Objective
This test method was developed to evaluate a lubricant’s performance protecting against adhesive wear between piston ring and cylinder liner.
Field Service Simulated
Heavy-duty, on-highway turbocharged and intercooled diesel engines equipped with EGR and running on ultra-low sulfur diesel fuel.
Test Fixture
Modified Detroit Diesel DD13 diesel engine, common rail fuel system, high-flow injectors, 12.8L, open chamber, in-line six-cylinder, four-stroke, turbocharged and intercooled.
Test Parameters
- The test engine is operated for up to 200 hours or until scuffing occurs.
- The test is performed using 15 PPM sulfur diesel fuel.
- The first 30 hours are conducted at rated speed and approximately 800 Nm (~50% throttle).
- The final 170 hours are conducted at rated speed and approximately 1,800 Nm (~80% throttle).
Test Parts Evaluation
- Cylinder Liner Scuffing Rating
- Top Ring Weight Loss
Used Lubricant Analysis
- Viscosity @ 100°C (ASTM D445)
- High Temp, High Shear (ASTM 4683)
- High Temp, High Shear (ASTM 4683)
- TAN (ASTM D664)
- TBN (ASTM D4739)
- Wear Metals (ASTM D5185)
- Oxidation by FTIR
- Soot by TGA
Pass/Fail Criteria
The pass/fail criteria of Hours to Scuff is based on the number of hours run prior to scuffing. This is evaluated based on a minimum level of cylinder liner scuffing, top ring weight loss achieved at EOT and point in test hours when a 25 PPM or greater iron concentration increase is observed in used oil analysis results.