CORROSION - RESISTANT METALS for Valves and Seats on Heavy-Duty Engines 480178
IT has become necessary to use a combination of materials, the author points out, in the design of exhaust valves for high-powered engines.
For heavy-duty ground vehicles, he says, the problem is complicated by the importance of cost, which eliminates many good materials from consideration. Nevertheless, the author believes that exhaust-valve and seat-insert combinations can be designed to meet the requirements of any of today's heavy-duty operations.
The continual stepping up of power, he says, however, will require further developments. For the near future Mr. Colwell foresees: a hardened seat insert of good properties, sodium-cooled valves, positive rotating valves, better materials to extend overhaul time, and the use of some of the heat-resisting alloys developed for aircraft turbines, if costs are lowered sufficiently.