Patent ID: 6182631
Filing Date: 2001-02-06
Classification: F01L,F01N,F02B,F05C,Y10T

Abstract:
A four-stroke internal combustion engine having a crankcase chamber, a cylinder head and a cylinder block, a valve actuating mechanism contained in said cylinder head for operating valves associated with a cylinder bore formed in said cylinder block, said valve actuating mechanism comprising rocker arms contained within a valve chamber defined by a valve cover attached to said cylinder head, a lubrication system for delivering lubricant to said valve actuating mechanism, a return passage extending from said cylinder head through said cylinder block to a crankcase chamber in which a crankshaft rotates for returning lubricant to said crankcase chamber from said valve chamber, said engine being provided with a cooling jacket, and means for introducing liquid coolant to said cooling jacket through a coolant delivery passage disposed in proximity to said oil return passage for cooling the returned oil and a piston reciprocating in said cylinder bore and driving said crankshaft, said valve actuating mechanism including a camshaft driven from said crankshaft for operating said valves, said camshaft being formed from a non-metallic material.