Mahle MS BMW S65 B40 4.0L 92.50mm x 27.3mm CH 12.2cc 372g 12.3CR Pistons (Set of 8)

Mahle Motorsport forged piston set, MPN 197843642, engineered for extreme performance in BMW S65 4.0L engines. Designed for higher compression (12.3:1) and a larger bore (92.50mm) for engine rebuilds, these pistons are significantly stronger and lighter than stock cast aluminum pistons. The set includes eight forged 4032 aluminum pistons with a dome style and two valve reliefs, complete with a comprehensive ring set (1.2mm, 1.2mm, 2.5mm thickness), wrist pins (21mm diameter, 117g steel), and round wire circlips. Mahle's advanced coatings, including Grafal on piston skirts for reduced friction and phosphate on other surfaces, enhance durability and performance. Coatings on the rings include Gas Nitrided (UCR), Phosphate (LCR), and Chrome plated stainless steel (OCR). These pistons are ideal for maximizing cylinder volume and handling increased power output, especially in turbocharged applications, requiring careful valve-to-piston clearance evaluation during assembly. Made in the USA.