Investigations of engine oil shear stability in laboratory tests and road tests

Conference · Thu Jan 01 00:00:00 EST 1987

OSTI ID:5137977

Rein, S W; Alexander, D L; Cryvoff, S A; Dahlstrom, M A

The relationship of shear stability in laboratory tests to shear stability in service was investigated in a diesel injector test, in the L-38 single-cylinder engine, in a multi-cylinder engine equipped for bearing film thickness measurement, and in road testing in an automobile and in trucks. All of the laboratory and road tests differed in severity of shearing and also showed that major VI improver types differed in the time needed for their kinematic viscosity to approach a fully-sheared value. Shear stability comparisons based on kinematic viscosities measured during the transition to the fully sheared condition did not accurately represent the relative shear stability of VI improvers in the fully-sheared condition. In the road tests, most of the oils were at their fully-sheared viscosity for the major part of their service life. The decrease of HTHS viscosity due to shearing in the road test and laboratory engines was usually less than half the kinematic viscosity decrease. Bearing oil film thicknesses showed little or no change with test duration in the multicylinder lab engine and correlate well with HTHS viscosity.

• OSTI ID: 5137977
• Report Number(s): CONF-871142-
• Resource Relation: Conference: International fuels and lubricants meeting and exposition, Toronto, Canada, 2 Nov 1987; Other Information: Technical Paper 872129
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
DIESEL ENGINES
LIQUID FLOW
LUBRICATING OILS
SHEAR
FUEL INJECTION SYSTEMS
MEASURING METHODS
STABILITY
STANDARDS
TESTING
VISCOSITY
ENGINES
FLUID FLOW
FUEL SYSTEMS
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
LUBRICANTS
OILS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PETROLEUM PRODUCTS
330102* - Internal Combustion Engines- Diesel