The Influence of Port Fuel Injection on Combustion of a Small Displacement Engine for Motorcycle
The demands on internal combustion engines for low emissions and fuel consumption are increasing year by year. On the other hand, engines to be used in motorcycles need to provide high output and quick response to meet user desire. In order to realize low fuel consumption while keeping high performance, it is necessary to properly understand cyclic variations during combustion as well as the influence of the injection system on fuel control during transient periods. The current paper reports on the results of a study in the influence of port fuel injection on combustion stability in a small displacement motorcycle engine, using both a series of experiments and CFD. The parameters of the injection systems under study are: (1) injection targeted area, (2) injection timing, and (3) fuel droplet size. The results of the current study show that injection aimed at the upstream wall yielded the best combustion stability.