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Despite the influence of folded metal material on the lubrication performance of engine cylinder liners has been largely investigated, its effect has not been isolated yet in terms of other surface parameters as Sa, Sq, Vo, Rpk etc. In the present contribution, the isolated effect of folded metal on the performance of engine cylinder liners was investigated by comparing the hydrodynamic and asperity contact pressures through a deterministic mixed lubrication model. From that, the friction coefficients and the engine friction losses were also estimated. The topography of a production car engine block was characterized employing a Non-Contact Surface Profiler System. Folded metal was quantified using in-house algorithms, and so its occurrences were digitally removed. Afterwards, the surfaces with and without folded metal were studied with the deterministic model.

The automotive industry has a lack of knowledge when the subject comes to screw joint technique, especially regarding tribological interferences. These themes are not commonly explored together on studies to comprehend the behavior between contacting surfaces. When there is a specific goal, as the one proposed in this paper: to ensure all control levels to eliminate sealing deficiency risks inside combustion chamber in a low investment cost, these needs are even higher. The tribological analysis between diesel engine block and its cylinder head is essential to understand the minimum requirements to achieve the best possible sealing, mostly when it comes to assembly tightening process routines. In this sense, this work puts forward a methodology to set best tightening conditions in order to guarantee the sealing to whatever surface topography. Additionally, the acquired knowledge can be used to other similar applications associated to bolted joints, such as in other vehicle parts.