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Mechanical Degradation of Multi-Grade Engine Oils
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English
Abstract
Polymer additives in commercial engine oils are mechanically degraded in flows involving large stresses. The oil stability is usually characterized by an asymptotic value called the fully-sheared viscosity. Published data from field and laboratory engine tests show that the kinematic viscosity of degraded oil does not approach such an asymptote. This viscosity reaches a minimum due to the compensating effects of mechanical degradation and oxidation. Kinematic viscosity data from various tests are correlated here using a logarithmic function. This correlation is used to compare the kinetics of degradation processes in different tests. These comparisons suggests that multi-grade oils degrade at a consistent rate in different engine tests. Simulation devices using a diesel fuel injector do not give results comparable to field test data. A milder technique for simulating mechanical degradation of engine oils is suggested to improve correlation with field data.
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Citation
Herbeaux, J. and VanArsdale, W., "Mechanical Degradation of Multi-Grade Engine Oils," SAE Technical Paper 930690, 1993, https://doi.org/10.4271/930690.Also In
References
- Schnabel W. Polymer Degradation , Hanser International, ( 1981
- Wunderlich W. “The Behaviour of Polymeric Oil Additives in the Engine” Colloques Inter-nationaux du C.N.R.S. N°233-Polyméres et Lubrification Brest 1974
- Casale A. Porter R.S. Polymer Stress Reactions 1 Academic Press New York 1978
- Salomon T. “Comment Agissent les Additifs de Viscosite Dans les Huiles Minérales” Revue de I'lnstitut Français du Pétrole 11 4 501 548 1956
- Harrington R.E. Zimm B.H. “Degradation of Polymers by Controlled Hydrodynamic Shear” The Journal of Physical Chemistry 1 1 161 175 1965
- Bartz W.J. “About the Irreversible Flow Prop-erties of Polymer Thickened Engine oils” Colloques Internationaux du C.N.R.S. N°233-Polymeres et Lubrification Brest 1974
- Porter R.S. Casale A. “Recent Studies of Polymer Reactions Caused by Stress” Polymer Engineering and Science 25 3 129 156 1985
- Jellinek H.H.G. Degradation of Vinyl Polymers Academic Press New York 1955
- Batique G. “Etude par Microbroyage de la Perte de Viscosité des Huiles Dites ‘Multi-grades’” Revue de I'lnstitut Français du Pétrole 15 2 419 430 1960
- Crail I.R.H. Neville A.L. “The Mechanical Shear Stability of Polymeric VI Improvers” Journal of the Institute of Petroleum 55 542 100 108 1969
- Rein S.W. Alexander D.L. Cryvoff S.A. Dahlstrom M.A. “Investigations of Engine Oil Shear Stability in Laboratory Tests and Road Tests” SAE # 872129 7.749 7.760 1987
- Alexander D.L. Kapuscinski M.M. Laffin M.V. “Shear Stability Index of VI Improvers ; Its Dependency on Method of Determination” Lubrication Engineering 45 12 801 806 1989
- Murphy C.K. Bennett P.A. “V.I. Improvers and Engine Performance” SAE # 680071 266 282 1968
- Ofunne G.C. Maduako A.U. Ojinnaka CM. “Studies on the Ageing Characteristics of Automotive Crankcase Oils” Tribology International 22 December 401 404 1989
- Sen J. VanArsdale W.E. “Condition Monitoring of Oil in a Single Cylinder Engine” SAE # 922291 1992
- Arlie J.P. Denis J. “Relations entre la Structure de Divers Polyméres Additifs de Viscosité et Leur Comportement en Solution dans les Huiles Lubrifiantes” Colloques Internationaux du C.N.R.S. N°233-Polyméres et Lubrification Brest 1974
- Herbeaux J.-L. “Mechanical Degradation of Multi-Grade Engine Oils” Master's Thesis, University of Houston ( 1992
- Schilling A. Motor Oils and Engine Lubrication Ferry Pickering Sales Ltd Hinckley 1968
- Alexander D.L. Rein S.W. “Relationship Between Engine Oil Bench Shear Stability Tests” SAE # 872047 7.288 7.297 1987