Mahle 3932MS-112-4 Piston Ring Set, 3.927" Bore, 1.0/1.0/2.0mm File Fit

Compatible Applications

• Universal - for 4-cylinder engine builds using a 3.927" (+0.005") bore piston

Fitment Notes

• 3.927" bore diameter (+0.005" oversize)
• 1.0mm top ring / 1.0mm second ring / 2.0mm oil ring, file-fit configuration
• File-fit rings require gap adjustment by the installer to match the specific bore - confirm your machinist or engine builder is equipped for this step
• 4-cylinder specific set - confirm your engine's cylinder count matches before ordering

Features

• Mahle pioneered the use of piston ring simulation and computer development tools to engineer rings that minimize friction and free up usable horsepower
• Ultra-flat ring flanks and precision finish maximize ring-to-piston sealing - a difference evident on both the dyno and the track
• Steel top ring features Mahle's patented HV385 supersonic thermal spray process for superior bonding, increased durability, and enhanced scuff resistance
• Steel Napier-style second ring improves oil control and reduces blow-by
• Industry-leading CP-20 oil ring rounds out the package for consistent oil control
• File-fit design allows precise gap customization for the specific bore and application

Specifications

• Type: Performance Piston Ring Set, File Fit
• Bore: 3.927" (+0.005")
• Top Ring: 1.0mm, Steel, HV385 Thermal Spray
• Second Ring: 1.0mm, Steel Napier
• Oil Ring: 2.0mm, CP-20
• Cylinder Configuration: 4-Cylinder

Included Components

• 1x Set of Piston Rings (Full 4-Cylinder Set)

Product Description

The Mahle 3932MS-112-4 ring set brings computer-simulated ring design to 3.927" bore four-cylinder engine builds, using Mahle's friction-minimizing technology to free up real horsepower - gains that show up clearly on the dyno and on track. The set's ultra-flat ring flanks and precision finish maximize ring-to-piston sealing for consistent compression and reduced blow-by across the RPM range.

The steel top ring's patented HV385 supersonic thermal spray coating delivers superior bonding, durability, and scuff resistance, while the Napier-style second ring and CP-20 oil ring round out a package built for serious performance applications. As a file-fit set, these rings require gap adjustment to the specific bore by the installer - a small extra step that rewards builders with precisely tuned ring-to-bore clearance for their exact engine combination.