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Motorsport Engineering is developing a foothold, around the World, as a field of academic preparation at the post-graduate level. To gain the appropriate practical skills to augment classroom education, and thus, for the graduates to successfully compete for employment in the Motorsport Industry, it is critical that the degree program has a strong experiential component. This paper describes the need to take an engineering approach to motorsport education by combining a discovery-based education with the traditional lecture format to realize synergistic results. The idea is that to effectively “engineer” the graduate, the student must have a strong skill set or a strong grasp of the fundamentals. The growth of the current educational program at Colorado State University and the effectiveness of merging the “inside-out” process, typical of the research mission, with the instructional practices of the University and with the needs of the Motorsport Industry are discussed.

Engine friction typically accounts for 10 - 20 % of the power output of an engine, and friction in the power cylinder assembly is responsible for 50 % or more of the total engine friction. Hence, improvements to this assembly are critical for maximizing mechanical efficiency in high-performance and race engines. Many strategies have been developed and are currently being employed with the intent of reducing engine friction and extracting additional engine power. However, quantitative proof of their effectiveness has been very limited. This paper discusses the design and development of a research grade ‘floating-liner’ engine for measuring the friction forces within the power cylinder assembly of a high-speed internal combustion engine.

A study is presented in which light-weight composite materials are used for an engine intake valve. This paper is an interim progress report and documents the successful demonstration of a net-shape, resin transfer molded intake valve in a running engine. A short review of a previous dynamic model is presented showing the advantages in engine performance by using the composite valves. It is shown that the use of reduced mass composite valves allows for increased engine speed and/or more aggressive cam profiles without sacrificing valve strength or stiffness while at the same time maintaining reliable operation. The use of composite materials allows for a significant weight reduction compared to more conventional materials such as steel and titanium. A brief review of the use of composite materials is presented. The development and design process for carbon fiber reinforced valves is discussed.

High performance engine tuners have traditionally relied primarily on empirical techniques for intake flow optimization. This paper describes the use of a commercial Computational Fluid Dynamics (CFD) package to complement the traditional optimization strategies. This paper describes why some experimental methods are difficult to apply, including an example of Particle Image Velocimetry (PIV), and demonstrates the benefits of using computational analysis to investigate geometry changes to the intake or exhaust systems. This paper also illustrates the use of a Coordinate Measurement Machine (CMM) to digitize an existing cylinder head to develop a solid model suitable for CFD analysis. A comparison of results from a CFD prediction from a digitized solid model to a flow bench measurement demonstrates the validity and usefulness of this approach.

This paper outlines the development of a diesel fuel burner for Diesel Particulate Filter (DPF) regeneration. The burner utilizes the application of a dual featured ignition system that may enable a burner system to be more cost effective, reliable, and efficient than other burners or Diesel Oxidation Catalysts (DOC). The ignition system incorporates high-energy ignition and ion sensing into a single controller. These two features provide many benefits for burner applications. The high-energy ignition provides enhanced light-off characteristics while simultaneously cleaning the electrode surfaces. Ion sensing allows precise flame control through high-speed ignition and flameout feedback. Initial data has already confirmed many of these anticipated benefits.

A technique was developed for measuring the Laminar Burning Velocity (LBV) of multi-component fuel blends for use in high-performance spark-ignition engines. This technique involves the use of a centrally-ignited spherical combustion chamber, and a complementary analysis code. The technique was validated by examining several single-component fuels, and the computational procedure was extended to handle multi-component fuels without requiring detailed knowledge of their chemical composition. Experiments performed on an instrumented high-speed engine showed good agreement between the observed heat-release rates of the fuels and their predicted ranking based on the measured LBV parameters.

