Racing Engine Research Articles

Enhancing oil pressure dynamics in a high-performance racing engine with innovative lubrication system tuning

This work focuses on fine-tuning the oil pressure dynamics of a single-seater formula car, a participant in international engineering competition organized by the Society of Automotive Engineers (SAE). Adhering to competition guidelines, the Honda CBR600RR 05-06® motorcycle engine, renowned for its 600 c.c. displacement and exceptional power-to-weight ratio, emerges as a popular choice. However, as this engine is originally equipped with a wet sump lubrication system (featuring deep wet sumps to prevent oil starvation during turns), this presents challenges when adapted to Formula Society of Automotive Engineers (FSAE) cars. Cornering leads to significant pressure drops, as sloshing exposes the pickup port, causing consequential engine issues. To tackle sloshing-related challenges and pressure loss during lateral and longitudinal g-forces, a dry sump lubrication system was introduced in the Formula car. The dry sump system also lowers the engine’s center of gravity, by reducing sump height. However, transitioning to the dry sump system and integrating it with the existing engine demanded extensive design modifications to various components, including the oil reservoir, lubrication lines, scavenging pump, and oil ports. These adjustments were essential to achieve the targeted elevation in oil pressures at higher engine RPMs. A relationship between the engine oil pressure and the engine RPM was developed as part of the study.

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>

STAND FOR RESEARCH GENERATORS OF MEDIUM AND HIGH POWER

The aim of the work is to synthesize the parameters of an energy-saving load stand with a mutual load of electrical machines. A functional diagram of a stand for testing high-power generators withirrecoverable energy absorption and with energy return and its reuse is considered. A comparative assessment of the power of mechanical energy, which must be supplied to the generator shaft at its nominalload, has been carried out. The energy-saving load stand includes two electric generators of the same power, one of which is used as an additional racing engine, and the second as an investigated generator and anadjustable electric drive designed to drive the investigated generator. The synthesis of parameters of an adjustable electric drive, which includes a subordinate armature current control loop with a relay currentcontroller and an external speed control loop with a proportional-integrating speed controller, has been  carried out. As an example, the design of the developed energy-saving stand for electric machines with acapacity of 220 kW is considered. Modeling of the operation of an energy-saving load stand with mutual load of electrical machines in the Matlab-Simulink environment has been carried out. The analysis of theenergy efficiency of the developed stand was carried out in comparison with the stand with irreversible energy absorption, which confirmed the high energy, static and dynamic characteristics of the developedstand with the mutual load of electrical machines. In particular, it was found that the use of an energysaving stand for testing a 220 kW generator with an efficiency of 91% makes it possible to almost 6 timesreduce the power of mechanical energy that must be supplied to the generator shaft at the stand with irreversible energy absorption.

Fatigue analysis of high performance race engines

This paper presents a multidiscipline dynamic simulation tool for fatigue testing. A non-linear finite element formulation embedding control system modeling is augmented to include fatigue analysis based on a mathematical representation of virtual brittle lacquer and strain rosettes. A new efficient method for rosette strain calculations based on super node displacements are applied and presented. These features are used to predict the hot spots and durability of a high performance race engine. Real physical testing is performed to capture all engine properties influencing the crank shaft stress distribution. The results predict the most critical failure modes during racing applications as well as the life in terms of drag laps before failure.

Discussion of Elective Sonolucent Cranioplasty for Real-Time Ultrasound Monitoring of Flow and Patency of an Extra- to Intracranial Bypass.

Discussion of Elective Sonolucent Cranioplasty for Real-Time Ultrasound Monitoring of Flow and Patency of an Extra- to Intracranial Bypass.

Experimental Study on the Effect of Bore Up, Stroke Up, and the Use of Valves on 105 cc Engine Perfomance

On a 4-stroke engine, valve work and function have a very big influence on engine performance and characteristics. To improve engine performance, one of them is by way of bore up. This study aims to determine and compare the performance of a standard 4 stroke 105 cc engine before and after bore ups, stroke ups and the use of racing valves in testing power (P), torque (T) and fuel consumption (mf). This research method uses a 4 stroke 105 cc standard engine and a 150 cc bore up engine with a variety of standard and racing valves. The testing method uses the throttle method spontaneously from 4000 rpm to 1100 rpm and the throttle method per 1000 rpm from 4000 rpm then is increased to 8000 rpm gradually. Data taken in this study are torque (T), power (P), and fuel consumption (mf). The results showed that by changing the volume of the cylinder (bore up) by using variations of the racing valve can significantly improve engine performance. The average value of the percentage increase in torque power and fuel consumption compared to the results on a standard 4-stroke engine. On a standard 105 cc engine for 8000 rpm engine speed, 4.63 (N.m) of torque, 3.90 (kW) of power obtained and 0.879 (kg/h) of fuel consumption. In a semi racing engine at 8000 rpm, torque is 9.45 (N.m)(104,10%), power is 8.13 (kW)(108,46%) and fuel consumption is 1.118 (kg/h)(27%). In a full 150 cc racing engine for 8000 rpm engine speed the torque is 12.87 (N.m)(177,97%), the power is 10.79 (kW)(176,67) and fuel consumption is 1.116 (kg/h)(26,96%).

