Effect of Injection Phasing on Valves and Chamber Fuel Deposition Burning in a PFI Boosted Spark-Ignition Engine
A satisfactory answer to the future severe normative on emissions and to the market request for spark ignition engines seems to be the use of downsized engines for passenger cars. Downsizing permits the increase in engines power and torque without the increase in cylinder capacity. The downsizing benefits are evident at part loads; on the other hand, more work should be done to optimize boosted engines at higher and full load. To this goal, a detailed knowledge of the thermo-fluid dynamic processes that occur in the combustion chamber is fundamental. The aim of this paper is the experimental investigation of the effect of the fuel injection in the intake manifold on the combustion process and pollutant formation in a boosted spark ignition (SI) engine. The experiments were performed on a partially transparent single-cylinder port fuel injection (PFI) SI engine, equipped with a four-valve head and boost device.