Advanced natural gas fueled engine development: Part 2. Final report, February 1988-January 1990

Tests were performed on recently developed ceramic seat inserts and intermetallic hardfaced valves which have shown a factor of 3 improvement in natural gas engine valve and seat insert durability in 300 hour short term testing. The report covers follow-on research to extend the previous test work to 1000 hours of test duration with the same and additional materials previously identified to improve valve and seat insert durability. Unfortunately only 581 hours of the target 1000 hours was run due to problems not related to the test components. During the test period an improvement factor of at least 3 was shown in valve and seat insert durability. Work at NIST has produced an analysis of the wear phenomena taking place between the valve and seat insert. Industry interest in the program is high but will require additional funded work to obtain their direct involvement for application of these materials to their engines.