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Engine Laboratory Department | ||||||||||||||||||||||||||||||||||||||||||||||
        
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Laboratory tests Engine bench tests with full-scale engines Measurements on chassis dynamometer MAHA LPS 2000 Engine tests on special single-cylinder engines Other activities Contact persons
The Performance of laboratory and engine tests of motor fuels, motor and gear oils, hydraulic fluids and greases using special test and full-scale engines and laboratory testing equipment. Specialised advisory services for customers.
Mechanical testing of lubricants in the FZG gear rig test machine according to standard STN 65 6280 The anti-seizure properties of lubricating oils and fluid (semi-fluid) lubricants are determined using the laboratory test equipment FZG-Niemann. Stating of the lubricating film load-carrying capacity and the effect of tested oil (lubricant) on tooth flanks wear of the test toothed wheel, are the result of the test. The test is done at twelve (12) load stages; after each load stage the state of tooth work area (kind of wear) is evaluated and the loss of weight of the test gearing is find out.
The mechanical - dynamic stability of greases is determined by long-term test with the test apparatus SKF; the test duration is 480 hours. The tested grease is exposed to mechanic - dynamic stressing in two radial loaded bearings in accordance with the test type:
After the test the wear of cages and rollers of test bearings is determined (by weighing) and the state of tested lubricant evaluated (by the merit rating system of the method).
The determination of anti-wear properties of hydraulic oils and fluids is done with the laboratory test equipment Vickers. The gravimetric wear evaluation of friction elements of the test lamella hydro-generator (stator ring and lamellae), that are running during 250 hours under extreme conditions. The test results determine the anti-wear properties of the tested hydraulic oils. In the case of customer’s interest the test can be completed by the gravimetric wear evaluation of hydrogenerator´s parts during the test (interrupting the test run) according to the internal method.
The four-ball machine is used to find out the antiscuffing and antigalling properties of lubricating oils, lubricating greases and fuels, classified in the 3. class of combustion (diesel fuel). Using this apparatus it is possible to carry out tests according to 7 kinds of valid test methods; among which are 2 STN standards, 2 ASTM standards, one DIN standard and two types of internal test methods. The test machine is the most frequently used test procedure for determination of the maximum non-seizing load, the load of balls´ welding and the wear trace size at constant loads (the duration of test is from 2 to 9 hours depending on the used method). The test methods are differed according to the test type as follows:
Detergent properties of petrol according to test method CEC F-04-A-87 The detergent properties of petrols or the effect of additives upon the fuel properties are determined by engine bench test - duration 40 hours (133 cycles) with the engine VAZ 2103 according to the test method CEC F-04-A-87. The condition (cleanliness) of carburettor, intake system and intake valves, as well as, the amount of deposits on intake valves are evaluated after the test. During the test the fuel consumption and exhaust emissions (HC, CO, CO2, O2) are periodically measured and recorded. In the case of customers interest the test can be completed by the evaluation of deposits amount in the combustion chamber of the engine, according to the internal method.
The detergent properties of petrols or the effect of additives are determined by engine bench test – duration 30 hours (72 cycles) with the engine VAZ 2103 according to the test method CEC F-03-T-81. The condition of carburettor (cleanliness) is evaluated after the test. Exhaust valve seat recession engine test - according to the internal method PP VÚRUP The test is designed for verification of the tested petrol’s effect to protect the exhaust valve seat recession using engine bench test with Škoda 742.13 (Š 130) engine. The test is limited by the running of 54 cycles lasting one hour, or by the total change of valve clearance of some of exhaust valves exceeding the value of 1,2 mm. During the test the exhaust valve recession of the individual exhaust valves, the fuel consumption and performance of engine are recorded at constant time intervals. After the test the condition (cleanliness) of motor parts and amount of deposits on the individual valves are evaluated and recorded.
The detergent properties of diesel fuels are determined using engine bench test according to the test method CEC PF 26 with diesel naturally aspirated engine Peugeot XUD 9 (4 cylinders, 1.9 litre swept volume). Each test started with a set of new injection nozzles. After the test the degree of injector clogging (coking index) at individual needle strokes 0,1 to 0,5 mm, is calculated as arithmetic average of coking index at three measurements. The total test result (total coking index) is calculated as arithmetic average of coking indices value for the four injectors.
Measurement of engine performance The measurement is done on chassis performance dynamometer
by the method of measuring the performance curve on the car wheels, scanning the loss of
power, and calculating the final performance curve at the engine output. The equipment
determines the torque curve. The parameters are scanned and evaluated according to DIN 70
020. The maximum performance of the engine to be measured is 320 kW. Car service parameters measurements
The car is braked with constant force F = m x g x sin a ,
where:
The car is loaded with such a force so as not to exceed the defined engine speed. During this service various kind of measurement can be accomplished (fuel consumption, exhaust emissions, smoke etc.).
