MAHLE 3021301 Performance Napier Ring Set Bore - 3.937 1.2mm 1.5mm 3.0mm

The MAHLE 3021301 is a high-performance piston ring set designed for precision engine builds requiring a 3.937-inch bore diameter. This three-piece ring set features MAHLE's proven Napier design for superior oil control and combustion sealing in demanding applications.

Ring Configuration:

• Top compression ring: 1.2mm thickness with plain profile
• Second compression ring: 1.5mm Napier design for enhanced oil control
• Oil control ring: 3.0mm three-piece assembly
• Radial wall thickness: 0.135 inches

Key Features:

• Precision-manufactured to 3.937-inch bore specification
• Performance-grade materials for high-temperature durability
• Napier second ring design improves oil management
• Plain top ring profile for consistent sealing
• Ideal for performance rebuilds and racing applications

MAHLE's performance ring sets are engineered to exacting tolerances, ensuring proper ring tension, minimal friction, and maximum cylinder sealing. The Napier configuration on the second ring provides an oil scraping edge that helps prevent oil consumption while maintaining efficient compression sealing.