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Some lubricant effects on octane requirement increase

Conference · · Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States)
OSTI ID:6396553
The instantaneous effects of consuming lubricant on octane requirement and the effects on octane requirement increase (ORI) resulting from accumulation of combustion chamber deposits were studied. It was found that the decrease in fuel octane number of clear gasoline (containing no antiknock additives) due to the instantaneous consumption of motor oil was one octane number or less. Depending on the engine test procedure, approximately 19% or less of the combustion chamber deposit derived ORI was due to the fuel with the remainder due to consumption of lubricant. Fuel variations had no effect on ORI. The amount of lubricant consumed by the knocking cylinder determined the ORI of a multi-cylinder engine. The effect of the rate of oil consumption on ORI from a multi-cylinder engine test compared favorably with results from a single-cylinder engine test. Assessing the combustion chamber deposit contribution to ORI of multi-cylinder engines by using the check-back ORI (final octane requirement minus octane requirement after removal of combustion chamber deposits) was superior to using the final minus initial octane requirement as the ORI. The variation of ORI between six motor oils was due to their different ash levels; the lowest sulfated ash oil had the lowest ORI; the highest sulfated ash oil had the highest ORI. Of the components in a SE quality, high sulfated ash motor oil, the overbased petroleum sulfonate accounted for most of this oil's ORI.
Research Organization:
Phillips Petroleum Co., Bartlesville, OK
OSTI ID:
6396553
Report Number(s):
CONF-780902-P3
Conference Information:
Journal Name: Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States) Journal Volume: 23:3
Country of Publication:
United States
Language:
English