The car is loaded with such a force so as not to exceed the defined car speed. During this service various kind of measurement can be accomplished (fuel consumption, emissions, smoke etc.).
The dynamometer is simulating the road driving after entering the following parameters:
It is necessary to define the initial and final speed of the car after the driving parameters were entered. The acceleration can not be measured with zero initial speed. When the initial speed is reached the dynamometer starts to measure the acceleration, when the final velocity is reached the monitor reads the measured acceleration value.
The dynamometer provides simulation of driving according to so called driving curves. The driving curves can be arbitrary programmed and arbitrary times repeated and so to form the driving cycle. The weight of the car at start-up and braking are simulated by the configuration of loading flywheel (according to reference car weight). With this system standard testing cycles can be carried out e.g. ECE 15 cycle. During cycle the consumption of fuel, exhaust emissions, etc. can be measured.
1.) Control of instantaneous velocity precision The dynamometer, after the required velocity values, in the range 10 to 250 km/hour, were entered, compares the instantaneous car velocity to the selected entered value and finds the deviation for each selected velocity separately. 2.) Test of passed though distances The arbitrary test distance can be selected after entering the required value of passed through distance. The comparison of the entered distance with the indicator in the car, after the entered distance was passed-through, can be done with the precision of +/- 1 m.
The measurement of smoke (opacity) of diesel engine cars is done with the smoke-meter AVL DiSmoke 435.
The spark-ignition engine exhaust emission measurement is carring out using exhaust gas analyser SUN MGA 1200.
D. Engine tests on special single-cylinder engines
At the present time the engine laboratory is performing engine bench tests on two testing stands SCHENCK W 70. The testing stands SCHENCK are automated and consist of the regulating, measuring and controlling panels, testing engines, dynamometers, cooling circuits and additional equipment used according to the test type. The given test equipment provides tests of engine oils on three special testing single - cylinder engine types:
The test on the testing engine Petter AV-1 states the capability of the lubricating oil to be applied in heavy duty operation:
The engine Petter AV-1 is a single cylinder diesel engine naturally aspirated (power output 3,5 ¸ 3,8 kW at 1500 rpm, defined fuel consumption 1088,5 ± 22,7 g/hour). The test consists of 8 hours run-in of the engine and the 120 hours continuous test run at defined conditions specified in the test method. The test fuel is diesel fuel with high sulphur content. The cleanliness of motor parts - piston, covers, state of liner, piston rings and connecting rod bearings - are evaluated after termination of the test. The comparison of the oil condition, with the chemical analysis of the new oil is a part of oil evaluation after the test.
The test on the testing engine Petter AVB evaluates the lubricating oil capability, used in overcharged diesel engines working at high temperatures:
The test engine Petter AVB is a single supercharged diesel engine with direct injection (power output 12,5 ¸ 12,8 kW at 2000 rpm, defined fuel consumption 3310 ± 20 g/hour). The test consists of 4 hours run-in of the engine and the 50 hours continuous test run with the specified diesel fuel with high sulphur content. The cleanliness of engine parts - piston, covers, state of cylinder liner, piston rings and connecting rod bearings - are evaluated after the test. The comparison of the oil condition with the chemical analysis of the new oil is a part of oil evaluation after the test.
The test in the testing engine Petter W1 determines the tendency of engine oils, when used in combustion engines, to form oxidation products that contribute to the corrosion of Cu-Pb bearings, increase of viscosity and formation of lacquers type deposits on the piston at high-temperature operating conditions (operating temperature of oil during the test 130-140°C depending upon the oil’s viscosity class). The performance of oil is evaluated by the Cu-Pb bearing corrosion, the oxidation degree of oil and the formation of deposits on the piston. The testing engine Petter W1 is a single cylinder four-stroke spark-ignition engine (power output 2,4 ¸ 2,6 kW at 1500 rpm; specified fuel consumption 1142 ± 5 g/hour). The test consists of 4 hours run-in period of the engine and the 36 hours continuous test run under the defined condition specified in the test method. The test fuel is leaded petrol with octane number RON 90 ¸ 91. The cleanliness of piston, condition of cylinder, piston rings and the state of connecting rod bearings with regard to corrosion type, colour, depositions and loss of weight are evaluated after the test. The increase of oil viscosity, in percentage, in relation to the new oil, is a part of evaluation after the testing.
E. Other activities
Training of service station staff Regular repeated training of service station staff with regard to quality, properties and application of petrol, diesel fuels, additives to fuels and coolants. The assessment of petrol station site can be used to specify the fee of lease, the planned reconstruction of existing or construction of new service stations in the assumed locality. The method to determine the specific assessment of site was developed in Slovnaft VURUP, a.s. and in 1996 it was used to evaluate the sites of Slovnaft, a.s. service stations. The method includes almost 1500 objective criteria, out of which the main part can be directly in numerical form expressed (95%) the rest (5%) is digitised appraising, according to unequivocally described rules.
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