Hakan Kaleli

The impact of crankcase oil containing phosphorus on catalytic converters and engine exhaust emissions

Two 10W30 mineral‐base phosphorus containing (commercial) and phosphorus‐free (P‐Free) crankcase oils were tested in the engine dynamometer for the poisoning effects on a catalytic converter and emission‐engine’s performance. The emission results of the two oils were compared with and without a catalytic converter, including the light‐off temperature of the catalyst. Surface characterisation was used to determine accumulated catalyst poisoning from the oil additives. The performance analysis shows that the catalytic converter lowers the torque and power for the commercial and P‐Free oils, whereas the specific fuel consumption increases for both oils in the presence of the catalytic converter. In both cases of the presence and the absence of catalytic converter the torque, power and specific fuel consumption remain the same for phosphorus containing and P‐Free oils. The presence of the catalytic converter shows lower HC and CO and higher CO2 emissions for both P‐Free and commercial oils. Surface characteri...

Measurement of friction force and effects of oil fortifier in engine journal bearings under dynamic loading conditions

Commercial base oil and oil fortifier added to this oil are used to investigate the frictional behavior of the engine journal bearings using the theoretical Reynolds equation and experimental test rig. In the theoretical part of the study, the Reynolds equation that states the pressure distribution and friction force with finite width was solved by using the finite difference method. In the experimental part of the study, a new design test rig was conducted to measure the friction force, the lubricant film thickness of the engine journal bearing using base oil under dynamical loaded conditions. The effect of oil fortifier was detected measuring the friction force every three minutes in each 360 crank angle during 15 minutes of experiment. As the theoretical friction results showed similar variation with the experimental measurements of engine bearings, adding oil fortifier to the base oil presented a substantial reduction of friction force during the testing period.

Oil ageing ‐ drain period in a petrol engine

The more frequently an engine oil is changed, the more the overhaul life of the engine is extended but with an increase in the cost both of the oil and of the oil drain services. If engine oil is changed less frequently the associated costs will decrease. In order to find the optimum drain interval, it is necessary to establish the relationship between the cost of the oil and oil drain services and the cost of more frequent overhauls. Presents an investigation into the degradation of a proprietary lubricant marketed in Turkey, and the wear rate of a petrol engine driven in urban traffic. Lubricant samples were examined approximately every 2,000km for deterioration of the lubricant and evidence of wear of the engine components. From the experimental results, determines the optimum oil drain period of the engine.

The mechanism of layer formation and the function of additives used in fully formulated engine crankcase oils

Abstract Lubricant additives are chemicals which, when present in small amounts, improve the physical, chemical or tribological properties of the lubricant. They form a tribochemical (antiwear) film on the rubbing surfaces which protect the engine from excessive wear. In this study fully formulated crankcase oil (SAE 20W50) is used to investigate the role of additives and determine the mechanical conditions of the formation of protective additive layers between sliding surfaces. As many and various scientifical work exist on additive tribo-chemistry, we are mostly oriented on tribo-mechanics. In what mechanical conditions such as coefficient of friction, velocity, temperature, surface roughness, load and lubrication condition (hydrodynamic or boundary) additives play their role appropriately? Tests were performed on a reciprocating pin-on-plate machine using steel and steel sliding partners under boundary lubrication conditions. Various tests were carried out at different loads, velocities and temperatures then the conclusions were demonstrated using analytical methods such as light microscopy, electron microscopy and X-Ray diffraction. Although various results were obtained, low coefficient of friction, slightly worm surface and drop of oil mostly in boundary conditions play an important role to have partial additive layers (as a small islands) covering the wear scar. Additive layers have mostly been detected in the darkest grooves (such as addtives islands) of the slightly worn surfaces in the case of using Scanning Electron microscopy. X-Ray maps show that darker points contain more additives elements such as Ca, Zn, P, S and Cl than lighter points.

Protective effect of commercial oil fortifier in fully‐formulated crankcase oils

Commercial oil fortifier was added to fully‐formulated crankcase oils, and their performance, in terms of friction, wear and, most importantly, the role of the additive protective layer on the sliding surfaces, was investigated. Tests were performed on a pin‐on‐disc machine using steel and steel sliding partners under boundary lubrication conditions. Tests were carried out at a constant load and velocity at different temperatures with different lubricants and the results were achieved using analytical methods such as light microscopy, electron microscopy and X‐ray diffraction. Related to the experimental work, lubricants and the lubricants containing oil fortifier presented satisfactory protective additive layers which were identified on the wear track at high and low temperatures.

