Thermal-hydraulic analyses inside internal combustion engines (ICEs) using computational fluid dynamics (CFD) are challenging for several reasons. The fast jet moving through the small intake valve gap imposes very small time-steps thus making the simulation computationally expensive. Capturing mesh deformation and maintaining adequate resolution in a moving domain also presents technical challenges. The calculation can become even more expensive with poor mesh quality which can reduce accuracy and cause high iterations in the pressure solve which will ultimately increase the time-to-solution. In this talk, I will present new developments to the Nek5000 code which are aimed at addressing these challenges. In particular, I will describe multiple numerical algorithms and discuss their performance on ALCF’s BG/Q and Cray XC40 machines. The potential impact of this work is an unmatched, accurate and highly-scalable tool for researchers (academic and industrial) to facilitate t he efficient design of ICEs with short turn-around time.