Design and Development of a Bench Test-rig for Investigating Diesel Engine Inlet Valve and Seat Insert Wear

The following describes the design, construction and preliminary work on a bench test-rig that simulates the environment and contact conditions to which a diesel engine inlet valve and seat insert are subjected. This provides a means to objectively rank valve and seat insert materials and designs. It also facilitates investigations into the wear mechanisms causing valve recession in automotive engines. An extensive review of the literature has been carried out to isolate the important parameters. Validating the test facility by varying these test parameters (load, temperature, number of cycles and valve misalignment relative to the seat insert) enabled a baseline for future testing to be established. The results were compared with valves and seat inserts from engine dyno tests, using techniques such as profilometry and optical microscopy. It was concluded that the test-rig provides a good simulation of the wear of both inlet valves and seat inserts used in diesel engines.