Wiseco 3950VK 4-Cycle Piston Ring Set 3.950 in. Bore

The Wiseco 3950VK is a high-performance 4-cycle piston ring set designed for a 3.950-inch bore. Engineered to Wiseco's exacting specifications, this replacement ring set delivers superior compression sealing and oil control for both street and race applications. Each set fits one piston and is developed and validated for race-ready durability and performance.

Wiseco offers matched piston pin options in three material grades to complement your piston build:

5115 Material Piston Pin

• Standard chromium alloy steel construction
• Case hardened to 58–64 Rockwell C
• Ground to a surface finish of 0.15 Ra or better
• Engineered for the normal wear demands of an aftermarket high-performance engine

52100 Material Piston Pin

• High-carbon, chromium-bearing steel — aircraft-quality alloy
• Case hardened to 54–56 Rockwell C and through hardened
• Ground to a fine finish for precise fitment
• Designed for high load capacity with outstanding wear and abrasion resistance

9310 Material Piston Pin

• High-quality, low-carbon case-hardened steel
• Case hardened to 59–63 Rockwell C
• Ground to a superfinish of 0.025 Ra or better
• Optimized for high surface strength combined with high core toughness
• Ideal for forced induction (turbo) and nitrous oxide applications where high contact stress, shock, and impact loading are present

This ring set is sold as a single-piston set. For complete engine builds, order one set per cylinder. Wiseco is a trusted name in performance engine components, with decades of proven results on the track and street.