Influence of advanced cylinder coatings on vehicular fuel economy and emissions in piston compression ring conjunction

IC engines contribute to global warming through extensive use of fossil fuel energy and emission of combustion by-products. Innovative technologies such as cylinder de-activation (CDA), after-exhaust heat treatment, surface texturing and coatings are proposed to improve fuel economy and reduce emissions of the vehicle fleet. Therefore, study of coating technology through a comprehensive multi-physics analytical model of engine top compression ring is important to ascertain ways of promoting energy savings. This paper presents a multi-scale, multi-physics model of the compression ring-cylinder bore conjunction, using three alternative bore surfaces. The model comprises ring dynamics, contact tribology, heat transfer and gas blow-by. Tribological and thermal properties of advanced coatings, such as Nickel Nanocomposite (NNC) and diamond-like carbon (DLC) are compared with an uncoated steel bore surface as the base line configuration. Such a comprehensive analysis has not hitherto been reported in open literature, particularly with original contributions made through inclusion of salient properties of alternative bore materials for high performance race engines. Power loss and FMEP are evaluated in a dynamometric test, representative of the World-wide harmonised Light vehicles Test Cycle (WLTC). The NNC coating shows promising tribological improvements. The DLC coating is detrimental in terms of frictional power loss and FMEP, although it can effectively improve sealing of the combustion chamber. The differences in power loss of nominated bore surfaces are represented as fuel mass and CO emissions, using theoretical and empirical relations. For the first time the paper shows that advanced coatings can potentially mitigate the adverse environmental impacts of spark ignition (SI) engines, with significant repercussions when applied to the global gasoline-powered vehicle fleet.

Analysis Of The Effect Of Camshaft Duration On The Performance Of Honda Tiger 200 Cc Fuel Motor Tune-Up Drag Bike

Camshaft modification is often done in drag race. This research was conducted to determine the performance of the drag race engine with camshaft modification on the Honda Tiger 200 cc which includes torque, power, and fuel consumption specifications (SFC). This experimental method uses 8 cc premium fuel at 1500 rpm, 2500 rpm, 3500 rpm, 4500 rpm and 5500 rpm. Torque, power and SFC of the Honda Tiger 200 cc combustion motor are measured above dynotest. The final result of the research is that there is an increase in torque and power of 14.5% respectively. Maximum torque and power is obtained using a camshaft with a duration of 270 °, which is 8, 012 Nm and 4, 612 kW at the same speed of 5500 rpm. On the contrary, the minimum torque and power are generated from the use of a standard 240 ° camshaft of 6, 850 Nm and 3, 943 kW at 5500 rpm. Specific fuel consumption (SFC) obtained has a small effect of 8.53%. The maximum specific fuel consumption (SFC) produced is 0.410 kg / kWh at 2500 rpm rotation with 270 ° camshaft usage. For specific fuel consumption (SFC) at least 0.375 kg / kWh at 2500 rpm rotation with 240 ° camshaft usage.

Transient temperature calculation method for complex fluid-solid heat transfer problems with scattering boundary conditions

A calculation method for engine temperatures is presented. Special focus is placed on the transient and scattering boundary conditions within the combustion chamber, including fired and coasting conditions, as well as the dynamic heat transfer of the water jacket. Model reduction is achieved with dimensional analysis and the application of probability density functions, which allows for a timescale separation. Stationary in-cylinder pressure measurements are used as input values and, according to the transient behavior, modified with an own part-load model.A turbocharged spark ignition race engine is equipped with 70 thermocouples at various positions in proximity to the combustion chamber. Differentiating from already published works, the method deals with the transient engine behavior during a race lap, which undergoes a frequency range of 0.1–1 Hz. This includes engine speed build-ups under gear changes, torque variations, or the transition from fired to coasting conditions.Different thermal behaviors of various measuring positions can be simulated successfully. Additionally, cylinder individual temperature effects resulting from an unsymmetrical ignition sequence and different volumetric efficiencies with unequal residual gas can be predicted. Up to a few percent, the energy balance of the water jacket is fulfilled and variations of water inlet temperatures can be simulated accurately enough.

