Engine Test Bench Research Articles

Knock recognition of knock sensor signal based on wavelet transform and variational mode decomposition algorithm

Natural gas has become the most widely used alternative energy for engines because of its low emission pollution and sufficient energy reserve. In order to improve the thermal efficiency of the natural gas engine, it is necessary to increase the compression ratio, but knock restricts the increase of the engine compression ratio. The main knock detection method of engine is to use knock sensor. However, the body vibration detected by the knock sensor contains a lot of interference noise, which brings bad effect on the accuracy of knock detection. Thus, in this paper, a knock recognition method based on wavelet transform (WT) and variational mode decomposition (VMD) algorithm is proposed to process the knock sensor signal and extract the knock feature. Based on the test bench of natural gas engine, experimental investigation of knock combustion characteristics was conducted by adjusting the spark timing, and simultaneously collects cylinder pressure signal and knock sensor signal. Burg algorithm based on Auto-regressive (AR) model was used to extract the knock characteristic frequency of the research engine. Then, wavelet transform and variational mode decomposition algorithm were employed to process the knock sensor signal to remove the interference noise and extract the knock feature. Maximum amplitude of pressure oscillation (MAPO) was selected as the knock intensity evaluation index of cylinder pressure signal. Then, taking the evaluation result of the knock intensity of cylinder pressure signal as reference, the root-mean-square of the knock characteristic signal was used as knock intensity evaluation index of knock sensor signal to determine the knock intensity classification of the knock sensor signal. The results show that the proposed method can effectively extract the knock feature from the knock sensor signal and realize the accurate engine knock recognition. The recognition accuracy is higher than the most existing knock recognition methods.

Surge margin monitoring of one turboshaft engine with inlet distortion

In order to explore the engine surge when inlet distortion index and engine surge margin, the relationship between the parameter characteristics of research engine surge, strengthen safety monitoring assessment engine, this paper designed a kind of a certain type of engine bench test surge monitoring system, and unstable flow field of a certain type of vortex axis engine working parameters for monitoring and analysis. In this paper, a plug-plate distortion generator is used to induce a surge engine, and the circumferential static pressure changes of the inlet and outlet of the engine, the axial compressor and the centrifugal compressor under different working conditions are obtained. The changes of circumferential unevenness and mean turbulence, the pressure ratio at working point and the converted air flow rate at working point are analyzed with the increase of the height of the plug-plate under different working conditions. The results show that the distortion index of the working point increases and the surge margin decreases with the increase of the height of the plug-plate at the same rotating speed. When the height of the plug-plate is similar, the higher the speed is, the greater the distortion index of the working point is, and the smaller the surge margin is.

A new vehicle specific power method based on internally observable variables: Application to CO2 emission assessment for a hybrid electric vehicle

As an important vehicle activity recognition method, vehicle specific power (VSP) has been widely used for on-road traffic emission modelling since its introduction in 1999. The conventional VSP (VSP_veh) is calculated from externally observable variables (EOVs) on the vehicle level and represents the power that a running vehicle needs to overcome. However, for hybrid electric vehicles (HEVs) with two power sources, vehicle activity is not always directly related to engine emissions. This study introduces the engine level VSP (VSP_eng), which estimates engine power from internally observable variables (IOVs) obtained from the vehicle’s on-board electronic control unit (ECU). An engine bench test is first implemented to validate the estimation algorithm for VSP_eng. A real-world driving emission (RDE) test is then conducted with a HEV in Ningbo city of China to evaluate the performance of VSP_veh and VSP_eng in emission estimation. The results show a strong correlation between emission and VSP_eng (R2 = 0.9783), while a much weaker correlation was found between emission and VSP_veh (R2 = 0.4216). Further analysis indicates that this strong correlation between emission and VSP_eng applies to all driving conditions (urban, rural and highway). The differences between VSP_veh and VSP_eng are then highlighted by a combined correlation analysis where the four work modes of HEV can be graphically identified. Lastly, this study discusses the feasibility and potential benefits of the intelligent and remote vehicle emissions monitoring through the upcoming vehicle to everything (V2X) network.

