MAHLE 930286145-1 PowerPak Forged Piston 87.50mm 11.6CR S54 B32 3.2L

The MAHLE 930286145-1 is a single PowerPak forged performance piston engineered specifically for the BMW S54 B32 3.2L inline-six engine. This is the 2nd oversize bore piston at 87.50mm, designed for engine rebuilds requiring an oversized bore while maintaining stock-equivalent compression. It is sold individually (each), making it ideal for replacing a single piston or completing a custom set.

Manufactured from MAHLE's premium 2618 aluminum alloy, this piston is purpose-built for high-performance and motorsport applications. The 2618 alloy is a low-silicon, high-expansion material prized for its superior resistance to detonation and high-temperature strength — qualities typically reserved for forced-induction and race-duty builds. The alloy's increased ductility allows the piston to absorb combustion forces before failure, offering a critical safety margin under extreme conditions.

Key Specifications:

• Bore Diameter: 87.50mm (2nd oversize)
• Compression Height (CH): 32.3mm
• Stroke: 91.0mm
• Rod Length: 139mm
• Pin Diameter: 21mm (floating pin style)
• Crown Volume: -13.1cc (dished with valve reliefs)
• Piston Mass: 343g
• Compression Ratio: 11.6:1 (calculated at 0.20mm below deck, 0.69mm head gasket)
• Alloy: Forged 2618 aluminum
• Ring Set: 1.2mm / 1.2mm / 2.8mm performance ring set included

Key Features:

• Hard-Anodized Top Ring Groove — provides extreme-duty wear resistance for the ring land surface
• Grafal Anti-Friction Skirt Coating — MAHLE's proprietary coating reduces friction and wear on the piston skirt
• Phosphate Dry Lubricant Coating — protects ring grooves from micro-welding and pin bores from galling during startup and break-in
• Slipper Skirt Design — lightweight, low-drag forging geometry for reduced reciprocating mass
• Floating Pin Design — includes steel wrist pin and round wire clips

This piston is compatible with the BMW S54 B32 3.2L found in the E46 M3, Z3 M Roadster/Coupe, and Z4 M. The MAHLE 930286145-1 is sold as a single piston; a complete engine rebuild typically requires six (6). Rings, pin, and clips are included per piston.