A hydrodynamic flow analysis for optimal positioning of surface textures

The current study uses Reynolds equation and the cross-film flow velocity profile to analytically determine pertinent locations for texture feature positioning in sliding hydrodynamic contacts. The position of textures is shown to have a significant effect on the lubricant film thickness, thus the load carrying capacity and generated friction and power loss. It is shown that textures, residing after the inlet lubricant recirculation boundary and prior to the position of maximum contact pressure enhance film thickness and reduce friction in the contact of real rough sliding surfaces. The methodology is applied to partial surface texturing of a thin compression ring of a high performance race engine, with the predicted results confirming the utility of the expounded analytical technique and its conformance to the findings of others reported in literature. The time–efficient analytical and fundamental approach constitutes the main contribution of the paper to furtherance of knowledge.

Optimisation of the piston compression ring for improved energy efficiency of high performance race engines

The primary function of the piston compression ring is to seal the combustion chamber from the bottom end of the engine. As a result, its conformance to the cylinder liner surface is of prime importance. This close-contact contiguity results in increased friction, making this contact conjunction responsible for a significant proportion of energy losses. The frictional losses can be as much as 2–6% of the expended fuel energy, which is quite significant for such a diminutive contact. Under these conditions, the geometrical profile, the surface topography and the inertial properties of the ring assume significant importance. The paper presents an integrated mixed-hydrodynamic analysis of the compression ring–cylinder liner contact with multi-parameter optimisation, based on the use of a genetic algorithm. The multi-objective functionality includes minimisation of the parasitic energy loss, reduction in the incidence of asperity level interactions as well as minimisation of the ring mass. Both cold running engine conditions and hot running engine conditions in line with the New European Drive Cycle were considered. Hitherto, such an approach has not been reported in the literature.

Race Engine Development Shifts Gear

Race Engine Development Shifts Gear

Surface-specific flow factors for prediction of friction of cross-hatched surfaces

The paper presents a combined numerical and experimental study of generated sliding friction at low sliding speeds and high load intensity, typical of the top compression ring–cylinder liner conjunction at top dead centre in the compression stroke of high performance race engines. Frictional losses in the transition from compression to power stroke represent a significant portion of cyclic cylinder losses. The cylinder liner is cross-hatch honed with non-Gaussian topography, including larger groove features and a fairly smooth plateau roughness. Surface-specific flow factors are derived to closely represent the actual real rough conjunction. The predictions closely agree with the representative reported precision tribometric study of measured friction.

Nanoscale friction as a function of activation energies

Understanding the scale-dependence of friction is increasingly viewed as a critical quest. With progressively thinner films, mixed and boundary regimes of lubrication have become commonplace. Therefore, at the micro-scale a greater need for mitigating friction is desired in order to improve operational efficiency of many machines and mechanisms. Furthermore, there is a growing tendency to use low friction hard wear-resistant advanced coatings to guard against wear. In parallel, there has been much attention paid to lubricant rheology and formulation. However, only in recent times there has been an emerging view of lubricant–surface combination as a system. In this perspective it is essential to relate the observed and measured friction at component level to the underlying interactions in micro/nano-scales. This is the approach in this paper. Observed phenomenon at micro-scale are related back to the activation energies of lubricant–surface system, providing in particular results for surface modified Ni–SiC coated specimen in combination with formulated lubricants, the combination of which represent the lubricant–surface system of choice in cylinders of high performance race engine. The nano-scale conjunction of an AFM tip with lubricated surface-engineered specimen, subjected to various conjunctional loading and sliding kinematics is investigated. It is shown that the measured frictional characteristics can be adequately described in terms of activation energies in line with the Eyring’s thermal activation model for cases of fairly smooth asperity tip contact conjunctions.

Assessment of friction from compression ring conjunction of a high-performance internal combustion engine: A combined numerical and experimental study

The paper presents direct measurement of in-cylinder friction from a single cylinder motocross race engine under motored conditions and compares the same with a new analytical predictive method. These conditions are encountered in piston–cylinder system with the application of cylinder deactivation (CDA) technology, which is a growing trend. The analytical method takes into account the various regions within instantaneous contact of compression ring–cylinder liner, including lubricant film rupture, cavitation zone and the subsequent lubricant film reformation. The analysis also includes the effect of boundary friction and lubricant rheology. The predictions and direct measurements of cyclic friction show good agreement and indicate dominance of viscous friction under the investigated engine running conditions. In particular, it is shown that the compression ring contribution to in-cycle friction is most pronounced in the region of high cylinder pressures because of combined Poiseuille friction and some boundary solid interactions. The combined experimental-analytical approach has not hitherto been reported in literature.

