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In a Diesel engine, temperature reduction on a power cylinder unit (PCU) is an important demand due to increasingly engine load and performance of modern engines. Both piston and piston ring pack need to be prepared to attend this demand. In general, Diesel engine pistons use cooling galleries to remove heat from high temperature regions and, therefore, reduce tensions on piston combustion bowl and bowl rim. Piston concept gallery was designed to improve piston performance: it consists on more efficient heat dissipation through an elevation of the gallery and new shape. The elevated piston promoted a temperature reduction of 39°C in the maximum temperature region without compromising product robustness and, thus, an improvement on lifetime prediction in 2 times in the piston combustion bowl region. Furthermore, a reduction on carbon build-up on ring belt region was also observed.

Governmental legislation with regards to emissions is an important driver for Heavy Duty Diesel (HDD) engine developments. To reach the targets, in most of cases it is necessary to increase the thermal-mechanical loads, increasing the level of technical demand for the engine components. Besides that, other important aspects drive the engine development, as the cost of ownership, demanding for instance an extended oil draining interval, which leads to harsher environment for the engine components. In order to cope with the modern engine demands, this article presents a piston and piston rings specially designed to meet these targets in a robust way. Starting with the ring pack, CrN based coatings applied by PVD (Physical Vapor Deposition) are commonly applied to top ring face to reach durability targets.