Development of the Ball Rust Test-A Laboratory Test Replacing the Sequence IID Engine Test
A laboratory Ball Rust Test (BRT) has been jointly developed by General Motors and Ethyl Corporation to replace the current Sequence IID engine test, and standard test procedures have been established to assess the rust/corrosion protection ability of experimental and commercial oils. Under the optimum test conditions developed, BRT data on eight industry reference and eighteen industry supplied oils showed a reasonable correlation with Sequence IID average rust test results. The capability of the BRT for differentiating oil quality was further demonstrated by evaluating 132 commercial oils obtained from around the world: oils with insufficient protection, such as those with API performance ratings of SA to SE, performed poorly in the BRT; oils with API ratings of SF, SG, and SH performed well in the test. The BRT will be made available to ASTM for development of a precision statement and for inclusion in future engine oil performance specifications.