The document contains valve and port timing diagrams for 4-stroke compression ignition (C.I.) and 2-stroke spark ignition (S.I.) engines. It lists the opening and closing timings in degrees before and after top dead center (TDC) and bottom dead center (BDC) for the intake valve (IVO, IVC), exhaust valve (EVO, EVC), and ignition advance (IGA) of a 4-stroke C.I. engine, and the transfer port opening (TPO) and closing (TPC) and exhaust port opening (EPO) and closing (EPC) of a 2-stroke S.I. engine.