The Relationship of Low-Temperature Rheology to Engine Oil Pumpability

730478

02/01/1973

Event
National Automobile Engineering Meeting
Authors Abstract
Content
An analysis of oil pumpability reveals that engine oil pumping failures may occur because either the oil cannot flow under its own head to the oil screen inlet, or the oil is too viscous to flow through the screen and inlet tube fast enough to satisfy pump demands. To determine which factor is controlling, the behavior of commercial, multigraded oils was observed visually at temperatures from -40 to 0°F (-40 to - 17.8°C) in a laboratory oil pumpability test apparatus. Test results revealed that pumping failures occur by the first alternative: a hole is formed in the oil, and the surrounding oil is unable to flow into the hole fast enough to satisfy the pump. Of 14 oils tested, 7 failed to be pumped because of air binding or cavitation which developed in this manner. A model, which explains these failures in terms of yield point considerations and the low shear apparent viscosity of the oils, is proposed.
Meta TagsDetails
DOI
https://doi.org/10.4271/730478
Pages
18
Citation
McMillan, M., and Murphy, C., "The Relationship of Low-Temperature Rheology to Engine Oil Pumpability," SAE Technical Paper 730478, 1973, https://doi.org/10.4271/730478.
Additional Details
Publisher
Published
Feb 1, 1973
Product Code
730478
Content Type
Technical Paper
Language
English