Abstract: In an intake system for an internal combustion engine having an air filter with a fresh-air line opening into the fresh-air side of the air filter and a clean-air line leading from a clean-air side of the air filter to the internal combustion engine, an additional line which is in communication with the engine compartment extends into the fresh-air side of the air filter starting from the engine compartment, so as to be tapered in the direction toward the clean air side of the air filter with the inlet opening of the additional line being directed toward the adjacent passenger compartment.

Abstract: In an intake system for an internal combustion engine having a cylinder head with at least one inlet duct per cylinder, an essentially flat control flap is supported in the inlet duct on a pivot shaft pivotally about an axis which is disposed in spaced relationship upstream from the control flap by way of side support arms such that, in an open position, the control flap rests against a wall portion of the inlet duct from where it can be swiveled into the intake duct into a flow directing turbulence generating position.

Abstract: In a method for detecting knocking combustion during the operation of an internal combustion engine with a device for measuring the ionic current, the raw ionic current signal or the evaluated value of the knocking intensity are normalized. This enables the value of the knocking intensity to be reliably compared with a threshold value. The normalization avoids the falsifying influence of large intensity fluctuations of the raw ionic current signal from one combustion cycle to the next without any relation to the true knocking intensity.

Abstract: In an intake system for an internal combustion engine having a cylinder head with at least one inlet duct per cylinder, an essentially flat control flap is supported in the inlet duct on a pivot shaft pivotally about an axis which is disposed in spaced relationship upstream from the control flap by way of side support arms such that, in an open position, the control flap rests against a wall portion of the inlet duct from where it can be swiveled into the intake duct into a flow directing turbulence generating position.

Abstract: The present invention relates to a method for detecting knocking combustion during the operation of an internal combustion engine with a device for measuring the ionic current, in which the raw ionic current signal or the evaluated value of the knocking intensity are normalized, which enables the value of the knocking intensity to be reliably compared with a threshold value.

Abstract: A method for detecting flow-reducing changes in an exhaust-gas catalyst body is provided. The method includes measuring the ion-current signal from an ion-current probe in an internal combustion engine and monitoring the signal to determine whether its signal strength for a particular operating cycle falls below a minimum strength which can be specified as a function of the engine operating state. The method also include providing warning information to the control system when such an event occurs. The method further includes a variety of embodiments used to determine whether the ion current signal falls below a minimum strength.

Abstract: An internal combustion engine with a piston arranged in a cylinder bore, a pair of intake passages to the cylinder bore, and having a piston crown provided with a crescent-shaped depression. The inlet passages are arranged symmetrically with respect to an axis of symmetry running through the center of the cylinder bore between the two intake passages. The crescent-shaped depression formed in the piston crown extends across and is symmetrical with respect to the axis of symmetry.