Internal combustion engines having side by side inlet and exhaust ports

Claim 1

AN INTERNAL COMBUSTION ENGINE COMPRISING A CYLINDER HEAD IN WHICH ARE FORMED, FOR EACH CYLINDER, INLET AND OUTLET PORTS SPACED APART SIDE BY SIDE AND WHICH PORTS ARE ENCIRCLED BY CONICAL VALVE SEATS COUNTERSUNK BELOW AN INNER FACE OF THE CYLINDER HEAD, INLET AND EXHAUST VALVES CO-OPERATING WITH SAID VALVE SEATS AND WHICH INNER FACE OF THE CYLINDER HEAD IS FORMED WITH A CHANNEL EXTENDING BETWEEN THE INLET AND OUTLET PORTS, SAID INLET AND EXHAUST VALVES HAVING HEADS HAVING CONICAL SEATS THEREON, SAID SEATS ON THE INLET VALVE HEADS AND AROUND THE INLET PORTS HAVING FACES WHICH SUBTEND AN ANGLE OF LESS THAN 45* TO A PLANE AT RIGHT ANGLES TO THE AXIS OF THE RESPECTIVE INLET PORT, AND WHICH INLET VALVE IS FORMED WITH A SMALL PART CYLINDRICAL MASK SUBTENDING AN ANGLE OF ABOUT 47* AND WHICH VALVE IS DISPOSED SO AS THAT SAID MASK IMPARTS A REQUIRED DEGREE OF SWIRL TO THE INFLOWING GAS.