A technology path has been identified for development of a high efficiency, durable, gasoline engine, targeted at achieving performance and emissions levels necessary to meet heavy-duty, on-road standards of the foreseeable future. Initial experimental and numerical results for the proposed technology concept are presented. This work summarizes internal research efforts conducted at Southwest Research Institute. An alternative combustion system has been numerically and experimentally examined. The engine utilizes gasoline as the fuel, with a combination of enabling technologies to provide high efficiency operation at ultra-low emissions levels. The concept is based upon very highly-dilute combustion of gasoline at high compression ratio and boost levels. Results from the experimental program have demonstrated engine-out NOx emissions of 0.06 g/hp/hr, at single-cylinder brake thermal efficiencies (BTE) above thirty-four percent.

A new combustion concept has been developed and tested for improving the low to moderate load efficiency and NOx emissions of natural gas engines. This concept involves operation of a dual-fuel natural gas engine on Homogeneous Charge Compression Ignition (HCCI) in the load regime of idle up to 35 % of the peak torque. A dual-fuel approach is used to control the combustion phasing of the engine during HCCI operation, and conventional spark-ignited natural gas combustion is used for the high-load regime. This concept has resulted in an engine with power output and high-load fuel efficiency that are unchanged from the base engine, but with a 10 - 15 % improvement to the low to moderate load fuel efficiency. In addition, the engine-out NOx emissions during HCCI operation are over 90% lower than on spark-ignited natural gas operation over the equivalent load range.

The impingement of liquid fuel onto the surfaces of the combustion chamber (wall-wetting) has been shown to be an important source of HC emissions from direct-injected SI engines, and can even result in pool fires and diffusion flames. Some degree of wall wetting, particularly on the piston top, is believed to occur in every current DIG engine design, but the behavior of the wall-bound fuel throughout the engine cycle is poorly understood. The goal of this study was to gain a better understanding of the fundamental interaction between liquid fuel droplets and the piston under engine-like conditions, by observing the vaporization of individual fuel drops as the surface temperature and ambient pressures were varied in a controlled environment. The vaporization of several single-component fuels, binary mixtures, and multi-component fuels was examined in the range of surface temperatures between 50 and 300 °C and ambient pressures between 50 and 1270 kPa (abs).

Fiber Reinforced Composites (FRCs) offer the possibility for reduced mass and increased performance in internal combustion engines, yet the automotive and aerospace industries have been slow to adopt these materials. Extensive research has been done over the past 25 years, producing nearly every components of an internal combustion engine out of some form of FRC. This Previous work is summarized herein. A prediction of engine weight reduction is made for direct substitution of FRCs. An additional prediction is made to quantify the additive effects of mass reduction on component mass, and power. It is estimated that engine mass might be reduced by as much as 70% using FRCs and reciprocating mass might be reduced by as much as 90%. In addition, increased mechanical efficiency on the order of 2% may be possible from reduced inertial and frictional loads.

A low pressure fuel distillation system is proposed for extracting a high-volatility fraction of gasoline, and to improve start-up and warm-up behavior of SI engines. More complicated methods for generating high-volatility start-up fuels have demonstrated improved cold start driveability and reduced HC emissions, but so far they have not been put into mass production. In this project, a ‘bench-top’ apparatus was used to investigate the feasibility of using sub-atmospheric pressures to extract a lighter and more volatile fraction from the parent gasoline. A series of experiments was conducted to evaluate the characteristics of the extracted fuel vapor as a function of temperature and pressure. The sensitivity to different brands and grades of gasoline was also explored. The results show that the extracted fuel consists mostly of C5 and C6 compounds, and that its Molecular Weight and Stoichiometric A/F ratio show little sensitivity to the pressure level used for the extraction.

Specification (spec) race engines are intended to reduce costs and increase the competitiveness in many racing classes. However, engines prepared by the best race engine builders routinely outperform truly ‘standard’ engines or engines prepared by less experienced tuners. This paper describes how engines can be modified to increase their power output and discusses various spec engine preparation techniques. Experimental and computational evidence is used to quantify the potential benefits that can be expected from each of the modifications discussed. By combining several relatively small improvements, a well prepared engine may be expected to enjoy a 5-8 % power benefit over an ‘average’ race engine, and perhaps as much as a 14-17 % benefit in power versus a truly standard production engine off the assembly line. This analysis also reveals the claims of much larger power improvements by some high-performance engine tuners can not be substantiated unless further modifications are made.

