Development of a Low Emission Two-Stroke Cycle Engine

This paper focused experimental and theoretical studies on the effects of air-head stratified scavenging and leaner combustion on reducing hydrocarbon emission and improving thermal efficiency of two-stroke cycle spark-ignition engine.

The result showed that the amount of short-circuiting mixture with a conventional Schnurle scavenging two-stroke cycle engine was reduced from 30% to 9% with the air-head stratified scavenging two-stroke cycle engine which was developed in this study. Thermal efficiency was improved from 13.6% to 20.6%. As the result, the engine with air-head stratified scavenging and leaner combustion in this study can conform to the California Air Resources Board (CARB) 1999 or tier 2 emission standards regarding THC, CO and NOx emission.