BBTV 2M4720 Engine Piston Ring

Engine piston ring set for 4.0L bores

This engine piston ring set is built for 4.000-inch, standard-bore applications and uses a plasma moly top ring for wear resistance. It is a fitment-based replacement for select Chevrolet, GMC, and Oldsmobile V6 applications, including Chevrolet Astro and GMC Safari models.

Key features

• Standard bore sizing for 4.000-inch cylinder bores
• Plasma moly top ring surface for improved ring face durability
• Steel top ring construction for strength under combustion load
• Grey iron second ring with phosphate surface treatment
• Steel rail and stainless expander oil ring design with chrome treatment

Detailed description

Part number 2M4720 is an engine piston ring set engineered around a 4.000-inch bore and standard oversize specification. The ring package uses a plasma moly top ring, a grey iron second ring, and a steel rail/stainless expander oil ring arrangement to support cylinder sealing and oil control in compatible V6 engines. This part number 2M4720 is listed for 1992-1995 Chevrolet Astro, 1992-1995 GMC Safari, and other select Chevrolet and GMC truck and SUV applications, with fitment also covering 1995 Chevrolet Blazer and 1992-1994 Oldsmobile Bravada.

What it is used for

• Restoring cylinder compression in worn engine bores
• Addressing oil consumption caused by worn ring sealing
• Replacing damaged or heat-worn piston rings during engine service
• Supporting proper combustion sealing in compatible V6 engines
• Correcting blow-by related to ring wear or loss of tension

Installation notes and tips

Verify bore size, ring groove dimensions, and engine configuration before installation. Clean piston ring grooves thoroughly and confirm end gap and side clearance against service specifications. This part cross-references Monroe Shocks & Struts (e.g., E627K) for the same application.