MAHLE 930077100 Big Block Chevy 509ci Forged Piston Kit 4.500 Bore 4032 Alloy

The MAHLE Motorsport 930077100 is a complete PowerPak forged piston kit designed as a drop-in replacement for Big Block Chevy 502 Marine applications, displacing 509 cubic inches with a 4.500" bore.

Key Features:

• Forged 4032 aluminum alloy construction for superior strength, reduced thermal expansion, and tighter piston-to-wall clearances
• Grafal® anti-friction skirt coating reduces drag, scuffing, friction, and cylinder bore wear while minimizing piston noise
• Phosphate coating on pin bores and ring grooves provides dry-film lubrication during initial startup and break-in, protecting against galling and micro-welding
• Forced pin oiling for enhanced wrist pin lubrication under high-load conditions
• CNC precision-machined pin bores for exacting tolerances and consistent fitment
• Flat-top crown with -3.0cc intake valve relief for optimized combustion chamber geometry
• Performance 1.5mm / 1.5mm / 3.0mm ring pack (1/16", 1/16", 3/16") included
• Round wire locks included — race-proven retention design

Specifications:

• Displacement: 509 CID
• Bore: 4.500"
• Compression Height: 1.645"
• Stroke: 4.000"
• Rod Length: 6.135"
• Pin Diameter: 0.990" (Steel, Floating)
• Pin Length: 2.520"
• Crown Volume: -3.0cc
• Piston Mass: 679g
• Compression Ratio: 8.9:1 (with 118cc heads)
• Alloy: 4032
• Coatings: Phosphate + Grafal®

Replaces OEM/legacy part number BBC395500F03. Ideal for performance marine, street, and circle track Big Block Chevy builds demanding precise fitment and long-term durability.