EFFECTS OF CONTINUOUSLY VARIABLE VALVE TIMING (CVVT) ON ETHANOL SPARK IGNITED DIRECT INJECTION (SIDI) DOWNSIZED ENGINE

Resumo

The Continuously Variable Valve Timing (CVVT) strategies has been investigated at part-load and un-throttled conditions in the downsized 3 cylinder, 1.0 liter, Spark Ignited Direct Injected (SIDI) engine running on Brazilian ethanol. The aim of the investigation has been to identify optimal camshaft valve timing strategies which maximize engine fuel conversion efficiency through improvements in Indicated specific fuel consumption (ISFC) at fixed engine load. The results of the investigation demonstrate a consistent fuel conversion efficiency response to the valve timing changes. The CVVT system here analyzed revealed as an effective tool in reducing pumping loss, hence the specific fuel consumption