John R. Lindsay Smith, Moray S. Stark,* Julian J. Wilkinson Department of Chemistry, University of York, York YO10 5DD, UK Peter M. Lee, Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK R. Ian Taylor Shell Global Solutions, Chester, CH1 3SH, UK Simon Chung Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK STLE Annual Meeting : Toronto 17 th - 20 th May 2004 The Degradation of Lubricants in Gasoline Engines Department of Chemistry

John R. Lindsay Smith, Moray S. Stark,* Julian J. Wilkinson Department of Chemistry, University of York, York YO10 5DD, UK Peter M. Lee, Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK R. Ian Taylor Shell Global Solutions, Chester, CH1 3SH, UK Simon Chung Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK The Degradation of Lubricants in Gasoline Engines Part 1: Introduction, Lubricant Flow in Engine, Effects of Detergents Moray Stark

Aims To Predict Increase in Piston Friction with Oil Degradation  Chemical Model for Base Fluid Oxidation  Rheological Model for Increase in Viscosity  Tribological Model for Piston Friction To Develop Bench-top Reactors that Mimic the Piston Ring Pack Department of Chemistry

Introduction to Project  This Talk: Introduction to Project Fluid Flow in Engine Effects of Detergent  Next Talk: (Peter Lee) Tribology of Project Engine Modifications Enhanced Degradation Tests  Third Talk: (Julian Wilkinson) Chemical Models of Hydrocarbon Base Fluids Chemical Mechanisms of Base Fluid Oxidation Department of Chemistry

Engine : Ricardo Hydra  Fuel Injected Gasoline  Single Cylinder  0.5 litre Capacity Department of Chemistry

Engine : Ricardo Hydra  Fuel Injected Gasoline  Single Cylinder  0.5 litre Capacity Engine Conditions  rpm  33% - 75% Load Department of Chemistry

Engine : Ricardo Hydra  Fuel Injected Gasoline  Single Cylinder  0.5 litre Capacity Engine Conditions  rpm  33% - 75% Load Engine Modifications  External Sump ( ºC)  Sampling of Ring Pack Lubricant Department of Chemistry

Lubricant Specification Build up complexity of Lubricant Base Fluid only Base Fluid :Shell XHVI ™ 8.2 Department of Chemistry

Lubricant Specification Build up complexity of Lubricant Base Fluid only Base Fluid + Detergent (2 % w/w) Base Fluid :Shell XHVI ™ 8.2 Detergent :Neutral Alkyl Sulfonate Department of Chemistry

Lubricant Specification Build up complexity of Lubricant Base Fluid only Base Fluid + Detergent (2 % w/w) Base Fluid + Detergent (2 % w/w) + Dispersant (2 % w/w) Base Fluid :Shell XHVI ™ 8.2 Detergent :Neutral Alkyl Sulfonate Dispersant :Alkyl Succinimide Department of Chemistry

Extraction of Oil from Top Piston Ring Department of Chemistry

Oil Flow in Engine Sump Ring Pack Small Volume Short Residence Time Large Volume Long Residence Time Flow Rate S. Yasutomi, Y. Maeda, T. Maeda, Ind. Eng. Chem. Prod. Res. Dev., 20, 530, 1981

Ring Pack Residence Time 1-e -1  RingPac k S B Saville, F D Gainey, S D Cupples, M F Fox, D J Picken, SAE Technical Paper, International Fuels and Lubricants Meeting, Oct 10-13, 1988

Ring Pack Residence Time : 60 sec Submitted to Tribology Letters: M. S. Stark, R. J. Gamble, C. J. Hammond et al., 2004 Conditions : 1500 rpm, 50 % Load. Lubricant : XHVI TM 8.2 only

Oxidation Chemistry Hydrocarbon Base Fluid Department of Chemistry

Oxidation Chemistry Hydrocarbon Base Fluid Hydroperoxides Department of Chemistry

