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Since January 2015, Brazil put into effect the PROCONVE/MAR-I (Programa de Controle da Poluição do Ar por Veículos Automotores para Máquinas Agrícolas e Rodoviárias), which drives the country to the same stringent emissions standards used by the American (EPA Tier III) and European (Euro Stage IIIA) markets. As a result, new pollutants and noise emissions levels were established and although very important for the society health, this issue (noise) has been left behind in this kind of vehicle. Therefore, an extremely challenging target has to be pursued, regarding the current political and economical situation and also the resources availability to achieve those targets. The present work investigates the influence of the noise generated during the combustion process in MAR-I engines by modeling the calibration parameters, which allows to identify the contribution of the combustion in the global engine noise and possibly reducing it and hence the product reckoned costs.

Nowadays the mains techniques to obtain Sound Power of machines and equipments are: - Sound Power obtained by Sound Pressure and - Sound Power obtained by Sound Intensity. This paper intends to compare results and show some advantages and disadvantages found during the tests. This discussion will be based on heavy-duty diesel engines and the data show different results (Δ=2dBA) comparing ISO 3744 and ISO 9614, but allow us to have a correlation factor, at least for this engine type.

This work brings and proposes a simulation methodology to virtually investigate a 2-stage Turbocharger application for a heavy duty diesel engine. The motivation of the work is the research and development of an engine which is supposed to comply with very restrictive emission regulation policies, namely Euro V, VI and EPA 10, besides Tier 4 Final. Although emission level is, itself, a main concern (mainly NOx and engine-out PM), the present work present a methodology which covers air flow and boost ability of the entire engine and it is designed to be able to properly evaluate turbocharger designs possibilities (TC matching). In order to find the unknowns of the physical problem and, then, to verify the methodology success, some not usual measurements were done, such as of TC shaft speed using NVH techniques.

Sound quality requirements have been more often used in light and heavy duty trucks market. Then, vehicle owners fell uncomfortable with rattle noise mainly at idle speed with air compressor operating in load phase. Sometimes they associate this noise as a failure, which can generate a car shop dealer claim, as well as product and company image deterioration. One option to deal with this kind of noise is to apply an anti-backlash gears. The literature shows that as we decrease the backlash the rattle is reduced too. Then, to understand the effect of this solution is mandatory before to apply into production. The object of this work is to study the vibroacoustics effects of the anti-backlash gear system regarding to the air compressor rattle noise of the MWM ACTEON 4.12TCE diesel engine. The angular displacement and velocities fluctuation of the air compressor anti-backlash gear were analyzed in order to characterize the air compressor gear rattle.

Now a day's several techniques are used to help in noise source identification. This paper intends to comment compare some of them including advantages and disadvantages. We will show the results of the follows techniques: Experimental Modal Analysis Operational Modal Analysis Acoustic Holography Sound Intensity This discussion will be based on a high speed diesel engine crankcase which is applied in a SUV and the focus was to improve the Cab Articulation Index (AI).

In diesel engines, the timing system is normally composed by gears, sometimes with toothed belt and recently with chains. But for trucks and buses, vans and SUV's the most common is gears due to reliability. But this reliability can not be misunderstood with durability, other wise some gear noise can appears and this noise can be considered as a kind of failure at least in terms of comfort. The gear train can produce mainly two kinds of noise, rattle and whine, in this paper we will discuss about the whine noise. The discussion will be done based in a case with the 4.07TCE Sprint engine. Whine noise: Definition - It is a tonal gear frequency and their harmonics. [1] In this paper we will analyze how the whine noise is presented, what are the significant factors and how to deal with them. The methodology used can be seen in figure (1).