Proceedings of SerbiaTrib '13

stroke engines by physic-chemical methods in orderto evaluate possibilities of engine conditionmonitoring by oil analysis. This part presents theresults of experimental research of physic-chemicalcharacteristics of engines oil which was sampledfrom engines of PUCH 300GD, Pinzgauer 710 andIKARBUS IK 104P vehicles [9], [10].The research was carried out in two vehiclesPUCH 300GD (PUCH-1, PUCH-2), two vehiclesPINZGAUER 710M (PINZ-1, PINZ-2) and twovehicles IKARBUS IK 104P (IK104P-1, IK104P-2).The research was conducted through periodicsampling oil from engine vehicles listed above.Apart from the fresh oil (“zero” sample), samplesare taken after 1.000 km, 2.000 km, 3.000 km,4.000 km and 5.000 km for vehicles.The physical-chemical characteristics of oil inaccordance with standard methods are examined,shown in table 1.Table 1. Implemented tests and methods for examiningthe physic-chemical characteristics of oilCharacteristicMethodKinematic viscosity, mm 2 /s SRPS B.H8.022Viscosity IndexSRPS B.H8.024Flash Point (C) ISO 2592, ASTM D 92Pour Point (C) ISO 3016Water Content, mas.% ASTM D 95Total Base Number (TBN),mgKOH/gASTM D 2896Insoluble substances inpentane, %ASTM D 893Insoluble substances inbenzene, %ASTM D 4055Fe Content, %ASSCu Content, %ASSThe analysis was done on the fresh (new) oilsand oils that are used in the engines of vehicles.During the sampling of oil choice of the samplingwere conducted carefully according to the actual oilusage, which enabled each sample as representativeone.The wear mechanism of a tribologicallubrication system consists in the wear of contactsurfaces, and lubricant consumption. If there iswear of the contact surfaces, there are wearparticles present.Regardless of the availability of numerousmethods for diagnosing the physic-chemicalchanges of lubricants, in order to create a truepicture of the condition of lubricants from the usersystem, it is of importance to satisfy theprecondition of the possibility to obtain arepresentative sample. That is why it is extremelyimportant to take the sample in a proper way.Allowable values of deviation limits ofindividual characteristics of the oil are conditionedby the type of oil, working conditions and internalrecommendations of the manufacturer of lubricantsand users. Limited value characteristics of oils thatcondition the change of oil charging from engineare given in table 2. They represent the criteria forthe change of oil charge. Deviation of only onesource changes characteristics of oil charge, nomatter of what a characteristic is about.Table 2. Allowed values deviation of physico-chemicalcharacteristics of new and used oilPhysical-chemicalcharacteristics oil andproducts wearViscosity at 40C and100C, mm 2 /sMaximum allowedvariationMotor oil20%Viscosity Index, % 5 %Total Base Number (TBN),mg KOH/gr The fall to 50%Flash Point, C 20 %Water Content, % 0,2 %Products wear – Content Fe,ppm(μg/gr)100 ppmProducts wear – Content Cu,ppm(μg/gr)50 ppmUsed engine oil in examined vehicles are shownin table 3. Characteristics of zero samples of motoroil are shown in table 4, and the results used oilsamples in table 5.Table 3. Used engine oil in examined vehicles [9]Engine oil from engine of PUCH 300 GD vehiclesSAEclassificationAPIclassificationManufacturerFAMSAE 15W-40 API SG/CEKrusevacEngine oil from engine of PINZGAUER 710 M vehiclesSAEclassificationAPIclassificationManufacturerGALAXSAE 30/S3 -BeogradEngine oil from engine of IKARBUS 104 P vehiclesSAEclassificationSAE 15W-40APIclassificationAPI SG/CEManufacturerFAMKrusevacThe viscosity index is an empirical numberwhich shows how the viscosity of some oilschanges by increasing or reducing the temperature.High viscosity index shows relatively smalltendency of viscosity to change upon influence ofcertain temperature, as oppose of low viscosityindex which shows greater viscosity change withtemperature.242 13 th International Conference on Tribology – Serbiatrib’13