Today, globally, automotive manufacturers are striving to meet the increasing demand for fuel economy, high performance, and silent engines. The fundamental approach to achieving these requirements is through designing low friction mechanisms, resulting in less wear and higher durability.
The demand for CNG vehicles has surged exponentially in recent years, prompting increased government focus on alternative fuels such as CNG and hydrogen. These dry fuels lack lubricating properties, unlike conventional fuels like petrol, diesel, and biofuels, which are wet and liquid. Consequently, the operations and failures associated with these fuels differ. The materials and designs of engine parts, such as fuel lines, ECU, exhaust valves, and cylinder heads, vary depending on the fuel used.
This study discusses the countermeasures adopted to address the high seat and guide wear in cylinder heads and valves. The investigation focuses on material, design, and manufacturing process improvements, supported by part-level and vehicle-level validation and testing for CNG exhaust valves and cylinder heads. The design is optimized to reduce wear that occurs after corrosion (micro pitting) in the valve stem, causing valve seat wear followed by valve guide wear, leading to engine misfiring and performance loss.