Combustion Analysis on a Variable Valve Actuation Spark Ignition Engine Operating With E22 and E100
Variable Valve Actuation system (VVA) is a technology developed for improving fuel economy, reducing emissions, and enhancing engine performance mainly by reducing pumping losses. Many automakers have used VVA in their engine projects with excellent results. Usually, VVA systems are built to control the valve events in four different ways: changing the amplitude of the valve lift, the valve opening angle, the valve closing angle or a combination of those modes. A special attention at the calibration activity is needed to reach the optimum performance of this system, beyond this, it was necessary to develop a different way to calibrate, much more focused on the development of the combustion and the gas exchange process requiring an intense use of a pressure indicating system. This work presents a comparison between different way of actuation in combustion analysis of a VVA system on a spark ignition engine.