Oxidation Chemistry Hydrocarbon Base Fluid Hydroperoxides Alcohols Department of Chemistry

Oxidation Chemistry Hydrocarbon Base Fluid Hydroperoxides Alcohols Carboxylic Acids Ketones Department of Chemistry

Oxidation Chemistry Infrared Spectroscopy of Carbonyl Group Hydrocarbon Base Fluid Hydroperoxides Alcohols Carboxylic Acids Ketones Department of Chemistry

Oil Flow and Chemistry in Engine Sump Ring Pack High Temperature Small Volume Short Residence Time Low Temperature Large Volume Long Residence Time Department of Chemistry

Oxidation in Ring Pack : Carbonyl IR Submitted to Tribology Letters: M. S. Stark, R. J. Gamble, C. J. Hammond et al., 2004 Conditions : 1500 rpm, 50 % Load. Lubricant : XHVI TM 8.2 only

Oxidation in Ring Pack : Carbonyl IR vs TAN Submitted to Tribology Letters: M. S. Stark, R. J. Gamble, C. J. Hammond et al., 2004 Conditions : 1500 rpm, 50 % Load. Lubricant : XHVI TM 8.2 only

Effect of Detergent on Ring Pack Oxidation Conditions : 1500 rpm, % Load Lubricant : XHVI TM 8.2 (Detergent: 2 % w/w Sulfonate)

Effect of Engine Conditions : Load Conditions : 1500 rpm, % load Lubricant : XHVI TM 8.2. Detergent: 2 % w/w Sulfonate

Oxidation in Ring Pack Comparison with Previous Work S B Saville, F D Gainey, S D Cupples, M F Fox, D J Picken, SAE Technical Paper, International Fuels and Lubricants Meeting, Oct 10-13, 1988

Sump Residence Time and Oil Flow Rates Department of Chemistry

Sump Residence Time and Oil Flow Rates Department of Chemistry

Sump Residence Time and Oil Flow Rates Department of Chemistry

Sump Residence Time and Oil Flow Rates Department of Chemistry

Sump Residence Time and Oil Flow Rates Department of Chemistry

Sump Residence Time and Oil Flow Rates

Ring Pack Residence Time 60 ± 15 seconds Volume of Oil 0.30 ± 0.08 cm 3 Temperature  200 °C Flow Rates Into Ring Pack 0.32 ± 0.03 cm 3 min -1 Returning to Sump 0.27 ± 0.03 cm 3 min -1 Oil Loss 0.05 cm 3 min -1 Sump Residence Time 62 ± 6 hours/litre Temperature 70 °C Conditions: 1500 rpm, 50% Load. Lubricant, XHVI TM 8.2 only Characterisation of Ricardo Hydra Engine Submitted to Tribology Letters: M. S. Stark, R. J. Gamble, C. J. Hammond et al., 2004

Flow Rates Sump Residence Time (cm 3 min -1 ) (hours/litre) 50 % Load, No Detergent0.27 ± ± 6 33 % Load, 2 % Detergent 0.69 ± ± 3 50 % Load, 2 % Detergent 0.74 ± ± 2 75 % Load, 2 % Detergent 0.54 ± ± 3 Conditions: 1500 rpm, 33 % - 75 % Load Lubricant, XHVI TM 8.2 (Detergent: 2 % w/w Sulfonate) Lubricant Flow : Effect of Detergent Department of Chemistry

Conclusions  Lubricant Flow in Gasoline Engine Measured  Effects of Detergent Established Department of Chemistry

Conclusions  Lubricant Flow in Gasoline Engine Measured  Effects of Detergent Established Acknowledgements Shell Global Solutions Moray Stark

Institute of Tribology University of Leeds Peter M. Lee,* Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK John R. Lindsay Smith, Moray S. Stark, Julian J. Wilkinson Department of Chemistry, University of York, York YO10 5DD, UK R. Ian Taylor Shell Global Solutions, Chester, CH1 3SH, UK Simon Chung Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK The Degradation of Lubricants in Gasoline Engines STLE Annual Meeting : Toronto 17 th - 20 th May 2004

