MAHLE 41859CP.040 Premium Piston Ring Set Oversize Bore - 0.040 3.780

The MAHLE 41859CP.040 Perfect Circle Premium Piston Ring Set is engineered for professional engine builders rebuilding GM truck 4.8L and 5.3L LS engines. This 8-cylinder ring set features a 0.040" oversize bore dimension (3.780") and incorporates advanced materials and coatings optimized for reduced friction, extended service life, and minimal oil consumption.

Premium Construction and Materials:

• Upper compression ring: Carbon steel with plasma-moly facing (1.5mm thickness)
• Lower compression ring: Carbon steel construction (1.5mm thickness)
• Oil control ring: Stainless steel with chrome facing (3.0mm thickness)
• SAE 9254 high alloy steel base material provides superior tensile strength, extended fatigue resistance, and increased hardness

Advanced Design Features:

• Pre-lapped rings seat immediately, virtually eliminating break-in time for faster engine commissioning
• Barrel-faced compression rings provide more efficient compression with CNC-controlled gap chamfer to optimize sealing and reduce blow-by
• Reverse twist intermediate rings deliver better groove side sealing with taper race machining for enhanced contact
• CP-20 oil ring assemblies feature exclusive 20-degree ear angle for superior side seal against cylinder walls
• Special chemical polish on oil ring expander enhances oil drain-back performance

What's Included:

Complete 8-cylinder piston ring set with clearly marked rings for easy identification and installation. Ring materials, coatings, and tension are all optimized for each ring position to ensure maximum performance and durability.

Manufactured to OE specifications by MAHLE, a leading global supplier of original equipment piston rings. Perfect for engine overhauls, rebuilds, and re-ring jobs requiring 0.040" oversize rings.