1. Introduction
An analysis of theeng ineper for mancea swell a scriteria for de veloping of the in letand exhaustpipe system require the deep knowledge about acoustics of the both systems. The up-to-date known information from this area can be summarized into several conclusions.
In many scientific articles there are presented experimental results and theoretical models of the acoustic waves and their impact on global efficiency of the piston combustion engines. The fundamental information sources about the instable gas dynamics in internal distribution channels of combustion engines were presented during the 1950sof the last century.Measuringmethodsofthe local throughput in the pipe, together with computerised calculations, were improved considerably during the 1980s [1]. A complete overview of topical knowledge oriented to the analysis and proposal of the inlet (suction)
and exhaust systems of the internal combustion engine was published at the end of the 1990s [2]. The theoretical principia of one-dimensional acoustic models were described at the turn of the centuries. At that time the more complicated non-linear dynamic gas models were transformedsuccessfullytothesimplerlinearacousticmodels [3]. Very interesting results were obtained also by means of the Euler’s equation solution for a pipe. This solution offered a high level of result reliability [4]. A principle of this methodologyconsistsin solutionof velocities and pressure equations with regard to the frequency using a method of matrix transfer, taking into consideration also theoretical limits for real values of the high-pressure levels in the exhaust gas system. This solution seems to be the most suitable method for analysis of the inlet and exhaust system with regard to noise reduction [5]. Some of the scientific works are demonstrating a acceptable conformity of the linear acoustic models with the experiments performed in the inlet and exhaust pipe of the piston combustion engines [6]. A wide range of the experimental tests and practical applications are supporting the development criteria for proposal of new theories. They are integrating together a lot of results obtained from the research activities performed in the area of resonance and acoustic feedback among the inlet parts. At the same time the above-mentioned amount of information enables to propose the new methods for projection of the inlet and exhaust systems of the piston engines [7]. A complex view on design and simulation of the highpowerengines,including a proposalof the empirical methods for designers as well as the experimental data about efficiency of the high-speed engines, are summarized in the literature [8]. In spite of a large amount of the publications and professional articles there is at disposal only a small amount of the measured data concerning mutual interrelations and influences among the individual parts of the inlet system. An arrangement of the inlet system is independent usually on a constructional and technological conception of the engine itself in the case of the high-power combustion engines. This article presents an experimentalstudy of the high-power combustion engine applied in the motorbike, which was specified for the racing purposes. In this articlethereisinvestigatedaninfluenceofthevariousinlet and exhaust systems as well as their individual components on the volumetric efficiency. This investigation was performed by means of the various measurements using the data-recording system. The several various inlet and exhaust system configurations were tested during this research process. The final complete configuration of the inlet system, which is presented in Fig. 1, is a result of our own long-time development process. Another output of the successful development activities is also the patent application of this invention, which was registered in the last year. This patentconcernsaconceptualarrangementofthenewlydeveloped system. This experimental analysis was realised according to various remarks and problem solutions occurring during realisation of various engine design [9].