MAHLE 3021207 Steel Napier THM Piston Ring Set 4.040" Bore 1.5mm

The MAHLE 3021207 is a high-performance steel Napier THM piston ring set designed for 4.040-inch bore applications, engineered for superior strength and sealing performance. Napier rings are very common in performance ring sets, offering proven reliability in demanding applications.

Key Specifications:

• Bore Size: 4.040 inches
• Ring Width: 1.5mm
• Radial Wall Thickness: .151 inches
• Material: Steel construction
• Design: Napier THM (Taper Hook Groove) configuration
• Finish: Plain (uncoated)

Performance Features:

• Smaller ring thickness means less mass and less inertia to overcome when the ring reaches TDC or BDC and has to reverse direction in the cylinder
• MAHLE pioneered the use of piston ring simulation and computer development tools to engineer rings that provide "free" horsepower by successfully minimizing friction, with ultra flat ring flanks and precision finish that maximize ring to piston sealing
• Steel construction provides exceptional durability and heat resistance
• Napier design enhances oil control and cylinder wall sealing

MAHLE is the largest piston ring manufacturer in the world, with over 60% of current production engines built in North America using MAHLE pistons or rings. This ring set is ideal for engine rebuilds, performance applications, and racing environments where reliability and precision are critical.