Clevite 40203CP Plasma-Moly Piston Ring Set Bore - 4.250

The Clevite 77 40203CP is a premium plasma-moly piston ring set designed for big block Chevy 427/454ci engines and Chrysler 426 HEMI/Wedge applications from 1959-1999. This high-quality ring set features a standard 4.250-inch bore size and is manufactured by MAHLE, one of the largest OE piston ring manufacturers in the world.

Key Features:

• Plasma-moly coating on top compression ring for superior wear resistance and reduced friction
• Barrel-faced compression rings with CNC-controlled gap chamfer to optimize compression and reduce blowby
• Reverse twist intermediate rings for better groove side sealing and enhanced contact with taper race machining
• CP-20 oil ring assemblies with exclusive 20-degree ear angle for optimal side seal against cylinder walls
• Pre-lapped rings seat immediately, virtually eliminating break-in time
• SAE 9254 high alloy steel construction provides higher tensile and yield strength with extended fatigue resistance

Specifications:

• Bore Size: 4.250 inches (Standard)
• Ring Widths: 5/64", 5/64", 3/16"
• Materials: Top Ring - Cast Iron with Plasma-Moly facing; Second Ring - Cast Iron; Oil Ring - Stainless Steel with Chrome facing
• Ring Types: UCR: RF-10PF; LCR: RBT-10; OCR: CP-20

This MAHLE Original piston ring set delivers OE form, fit, and function with installer-friendly design. Ring materials, coatings, and tension are all optimized for reduced friction and extended service life, making this the ring of choice for professional engine builders.