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The increasingly strict emission regulations in combustion engines are raising high requirements for the engine valve train system. In this paper, a novel multifunctional wear apparatus is designed to study the performance of engine valve train components. The apparatus employs a mechanical loading system, which consists of a special eccentric wheel and disc springs that apply the combustion loads, and the contact configurations and loading conditions of valve train components are simulated. It has three test functions for different components through specifically designed fixtures. The first function aims to evaluate the interaction between the valve seating face and the seat insert at high temperatures and loads. The second function is used to study the friction and wear properties of the valve stem and the valve guide. The third function is designed to evaluate the performance of the valve seals. At last, a verification test was carried out by the proposed experimental method. A pair of new exhaust valve and seat insert is tested for the performance evaluation of the first function. The wear mechanisms acting on the pairs interface are shown to be a combination of oxidative wear, adhesive wear, as well as fatigue flaking.

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Increasing performance requirements of IC engines often leads to higher combustion chamber temperatures that cause premature failure of exhaust valves. This paper presents a tribological assessment of hollow head & sodium filled valves (HHSVs) produced using a new manufacturing process. Tests were conducted using bespoke bench-top wear and fatigue apparatus, and the HHSV specimens survived defined durability tests. When compared to traditional solid valves, the highest temperature of the hollow stem & sodium filled valves decreased from 745 °C to 590 °C. It was established that the new process did not adversely affect the wear mechanisms (oxidation accelerated adhesion) and the material loss magnitude when compared to solid valves. The design of HHSVs tested gives a 16.1% reduction in mass.