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Viewing 241 to 270 of 15992
2017-03-28
Journal Article
2017-01-0329
Ayhan Ince
Abstract Driveline and suspension notched components of off-road ground vehicles often experience multiaxial fatigue failures along notch locations. Large nominal load histories may induce local elasto-plastic stress and strain responses at the critical notch locations. Fatigue life prediction of such notched components requires detailed knowledge of local stresses and strains at notch regions. The notched components that are often subject to multiaxial loadings in services, experience complex stress and strain responses. Fatigue life assessment of the components utilizing non-linear Finite Element Analysis (FEA) require unfeasibly inefficient computation times and large data. The lack of more efficient and effective methods of elasto-plastic stress-strain calculation may lead to the overdesign or earlier failures of the components or costly experiments and inefficient non-linear FEA.
2017-03-28
Journal Article
2017-01-0327
Christian Gaier, Stefan Fischmeister, Julia Maier, Gerald Pinter
Abstract Lightweight constructions and the reduction of production time and costs is of increasingly importance. Therefore, engineers make a lot of effort to replace metallic parts by other materials. Carbon fiber reinforced laminates are suitable in many cases because of their high specific strength and the low specific weight. The available material-data of this material group from datasheets are mostly static values like tensile strength and fracture elongation. For the fatigue assessment of parts regarding geometry, loading conditions and material behavior, static material data are not sufficient, but also the knowledge of the local S-N curve is necessary. Component specific effects, such as fiber orientation, type of loading, mean stress, temperature, production process and many more, essentially influence these local S-N curves, determined by the material.
2017-03-28
Technical Paper
2017-01-0173
Stephen Andersen, Sourav Chowdhury, Timothy Craig, Sangeet Kapoor, Jagvendra Meena, Prasanna Nagarhalli, Melinda Soffer, Lindsey Leitzel, James Baker
Abstract This paper quantifies and compares the cooling performance and refrigerant and fuel cost savings to automobile manufacturers and owners of secondary-loop mobile air conditioners (SL-MACs) using refrigerants hydrofluorocarbon (HFC)-134a and the available alternatives HFC-152a and HFO-1234yf. HFC-152a and HFO-1234yf are approved for use by the United States Environmental Protection Agency (US EPA) and satisfy the requirements of the European Union (EU) F-Gas Regulations. HFC-152a is inherently more energy efficient than HFC-134a and HFO-1234yf and in SL-MAC systems can generate cooling during deceleration, prolong comfort during idle stop (stop/start), and allow powered cooling at times when the engine can supply additional power with the lowest incremental fuel use. SL-MAC systems can also reduce the refrigerant charge, emissions, and service costs of HFO-1234yf.
2017-03-28
Technical Paper
2017-01-0164
Venkatesan Muthusamy, S. Sathish Kumar, Saravanan Sambandan
Abstract In an automotive air-conditioning (AC) system, upfront prediction of the cabin cool down rate in the initial design stage will help in reducing the overall product development (PD) time. Vehicle having higher seating capacity will have higher thermal load and providing thermal comfort to all passengers uniformly is a challenging task for the automotive HVAC (Heating Ventilation and Air conditioning) industry. Dual HVAC unit is generally used to provide uniform cooling to a large cabin volume. One dimensional (1D) simulation is being extensively used to predict the HVAC performance during the initial stage of PD. The refrigerant loop with components such as compressor, condenser, TXV and evaporator was modeled. The complicated vehicle cabin including the glazing surfaces and enclosures were modeled as a three row duct system using 1D tool AMESim®. The material type, density, specific heat capacity and thermal conductivity of the material were specified.
2017-03-28
Technical Paper
2017-01-1240
Koki Matsushita
Abstract For the purpose of improving vehicle fuel efficiency, it is necessary to reduce energy loss in the alternator. We have lowered the resistance of the rectifying device and connecting components, and control the rectifying device with an IC to reduce rectification loss. For the package design, we have changed the structure of the part on which the rectifying device is mounted into a high heat dissipation type. The new structure has enabled optimizing the size of the rectifying device, resulting in the reduction of size of the package. In addition, the rectifying device is mounted using a new soldering material and a new process, which has improved the reliability of the connection. Moreover, since the alternator has introduced a new system, the controller IC has a function for preventing malfunction of the rectifying device and a function for detecting abnormalities, in order to ensure safety.
