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The present article shows the influence of the measurement method on a transversal section of exhaust system, downstream of the manifold, the dimensional and the acoustics package simulation. For this task the same system section was instrumented with five different configurations; the values of backpressure were measured on maximum power and used as data for the GTPOWER software to make a virtual simulation of acoustics intensity as a function of engine speed. Therefore it was possible to compare the virtual curves with the real measured values of acoustics intensity. Due to the stream lines influence of the analyzed section, we obtained different values of backpressure and curves of acoustics intensity. Finally, it is shown the measured value of backpressure which has the best correlation with the real measurement and identifies the measurement method with piezo ring as the best configuration.

The present article shows the effect of the mass and friction reduction inside the engine over the carbonic gas emission reduction in the atmosphere. Authors have confirmed that the mass reduction and low friction in the internal components of the OTTO cycle engine, achieved by exhaust and admission valves re-dimensioning and sealer's substitution can help to reduce fuel consumption and, consequently, CO2, the main greenhouse effect gas. It is exposed and discussed different measurements of torque and power curves, friction power, and specific fuel consumption compared in the same engine without the proposed improving actions.

The selection of the materials to a specific application in the Industry has a great importance for the success of a project, particularly when there exists the union of two or more parts, by a weld fillet. The mixture of different classes and chemical compositions in stainless steels in high temperature applications can cause the nucleation and early propagation of fatigue failures, decreasing the life of the product. The present article shows a case study, on which the adequation of the chemical and physical compatibility, and consequent thermal dilation in a specific structure, increased the durability of the component. The study consists of chemical analysis, macroscopic and microscopic evaluation tests on variated materials combination on welding fillets.