Integration of a Compact 4-Stroke Engine into a Model Vehicle with Dynamic Emission Analysis on a Small Chassis Dynamometer

The increasing importance of reducing emissions and improving the efficiency of internal combustion engines extends not only to applications in large vehicles, but also to small drive systems. This study focuses on the implementation of a compact 4-stroke engine in a model vehicle and on dynamic emission tests carried out with a specially developed test rig. The aim was to investigate the integration of small combustion engines into model platforms and to evaluate their emission behavior under transient conditions. The 4-stroke engine was carefully selected and adapted to the physical and operational conditions of the model vehicle. A test rig with a small roller dynamometer was developed to simulate real driving cycles and enable dynamic measurement of emissions. To optimize oil emissions, an online mass spectrometer was used to analyze the effects of lubricant composition and hardware variations, such as different piston ring designs, on emission behavior. High-resolution measuring devices recorded transient emissions and provided insights into the engine's behavior at different loads and speeds. The results demonstrated that small 4-stroke engines can be effectively integrated into model vehicles while providing acceptable performance and emission levels. However, dynamic testing showed significant emission spikes during transient operation, particularly in relation to oil emissions, highlighting the challenges of controlling emissions during acceleration and deceleration phases. These results underline the importance of optimizing combustion control strategies, lubricant formulations and hardware design for small engines. This work makes a valuable contribution to the field of miniature propulsion systems and provides a basis for future research to improve the environmental performance of small internal combustion engines.