Recent advances in Variable Valve Actuation (VVA) methods have led to development of optimized valve timing strategies for a broad range of engine operating conditions. This study focuses on the cold-start period, which begins at engine cranking and lasts for approximately 1 minute thereafter. Cold-start is characterized by poor mixture preparation due to low component temperatures, aggravated by fixed valve timing which has historically been compromised to give optimal warm engine operation. In this study, intake cam phasing was varied to explore the potential benefit in hydrocarbon emissions and driveability obtainable for cold-start. A simple experimental approach was used to investigate the potential emissions benefits realizable through intake cam phasing. High speed cylinder pressure and Fast Flame Ionization Detector (FFID) engine-out hydrocarbon (HC) measurements were made to characterize instantaneous cold-start emissions and driveability.

Large reductions in low-load NOx emissions can be obtained by replacing conventional Diesel or spark ignited combustion by HCCI combustion in reciprocating engines. Currently, HCCI combustion is limited to operating conditions with lean air/fuel ratios or large amounts of EGR. However, a numerical model shows that, even if high equivalence ratio HCCI operation were satisfactorily attained, the NOx reduction potential vs. DI-Diesel combustion would be much smaller. Thus, high-load HCCI operation may best be obtained through highly boosted fuel-lean operation. Alternatively, HCCI combustion may be suited well for “dual mode” engine applications, in which spark ignition or conventional Diesel combustion is used to obtain full load. Avoiding wall impingement with heavy fuels is critical for achieving good emissions and fuel consumption, and it appears that a large degree of mixture inhomogeneity can be tolerated from a NOx benefit standpoint.

The effect of combustion chamber wall-wetting on the emissions of unburned and partially-burned hydrocarbons (HCs) from gasoline-fueled SI engines was investigated experimentally. A spark-plug mounted directional injection probe was developed to study the fate of liquid fuel which impinges on different surfaces of the combustion chamber, and to quantify its contribution to the HC emissions from direct-injected (DI) and port-fuel injected (PFI) engines. With this probe, a controlled amount of liquid fuel was deposited on a given location within the combustion chamber at a desired crank angle while the engine was operated on pre-mixed LPG. Thus, with this technique, the HC emissions due to in-cylinder wall wetting were studied independently of all other HC sources. Results from these tests show that the location where liquid fuel impinges on the combustion chamber has a very important effect on the resulting HC emissions.

An innovative pedal-assist system for bicycles has been designed and demonstrated by RevoPower Inc. This system incorporates a single-cylinder piston-ported two stroke engine, mounted radially within the front wheel hub of a bicycle. This design is light, compact, and easily adaptable to any common bicycle. However, this application presents some unique challenges for the engine and drivetrain. This paper describes a project undertaken to further develop this self-contained engine-driven bicycle wheel to improve its performance and reduce its noise emission. As described, a variety of computational end experimental techniques were used to analyze and improve the initial engine and wheel design. The work presented here resulted in a tripling of engine power over the baseline configuration, and a simultaneous overall sound reduction of nearly 20 dB(A).

A recently developed in-cylinder fuel injection probe was used to deposit a small amount of liquid fuel on various surfaces within the combustion chamber of a 4-valve engine that was operating predominately on liquefied petroleum gas (LPG). A fast flame ionization detector (FFID) was used to examine the engine-out emissions of unburned and partially-burned hydrocarbons (HCs). Injector shut-off was used to examine the rate of liquid fuel evaporation. The purpose of these experiments was to provide insights into the HC formation mechanism due to in-cylinder wall wetting. The variables investigated were the effects of engine operating conditions, coolant temperature, in-cylinder wetting location, and the amount of liquid wall wetting. The results of the steady state tests show that in-cylinder wall wetting is an important source of HC emissions both at idle and at a part load, cruise-type condition. The effects of wetting location present the same trend for idle and part load conditions.