2017-03-28
Technical Paper
2017-01-1248
Ming Su, Chingchi Chen, Krishna Prasad Bhat, Jun Kikuchi, Shrivatsal Sharma, Thomas Lei
Abstract Due to global trends and government regulations for CO2 emission reduction, the automotive industry is actively working toward vehicle electrification to improve fuel efficiency and minimize tail-pipe pollutions. Silicon IGBTs and power diodes used in today’s HEV inverter systems are mature and reliable components, but have their limitation on energy losses. SiC, on the other hand, has potential to offer additional boost of efficiency for the HEV drive system. In recent years, commercial SiC MOSFETs have improved significantly in performance. However, reliability concerns and high prices still limit their overall competitiveness against silicon. Ford Motor Company has partnered with semiconductor manufacturers to evaluate SiC products for automotive applications. In this study, 900V SiC MOSFET modules from Wolfspeed are tested and compared with an 800V silicon IGBT module of similar power handling capability.
2017-03-28
Technical Paper
2017-01-1234
Srikanthan Sridharan, Joseph Kimmel, Jun Kikuchi
Abstract Dc-link capacitor sizing considerations are discussed for HEV/EV e-Drive systems. The capacitance value of the dc-link in HEV/EV e-Drive systems affects numerous factors. Some of the most significant are the system stability and the maximum tolerable dc-bus transient voltage with operating point change or with worst-case energy dump into the capacitor. Also requiring attention is the equivalent series resistance and inductance of the capacitor module. The former affects thermal behavior of the capacitor module and the latter affects voltage spikes occurring at every turn-off of a power semiconductor switch. In addition, these factors are dependent on other power-stage component parameters, control structures and controller gains. Also such effects and cross-couplings are operating-point dependent.
2017-03-28
Technical Paper
2017-01-1333
Sasikumar P, C. Sujatha, Chinnaraj K.
Abstract In commercial vehicles, exhaust system is normally mounted on frame side members (FSM) using hanger brackets. These exhaust system hanger brackets are tested either as part of full vehicle durability testing or as a subsystem in a rig testing. During initial phases of product development cycle, the hanger brackets are validated for their durability in rig level testing using time domain signals acquired from mule vehicle. These signals are then used in uni-axial, bi-axial or tri-axial rig facilities based on their severity and the availability of test rigs. This paper depicts the simulation method employed to replicate the bi-directional rig testing through modal transient analysis. Finite Element Method (FEM) is applied for numerical analysis of exhaust system assembly using MSC/Nastran software with the inclusion of rubber isolator modeling, meshing guidelines etc. Finite Element Analysis (FEA) results are in good agreement with rig level test results.
2017-03-28
Technical Paper
2017-01-1309
S. M. Akbar Berry, Hoda ElMaraghy, Johnathan Line, Marc Kondrad
Abstract Modularity in product architecture and its significance in product development have become an important product design topics in the last few decades. Several Product Modularity definitions and methodologies were developed by many researchers; however, most of the definitions and concepts have proliferated to the extent that it is difficult to apply one universal definition for modular product architecture and in product development. Automotive seat modular strategy and key factors for consideration towards modular seat design and assemblies are the main focus of this work. The primary objectives are focused on the most “natural segmentation” of the seat elements (i.e., cushions, backs, trims, plastics, head restraints, etc.) to enable the greatest ease of final assembly and greatest flexibility for scalable feature offerings around common assembly “hard-points.”
2017-03-28
Journal Article
2017-01-1221
Shingo Soma, Haruhiko shimizu, Eiji Shirado, Satoshi Fujishiro
Abstract As heavy rare earth elements are become less prevalent, because one-tenth as often in ore deposits as light rare earth elements. Future usage of need to be reduces heavy rare earth, because of resource risks and costs. As such, a method was developed to recover reductions in coercive force and prevent demagnetization temperature from reducing without adding any heavy rare earth elements. First, a heavy rare-earth-free magnet was developed by hot deformation, which limits growth of crystal grain size, and relationships were clarified between coercive force and optimal deforming temperatures, speed, and total rare earth amounts for heavy rare-earth-free magnets. Second, it was made clear that the permeance coefficient can be increased by reshaping the flux barriers, and that the developed hot deformed magnet can be adopted.
