Abstract: A spark-ignition engine comprises a plug hole (13) formed in a cylinder head (2), an ignition plug (10) and a plug cap (9) of the type integral with an ignition coil, which is attached to the ignition plug (10) as it is inserted into the plug hole (13). In this spark-ignition engine, the plug hole (13) is arranged at a position outside a head cover (5) in the cylinder head (2), a head surface (2a) of which is opened to provide the plug hole (13) and has a plug-cap attaching flange (11) attached thereto, and the plug-cap attaching flange (11) is formed with an extending cylinder-portion (15A) having an extension-hole (15) communicated with the plug hole (13). The plug cap (9), as it is inserted from the extension hole (15A) into the plug hole (13), has a coil portion (9C) fixed to the extending cylinder-portion (15).

Abstract: A spark-ignition engine comprises a plug hole (13) formed in a cylinder head (2), an ignition plug (10) and a plug cap (9) of the type integral with an ignition coil, which is attached to the ignition plug (10) as it is inserted into the plug hole (13). In this spark-ignition engine, the plug hole (13) is arranged at a position outside a head cover (5) in the cylinder head (2), a head surface (2a) of which is opened to provide the plug hole (13) and has a plug-cap attaching flange (11) attached thereto, and the plug-cap attaching flange (11) is formed with an extending cylinder-portion (15A) having an extension-hole (15) communicated with the plug hole (13). The plug cap (9), as it is inserted from the extension hole (15A) into the plug hole (13), has a coil portion (9C) fixed to the extending cylinder-portion (15).

Abstract: In a sound-proof type engine working machine with a waste heat recovery apparatus, including a sound-proof type engine working machine which comprises a liquid cooled internal combustion engine and a working machine such as an electricity generator, a compressor and the like adapted to be driven by the engine and a waste heat recovery apparatus adapted to recover the waste heat from the engine, the engine cooling liquid within the water jacket of the engine is adapted to circulate through a waste heat recovery heat exchanger and a radiator, as well as the heat to be radiated in the radiator is adapted to be controlled by means of a radiated heat control device, and the engine and the working machine are horizontally arranged side by side each other within the sound-proof casing in a longitudinal direction thereof, an upper support frame is fixed on the upper side of the sound-proof casing, and the radiator and a radiator fan associated therewith are disposed on the upper support frame.