Tan, Y., Gitano, H., and Mohd Khalil, A., "Development of a Transfer Port Injection System for Two-Stroke Engines," SAE Technical Paper 2012-32-0115, 2012, doi:10.4271/2012-32-0115.
Introducing direct injection technology into two stroke engines can greatly improve the exhaust emission and fuel efficiency. In this paper, we investigate LPG direct injection from the transfer port of a loop-scavenged two stroke engine. The injector nozzle is placed in an area where it can inject through the transfer port window directly into combustion chamber with minimal fuel spillage into the port and minimal loss of fuel to the exhaust port. Several portions and orientations are simulated to determine the best injector nozzle location and orientation. The simulation results indicate that high fuel trapping efficiency is possible with the proper location of the injector and injection timing. Experimental results show an 80% reduction in exhaust emissions with the transfer port mounted injector nozzle compared to the baseline carbureted engine.