Four-cycle internal-combustion engines having the supply and exhaust valves thereof arranged in alinement and in a single valve-chamber, the common axis of such valves being parallel with the axial line of the working cylinder, and a reciprocating rod or rods extending longitudinally of the engine and operated by and in unison therewith for operating one or both such valves in the proper order to secure the continuous automatic operation of the engine, and similar arrangements of valves and operating means therefor, but not shown in connection with all the elements necessary to form a complete and operative engine.
