Gasoline engine valve train design evolution and the antiwear requirements of motor oils

1998 ◽  
Vol 212 (4) ◽  
pp. 243-257 ◽  
Author(s):  
J. C. Bell
Keyword(s):  
Gasoline Engine ◽  
Control Valve ◽  
Practical Experience ◽  
Valve Train ◽  
Gasoline Engines ◽  
Design Evolution ◽  
Strong Trend ◽  
Wear And Friction ◽  
Direct Acting ◽  
Motor Oils

The ability of motor oils to control valve train wear adequately is ensured by the evaluation of new formulations in a variety of standard industry tests. The most critical of these tests have single-overhead-cam valve train systems with pivoted (rocker- or finger-type) followers. Although many vehicles in service have these types of valve train, there is a strong trend towards the use of roller-follower and direct-acting tappet (DAT) systems in recently introduced passenger car engine designs. Roller designs virtually eliminate sliding between the cam and follower and in gasoline engines reduce wear and friction to low levels. Practical experience indicates that DAT systems also give lower wear and friction than pivoted systems do. The parameters affecting wear in the pivoted-follower valve trains of the Sequence VE and Peugeot TU-3 tests are analysed in comparison with equivalent DAT systems. The friction and wear benefits observed with DAT systems are shown to be inherent in the geometry and kinematics of this type of valve train. The consequences of this finding are discussed in relation to the requirements for antiwear protection provided by future motor oils.

Performance Analysis and Improvement Approach of HEV Extended Expansion Gasoline Engine

2011 ◽  
Vol 317-319 ◽  
pp. 1999-2006
Author(s):  
Yu Wan ◽  
Ai Min Du ◽  
Da Shao ◽  
Guo Qiang Li
Keyword(s):  
Mathematical Model ◽  
Performance Analysis ◽  
Fuel Consumption ◽  
Economic Performance ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Valve Train ◽  
Gasoline Engines ◽  
Simulation Results ◽  
Negative Impacts

According to the boost mathematical model verified by experiments, the valve train of traditional gasoline engine is optimized and improved to achieve extended expansion cycle. The simulation results of extended expansion gasoline engine shows that the extended expansion gasoline engine has a better economic performance, compared to traditional gasoline engines. The average brake special fuel consumption (BSFC) can reduce 22.78 g / kW•h by LIVC, but the negative impacts of extended expansion gasoline engine restrict the potential of extended expansion gasoline engine. This paper analyzes the extended expansion gasoline engine performance under the influence of LIVC, discusses the way to further improve extended expansion gasoline engine performance.

scholarly journals The impact of running-in on the friction of an automotive Gasoline-engine and in particular on its piston assembly and valve-train

2019 ◽  
Author(s):  
Christoph Knauder ◽  
Hannes Allmaier ◽  
Stefan Salhofer ◽  
Theodor Sams
Keyword(s):  
Gasoline Engine ◽  
Combustion Engine ◽  
Valve Train ◽  
Term Operation ◽  
Machine Elements ◽  
The Individual ◽  
Direct Acting ◽  
The Impact ◽  
Piston Assembly

Generally, mating surfaces that are in tribological contact undergo a running-in process at the beginning of theiroperational lifetime. During this running-in phase the tribological operating condition change significantly leading ideallyto long term operation with a minimum of continuous wear. While this process and its duration is rather well understoodfor single machine elements like journal bearings, it is the aim of this work to investigate the running-in behaviour ofmore complex systems like an internal combustion engine and its sub-assemblies. To gain insight into the influenceand duration of this running-in phase a series of tests have been performed under realistic engine operating conditions.To be able to separate the running-in processes for the individual subsystems piston assembly, valve-train and journalbearings of the crank train, a large series of tests have been conducted for a conventional gasoline passenger carengine. The results show a strong influence of the running-in process on total engine friction, which can be attributedmostly to the direct acting valve-train and to a considerably lesser extent to the piston assembly.

scholarly journals The impact of running-in on the friction of an automotive gasoline engine and in particular on its piston assembly and valve train