Comprehensive Experimental and Numerical Optimization of Diesel Engine Thermal Management Strategy for Emission Clarification and Carbon Dioxide Control

Improving the thermal efficiency of truck diesel engines requires comprehensive optimization of the engine, exhaust aftertreatment (EAT), and possible waste heat recovery (WHR). Lower exhaust temperature at mid and low working points has caused difficulty in both emission clarification and heat recovery, which requires thermal management. Based on the diesel engine bench test and separate bench tests, this paper focuses on the thermal management strategy optimization, to increase the exhaust temperature at lower working points and optimize the thermal efficiency of the whole system. The test and numerical analysis showed that as exhaust temperature increased from 200~250 °C to 300~350 °C, soot passive regeneration reactions were enhanced, nitrogen oxide emission decreased, and energy recovery was improved. Moderate throttle valve adjustment coupled with early post injection could effectively achieve the required temperature increase. The optimized thermal management strategy increased the fuel consumption rate by no more than 1%. Meanwhile, the WHR system output increased significantly, by 62.55% at a certain mid–low working point. System CO2 emission decreased by an average of 5.4% at selected working points.

Combustion Chamber Development to Maximize the Performance of the Hydrogen Combustion Engine for the T1 Ultimate Category of the Dakar Rally Competition

<div class="section abstract"><div class="htmlview paragraph">As the world strives toward the common goal of carbon neutrality by 2050, motorsport cannot be allowed to stand alone as an exception. A gradual energy transition is clearly underway in the automotive industry but has already begun in motorsport as well. Among other initiatives, the Dakar Rally and the FIA have created the T1 ultimate category for prototypes powered by low-carbon fuels, including hydrogen. The Dakar is the pinnacle of off-road endurance rally competitions. It offers a great opportunity to ORECA Magny-Cours and FEV to expose their jointly developed internal combustion engine (ICE), fuelled with hydrogen only, to extreme conditions. In addition, the racing environment imposes a unique pace of development which can serve as a catalyst for spurring the H<sub>2</sub>-ICE technology. Moreover, a hydrogen powered engine is an interesting fit for motorsports because it combines high power output, a relatively long driving range and driving pleasure with an excellent carbon footprint.</div><div class="htmlview paragraph">This article outlines how ORECA Magny-Cours and FEV are currently converting a gasoline racing engine to hydrogen direct injection to meet the numerous challenges of the Dakar Rally. In several development steps, a combustion chamber was newly developed that is tailored to gaseous hydrogen combustion. A high level of charge motion and optimized mixture formation have ultimately been realized using FEV’s dedicated H<sub>2</sub>-ICE simulation tool chain. Design changes resulting from the simulation results are incorporated into the engine. Further thermodynamic investigations on an engine test bench will be undertaken by ORECA Magny-Cours to maximize performance while ensuring knock free operation and best engine efficiency. Although there are still development hurdles to overcome, the combined ORECA/FEV experience will bring a viable carbon neutral powertrain solution to compete in the future Dakar Rally.</div></div>

Variable nozzle turbocharger: gas-dynamic calculation, 3D modeling, CFD analysis, characteristics

Introduction (problem statement and relevance). The environmental requirements for vehicle engines becoming more stringent require development and introduction of high-performance turbo chargers. Transition from external to internal varying, namely to the variable nozzles of the turbine, is caused by the necessity to reduce the transient process time during operation of the engine and the vehicle itself.The purpose of the study is development and confi rmation of the methodology (general strategy) for designing and modernization of radial-axial turbines with variable nozzles.Methodology and research methods. The study used the combination of calculation models for the engine itself with preliminary verifi cation based on the results of tests on the engine test bench (AVL BOOST, CRUISE M), gas-dynamic calculation of the turbine stage with determination of geometric parameters of the blade ring, housing (volute) and blade drive mechanism, their geometric modeling (Siemens NX) followed by 3D models export, CFD simulation of the stage fl ow including taking into account the transfer element (with impeller rotation) and generation of the stage curves (AVL FIRE).Scientific novelty and results. Combination (synthesis) of calculation models of different levels makes it possible to determine geometric parameters of the turbocharger turbine with variable nozzles providing high effi ciency (performance factor) of the turbine stage with a simultaneous shift of the maximum torque mode of the engine itself to the area of lower crankshaft rotation rate (along the full-load curve).Practical signifi cance of the paper consists in reduction of the time of design and subsequent refi nement (experimental) works during creation and modernization of turbines with variable nozzles of small-sized turbochargers. The obtained values of relative geometric parameters can be used at the design stage

