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Conventional expansion-element thermostats allow a fixing of only one coolant temperature level. This results in significantly different temperatures of the components which are near the combustion chamber depending on the load and rpm state of the engine. The fuel consumption and the emission are increased. Therefore a requirements-adapted cooling control is suggested. The main challenge for the development of such a system is to get an attractive proportion of cost and benefit. For the expense of the actuator the motor is dominant. For this reason a valve was chosen which integrates the regulation of the radiator circuit, the bypass and the heat exchanger circuit in one part. A control algorithm was developed which can be easily integrated in the engine management and is supplied from existing sensors. Dynamic tests show that a sufficient fast regulation of the coolant temperature is possible with the realized system.

In closed crankcase ventilation systems, the oil-loaded blow-by is fed back into the intake air. Due to the incomplete combustion of the oil, it produces higher particle and hydrocarbon emissions, a reduced catalytic converter lifetime, and deposits in the intake manifold. A survey of state-of-the-art ventilation systems is given. The procedures for measuring the ventilation aerosol on the engine and the requisite measuring instruments, especially for determining the particle size distribution, are described. The results of the measurements prove the usually unsatisfactory separation efficiency of the production parts. A significant increase in separation efficiencies can be obtained by using nonwovens. To optimize the construction concerned, several measurements with varied separation parameters of the nonwovens were conducted on an oil mist test bench.