Metal head gasket with push rod guides

Abstract

In an air cooled overhead valve internal combustion engine, a metal gasket plate is disposed between the cylinder portion and the cylinder head. The metal gasket plate includes apertures for receiving the push rods therethrough and guide tabs disposed on opposite sides of the push rod for controlling lateral displacement of the push rods. The metal gasket plate includes adjacent annular stepped portions extending alternately in opposite directions out of the plane of the gasket plate adjacent the periphery of the aperture. Cylinder head bolts are received through the cylinder head and threadedly received in the cylinder portion and pass through the metal gasket plate. Dish shaped spring washers are provided between the cylinder head and the underside of the head portion of the cylinder head bolts. The cylinder head bolts are tightened into the cylinder portion sufficiently to partially compress the spring washers such that the spring washers maintain substantially constant compressive force between the cylinder head and the cylinder portion on the metal gasket plate throughout thermal cycling of the engine. Leakage of the cylinder head gasket which might otherwise occur as a result of temperature induced expansion and contraction of the engine is thereby avoided.