Analysis of Inlet and Outlet System of Racing Engine and Influence of Various Configurations on Brake Mean Effective Pressure

This article is focused on experimental analysis of acoustic wave influences on the brake mean effective pressure. An experimental base was created using a racing motorbike driven by piston combustion engine, which is equipped with a developed inlet pipe. The inlet air pressure value changed from the atmospheric level to the under-pressure level. This change is connected directly with increasing of the power output and torque. The tuned racing outlet system was applied for measuring of the outlet pipe characteristics. There were investigated influences of the individual configurations in the case of both analysed systems by means of the sequential experimental measurements. During measurement performed using the final configuration of the inlet system there was recorded an increment of the power output on high speed what is illustrated at comparison of global benefit relating to the basic version. The presented inlet pipe was successful in the motorsport area and it was patented, as well.

Tuning the Engine Skoda 781 for Sport Competitions

Abstract This article deals with the tuning of a mass-produced engine Skoda 781.136B and its rebuilding into a racing engine. The introduction briefly describes the basic parameters of the massproduced engine. The information is then followed by a detailed description of adjustments to the pipe system, valve timing, cylinder head and crank mechanism. The article presents the benefits in terms of increasing power parameters and there is also a comparison of speed characteristics. The aim of the tuning was to increase the engine power parameters, in particular the torque in the range of 4 000-6 000 min-1, at which the engine most often operates during competitions. The adjustments and optimization of the engine have increased the power parameters in the required range of revolutions by 38-47%.

Laminar burning velocities of premixed nitromethane/air flames: An experimental and kinetic modeling study

Due to its high lubricity, nitromethane is a fuel regularly used in model engine or more generally in race engine. The objective of this study is to improve our knowledge and understanding of the combustion of nitromethane for better evaluating its potential as fuel for automotive spark-ignition engines. To achieve this goal, unstretched laminar burning velocities of nitromethane–air mixtures were measured using spherical propagation methodology at 423K over a pressure range from 0.5 to 3bar and equivalence ratios from 0.5 to 1.3. The data indicated a typical adverse effect of pressure on laminar burning velocities. Based on the work done by Zhang et al. (2011) [7], a modified detailed kinetic model including 88 species and 701 reactions was proposed. Comparisons between experimental and simulated un-stretched laminar flame speed were made and showed good agreement. The new kinetic mechanism was also used to successfully simulate published experiments and rationalize the unusual occurrence of maximum flame speed in the fuel-lean region.

Measuring method for feedback provision during development of fuel map in hexadecimal format for high-speed racing engines

Electronic systems of control units for powerful engines are distinguished by a structure of control algorithms and determined modification software. A modification of these systems is performed by means of data field editing in order to reach the maximum output parameters. Active algorithms of control units have got a notable complicity and a mutual interrelation. The control software operates with numerical combinations in hexadecimal format. There were suggested types of fuel maps and they were tested using measuring at powerful engine in four sequences. During all running measurements there were monitored simultaneously operational parameters by means of a data link. Results of measuring at the complex station of cylinder dynamometer confirm a relevant contribution in the area of an engine power output characteristic by means of a developed hexadecimal matrix. The characteristic of torque behaviour illustrates a fluent increase of torque values in a wide speed range.

VORD: A Versatile On-the-fly Race Detection Tool in OpenMP Programs

Shared-memory based parallel programming with OpenMP and Posix-thread APIs becomes more common to fully take advantage of multiprocessor computing environments. One of the critical risks in multithreaded programming is data races that are hard to debug and greatly damaging to parallel applications if they are uncaught. Although ample effort has been made in building specialized data race detection techniques, the state of art tools such as the Intel Thread Checker still have various functionality and performance problems. In this paper, we present a Versatile On-the-fly Race Detection (VORD) tool that provides an agile, efficient, and scalable race detection environment for various parallel programming models. VORD can automatically construct an empirically optimal set of race engines by utilizing classification and adaptation mechanisms. A Race-Detection Classification (RDC) table is created to categorize adequate engines in the aspect of labeling, detecting, and filtering. An Engine Code Property Selector (ECPS) uses the RDC table to adapt optimal engines for the given target programming models. In addition to RDC and ECPS, we have also implemented an OpenMP parser and a source instrumentor. The functionality and efficiency of VORD were compared with those of the Intel Thread Checker by using a set of OpenMP based kernel programs. The experimental results show that VORD can detect data races in more challenging programming models such as nested thread and synchronization models, and can achieve a couple of orders of a magnitude faster processing time than the Intel Thread Checker in the large parallel programs.