Thiruvallur Loganathan, B., Narasimhan, S., Varadha Iyengar, L., Sandur, A. et al., "Durability Improvement of Engine Valves and Interfacing Systems," SAE Technical Paper 2016-32-0020, 2016, doi:10.4271/2016-32-0020.
Development of small air cooled motorcycles is ever challenging due to combination of customer expectation, regulatory requirements and cost factors. Achieving higher performance, emission standards means higher engine and parts operating temperature. Under these changes meeting durability targets at reasonable cost needs good understanding of material, surface treatment and tribological aspects. In this paper some of the surface and process improvements done to reduce wear in engine valves and interface systems is discussed in detail.Design of engine valves shall ensure meeting thermal, mechanical strength requirements, wear and durability targets. Surface treatments, coating, surface finish and also use of special materials in tip, valve stem, seat ensures higher durability; low wear in valve and interfacing parts.During new engine development process verification tests, wear observed in valve stem- guide, valve tip- screw interface. Effect of various design parameters are studied through a simulation tests. Results of different trials are shown. Various solutions are evaluated based on performance and cost.