Carrillo RS1MGNHD-4090 CP Bullet Gas Nitrided Piston Ring Set 4.090 Bore

The Carrillo RS1MGNHD-4090 is a CP Bullet gas nitrided steel piston ring set designed for a 4.090-inch bore diameter. This single-cylinder ring set is engineered for high-performance and racing engine applications, delivering superior ring seal, reduced friction, and excellent oil control compared to conventional OEM-style rings.

Ring Pack Specifications:

• Top Ring: 1.5mm gas nitrided steel — provides exceptional durability and reduced friction under high heat and pressure
• Second Ring: 1.5mm Taper Hook Groove (THG) Napier-style — improves oil control over conventional taper-faced second rings
• Oil Ring: 3.0mm low-tension flex vent — promotes efficient oil return and reduced parasitic drag

Key Features:

• Gas nitrided steel construction for improved wear resistance and longevity
• Napier-style second ring geometry for superior oil control
• Low-tension oil ring reduces friction and supports maximum power output
• Designed to work exclusively with CP-Carrillo and CP Bullet forged pistons
• A ring end gap spec sheet is included to guide proper fitment for your application
• Made in the USA by CP-Carrillo, a leader in high-performance piston technology

This ring set covers one cylinder. Always verify ring end gap prior to installation, as recommended gaps vary by application and power adder type. Cylinder bore preparation with a 35–40 degree cross-hatch angle plateau hone is recommended for optimal ring seating.