Abstract: An expansion chamber, and first and second volume chambers on either side of said expansion chamber, are formed inside a muffler housing. Engine exhaust is led by an inlet tube to the first volume chamber, and an opening facing the expansion chamber is formed in an intermediate part of the inlet tube. Exhaust in the second volume chamber is discharged outside by a tail tube, and an opening is formed facing the expansion chamber in an intermediate part of the tail tube. A valve is provided for leading exhaust from the first volume chamber to the second volume chamber according to a pressure difference between the chambers. This forms two exhaust flowpaths. A resonance system with two degrees of freedom is thereby formed with respect to exhaust discharged via the two openings and the expansion chamber, and a high noise silencing efficiency is obtained.

Abstract: An inlet tube leads exhaust gas from an automobile engine to an expansion chamber inside a muffler housing. Exhaust gas from the expansion chamber is discharged to the atmosphere via a first tail tube. A dead space chamber and volume chamber are disposed on either side of the expansion chamber in the housing, and a first internal tube connects the volume chamber and expansion chamber. A second internal tube having a valve which opens under pressure of the exhaust gas connects the volume chamber and dead space chamber. Exhaust gas from the dead space chamber is discharged to the atmosphere via a second tail tube. As the dead space chamber and volume chamber are not adjacent, pressure waves in the volume chamber do not cause a volume change of the dead space chamber, and emission noise from the second tail tube due to excitation of a resonance system comprising the dead space chamber, is reduced.

Abstract: An oil pan for an internal combustion engine includes an outer shell made of metal plate an includes on at least a bottom surface of the outer shell and inner pan separate from the outer shell. The bottom of the oil pan includes a deep portion and a shallow portion and a baffle plate is disposed over the inner pan. The inner pan settles on the inner surface of the outer shell amidst the oil contained in the oil pan, thereby forming a layer of oil between the outer shell and the inner pan. Thus, oil flow is not impeded and vibration of the oil pan is significantly reduced. In addition, wall portions of the inner pan are made to be deformable so as not to cause strong impact to other portions of the oil pan structure or to engine components.

Abstract: A front cover has at a front surface central portion thereof an integral mounting seat for installation of a mounting bracket and at a rear surface central portion thereof an integral boss adapted to extend between the mounting seat and a front end of a cylinder head and cylinder block assembly. The boss is fastened together with the mounting bracket to the front end of the cylinder head and cylinder block assembly. A resilient sealing member is interposed between the peripheral end of the front cover and the front end of the cylinder head and cylinder block assembly such that the front cover is supported rigidly at the boss together with the mounting bracket and resiliently at the peripheral end upon the front end of the cylinder head and cylinder block assembly.

Abstract: An engine anti-knock control arrangement controls both the ignition timing system and an evaporative cooling system so that when the engine is operating in a predetermined engine speed and load zone and engine knock is detected, the cooling system is operated to reset the temperature to which the coolant (and therefore the engine) should be controlled, to a predetermined minimum value and the ignition timing incrementally retarded until the knocking phenomenon terminates. While the temperature is dropping and knocking is absent, the ignition timing is incrementally advanced until the knock threshold is reached and thus brings the timing as close as practical to the MBT value for the instant set of operating conditions. Cyclic repetition of the ignition timing advancement and retardation holds the timing at MBT while the engine is operating in the predetermined zone.

Abstract: An evaporative cooling system features a reservoir which contains only sufficient coolant to fill the radiator when the engine is not in use and thus reduces the weight of the system. The remaining sections of the cooling circuit such as the upper section of the coolant jacket which are fairly resistant to corrosion are filled with air during non-use periods. The air is suitably purged out during engine warm-up and operation in accordance with the temperature differential which exists between the coolant jacket and the bottom of the radiator.

Abstract: In order to prevent wasteful cooling fan energization when the radiator or condensor of an evaporative type cooling system is partially filled in a manner which hinders heat exchange promotion and defeats any merit derived by operating a fan at full power, the fan is operated at a lower level to reduce fan noise and power consumption.

Abstract: In order to diagnose a malfunction an evaporative cooling system upon the engine being initially started or in response to a demand for engine operation (e.g. cranking of the engine) the outputs of a sensor or sensors are monitored and diagnostic check of the system performed to determine if the sensors and or valves of the system are operating properly. In the event that a malfunction is indicated a warning is issued and/or the operation of the engine prevented.

Abstract: In order to predict a system malfunction which will lead to overheat and thermal damage of the engine the operation of a level sensor which controls the level of coolant in the coolant jacket of the engine is monitored and in the event that frequency or the time for which the level sensor indicates a low level, falls outside of a predetermine range which defines malfunction free operation, a warning of impending engine overheat or the like is issued.

