Hydro-mechanical overhead for internal combustion engine

Claim 1

An hydro-mechanical overhead for a multi-cylinder four-cycle internal combustion engine having a camshaft, a plurality of intake valve pushtube means driven by said camshaft, a plurality of exhaust valve pushtube means driven by said camshaft, at least one intake and exhaust valve for each cylinder of said multi-cylinder internal combustion engine and a piston for each cylinder of said engine comprising an intake valve master piston means for each engine cylinder, each said intake valve master piston means driven by one of said intake valve pushtube means, an exhaust valve master piston means for each engine cylinder, each said exhaust valve master piston means driven by one of said exhaust valve pushtube means, an intake valve slave piston means for each engine cylinder, each said intake valve slave piston means adapted to open one of said intake valves, an exhaust valve slave piston means for each engine cylinder, each said exhaust valve slave piston means adapted to open one of said exhaust valves, adjustable stop means associated with each slave piston means, first passageway means interconnecting each said intake valve master piston means and each said intake valve slave piston means for each cylinder of said internal combustion engine, second passageway means interconnecting each said exhaust valve master piston means and each said exhaust valve slave piston means for each cylinder of said internal combustion engine, a plurality of three-way control valves, one of said three-way valves interposed in each of said first and second passageways, said control valves having a powering position wherein each said master piston means communicates with said slave piston means of a first engine cylinder with which both said master and said slave piston means are associated, said control valves associated with said intake valve master piston means having a retarding position wherein each said intake valve master piston means communicates with said slave piston means associated with said first engine cylinder and also through third passageway means with the intake slave piston means of a second engine cylinder having a piston which is about 360 crankangle degrees out of phase with the piston of said first engine cylinder, said control valves associated with said exhaust valve master piston means having a retarding position wherein each of said exhaust valve master piston means associated with said first engine cylinder communicates through fourth and fifth passageway means with the exhaust slave piston means of third and fourth engine cylinders having pistons which are respectively in their compression and exhaust strokes when said piston in said first cylinder is in its expansion stroke, means to provide hydraulic fluid to each of said passageways and each of said master and slave piston means, control means to move each of said control valves between the said powering and retarding positions, lash adjusting means associated with each of said adjustable stop means and having powering and retarding positions, and means controlling said lash adjusting means to the same position as the position of said control valves.