Advanced model-based closed-loop combustion control strategies with combustion rate shaping

Combustion rate shaping (CRS) is an advanced closed-loop concept which controls the crank-angle resolved combustion trace by adapting the fuel injection profile. The thermodynamic potential of this concept to enable real-time combustion control independent of fuel property variations, injector drift, cylinder tolerances, or changing air-path boundary conditions has already been demonstrated. The highest benefit of this control concept is achieved when it is directly applied on the engine control unit (ECU) in combination with an in-cylinder pressure measurement. This enables online optimization and adaption of the fuel- and air-path settings to the fuel used during vehicle operation. Therefore, the development of a CRS concept with real-time capability has been the main focus so far. To ensure a robust online real-time combustion control, a key development step was the identification of control variables that describe the entire combustion process and only minimally influence each other. For this purpose, the combustion phasing, the combustion gradient and the indicated mean effective pressure have been determined as parameters for the feedback control. However, the stringent requirements for higher efficiencies, emission robustness and combustion noise necessitate the extension of the CRS control concept. Therefore, in this work, the CRS control concept is extended with the aim of realizing a combustion with constant volume pressure increase to the peak firing pressure limit to achieve highest efficiency. In addition, intelligent control of the fuel injection profile is to be used to achieve a combustion temperature for lowest possible NOx raw emissions and a robust combustion noise excitation limitation. The optimized control strategy is implemented on a heavy-duty single cylinder engine test bench using a Rapid Control Prototyping (RCP) system, and the control performance is demonstrated.

Novel measurement techniques for oil consumption and spark plug temperature measurement to support engine components development in terms of wear and in situ monitoring

Large engines will continue to play a major role in the transportation sector, especially in shipping. In the energy sector, they are essential due to increasingly complex networks and operating strategies. These two sectors are set up for a renewable world through their use of large engines operated with alternative, preferably carbon-free fuels. Intensive research will remain necessary to make these engines even more climate-friendly, to further increase their lifetime and to reduce production, operating and maintenance costs. This research will be supported by the development and deployment of novel key technologies. This paper describes two of these technologies that have been developed at the Large Engines Competence Center: a temperature measurement spark plug and a system for measuring engine oil consumption. Both technologies have in common that they should help engines to run more efficiently, cleaner and with less wear. Spark plug wear impacts engine reliability and maintenance costs. Likewise, wear of the piston assembly and its tribological system is of great importance. This paper provides insight into the development of both technologies and the first instance of their simultaneous application on an engine test bench. It also reveals how spark plug temperature, oil consumption and emissions parameters correlate with each other. The results of an extensive running-in program and endurance runs are presented, and the influence of the manufacturing tolerance of the piston rings on wear and lubricating oil consumption is shown.

Research on the thermohydrodynamic lubrication performance of engine main bearing with rough surface considering the axial motion and deformation of crankshaft

In this paper, the influence of the thermal effect on the lubrication performance of engine main bearing with rough surface considering the axial motion of crankshaft is investigated. In the analysis, the crankshaft-bearing system of a four-cylinder four-stroke engine is taken as the object. The axial motion of crankshaft is measured by the engine bench test. The journal load of main bearing and crankshaft deformation are calculated by the whole crankshaft finite-element method. The analysis model is established based on the average flow lubrication model. The lubrication of main bearing is analyzed by the dynamic method. The temperatures of lubricating oil and bearing are calculated by the energy equation and solid heat conduction equation. The results show that the influence degree of the axial motion of crankshaft on the lubrication of engine main bearing with rough surface is greatly affected by the thermal effect. When the thermal effect is considered, the influence of the axial motion of crankshaft on the lubrication of engine main bearing makes its working condition deteriorate further. When the axial motion of crankshaft is considered, the influence of the thermal effect on the lubrication of different main bearings varies significantly.