2017-03-28
Technical Paper
2017-01-1190
Patrick Maguire, Hyung Baek, Stephen Liptak, Olivia Lomax, Rodolfo Palma, Yi Zhang
Abstract As electrified powertrains proliferate through original equipment manufacturer vehicle offerings, the focus on system cost and weight reduction intensifies. This paper describes the development and evaluation of a High Voltage (HV) battery system enclosure molded from High Density Polyethylene (HDPE) to deliver substantial cost and weight opportunities. While previous HV battery system enclosure alternatives to steel and aluminum focus on thermoset composites and glass filled polypropylene, this solution leverages select HDPE design techniques established for fuel tanks and applies them to an HV battery system. The result is a tough, energy absorbing structure, capable of hermetic sealing, which simplifies manufacturing by eliminating nearly all fasteners.
2017-03-28
Technical Paper
2017-01-0960
Pankaj Kumar, Imad Makki
Abstract Traditionally, a three-way catalyst (TWC) is controlled to a set heated exhaust gas oxygen (HEGO) sensor voltage (typically placed after the monitored catalyst) that corresponds to optimal catalyst efficiency. This limits the control action, as we rely on emissions breakthrough at the HEGO sensor to infer the state of catalyst. In order to robustly meet the super ultra-low emission regulations, a more precise TWC control around the oxidation level of catalyst is desirable. In this work, we developed a comprehensive set of models to predict the oxygen storage capacity using measured in-vehicle signals only. This is accomplished by developing three models; the first model is a linear in parameter regression model to predict the feed gas emissions from measured signals like engine speed and air-to-fuel ratio (A/F). The second model is a low-dimensional physics based model of the three-way catalyst to predict the exhaust emissions and oxidation state of the catalyst.
2017-03-28
Technical Paper
2017-01-0339
Sandip Datta, Neil Bishop, Karl Sweitzer, Alexander Atkins
Abstract For many automotive systems it is required to calculate both the durability performance of the part and to rule out the possibility of collision of individual components during severe base shake vibration conditions. Advanced frequency domain methods now exist to enable the durability assessment to be undertaken fully in the frequency domain and utilizing the most advanced and efficient analysis tools (refs 1, 2, 3, 4, 5). In recent years new capabilities have been developed which allow hyper-sized models with multiple correlated loadcases to be processed. The most advanced stress processing (eg, complex von-Mises) and fatigue algorithms (eg, Strain-Life) are now included. Furthermore, the previously required assumptions that the loading be stationary, Gaussian and random have been somewhat relaxed. For example, mixed loading like sine on random can now be applied.
2017-03-28
Journal Article
2017-01-0346
Radwan Hazime, Thomas Seifert, Jeremy Kessens, Frank Ju
Abstract A complete thermomechanical fatigue (TMF) life prediction methodology is developed for predicting the TMF life of cast iron cylinder heads for efficient heavy duty internal combustion engines. The methodology uses transient temperature fields as thermal loads for the non-linear structural finite-element analysis (FEA). To obtain reliable stress and strain histories in the FEA for cast iron materials, a time and temperature dependent plasticity model which accounts for viscous effects, non-linear kinematic hardening and tension-compression asymmetry is required. For this purpose a unified elasto-viscoplastic Chaboche model coupled with damage is developed and implemented as a user material model (USERMAT) in the general purpose FEA program ANSYS. In addition, the mechanism-based DTMF model for TMF life prediction developed in Part I of the paper is extended to three-dimensional stress states under transient non-proportional loading conditions.
2017-03-28
Journal Article
2017-01-0349
Thomas Seifert, Philipp von Hartrott, Kristopher Boss, Paul Wynthein
Abstract Cast iron materials are used as materials for cylinder heads for heavy duty internal combustion engines. These components must withstand severe cyclic mechanical and thermal loads throughout their service life. While high-cycle fatigue (HCF) is dominant for the material in the water jacket region, the combination of thermal transients with mechanical load cycles results in thermomechanical fatigue (TMF) of the material in the fire deck region, even including superimposed TMF and HCF loads. Increasing the efficiency of the engines directly leads to increasing combustion pressure and temperature and, thus, lower safety margins for the currently used cast iron materials or alternatively the need for superior cast iron materials. In this paper (Part I), the TMF properties of the lamellar graphite cast iron GJL250 and the vermicular graphite cast iron GJV450 are characterized in uniaxial tests and a mechanism-based model for TMF life prediction is developed for both materials.