2017 ◽  
Vol 232 (6) ◽  
pp. 749-756 ◽  
Author(s):  
Christoph Knauder ◽  
Hannes Allmaier ◽  
Stefan Salhofer ◽  
Theodor Sams
Keyword(s):  
Gasoline Engine ◽  
Combustion Engine ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Valve Train ◽  
Term Operation ◽  
The Individual ◽  
Direct Acting ◽  
The Impact ◽  
Piston Assembly

Generally, mating surfaces that are in tribological contact undergo a running-in process at the beginning of their operational lifetime. During this running-in phase, the tribological operating condition changes significantly leading ideally to long-term operation with a minimum of continuous wear. While this process and its duration are rather well understood for single machine elements like journal bearings, it is the aim of this work to investigate the running-in behaviour of more complex systems like an internal combustion engine and its sub-assemblies. To gain insight into the influence and duration of this running-in phase, a series of tests have been performed under realistic engine operating conditions. To be able to separate the running-in processes for the individual subsystems’ piston assembly, valve train and journal bearings of the crank train, a large series of tests have been conducted for a conventional gasoline passenger car engine. The results show a strong influence of the running-in process on total engine friction, which can be attributed mostly to the direct acting valve train and to a considerably lesser extent to the piston assembly.

Diagnosis Research on Main Bearing Wear of Gasoline Engines in Mechanical Engineering

2013 ◽  
Vol 644 ◽  
pp. 304-307 ◽  
Author(s):  
Chang Shun Wang
Keyword(s):  
Gasoline Engine ◽  
Vibration Monitoring ◽  
Analysis Method ◽  
Characteristic Parameters ◽  
Main Bearing ◽  
Vibration Signals ◽  
Gasoline Engines ◽  
Test Spot ◽  
Monitoring Mechanism ◽  
Spectral Analysis Method

The different clearances of main bearing of previously designed on EQ6100 model gasoline engine is diagnosed by means of vibration monitoring mechanism. Breakdown signals of main test on different speed, clearance of main bearing, test spot and weather were analyzed by Spectral Analysis method and compared with normal and abnormal vibration signals. As a result, the characteristic parameters and the identifying methods of breakdown are given. In addition, the problems of fault detection are pointed out.

Tumble Flow Measurements Using Three Different Methods and Its Effects on Fuel Economy and Emissions

2006 ◽  
Author(s):  
Myoungjin Kim ◽  
Sihun Lee ◽  
Wootae Kim
Keyword(s):  
Fuel Economy ◽  
High Performance ◽  
Gasoline Engine ◽  
Exhaust Emissions ◽  
Combustion Stability ◽  
Lean Burn ◽  
Flow Measurements ◽  
Part Load ◽  
Gasoline Engines ◽  
Dynamometer Test

In-cylinder flows such as tumble and swirl have an important role on the engine combustion efficiencies and emission formations. In particular, the tumble flow, which is dominant in-cylinder flow in current high performance gasoline engines, has an important effect on the fuel consumptions and exhaust emissions under part load conditions. Therefore, it is important to know the effect of the tumble ratio on the part load performance and optimize the tumble ratio of a gasoline engine for better fuel economy and exhaust emissions. First step in optimizing a tumble flow is to measure a tumble ratio accurately. In this research the tumble flow was measured, compared and correlated using three different measurement methods: steady flow rig, 2-Dimensional PIV, and 3-Dimensional PTV. Engine dynamometer test was performed to find out the effect of the tumble ratio on the part load performance. Dynamometer test results of high tumble ratio engine showed faster combustion speed, retarded MBT timing, higher exhaust emissions, and a better lean burn combustion stability. Lean limit of the baseline engine was expanded from A/F=18:1 to A/F=21:1 by increasing a tumble ratio using MTV.

