2013–2016 kau for BMW 550i, 650i, 750i (N63 4.4L Engine)

The BMW N63B44 is a 4.4-liter twin-turbocharged V8 engine featuring a unique “Hot-V” design—meaning the turbochargers are positioned within the V-shaped cylinder banks. This engine produces a power output ranging from 402 to 523 horsepower, with peak torque falling between 443 and 553 lb-ft (approximately 600 to 750 Nm) across models produced from 2008 to the present. Its key technical specifications include an 89 mm bore, an 88.3 mm stroke, and a compression ratio ranging from 10:1 to 10.5:1; it is also equipped with Dual Overhead Camshafts (DOHC), Valvetronic electronic valve control technology, and the VANOS variable valve timing system. Renowned for its exceptional power performance, this engine is widely utilized in BMW 5 Series, 6 Series, 7 Series, and X Series models.