Analysis of Engine Braking System for Heavy Vehicle Performance Improvement

This paper focuses on the analysis of engine braking systems used in Internal Combustion Engines (ICEs) for heavy vehicles. It aims to evaluate the functionality of engine brakes and investigate the technologies used for their implementation. Engine braking is crucial for vehicle safety and efficiency since it reduces speed through the engine's mechanical resistances, thus saving energy, and limiting wear of friction brakes. While light vehicles typically downshift gears for engine braking, heavy vehicles use exhaust valve manipulation. Two diesel engines, E1 and E2 from FPT Industrial S.p.a., are analysed, each equipped with different engine brake types: mechanical for E1 and hydraulic for E2. The research activity involves component and system-level analysis, including thermal cycle examination, mechanical component performance evaluation, critical issue identification, and comparison of braking power characteristics. E2 demonstrates superior performance due to its fully hydraulic brake system, regulated by an Oil Control Valve (OCV), allowing quicker and more precise activation compared to E1. Additionally, E2 emits 9% less carbon dioxide, enhancing its competitiveness for future emissions regulations.