Optimization of Mode Switching Timing Control for a Lean-Burn Gasoline Engine With a Prototype Passive SCR System

2018 ◽  
Author(s):  
Dakota Strange ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko ◽  
James E. Parks
Keyword(s):  
Gasoline Engine ◽  
Nox Reduction ◽  
Cost Effective ◽  
Nox Storage ◽  
Mode Switching ◽  
Timing Control ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Effective Manner ◽  
Passive Scr

Passive selective catalytic reduction (SCR) has emerged as a promising NOx reduction technology for highly-efficient lean-burn gasoline engines to meet stringent NOx emission regulation in a cost-effective manner. In this study, a prototype passive SCR which includes an upstream three-way catalyst (TWC) with added NOx storage component, and a downstream urealess SCR catalyst, was investigated. Engine experiments were conducted to investigate and quantify the dynamic NOx storage/release behaviors as well as dynamic NH3 generation behavior on the new TWC with added NOx storage component. Then, the lean/rich mode-switching timing control was optimized to minimize the fuel penalty associated with passive SCR operation. Simulation results show that, compared to the baseline mode-switching timing control, the optimized control can reduce the passive SCR-related fuel penalty by 6.7%. Such an optimized mode-switching timing control strategy is rather instrumental in realizing significant fuel efficiency benefits for lean-burn gasoline engines coupled with cost-effective passive SCR systems.

scholarly journals Identification of Ru/Ceria Among Single Atom Ceria Catalysts as a Stable and Superior Material for Abatement of Diesel and Gasoline Engine Pollutants

2020 ◽  
Author(s):  
Konstantin Khivantsev ◽  
Nicholas R. Jaegers ◽  
Libor Kovarik ◽  
Jinshu Tian ◽  
Xavier Isidro Pereira Hernandez ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
No Oxidation ◽  
Oxidation Catalyst ◽  
Single Atom ◽  
Hydrothermal Aging ◽  
Gasoline Engines ◽  
Nox Adsorption ◽  
Ceria Catalysts ◽  
Better Than ◽  
Three Way Catalysis

Atomically dispersed transition metals (Ru, Pd and Pt) have been prepared on CeO<sub>2</sub> and evaluated for NOx/CO abatement applications for diesel and gasoline engines, such as low temperature passive NOx adsorption (PNA), NO and CO oxidation, and three-way-catalysis (TWC). 0.5 wt% Ru/CeO<sub>2</sub> catalyst (Ru is ~27 and ~7 times cheaper than Rh and Pd) shows remarkable PNA performance, better than 1 wt% Pd/Zeolite: it achieves 100% removal of NOx during vehicle cold start. FTIR measurements reveal the formation of stable Ru(NO) complexes as well spill-over of NO to CeO<sub>2</sub> surface via the Ru-O-Ce shuttle, explaining high NO storage. Notably, Ru/ceria survives hydrothermal aging at 750 ⁰C without loss of PNA capacity. It is also a robust NO oxidation catalyst, considerably more active than Pt or Pd/CeO<sub>2</sub>. Expanding the repertoire of Ru/CeO<sub>2</sub> catalytic applications, we further find 0.1 and 0.5 wt% Ru/CeO<sub>2</sub> to be excellent TWC catalysts, rivaling best single-atom Rh supported materials. Our study pushes the frontier of precious metal atom economy for environmental catalysis from uber expensive Rh/Pd/Pt to more sustainable cheaper Ru and highlights the utility of single-atom catalysts for industrially relevant applications.

Compressor Design for Multi-Point Operating Conditions of Turbocharged Gasoline Engines

2010 ◽  
Author(s):  
Tao Chen ◽  
Yangjun Zhang ◽  
Xinqian Zheng ◽  
Weilin Zhuge
Keyword(s):  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Design Method ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Gasoline Engines ◽  
Compressor Design ◽  
Operating Points ◽  
Load Conditions

Turbocharger compressor design is a major challenge for performance improvement of turbocharged internal combustion engines. This paper presents a multi-point design methodology for turbocharger centrifugal compressors. In this approach, several design operating condition points of turbocharger compressor are considered according to total engine system requirements, instead of one single operating point for traditional design method. Different compressor geometric parameters are selected and investigated at multi-point operating conditions for the flow-solutions of different design objectives. The method has been applied with success to a small centrifugal compressor design of a turbocharged gasoline engine. The results show that the consideration of several operating points is essential to improve the aerodynamic behavior for the whole working range. The isentropic efficiency has been increased by more than 5% at part-load conditions while maintaining the pressure ratio and flow range at full-load conditions of the gasoline engine.

