Abstract: A misfire detection system and method for use in conjunction with an internal combustion engine. An engine cylinder has a pressure sensor disposed therein for providing a signal indicative of the pressure in the cylinder's combustion chamber. Compression pressure measurements are obtained at crankshaft angles reached prior to the top dead center position of piston travel. For crankshaft angles greater than that at which top dead center is reached, the pressure measurements are reflected about a vertical axis extending through the top dead center point. The reflected compression pressures for crankshaft angles reached after the top dead center point are subtracted from the actual compression chamber measurements obtained over those crankshaft angles during the power stroke of the engine.

Abstract: A friction clutch coupling an engine and a gear transmission of a vehicle is controlled by a microprocessor based circuit using logic which defines operating modes according to engine and clutch conditions. During the time of clutch closure, when the vehicle is starting from rest in a startup or launch mode, the throttle or other engine control signal is restrained from quickly responding to the accelerator pedal. This avoids engine overspeeding which results from generating high torque before sufficient clutch capacity has been achieved. The control signal is developed as a function of the pedal position under control of throttle logic which, in turn, is dependent on clutch operating modes defined by the clutch logic.

Abstract: A friction clutch coupling an engine and a gear transmission of a vehicle is controlled by a microprocessor based circuit using logic which defines operating modes according to engine and clutch conditions. During the time of clutch closure, when the vehicle is starting from rest in a startup or launch mode, the throttle or other engine control signal is restrained from quickly responding to the accelerator pedal. This avoids engine overspeeding which results from generating high torque before sufficient clutch capacity has been achieved. The control signal is developed as a function of the pedal position under control of throttle logic which, in turn, is dependent on clutch operating modes defined by the clutch logic.

Abstract: A friction clutch coupling an engine and a gear transmission of a vehicle is controlled by a microprocessor based circuit using logic which defines operating modes according to engine and clutch conditions. During the time of clutch closure, when the vehicle is starting from rest in a startup or launch mode, the throttle or other engine control signal is restrained from quickly responding to the accelerator pedal. This avoids engine overspeeding which results from generating high torque before sufficient clutch capacity has been achieved. The control signal is developed as a function of the pedal position under control of throttle logic which, in turn, is dependent on clutch operating modes defined by the clutch logic.

Abstract: Two embodiments of V-belt tensioning devices are employed in a cooling system of a vehicle having an engine (20) transversely mounted for rocking motion relative the vehicle frame (42). The cooling system includes an engine cooling radiator (22) mounted forwardly of the engine and substantially parallel to the rotational axis of the engine crankshaft; a cross-flow fan (24) having a rotational axis fixed against movement relative to the vehicle frame, substantially parallel to the crankshaft axis, and between the crankshaft axis and the plane of the radiator; a V-belt drive (32, 34 36) for rotating the fan in response to rotation of the crankshaft; and the two embodiments of the tensioning devices which maintain the V-belt tension as the distance between the crankshaft and fan axes varies in response to rocking motion of the engine. In one embodiment the tensioning device (90) is a split pulley (36). In the other embodiment the tensioning device (108) is a spring loaded idler pulley (110).

Abstract: Disclosed is a vehicle having a liquid-cooled engine (20) transversely mounted for rocking motion relative to the vehicle frame (42); an engine cooling radiator (22) mounted forwardly of the engine and substantially parallel to the rotation axis of the engine crankshaft; a cross-flow fan (24) having a rotational axis substantially parallel to the crankshaft axis and disposed between the crankshaft axis and the plane of the radiator; the fan is engine driven by a belt (36), and a viscous coupling (29) to vary the fan speed in response to engine cooling requirements. In one embodiment the engine moves relative to the fan and the radiator. In this embodiment an air inlet duct assembly (40) is defined by a portion (26a) of the engine and members extending from the radiator to the engine. In the other embodiment the fan is fixed for movement with the engine and an air inlet duct assembly (126) allows movement between the fan and the radiator.

Abstract: Disclosed is a vehicle having an engine (20) transversely mounted for rocking motion relative to the vehicle frame (42); an engine cooling radiator (22) mounted forwardly of the engine and substantially parallel to the rotational axis of the engine crankshaft; a cross-flow fan (24) having a rotational axis fixed against movement relative to the vehicle frame, substantially parallel to the crankshaft axis, and between the crankshaft axis and the plane of the radiator; a belt drive (32, 34, 36) for rotating the fan in response to rotation of the crankshaft; means (100 or 120) for maintaining the belt tension relatively constant when the engine rocks; and means (29 or 121) to vary the fan speed relative to the crankshaft speed in response to the cooling requirements of the engine. In one embodiment the tensioning means is incorporated in split pulley (36) of the belt drive, in the other embodiment the tensioning means is a spring load idler pulley (120).

Abstract: Disclosed is a vehicle having a transversely mounted engine (20), an engine cooling radiator (22) mounted forward of the engine and substantially parallel to the rotational axis of the engine crankshaft, a cross-flow fan (24) mounted for rotation about an axis substantially parallel to the crankshaft axis and between the crankshaft axis and plane of the radiator, and a mechanical drive (32, 34, 36) which rotates the fan in response to rotation of the crankshaft.