Abstract
HC emission from the gasoline engine is mostly caused by poor fuel atomization during the cold start and warm- up period. In this expeiiment, a heated fuel-rail system is constructed to investigate the reduction effects on the size of the fuel droplet by heating the fuel in the fuel-rail. The fuel atomization is examined by measuring Sauter Mean Diameter (SMD) of the fuel droplets from the three different types (two-hole, pintle, and six-hole) of injectors based upon a returnless heated fuel-rail system. The results show that the six-hole type injector with the heated fuel provides the best fuel atomization results in terms of SMD among three different types of injectors.