The practical implementation of methanol as a clean and efficient alternative fuel for automotive vehicles

2018 ◽  
Vol 20 (3) ◽  
pp. 350-358 ◽  
Author(s):  
Harold Sun ◽  
Wesley Wang ◽  
Kim-Pui Koo
Keyword(s):  
Alternative Fuels ◽  
Gasoline Engine ◽  
Low Cost ◽  
Oxidation Catalyst ◽  
Automotive Application ◽  
Practical Implementation ◽  
Emission Standard ◽  
Gasoline Engines ◽  
Toxic Pollutant ◽  
Aldehyde Emission

Ever since the energy crises in 1970s, the methanol, among other alternative fuels, has been studied for automotive application. The methanol has been widely used for auto racing due to its superior anti-knock characteristics. However, aldehyde is a highly toxic pollutant and aldehyde emission out of alcohol fuel combustion could be considerably higher than spark-ignited gasoline engines. The corrosion and durability of methanol fuel components were also concerns for mass production of methanol-fueled vehicles. The authors have worked with an automotive manufacturer in China to investigate the brake thermal and emission improvement potentials of a methanol-fueled, spark-ignited engine over the original gasoline engine on a passenger car application and to demonstrate the performance and China V emission compliance over its useful life of 160,000 km. The study found that the methanol-fueled engine has 4%–6% brake thermal advantage over the original gasoline engine, and a three-way oxidation catalyst has successfully managed the tailpipe emissions under China V emission limit, consistently over the journey of 160,000 km. The test data show that the tailpipe aldehyde emission is actually reduced to a level that is below what is required by US LEV III emission standard, largely due to the three-way oxidation catalyst and the gasoline cold start assistance at the beginning of the transient emission cycle. This study indicates that methanol-fueled engine might be an attractive low-cost alternative for a more efficient and clean powertrain over conventional gasoline when a light-duty diesel engine faces challenges from future China VI emission regulations.

Influence of Low Ambient Temperatures on the Exhaust Gas and Deposit Composition of Gasoline Engines

2021 ◽  
pp. 1-11
Author(s):  
Dominik Appel ◽  
Fabian P. Hagen ◽  
Uwe Wagner ◽  
Thomas Koch ◽  
Henning Bockhorn ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Cold Start ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Ex Situ ◽  
Exhaust Gas ◽  
Gasoline Engines ◽  
Ambient Temperatures ◽  
Aftertreatment Systems

Abstract To comply with future emission regulations for internal combustion engines, system-related cold-start conditions in short-distance traffic constitute a particular challenge. Under these conditions, pollutant emissions are seriously increased due to internal engine effects and unfavorable operating conditions of the exhaust aftertreatment systems. As a secondary effect, the composition of the exhaust gases has a considerable influence on the deposition of aerosols via different deposition mechanisms and on fouling processes of exhaust gas-carrying components. Also, the performance of exhaust gas aftertreatment systems may be affected disadvantageously. In this study, the exhaust gas and deposit composition of a turbocharged three-cylinder gasoline engine is examined in-situ upstream of the catalytic converter at ambient and engine starting temperatures of -22 °C to 23 °C using a Fourier-transform infrared spectrometer and a particle spectrometer. For the cold start investigation, a modern gasoline engine with series engine periphery is used. In particular, the investigation of the behavior of deposits in the exhaust system of gasoline engines during cold start under dynamic driving conditions represents an extraordinary challenge due to an average lower soot concentration in the exhaust gas compared to diesel engines and so far, has not been examined in this form. A novel sampling method allows ex-situ analysis of formed deposits during a single driving cycle. Both, particle number concentration and the deposition rate are higher in the testing procedure of Real Driving Emissions (RDE) than in the inner-city part of the Worldwide harmonized Light vehicles Test Cycle (WLTC). In addition, reduced ambient temperatures increase the amount of deposits, which consist predominantly of soot and to a minor fraction of volatile compounds. Although the primary particle size distributions of the deposited soot particles do not change when boundary conditions change, the degree of graphitization within the particles increases with increasing exhaust gas temperature.

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