This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Low Viscosity Oil Studies and the Influence of Radial Clearance on Bearing Distress in a 3.8L Engine
Annotation ability available
Sector:
Language:
English
Abstract
Classical journal bearing equations predict the function of oil flow in dissipating heat, thereby governing the effective viscosity of the lubricant in bearings. From this perspective, experimental dynamometer tests explored low speed, high load, high temperature, operation of four low viscosity oils. Test length was 48 hours using a 3.8L V-6 engine under steady state and cyclic conditions.
With a 1.4 cP HTHSR viscosity oil the bearing distress appeared dependent on connecting rod bearing clearances serving to govern rate of oil flow through the main bearings. Front and rear main bearings exhibited severe overheat-distress. This was related to the design of the oil distribution system in the crankshaft. A severe cyclic acceleration test showed little bearing distress. Significant distress occurred only with an SAE 5W viscosity grade. SAE 5W-30 and 5W-40 multigrades showed no abnormal wear. Results were interpreted in terms of high temperature, high shear rate rheology of the test oils.
Recommended Content
Authors
Citation
Heath, D., Baczek, S., and Sterlekar, T., "Low Viscosity Oil Studies and the Influence of Radial Clearance on Bearing Distress in a 3.8L Engine," SAE Technical Paper 880682, 1988, https://doi.org/10.4271/880682.Also In
References
- Lonstrup, T. F. Smith, M. F. Jr. “Engine Oil and Bearing Wear” SAE Paper No. 810330
- Rhodes, R. B. Henderson, B. M. “Effects of Engine Oil Viscosity and Composition on Bearing Wear” SAE Paper 811224
- Okrent, E.H. “Engine Friction and Bearing Wear, III, The Role of Elasticity in Bearing Performance” ASLE Trans. 7 1964
- Van OS, N. Rhodes, R. B. Covey, D. F. “A Study of Lubricating Oil Performance in a Journal Bearing Rig. II” SAE Paper 810801
- Bates, T. W. Williamson, B. Spearot, J.A. Murphy, C. K. “A Correlation Between Engine Oil Rheology and Oil Film Thickness in Engine Journal Bearings” SAE Paper No. 860376
- ASTM D02.07 Bearing Oil Film Thickness Task Force 1986 Cryvoff, S. Texaco Inc. Box 509, Beacon, N.Y. 12508
- Filowitz, M. S. King, W. H. Appledoorn, J. K. “Oil Film Thickness in a Bearing of a Fired Engine” SAE Paper No. 820511
- McMillan, M. L. Rosenberg, R. C. Murphy, C. K. “Viscosity Effects on Engine Wear Under High-Temperature, High-Speed Conditions” SAE Paper No. 780982
- Flathmann, D. E. Barker, R. F. Wylie, W. S. “Wear Performance of an SAE 0W-30 Partial Synthetic Motor Oil Under High Speed Driving Conditions,” SAE Paper No. 821196
- Schilowitz, A.M. Waters, J. L. “Oil Film Thickness in a Bearing of a Fired Engine, Part IV, Measurement in a Vehicle on the Road” SAE Paper No. 861561
- Manner, D. M. Miller, R. A. “Buick's New Even Firing 90° V-6 Engine” SAE Paper No. 770821
- Ocvirk, F. W. Dubois, G. B. “Analytical Derivation and Short Bearing Approximation for Full Journal Bearings” N.A.C.A. Report 1953
- Booker, J. F. “Dynamically Loaded Journal Bearings: Mobility Method of Solution” Journal of Basic Engineering, Trans. ASME 87 1966
- Meernik, P. R. “Lubricant Flow to Connecting Rod Bearings Through a Rotating Crankshaft” SAE Paper No. 860229
- Cameron, A. The Principles of Lubrication, J. Wiley and Sons Inc. New York, N. Y. 1966
- Fuller, D. P. Theory and Practice of Lubrication for Engineers 2nd ed. J. Wiley and Sons Inc. New York, N. Y. 1984
- ASTM Fuel Efficient Engine Oil Task Force Research Report, RR:D2:1204 Philadelphia, PA 1986
- Durella, M. J. “Engine Failure Analysis at Shop Level, Engine Bearings” SAE Publication SP-235 1962
- Walker, J. W. Wiltse, R. F. Harhaus, V. W. “The GM 4.3 Liter V-6 Gasoline Engine” SAE Paper 841225