Mahle MS Piston Set BMW S52B 86.60mm Bore 89.6mm Stroke 135mm Rod 22mm Pin -25cc 9.0 CR Set of 6

Mahle Motorsports S52 pistons are forged for strength, light weight, and low drag, designed for specialized applications beyond stock BMW pistons. Forged pistons offer superior material strength and robustness for extreme conditions, especially in turbocharged engines. This set features a low compression specification (9.0:1) suitable for boosted engines, providing a 2nd (or 3rd) oversize bore at 86.6mm.

These pistons are crafted from Mahle's high-performance 2618 alloy, typically reserved for racing and heavy-duty turbo applications. The 2618 alloy is a low-silicon, high-expansion material offering improved tolerances and higher resistance to detonation. While this may result in temporary piston slap when cold, it allows the piston to deform and absorb combustion forces better, preventing catastrophic failure. The pistons also feature hard-anodized ring lands for enhanced wear resistance.

Mahle Motorsports pistons are engineered with superior quality and machining control. The piston crowns are coated with a ceramic-based thermal coating to reduce heat transfer and shock. Piston skirts feature a Grafal coating to minimize drag, friction, scuffing, and cylinder bore wear, while the rest of the piston has a phosphate coating. Each piston kit includes a complete ring set, wrist pins, and circlips. Made in the USA.