary passage means upon each rotation of said camshaft to provide a pulsed flow of oil through said secondary lubricating passage means and into said rocker box to lubricate said valve rocker mechanism;
• and
• a return oil passage means extending from a lower portion of said rocker box to the interior of said crankcase for returning the oil from the rocker box to said sump.

A lubrication system for a valve rocker mechanism of an overhead valve internal combustion engine comprising:

• a crankcase having an oil sump therein;
• a cylinder head secured to said crankcase, wherein said valve rocker mechanism is disposed on said cylinder head and housed within a rocker box;
• a valve rocker lubricating passageway formed in said crankcase and said cylinder head and extending from said sump into an upper portion of said rocker box, wherein a portion of said oil lubricating passageway is periodically obstructed during engine operation;
• an oil pump for delivering oil under pressure from said oil sump through said lubricating passageway and into said upper portion of said rocker box, wherein the oil falls onto said valve rocker mechanism in a pulsed fashion;
• and
• an oil return passageway extending from a lower portion of said rocker box to the interior of said crankcase for delivering oil from said rocker box to said sump.