Wiseco 4137GFX GFX-Style Piston Ring Set 4.137 in. Bore 1.2/1.2/3.0mm File Fit

The Wiseco 4137GFX is a GFX-style high-performance piston ring set designed for a 4.137-inch (105.08mm) bore. This file-to-fit ring set is engineered for late-model EFI applications and select small block engines, offering a premium three-ring package optimized for superior cylinder sealing and long-term durability.

Ring Package Specifications:

• Top Ring: 1.2mm Gas Nitrided Positive Twist Steel — provides exceptional wear resistance and heat tolerance
• Second Ring: 1.2mm Phosphate Napier Scraper Cast Iron — improves oil control and compression sealing
• Oil Ring: 3.0mm 3-piece Chrome Standard Tension Steel — stainless steel spacer with chrome-plated rails for reliable oil management

Key Features:

• File-to-fit design allows precise end gap tuning for your specific application
• Gas nitrided top ring delivers superior hardness and surface finish for reduced blow-by
• Napier-style second ring enhances oil scraping for improved combustion efficiency
• 3-piece oil ring assembly with stainless steel expander and chrome-plated rails
• Sold as a single-cylinder set — order the quantity equal to your engine's cylinder count

The Wiseco GFX ring set is the foundation for Wiseco's late-model EFI piston lineup and several small block Chevy performance builds. Each set fits one piston; order multiple sets as needed to complete a full engine build.