Should a Cobalite hard faced exhaust valve be resurfaced during valve service?

A Cobalite hard faced exhaust valve should not be resurfaced because the material is specifically designed to withstand high temperatures and resist wear in environments that would typically damage standard valves. Resurfacing can remove the hard facing layer, compromising its integrity and performance. This protection is crucial in maintaining the valve's longevity and efficacy under harsh operating conditions, such as those found in high-performance or turbocharged engines.

In contrast, other approaches to valve service focus on evaluating surface conditions and wear but do not change the core characteristics of specialized materials like Cobalite. Resurfacing could alter the sealing surfaces, leading to potential failure in engine performance or longevity issues. Hence, while monitoring the valve for wear is essential, resurfacing is not an option for Cobalite valves, which are engineered for their unique properties.