Valve Temperature Control in Multi-cylinder Diesel Engine 2001-28-0006
The life of the valves, especially exhaust valve, heavily depends on the temperature with which it operates. This paper explores various possibilities of reducing the valve temperature in multi cylinder diesel engine. Restricting the heat in flow to the valve and enhancing the heat out flow from the valve can reduce the temperature of the valve. The exhaust valve is tested with the Nickel coating as a heat barrier on its head and neck portion, which are heat-receiving areas. The seat insert and valve guide material have been changed to copper for enhancing the heat outflow from the valve, where most of the heat from the valve passes through. The seat contact area is increased with the aim to increase the heat-rejecting surface. These design changes are tested separately and in combination in a 4 cylinder naturally aspirated DI diesel engine.
The temperature measurement is done using hardened temperature check valves, and the results indicated that the use of copper seat insert has substantially reduced the exhaust valve temperature and the nickel coating had also reduced the temperature considerably.