2017-03-28
Technical Paper
2017-01-0331
Qiuren Chen, Haiding Guo, Katherine Avery, Xuming Su, HongTae Kang
Abstract Fatigue crack growth tests have been carried out to investigate the mixed mode fatigue crack propagation behavior of an automotive structural adhesive BM4601. The tests were conducted on a compound CMM (Compact Mixed Mode) specimen under load control with 0.1 R ratio and 3Hz frequency. A long distance moving microscope was employed during testing to monitor and record the real time length of the fatigue crack in the adhesive layer. The strain energy release rates of the crack under different loading angles, crack lengths and loads were calculated by using finite element method. The pure mode I and mode II tests show that an equal value of mode I strain energy release rate results in over ten times higher FCGR (Fatigue Crack Growth Rate) than the mode II stain energy release rate does. The mixed mode tests results show that under a certain loading angle, the mixed mode FCGR is changed by changing the load, which is contrary to the find in pure mode I and mode II tests.
2017-03-28
Technical Paper
2017-01-0255
Malli Kartheek Yalamanchili, Nitin Sharma, Kevin Thomson
Abstract The crashworthiness of body-in-white (BIW) plays a vital role in full vehicle crash performance. The structural integrity of BIW is controlled via strength of the spot welds and adhesives that are the primary entities to join sheet metal. The number of welds and amount of adhesives in the entire BIW directly affects the cost and the cycle time of the BIW; which makes them a good candidate for optimization. However optimization of the welds and/or adhesives not only reduces the number of connections but also provides the opportunity to improve the structural performance and mass saving by placing them optimally for the structural responses. This paper discusses the optimization of full vehicle structural performance for the small overlap crash event using the length of adhesives in the BIW as parameters. Included in the study were length of the adhesives and gage variables, defined in the front-end structure of the vehicle.
2017-03-28
Technical Paper
2017-01-0459
Salah H. R. Ali, Badr S. N. Azzam, T. A. Osman, A. M. Moustafa
Abstract The frictional composite is an important material in braking system for automotive, trucks or heavy-duty vehicles. In this paper, a proposed frictional composite material has been developed to achieve the ISO requirements for heavy-duty vehicle brakes. This new frictional material has been fabricated with various compositions. Tribological, chemical, mechanical, thermal conductivity and acoustic noise level tests have measure its performance compared to other two commercial samples under certain operating conditions. Surface characteristics of selected samples have been performed using white light optical microscopy (WLOM) in 2D images to insure the material homogeneity. Additionally, surface roughness analyses using atomic force microscopy (AFM) into 2D and 3D images before and after frictional operation have been investigated.
2017-03-28
Technical Paper
2017-01-0457
Kenji Matsumoto, Hideharu Koga
Abstract Piston ring wear in gasoline engine induces deterioration of emissions performance due to leakage of blow-by gas, instability of idling caused by reduced compression in combustion chamber, and to generate early degeneration of engine oil. We examined anti-wear performance of DLC coating on piston ring, which had been recently reported as an effective method for improving the abrasion resistance. As a result, wear rate remained low under the condition of DLC existence on sliding surface, but once DLC was worn out completely, wear of the piston ring was accelerated and its life became shorter than piston ring without DLC. In this research, we designed reciprocating test apparatus that operates at much higher velocity range, and characterized the frictional materials of the piston ring and sleeve and the DLC as a protective film, a vapor phase epitaxy (VPE) was actively used as a means to form certain level of convex and concave shape on its surface.
2017-03-28
Technical Paper
2017-01-0172
Suhas Venkatappa, Manfred Koberstein, Zhengyu Liu
Abstract The refrigerant transition from HFC-134a to HFO-1234yf has proven to be more challenging on controlling refrigerant flow-induced noises generated from automotive air-conditioning (A/C) systems than originally anticipated. The objectives of this paper are to describe the noise issues with HFO-1234yf, understand the mechanisms and key factors affecting HFO-1234yf refrigerant flow-induced noise. Finally, the countermeasures and guidelines for attenuating and suppressing the noise are presented.
