Monitoring of lubricating oils used in diesel engine by biodiesel contamination from fuel dilution

One of the most important physical quantities which has an influence on bearings and micro-bearings functioning is the viscosity of a lubricant. The data about a viscosity value dependence on temperature and shear rate are essential for designing sliding friction pairs. In design calculations usually there is assumed that a lubricant is a Newtonian fluid, therefore viscosity is constant over the full range of shear rates. During operation of friction pairs the contamination particles get into a lubricant and this causes that the lubricant becomes a non-Newtonian pseudoplastic or viscoelastic fluid. A similar effect on lubricating oil properties have combustion products or special performance additives. Furthermore, a lubricating oil ages and wears out, i.e. during its operating the initial structure of a particles is destroyed which can cause the change of the oil viscosity and lubricity values. The aim of this work is to determine the dynamic viscosity values in dependence on temperature and shear rate for selected new and used lubricating oils. In this research motor oils for passenger vehicles and tractors were investigated. This paper presents the results of measurements of the viscosity changes, in dependence on shear rate and temperature, made for the new and used oils. One of the investigated oils is Superol CC-40, which was used in four-stroke 4562 cm3 diesel engine for twenty months, which corresponds to 250 hours of operating. The second of investigated oils is Shell Helix Ultra AV-L which was used in four-stroke 2000 cm3 diesel engine for ten months at a distance of 15 000 kilometers. The viscosity measurements for the new and used lubricating oils were made with the Thermo Scientific Haake Mars III rheometer, in the range of temperatures from 10°C to 120°C and of shear rates to 51000 1/s. Moreover, the analysis of wear products, contaminants and additives in the investigated new and used lubricating oils was made with the rotating disc electrode atomic emission spectrometer Spectro Incorporated Spectroil Q100, which gives possibility to determine 22 most common elements which occur in motor, turbine and gear oils. The obtained information will be used in future studies related to hydrodynamic lubrication of slide bearings and micro-bearings. It also may be useful for designing bearings and sliding friction pairs.

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Assessment of infrared spectroscopy and multivariate techniques for monitoring the service condition of diesel-engine lubricating oils

Talanta ◽

10.1016/j.talanta.2006.02.054 ◽

2006 ◽

Vol 70 (2) ◽

pp. 344-352 ◽

Cited By ~ 50

Author(s):

Arnobio Roberto Caneca ◽

M. Fernanda Pimentel ◽

Roberto Kawakami Harrop Galvão ◽

Cláudia Eliane da Matta ◽

Florival Rodrigues de Carvalho ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Diesel Engine ◽

Service Condition ◽

Multivariate Techniques ◽

Lubricating Oils

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Analysis of the polycyclic aromatic hydrocarbon content of petrol and diesel engine lubricating oils and determination of DNA adducts in topically treated mice by 32P-postlabelling

Carcinogenesis ◽

10.1093/carcin/11.11.2025 ◽

1990 ◽

Vol 11 (11) ◽

pp. 2025-2032 ◽

Cited By ~ 31

Author(s):

Paul L. Carmichael ◽

Jürgen Jacob ◽

Gernot Grimmer ◽

David H. Phillips

Keyword(s):

Diesel Engine ◽

Polycyclic Aromatic Hydrocarbon ◽

Aromatic Hydrocarbon ◽

Dna Adducts ◽

Lubricating Oils ◽

Polycyclic Aromatic Hydrocarbon Content ◽

Hydrocarbon Content ◽

Polycyclic Aromatic

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Some Experiences of Fuel Dilution of Lubricating Oils in Small Diesel Engines

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1975_189_022_02 ◽

1975 ◽

Vol 189 (1) ◽

pp. 159-165

Author(s):

J. C. P. Thornber

Keyword(s):

Diesel Engines ◽

Combustion Process ◽

Lubricating Oil ◽

Nozzle Design ◽

Feed Pump ◽

Engine Operation ◽

Lubricating Oils ◽

Fuel Dilution ◽

Basic Characteristics ◽

Possible Cause

Fuel dilution of lubricating oils in small diesel engines is normally attributed to fuel leaking past seals, pumping elements or feed pump diaphragms. Some authorities advise that dilution greater than 10 to 15 per cent is inadvisable; others advocate an oil change if the viscosity is more than an S.A.E. grade. Another possible cause of dilution depends on fuel properties, nozzle design and aspects of air-How into a cylinder. The fuel introduced in this way plays some part in the combustion process and influences engine smoke levels. The dilution so caused is speed and temperature dependant. The paper describes tests to establish the basic characteristics, the mechanism at work and modifications to minimize this cause of oil dilution. Some tests are included to show that some fractions of fuel that is diluting lubricating oil can evaporate during engine operation; heavier fractions, however, are more likely to persist.

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