Data-Driven Model for Real-Time Estimation of NOx in a Heavy-Duty Diesel Engine

The automotive sector is greatly contributing to pollutant emissions and recent regulations introduced the need for a major control of, and reduction of, internal combustion engine emissions. Artificial intelligence (AI) algorithms have proven to hold the potential to be the thrust in the state-of-the-art for engine-out emission prediction, thus enabling tailored calibration modes and control solutions. More specifically, the scientific literature has recently witnessed strong efforts in AI applications for the development of nitrogen oxides (NOx) virtual sensors. These latter replace physical sensors and exploit AI algorithms to estimate NOx concentrations in real-time. Still, the calibration of the algorithms, together with the appropriate choice of the specific metric, strongly affects the prediction capability. In the present paper, a machine learning-based virtual sensor for NOx monitoring in diesel engines was developed, based on the Extreme Gradient Boosting (XGBoost) machine learning algorithm. The latter is commonly used in the literature to deploy virtual sensors due to its high performance, flexibility and robustness. An experimental campaign was carried out to collect data from the engine test bench, as well as from the engine electronic control unit (ECU), for the development and calibration of the virtual sensor at steady-state conditions. The virtual sensor has, since then, been tested throughout on an on-road driving mission to assess its prediction performance in dynamic conditions. In stationary conditions, its prediction accuracy was around 98%, whereas it was 85% in transient conditions. The present study shows that AI-based virtual sensors have the potential to significantly improve the accuracy and reliability of NOx monitoring in diesel engines, and can, therefore, play a key role in reducing NOx emissions and improving air quality.

Multi-objective optimization for combustion, thermodynamic and emission characteristics of Atkinson cycle engine using tree-based machine learning and the NSGA II algorithm

In this study, the effects of injection timing, injection pressure and exhaust gas recirculation (EGR) rate on combustion, thermodynamic and emission characteristics of the Atkinson cycle engine (ACE) were investigated experimentally, and the multi-objective optimization was performed so as to improve its overall performance. Firstly, the engine bench test was conducted, and a lot of associated characteristic parameters were collected, which were used as the data basis for the following model building. Secondly, three tree-based (classification and regression tree (CART), Random Forest (RF) and Adaptive Boosting (AdaBoost)) machine learning models for ACE were developed, in which RF and AdaBoost were built respectively by the parallel method and the serial method with CART as the base learner. Finally, the multi-objective optimization for combustion, thermodynamic and emission characteristics of ACE was carried out based on the AdaBoost model and the NSGA II algorithm. Research result show that three tree-based models have high prediction performance and generalization ability (AdaBoost is the best, followed by RF and then CART), and the serial method (AdaBoost) is better than the parallel method (RF) for the data set of this study. Both the second (Optimal BSFC) and fourth (Optimal PN) non-dominated solutions play a good optimization effect relative to the experimental data of the original engine, with CO, BSFC, NOx and PN reduced by 31.9%, 2.3%, 39.1%, 61.6% and 32.3%, 2.2%, 40.0%, 62.6%, respectively.

Electrified Powertrain Development: Distributed Co-Simulation Protocol Extension for Coupled Test Bench Operations

The increasingly stringent CO2 emissions standards require innovative solutions in the vehicle development process. One possibility to reduce CO2 emissions is the electrification of powertrains. The resulting increased complexity, as well as the increased competition and time pressure make the use of simulation software and test benches indispensable in the early development phases. This publication therefore presents a methodology for test bench coupling to enable early testing of electrified powertrains. For this purpose, an internal combustion engine test bench and an electric motor test bench are virtually interconnected. By applying and extending the Distributed Co-Simulation Protocol Standard for the presented hybrid electric powertrain use case, real-time-capable communication between the two test benches is achieved. Insights into the test bench setups, and the communication between the test benches and the protocol extension, especially with regard to temperature measurements, enable the extension to be applied to other powertrain or test bench configurations. The shown results from coupled test bench operations emphasize the applicability. The discussed experiences from the test bench coupling experiments complete the insights.

Reduction and thermodynamic treatment of NOx emissions in a spark ignition engine using isooctane and an oxygenated fuel (ethanol)

Abstract This research aims to study the effect of various blends of an alternative fuel environment (ethanol, isooctane) on the performance of a spark ignition gasoline engine. The blends were obtained from two additives: ethanol and isooctane. The tests were carried out on an engine test bench following DIN 70020. The results show that the petrol additives achieve excellent ecological results. On the other hand, the engine performance was slightly reduced compared with that obtained with pure fuel. We noted a variation in engine performance for the E10 (10% ethanol + 90% pure petrol) and I10 (10% isooctane + 90% pure petrol) blends, namely a reduction in nitrogen oxides (NOx) emissions of 7.5% for E10 and 5% for I10 compared with pure petrol. However, using E10 and I10 blends did not increase the specific fuel consumption. Thus, the increase in the octane rating resulted in a decrease in NOx emissions. The use of 96 octane fuels, which corresponds to I40 (40% isooctane + 60% petrol), is expected even though there is an 8% decrease in engine torque and a 5% decrease in power. We also noted that the blend (20% isooctane + 80% ethanol) led to a significant increase in NOx emissions, a significant increase in specific fuel consumption and a drop in performance (engine torque and power).

