Abstract: Improvements to a rotating-port-shaft intake and exhaust system in four-cycle internal combustion engines, the system being based on a hollow shaft mounted on a cylinder head and provided with ports leading independently to the cylinder chambers. The improvements consist in the fact that the cylinder head is made up of two halves which, on their opposing faces, are provided with semi-cylindrical cuts that form a cylindrical duct in which to house the port shaft. The cylinder head in question is provided with orifices for assembling sealing pistons with rectangular openings serving as ports and opposing the orifices/ports of the shaft. The upper faces of these pistons are ground with the same diameter as the shaft in order to achieve a perfect fit between both parts.

Abstract: An intake and exhaust system through rotatory port shafts, in four-stroke motors, through which are suppressed the camshaft, valve tappets, rocker arms and valves of conventional motors. The system is based on a hollow shaft located in a jacket and the whole assembly is mounted on the cylinder head body of the engine and supported on bearings. The shaft has ports transversely through in communication with the cylinder chambers, quite independently from the combustion order, having the ports shaft lubricating and water-cooling means, being engaged the shaft to a gear driven by the crankshaft of the engine, being 1:4 the ratio of the shaft to the crankshaft rotation.