Effect of lubricant additives on the transition pressure from mild to severe wear for grey cast iron sliding pairs

Abstract Over the years, a wide variety of chemical compounds have been introduced as additives to improve the performance of oil. The severity of the performance requirement of lubricating oils is rising continuously in terms of extended oil drain intervals, fuel economy, and reduced friction and wear of the components in internal combustion engines. In this work, using a pin-on-disc machine, the effect of various lubricant additives on the friction and wear (transition pressures) of cast iron and laser-cladded sliding partners were studied. Tests were carried out at different velocities and temperatures with different lubricants and the conclusions were demonstrated using different analytical methods such as light microscopy, electron microscopy, surface topography and X-ray fluorescent spectroscopy. Related to the experimental work, the base oil containing ZDDP (zincdialkyldithiophosphate) additive and the fully formulated oil show higher transition pressure than the base oil and base oil+CaSO4 lubricant. At high temperatures and velocities the effectiveness of the additives are less than at low speeds and temperatures.

Surface and Wear Analysis of Zinc Phosphate Coated Engine Oil Ring and Cylinder Liner Tested with Commercial Lubricant

The objective of this study was to evaluate the tribological performance through investigating protective additive layer and friction coefficient and implementing the quantitative wear measurements on the rubbed surface of the sliding pairs. The specimens of oil ring were rubbed against cast iron engine cylinder liner under boundary lubrication conditions. The ring and liner surfaces were examined by optical, scanning electron microscope and atomic force microscopy. The elemental analysis of surfaces was performed by using energy dispersive X-ray spectroscopy. Surface observations showed that coating was removed from the ring surface. Higher levels of Ca, Zn, P, and S elemental ratios (0.93%, 0.45%, 1.55%, and 1.60% as atomic percent) were detected on the cylinder liner surface. Wear width, length, and depth measurements were performed by optical and atomic force microscopies on the ring and cylinder liner surface. The results showed that wear widths for oil ring were 1.59 μm and 1.65 μm; wear widths for cylinder liner were 3.20 μm and 3.18 μm; wear depths for oil ring were 100 nm; and wear depths for cylinder liner were 482 nm. Wear data were taken mostly from the additive layer points detected by SEM and X-ray measurements.

Engine emissions and poisoning effect of synthetic oil's additives on catalytic converter using an engine dynamometer

Two 5W‐30 synthetic‐base phosphorus containing (commercial) and phosphorus‐free (P‐free) crankcase oils were tested for engine performance characteristics, engine emissions and poisoning effects of oil additives on a three‐way catalytic converter using engine dynamometer. The emission data of the two oils taken during engine operation were compared in the absence and presence of the catalytic converter. Surface characterization was used to determine the poisoning catalyst effect accumulated from the oil additives in the ceramic washcoat. Oil analyses were also used to examine the condition of the lubricant occurred during engine performance testing operation. The experimental engine performance tests indicated that the catalytic converter diminished the torque and power for the commercial and P‐free oils, whereas the specific fuel consumption increased for both oils in the presence of the catalytic converter.

Effects of boron oil fortifier on friction and pressure distribution in engine journal bearings

Additives are incorporated in engine oils to improve existing desirable properties of base stocks and to impart new specific properties required by modern engines. The additives include antioxidants, detergents, dispersants, corrosion and rust inhibitors, viscosity index improvers, pour point depressants, foam inhibitors and tribological agents. In this study, the effect of boron oil fortifier added into the base oil on friction coefficient and pressure distribution was investigated between sliding surfaces of engine journal bearings. Experiments were performed firstly using only base oil at different speeds and loads. Then, this test was repeated with different concentration ratio of 1, 3, 5 and 10 percent commercial boron additive.

Surface and wear mechanisms analysis of phosphorous-free and conventional engine lubricants on cylinder liner and piston rings surfaces

Purpose – This paper aims to investigate the wear mechanisms, formations and effectiveness of tribofilms of new developed, antiwear additive which is called mercapthocarboxylate. The mercapthocarboxylate is a sulphur-based and non-phosphorus additive. Design/methodology/approach – The effectiveness of the additive was examined through a set of laboratory endurance tests that applied with single cylinder spark ignition engine. Two types of lubricants were used to compare the engine tests which were thiophosphate (ZDDP) containing engine lubricant (phosphorus containing) and mercapthocarboxylate containing non-phosphorus and non-ash crankcase oil. Lubricants were tested under identical operating conditions for 100 hrs. The surfaces of cylinder liner and piston rings were inspected through optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. Findings – Catalysis-friendly and sulphur-based mercapthocarboxylate additive can be an alternative antiwear additive pa...