A Study of Fuel Economy in Small, Piston Ported Two-Stroke Engines 810294
A previously developed mathematical model of an operating two-stroke engine was modified to predict fresh air/fuel mixture loss through the exhaust port. At some operating conditions, losses as high as 30% of the newly scavenged mixture were predicted.
A servovalve is proposed for placement downstream of the exhaust port. By sensing the temperature of the exhaust flow and closing the valve when this temperature falls below some set temperature, the loss in fresh mixture was predicted to be reduced to virtually zero. This was accompanied by an increase in power.