By making the valves of a car engine variable, the German electronics company Siemens claims to have improved all aspects of engine performance. The system enables the timing and degree of opening of the valves to be adjusted according to engine speeds and driving conditions.
Tests by the company have shown that the new system can improve net power by up to 7 per cent, increase torque by 20 per cent, and reduce fuel consumption by between 5 and 10 per cent. The improved operating efficiency also means reduced emissions of pollutants. According to Rod Tucker of Siemens: 'A number of European car manufacturers are developing a range of engines with the new system.'
The inlet and exhaust valves control the intake of the fuel-air mixture into the combustion cylinders, and the exit of the burnt exhaust gases from them. Ideally, the degree of opening and closing would vary according ...
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