Part 2: A Study of the Link Between Base Oil Degradation and its Changing Rheological Properties Peter Peter M. Lee,* Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK John R. Lindsay Smith, Moray S. Stark, Julian J. Wilkinson Department of Chemistry, University of York, York YO10 5DD, UK R. Ian Taylor Shell Global Solutions, Chester, CH1 3SH, UK Simon Chung Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK The Degradation of Lubricants in Gasoline Engines

John R. Lindsay Smith, Moray S. Stark, Julian J. Wilkinson* Department of Chemistry, University of York, York YO10 5DD, UK Peter M. Lee, Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK R. Ian Taylor Shell Global Solutions, Chester, CH1 3SH, UK Simon Chung Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK The Degradation of Lubricants in Gasoline Engines STLE Annual Meeting : Toronto 17 th - 20 th May 2004 Department of Chemistry

John R. Lindsay Smith, Moray S. Stark, Julian J. Wilkinson* Department of Chemistry, University of York, York YO10 5DD, UK Peter M. Lee, Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK R. Ian Taylor Shell Global Solutions, Chester, CH1 3SH, UK Simon Chung Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK The Degradation of Lubricants in Gasoline Engines Julian Wilkinson Part 3: Chemical Mechanisms for the Oxidation of Branched Alkanes

Abstract for STLE Conference Toronto, May 2004 The Degradation of Lubricants in Gasoline Engines: Part 1: A Combined Tribological, Rheological and Chemical Model for Lubrication Degradation in the Piston Ring Pack Moray S. Stark*, John R. Lindsay Smith, Julian J. Wilkinson Department of Chemistry, University of York, York YO10 5DD, UK Peter M. Lee, Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK R. Ian Taylor Shell Global Solutions, Shell Research Ltd, PO Box 1, Chester, CH1 3SH, UK Simon Chung Infineum UK Limited, PO Box 1, Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK The automotive industry requires lubricants that will have longer drain intervals and higher performance (such as lower component wear and increased fuel economy) and this must be achieved within ever tightening compositional constraints, for example, reduced phosphorus levels. To help the design of the next generation of lubricants, this project is studying the fundamental behaviour of lubricants in gasoline engines. A detailed tribological model of the oil flow in the piston ring pack has been constructed. This is combined with a detailed chemical model describing the oxidation of the hydrocarbon base fluid and a rheological model that describes how lubricant degradation products affect the viscosity of the oil. The predicted viscosity change of the lubricant during use feeds back into the tribological model to give a prediction of the change in performance of the lubricant in the engine as the oil degrades. This talk will discuss the progress made on this project, and experiments that have been done to verify the models. * Biography for Presenting Author Moray Stark has a BSc and PhD in Physics, but has been working as a Chemist for longer than he can remember. The past few years have been spent specialising in the study of the oxidation mechanisms of hydrocarbon and ester lubricant base fluids, and the effects that oxidation products have on the rheology of lubricants. This work is sponsored by Shell Global Solutions (UK) and Infineum.

John R. Lindsay Smith, Moray S. Stark, Julian J. Wilkinson Department of Chemistry, University of York, York YO10 5DD, UK Peter M. Lee, Martin Priest School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT, UK R. Ian Taylor Shell Global Solutions, Shell Research Ltd., Chester, CH1 3SH, UK Simon Chung Infineum UK Ltd., Milton Hill, Abingdon, Oxfordshire, OX13 6BB, UK The Degradation of Lubricants in Gasoline Engines Part 1: A Combined Tribological, Rheological and Chemical Model for Lubrication Degradation in the Piston Ring Pack STLE Annual Meeting : Toronto 16 th - 20 th May 2004

Sedimentation of XHVI Detergent Department of Chemistry