Abstract: In order to obviate vapor locking and subsequent cavitation of a pump which returns coolant vapor condensate from a radiator to the coolant jacket of an evaporative type cooled internal combustion engine and maintains the highly heated structure of the engine immersed in a predetermined depth of liquid coolant, the load on the pump is sensed by determining the amount of electrical current the pump is drawing and in the event that the load is at a level indicative of pump cavitation the connection between the radiator and the pump is interrupted and communication between a reservoir and the pump is established so as to introduce cool liquid coolant into the induction port of the pump.

Abstract: In the event that the normal coolant return pump of an evaporative type automotive cooling system malfunctions, a back-up system establishes fluid communication between the cooling circuit and the circulation pump of a heater circuit in a manner which enables the heater circulation pump to be used in place of the normal unit until such time as repair can be effected.

Abstract: In order to minimize the size of an evaporation cooled internal combustion engine, the coolant vapor collection space located within the coolant jacket above the most strongly heated structure of the engine is reduced in size and a separator unit, which separates liquid coolant from the gaseous form, is disposed between a vapor manifold mounted on the engine a radiator in which the coolant vapor is condensed to its liquid state. The coolant collected in the separator is pumped back into the coolant jacket at locations where the coolant boils most vigorously. An amount of coolant extracted from a relatively cool section of the coolant jacket is also recirculated by the pump to the same locations.

Abstract: In order to rapidly bring the temperature of the coolant in the coolant jacket of an evaporative type cooling system to a derived target value, both the rate of heat exchange between the condenser or radiator of the system and the surrounding ambient atmospheric air and the amount of coolant in the cooling circuit are varied in a manner to change the pressure and therefore the boiling point of the coolant. With the invention coolant is positively pumped to and from a reservoir which is maintained at atmospheric pressure into and out of a cooling circuit which is hermetically sealed during engine operation.

Abstract: A vapor cooled type internal combustion engine is provided with an auxiliary reservoir and a coolant management system. The management system establishes fluid communication between the reservoir and a cooling circuit of the engine in a manner to fill the latter with liquid coolant when the engine is not in use and thus exclude contaminating non-condensible air from same, and monitors the operation of the system when operating in a closed mode to determine if too much or too little coolant has been retained in the circuit following a warm-up mode wherein the excess coolant which fills the system when cold, is displaced by its own vapor pressure. The management system also ensures that the cooling circuit is not switched from closed to open states while the possibility of superatmospheric pressures developing therein exist and thus prevents violent displacement of coolant out of the circuit to the reservoir in a manner which invites spillage of coolant and the entry of large amounts of contaminating air.

Abstract: An improved cylinder head of internal combustion engine cooled by a so-called boiling liquid cooling system is disclosed, which has in its coolant jacket baffle members in order to inhibit the movement of liquid coolant within the jacket due to changes in attitude of the engine.

Abstract: A noise-shielding panel comprises a flat section spacedly disposed from the surface of an engine body and formed of a fibrous composite, and a contacting section integral with the flat section and formed of the same fibrous composite as in the flat section. The contacting section is in direct contact with the engine body surface and lower in density of the fibrous composite than the flat section, thereby facilitating production thereof and exhibiting a high noise-shielding effect.

Abstract: A cylinder block of an internal combustion engine, comprises an integrally formed metallic main body including a cylinder section and bearing bulks and a part of a water jacket. First and second side cover members are secured respectively to the opposite side surfaces of the main body so as to maintain a fluid-tight seal therebetween, each side cover member defining thereinside a part of said water jacket and including a skirt section. The side cover members are made of a non-metallic material which is light in weight and high in damping capacity, thereby effectively damping the engine vibration transmitted to the side cover members to prevent the skirt section of the side cover members from emitting noise.

Abstract: A spark timing control system for reducing engine noise in an internal combustion engine utilizing a sensor for detector for detecting engine vibration, a filtering device receiving the output of the sensor and passing frequency components within a range of 500 to 2000 Hz, and a generating circuit responsive to the passed frequency components for generating an output signal when the level of the passed frequency outputs exceeds a reference value. Spark timing is retarded when the output signal is received from the generating circuit thereby reducing engine noise.

Abstract: Disclosed is a reciprocating piston internal combustion engine comprises a housing device connected to a cylinder block for receiving therein a crankshaft of the engine. The housing device is formed with open chambers spaced from each other by partition walls which support the journals of the crankshaft via main bearings mounted to the partition walls. A sound-insulating panel is attached to the housing device in a manner to sealingly close the open ends of all of the open chambers thereby to permit the chambers to serve as lubricant oil reservers.

Abstract: An engine of a motor vehicle is equipped with a sound-insulating cover which is secured to a portion of an engine proper to surround the engine proper. An oil pan filled with engine oil is hermetically connected to the bottom portion of the sound-insulating cover so that the oil pan is spaced apart from the skirt portion of a crankcase.