Research on cooling-temperature control strategy of fuel-cell engine test bench

AbstractAs one of the important ways to utilize hydrogen energy, fuel cells are receiving more and more attention and research from countries and institutions. To meet the practical needs of testing the performance of high-power fuel-cell systems and simulate the actual application environment as much as possible, a fuel-cell system test bench is usually used to test the system performance, in which the cooling-temperature control of the test bench has a great impact on the results of the performance of the fuel-cell system. This paper studies the cooling-temperature control strategy of a 150-kW-class fuel-cell engine test platform, proposes a new test-bench cooling-system structure with a thermostat and heat exchanger as the main heat-dissipation components, and compares and analyzes the impact of coordinated thermostat and heat-exchanger control on the fuel-cell system test performance. The test results show that the control strategy of the coordinated operation of a thermostat and heat exchanger can maintain the steady-state error to within ±0.3℃ and maintain the temperature variation to within ±1.5℃ during the loading-condition test, so as to avoid the limitation of system output performance due to excessive cooling-temperature fluctuation and ensure that the fuel-cell engine performance-test process is carried out smoothly and efficiently.

Coatings protecting against aviation piston engine seizure

The article presents the basics of manufacturing porous (16%) composite coatings based on phenolic resin reinforced with glassy carbon particles (30 wt%). These coatings, when applied to a steel push rod surface, prepared by sandblasting, of the timing system of an aircraft piston internal combustion engine, prevent seizure of the contact in conditions of lubrication failure up to 10 h (μ≈0.1 by p = 8 MPa, v = 0.5 m/s), extending the last stage of flight time of the aircraft. The reference coating undergone seizure, μ> 1 after 5 h. The conditions and results of laboratory tests on a pin-on-disc tribological tester and tests on an engine test bench are described. The dependencies of the coefficient of friction and wear of the push rod on the glassy carbon content, thinner viscosity and sandblasting pressure, described by the equations of the second degree, allowed the optimal conditions to be determined to the produce coatings. The test results of the developed composite porous coatings were compared with the results of non-porous commercial coatings. The wear of developed coating compared to reference one and matrix coatings was respectively ΔmCC = −1.63 mg (mass increase), ΔmRC = 1.3 mg and ΔmMC = 5.56 mg.

Химмотологическая оценка масел и присадок

Preliminary evaluation of oils and additives, when creating a working composition, is extremely relevant. This allows you to significantly reduce the time for development and, quite objectively, recommend the created samples for further engine bench tests. The article deals with the general aspects and directions of chemmotological evaluation of oils for automotive engineering.

Comparative Study of Sub-23nm Particle Number Emission Characteristics for Non-road Diesel Engine on RMC and NRSC Test

A non-road diesel engine meeting China IV emission regulation was selected, the RMC and NRSC test procedures of the EU non-road Stage V emission regulation were run on the engine test bench. The emissions of particle number (PN) with particle sizes above 23 nm and 10 nm were tested simultaneously using direct exhaust sampling and full-flow dilution channel CVS dilution sampling equipment. The results showed that the emission characteristics of particulate matter above 23 nm and above 10 nm in the RMC test had the same trend, and the cumulative PN emissions were 1.9×1012 and 2.3×1012 for the whole test cycle, respectively. The PN23 values of dilution sampling were higher than those of direct sampling. The main reason for the difference in PN emission values at the same working modes in RMC and NRSC is the change in DPF capture efficiency caused by the different order of working modes and conditions.

