No abstract

This article describes the development of MAHLE piston technology with the goal of meeting increasing requirements of advanced, highly efficient gasoline engines. The new EVOLITE® lightweight piston from MAHLE is a continuation of the development of its predecessor, the EVOTEC® 2, and is based on the EVOTEC® design concept. This concept differs from the design approach of previous decades in that the piston geometry has inverted asymmetry on the thrust and antithrust side. A narrow thrust side is combined with a wide, elastic antithrust side for skirt guidance. The light, robust EVOTEC® 2 piston is available with ring carrier or cooling gallery - Figure 1. The EVOLITE® concept represents further refinement of the EVOTEC® design concept by increasing asymmetry further. By geometrically optimizing the box wall connection between the skirt and crown, the lifetime has been increased by up to 8 times in comparison with the EVOTEC® 2, depending on stress location, while the weight has been reduced by up to 5%. Friction, which is critical for low CO2 emissions, is also reduced with this new piston type.