2017-03-28
Technical Paper
2017-01-0121
Zhijia Yang, Jesus PradoGonjal, Matthew Phillips, Song Lan, Anthony Powell, Paz Vaqueiro, Min Gao, Richard Stobart, Rui Chen
Abstract Thermoelectric generator (TEG) has received more and more attention in its application in the harvesting of waste thermal energy in automotive engines. Even though the commercial Bismuth Telluride thermoelectric material only have 5% efficiency and 250°C hot side temperature limit, it is possible to generate peak 1kW electrical energy from a heavy-duty engine. If being equipped with 500W TEG, a passenger car has potential to save more than 2% fuel consumption and hence CO2 emission reduction. TEG has advantages of compact and motionless parts over other thermal harvest technologies such as Organic Rankine Cycle (ORC) and Turbo-Compound (TC). Intense research works are being carried on improving the thermal efficiency of the thermoelectric materials and increasing the hot side temperature limit. Future thermoelectric modules are expected to have 10% to 20% efficiency and over 500°C hot side temperature limit.
2017-03-28
Technical Paper
2017-01-0949
Makoto Ito, Mitsuru Sakimoto, Zhenzhou Su, Go Hayashita, Keiichiro Aoki
Abstract New 2A/F systems different from usual A/F-O2 systems are being developed to cope with strict regulation of exhaust gas. In the 2A/F systems, 2A/F sensors are equipped in front and rear of a three-way catalyst. The A/F-O2 systems are ideas which use a rear O2 to detect exhaust gas leaked from three-way catalyst early and feed back. On the other hand, the 2A/F systems are ideas which use a rear A/F sensor to detect nearly stoichiometric gas discharged from the three-way catalyst accurately, and to prevent leakage of exhaust gas from the three-way catalyst. Therefore, accurate detection of nearly stoichiometric gas by the rear A/F sensor is the most importrant for the 2A/F systems. In general, the A/F sensors can be classified into two types, so called, one-cell type and two-cell type. Because the one-cell type A/F sensors don’t have hysteresis, they have potential for higher accuracy.
2017-03-28
Technical Paper
2017-01-0873
Senthilkumar Masimalai, Jai Kumar Mayakrishnan, Natraj Ganesan
Abstract This paper presents a comprehensive study on using MO (Mahua oil) as fuel effectively in a diesel engine by adopting emulsification and TBC (Thermal Barrier Coating) techniques. A mono cylinder diesel engine was used for the study. Initially trials were made on the engine using neat diesel (ND), Neat Mahua oil (NMO) as fuels. In the second phase, NMO was converted into its stable emulsion (called as MOE) and tested in the engine. Finally thermal barrier coating of 0.2 mm was made on the piston, valves and cylinder head of the engine using the ceramic power of Al2O3 and the engine was tested using NMO and MOE as fuels in the TBC engine. Results indicated improvement in BTE (brake thermal efficiency) with MOE as compared to NMO mainly at high power outputs in the unmodified engine. The maximum BTE was found as 31.5% with ND, 27.2% with NMO and 30.4% with MOE at the peak power output.
2017-03-28
Journal Article
2017-01-0122
Gursaran D. Mathur
Water drainage characteristics are dependent on the design of the evaporator: specifically the design of the fins and plates along with hydrophilic coating. A part of the hydrophilic coating washes off with the moisture that condenses over the evaporator core from the air-stream. Hence, water drainage characteristics of an evaporator changes with the vehicle mileage or the age of the vehicle. Since a part of the hydrophilic coating washes away, more water is retained within the evaporator at this condition. Hence, the effectiveness of the evaporator drainage deteriorates with the age of the vehicles. At this condition, the contact angle measured at the plate increases. Author has conducted an experimental study to measure the effectiveness of hydrophilic coating from evaporators taken out from arid (9 cores) and humid areas (16 cores) as a function of vehicle mileage or vehicle age. Contact angles and water retention were measured for a number of evaporators from different OEMs.
2017-03-28
Journal Article
2017-01-0484
Harchetan Singh Aneja, Harmeet Singh, Aashish Parmar, Rohan Sharma
Abstract The automotive industry, known for its competitiveness & innovations globally, researches for continuous improvement of part performances along with reduction of cost & weight. These are amongst the top priority goals across all OEMs. In the long list of automobile parts, pipe clamps have paved their way of design through generations from being of metal to plastic that has expanded its scope of application & performance. In an automobile, plastic clamps are widely used to hold single or multiple water, fuel or brake pipes of various diameters to vehicle body at various locations such as underbody (prone to stone chipping) or engine room (prone to high temperatures), etc. Plastic clamps are preferred over metallic clamps for their cost, weight, performance & productivity. Primarily, in all application areas, a clamp must be able to hold the pipes with consistent & sufficient performance that is quantified through parameters such as thrust force and pipe removal force.
