This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Mechanical Degradation of Multigrade Oils in Laboratory Engine Tests
Annotation ability available
Sector:
Language:
English
Abstract
Eight SAE 10W-30 oils were formulated with different viscosity index (VI) improvers and used in single and multicylinder engines. A significant number of measurements were made during each engine test to accurately determine changes in kinematic viscosity with time. These measured values appear to decay logarithmically over a large portion of each test. This behavior is qualitatively similar to results reported in other engine tests involving multigrade oils. A coefficient in the data correlation is suggested as a measure of engine severity for a particular formulation. This coefficient and the shear stability index are used to monitor severity changes during the test period. These changes are correlated to an increase in ring gap and a decrease in ring mass for the single cylinder engine. A procedure is suggested for extrapolating severity measures to a value representative of the initial engine configuration. While the ratio of these initial values is nearly constant for fired engine tests, poor correlation is obtained between fired and motored tests on the same engine. Bench tests based on an ultrasonic oscillator and the Bosch diesel injector correlate poorly with all engine tests.
Recommended Content
Technical Paper | Reduction of HC Emission for Passenger Car Diesel Engine |
Technical Paper | Experimental Optimization of the Cold Start for the EcoBoost Engine |
Technical Paper | Development of Highly Durable Optical Probe for Combustion Measurement |
Authors
Topic
Citation
Flamberg, A., Koller, R., Herbeaux, J., and Van Arsdale, W., "Mechanical Degradation of Multigrade Oils in Laboratory Engine Tests," SAE Technical Paper 942024, 1994, https://doi.org/10.4271/942024.Also In
References
- Herbeaux J.L. VanArsdale W. E. “Mechanical Degradation of Multigrade Engine Oils” in Tribology of Engines and Engine Oils Covitch M. J. Tung S. C. SAE Warrendale SP-959 1993
- Herbeaux J.-L. Flamberg A. Koller R. D. “Effect of Engine Operation on the Viscosity of Polymer-Containing Engine Oils” Polymer Preprints 35 1 745 746 1994
- Wright B. du Parquet J. P. R. “Degradation of Polymers in Multigrade Lubricants by Mechanical Shear” Polymer Degradation and Stability 5 425 447 1983
- Casale A. Porter R. S. Polymer Stress Reactions 1 Academic Press 1978
- Okrent E. H. “The Effect of Lubricant Viscosity and Composition on Engine Friction and Bearing Wear” ASLE Trans 4 97 108 1961
- Dancy J. H. Alexander D. L. Lindholm S. O. DiBerto D. C. “An Investigation of Engine Oil Viscosity Loss in Passenger Car Service and Its Characterization” SAE 922295 29 40 1992
- Shear Stability of Multigrade Crankcase Oil ASTM Data Series Publication DS 49 ASTM Philadelphia, PA 1973