Abstract: This invention provides an engine cleaning composition for removing sediment formed in an engine. Such engine cleaning composition comprises: a dispersant containing a carboxylic acid and an amine; a chelating agent; a glycol solvent; and a naphthenic oil.

Abstract: Disclosed is a power transmission apparatus to detect the deterioration state of a timing belt in use, thereby making it possible to detect at a high accuracy whether or not the timing belt reaches an exchanging time. The power transmission apparatus comprises a crankshaft pulley, an intake camshaft pulley, and a timing belt wound around the crankshaft pulley and the intake camshaft pulley. The timing belt contains a stress light emission material capable of emitting light when receiving an external force. The power transmission apparatus further comprises an optical sensor and an ECU. The optical sensor is disposed to measure light emitted from the timing belt. The ECU is operative to judge whether or not the timing belt is deteriorated and to judge that the timing belt reaches the exchanging time when the timing belt is judged to be deteriorated.

Abstract: This invention provides an engine cleaning composition for removing sediment formed in an engine. Such engine cleaning composition comprises: a dispersant containing a carboxylic acid and an amine; a chelating agent; a glycol solvent; and a naphthenic oil.

Abstract: Disclosed is a power transmission apparatus to detect the deterioration state of a timing belt in use, thereby making it possible to detect at a high accuracy whether or not the timing belt reaches an exchanging time. The power transmission apparatus comprises a crankshaft pulley, an intake camshaft pulley, and a timing belt wound around the crankshaft pulley and the intake camshaft pulley. The timing belt contains a stress light emission material capable of emitting light when receiving an external force. The power transmission apparatus further comprises an optical sensor and an ECU. The optical sensor is disposed to measure light emitted from the timing belt. The ECU is operative to judge whether or not the timing belt is deteriorated and to judge that the timing belt reaches the exchanging time when the timing belt is judged to be deteriorated.

Abstract: An oil ring mechanism of a piston includes a circumferential ring groove formed in an outer peripheral surface of the piston, and a two-piece oil ring having a ring-shaped ring main body that is arranged in the ring groove and urged in the outer peripheral direction inside the ring groove by a coil expander arranged on the inner peripheral side of the oil ring main body. On lower side surface on a crankcase side of a side wall surface of the ring groove that is on the opposite side of the ring groove from an engine combustion chamber, first and second recessed portions that reduce the abutment area where a lower surface of the ring main body abuts against the lower side surface formed in a lower side abutment surface that serves as a surface for abutting against the lower surface of the ring main body.