2017-03-28
Journal Article
2017-01-0501
Sajiree Vaidya, Naga Sai Chakravart Velamakuri, Piyush Agarwal, Srikanth Pilla, David Schmueser
Abstract In modern passenger vehicles, A-pillar plays an important role in its passive safety by minimizing the deformation of passenger compartment during the crash. To meet various crash requirements, as well as sometimes due to demand of vehicle styling, A-pillar cross section of modern vehicles is generally wider. This wider cross section acts as an increased obstruction to the field of vision of the driver. It is considered detrimental for the safety of road users. The current work proposes an innovative design solution to reduce the obstruction angle due to an A-pillar. It also addresses the weight reduction objective. This is done by utilizing the noble properties of Carbon Fiber Reinforced Polymers (CFRP). Carbon Fiber Reinforced Polymers (CFRP) offer flexibility for complex design. Due to high specific strength and stiffness, CFRP's are suitable candidate for design considerations presented in this study.
2017-03-28
Journal Article
2017-01-1305
Yucheng Liu, Jeremy Batte, Zachary Collins, Jennifer Bateman, John Atkins, Madelyn Davis, David Salley, Cindy L. Bethel, John Ball, Christopher Archibald
Abstract A robot mining system was developed by the State Space Robotic undergraduate student design team from Mississippi State University (MSU) for the 2016 NASA Robotic Mining Competition. The mining robot was designed to traverse the Martian chaotic terrain, excavate a minimum of 10 kg of Martian regolith and deposit the regolith into a collector bin within 10 minutes as part of the competition. A Systems Engineering approach was followed in proceeding with this design project. The designed mining robot consisted of two major components: (1) mechanical system and (2) control system. This paper mainly focuses on the design and assessment process of the mechanical system but will also briefly mention the control system so as to evaluate the designed robotic system in its entirety. The final designed robot consisted of an aluminum frame driven by four motors and wheels. It utilized a scoop and lifting arm subsystem for collecting and depositing Martian regolith.
2017-03-28
Journal Article
2017-01-0411
Yuming Yin, Subhash Rakheja, Jue Yang, P-E. Boileau
Abstract This study is aimed at characterizing the nonlinear stiffness and damping properties of a simple and low cost design of a hydro-pneumatic suspension (HPS) that permits entrapment of gas into the hydraulic fluid. The mixing of gas into the oil yields highly complex variations in the bulk modulus, density and viscosity of the hydraulic fluid, and the effective gas pressure, which are generally neglected. The pseudo-static and dynamic properties of the HPS strut were investigated experimentally and analytically. Laboratory tests were conducted to measure responses in terms of total force and fluid pressures within each chamber under harmonic excitations and nearly steady temperature. The measured data revealed gradual entrapment of gas in the hydraulic fluid until the mean pressure saturated at about 84% of the initial pressure, suggesting considerably reduced effective bulk modulus and density of the hydraulic fluid.
2017-03-28
Journal Article
2017-01-0462
Marcel Meuwissen, Jippe Van Ruiten, Thijs Besseling, Robbert van Sluijs, Maik Broda, Brian Pearce, Fenton I. O'Shea
Abstract Fuel economy improvement efforts in engines have focused on reducing parasitic losses. This paper addresses the friction losses in the valve train chain drive system where about half of the losses is caused by the chain sliding on plastic guide and tensioner arm faces (Figure 1). Efforts have been made to reduce these friction losses by optimizing the chain link profile, the geometry of the guide and tensioner arm rails, and developments towards low friction materials. This paper describes the approach taken for the development of new low-friction chain tensioner arm plastic materials. The approach is characterized by building an understanding of the friction mechanisms and identifying the most critical material’s properties. A lab-scale test is used for a first assessment of the friction performance of materials. The correlation between this lab-scale test and the actual chain-on-tensioner arm application is discussed.
Viewing 241 to 270 of 15992