USE OF TEST CYCLES FOR STUDYING THE OPERATIONAL PROPERTIES OF TRANSPORT CONSTRUCTION MACHINERY

The article discusses the main test cycles that can be used to evaluate the operational properties of transport construction machines. In particular, with their help, it is possible to study the environmental safety and fuel efficiency of machines of various purposes, which are used in transport construction. The work presents the methods and procedures by which the operational properties of such machines are investigated. The considered test cycles of engines of agricultural machinery, road construction machines, excavators, ship, industrial and locomotive engines, provided by the international standard ISO 8178. This standard consists of 11 chapters, which describe in detail the test procedure and methods of measuring the content of harmful substances in exhaust gases of various types engines, fuel type requirements and analysis of the obtained results. ISO 8178 contains a series of engine bench test cycles designed for different classes of engines and equipment, each of which is a sequence of steady-state or transient modes with different load factors. In the event that conducting tests on a motor stand is difficult, this standard provides for measurement under operating conditions. In this case, the standard test cycles do not apply and the tests are carried out while the vehicle is operating in its normal operating mode. Emissions are measured using the Portable emissions measurement system (PEMS). Test cycles are one of the effective tools for evaluating the fuel economy and environmental performance of transport construction machines. They allow you to get a lot of useful information about various aspects of the machines, such as fuel consumption, emissions of harmful substances, noise level, engine efficiency, etc. One of the disadvantages of using test cycles is their limited versatility. Different types of machines have their own unique features, so in order to achieve the maximum efficiency of research, it is necessary to develop test cycles that correspond to the specifics of different types of machines.

Experiment Study on the Exhaust-Gas Heat Exchanger for Small and Medium-Sized Marine Diesel Engine

This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels, which can then be used to heat water up to 55°C–85°C for membrane desalination devices to produce fresh water. A new exhaust-gas heat exchanger of fins and tube, with a reinforced heat transfer tube section, unequal spacing fins, a mixing zone between the fin groups and four routes tube bundle, was designed. Numerical simulations were also used to provide reference information for structural design. Experiments were carried out for exhaust gas waste heat recovery from a marine diesel engine in an engine test bench utilizing the heat exchanger. The experimental results show that the difference between heat absorption by water and heat reduction of exhaust gas is less than 6.5%. After the water flow rate was adjusted, the exhaust gas waste heat recovery efficiency was higher than 70%, and the exhaust-gas heat exchanger’s outlet water temperature was 55°C–85°C at different engine loads. This means that the heat recovery from the exhaust gas of a marine diesel engine meets the requirement to drive a membrane desalination device to produce fresh water for fishers working in small and medium-sized fishing vessels.

Метод исследования формоизменения шатунных вкладышей коленчатого вала автомобильного двигателя в эксплуатации (на примере КамАЗ-740)

The relevance of the topic of the article is due to the unresolved problem of failures of automobile engines, in particular, modern mass-produced engines of the KAMAZ-740.10, 7403 families, due to cranking of the connecting rod bearings, and the need for deeper studies of the processes and phenomena that lead to them, and the development of solutions that exclude them in operation. The purpose of the study is to ensure the reliability of automobile engines by reducing the risk of crankshaft connecting rod bearings turning in operation by developing a method for studying their shape change and applying it when substantiating and implementing various design, technological and operational solutions. A prototype is described and a developed method and device for determining the clearance in a connecting rod bearing, suitable for studying the formation of connecting rod bearings under engine test bench conditions. The prototype was a differential-type pneumatic device used in active control devices for honing cylinder liners. With the use of the described device, a method for studying the formation of connecting rod bearings under the conditions of bench tests of KAMAZ-740.10 diesel engines was developed and tested. The use of new methods, devices and techniques makes it possible to investigate the patterns of shape changes of connecting rod bearings in relation to lubrication conditions, temperature and load conditions of the engine, and other factors. The presented experimental results show that the gap in the connecting rod bearing is not stable, is caused not only by wear, but also by the resulting deflection of the liner, and significantly depends on the temperature regime of the engine - with an increase in oil temperature, the gap decreases due to an increase in deflection. The authors explain the formation of deflection and shape change of the liners by the loss of its stability from the action of loads and internal stresses under conditions of instability of the oil supply. The results of experimental studies presented in the article have a scientific novelty, since a previously undescribed and not fixed decrease in the gap due to the deflection of the liners, which is formed immediately from the start of operation after the engine is assembled, is established, and its value is variable and determined by the temperature regime. Practical significance – the developed method makes it possible to study the formation patterns of crankshaft connecting rod bearings to test the effectiveness of design, technological and operational solutions to prevent their turning during the operation of an automobile engine. The main directions of promising research is the substantiation of practical solutions to ensure the stability of the shape of the liners during long-term operation of the engine.