BBTV 2M694 Engine Piston Ring

Engine Piston Ring Overview

This engine piston ring is built for classic V8 applications that require standard bore sizing and a plasma moly top ring surface. It is specified for a 4.040-inch engine bore and uses steel, grey iron, and chrome/phosphate surface treatments to support sealing and wear control.

Key Features

• Standard oversize specification for 4.040-inch bore applications.
• 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 treatment for controlled wear.
• Steel rail and stainless expander oil ring design with chrome finish.
• Fits a wide range of classic Dodge and Plymouth V8 applications, including Dodge Challenger, Charger, Coronet, Dart, and Plymouth Barracuda, Cuda, Duster, Satellite, and Valiant.

Detailed Description

Part number 2M694 is an engine piston ring set specification for standard bore classic performance and street applications. The ring package uses a plasma moly top ring, a steel second ring, and a steel rail/stainless expander oil ring arrangement to help maintain cylinder sealing, oil control, and consistent ring contact. This part number 2M694 is listed across multiple Dodge and Plymouth models from the late 1960s through the early 1970s, including Dodge Challenger and Plymouth Barracuda applications.

This part cross-references Monroe Shocks & Struts (e.g., 40787, E286K) for the same application.

What It Is Used For

• Restoring compression loss caused by worn ring faces.
• Reducing oil consumption from tired cylinder sealing.
• Replacing rings during a rebuild on a standard bore engine.
• Addressing blow-by that can affect idle quality and crankcase pressure.
• Refreshing ring seal in classic Dodge and Plymouth V8 engines.

Installation Notes and Tips

Confirm the engine bore measures 4.040 inches before ordering. Match the ring groove dimensions to the piston specification: 5/64-inch top groove, 5/64-inch second groove, and 3/16-inch oil groove. Proper ring end gap measurement and cylinder preparation are critical during installation, especially on rebuilt engines.

Quality Assurance

Verify all dimensions and surface treatments against the engine build sheet before assembly. This piston ring is specified with plasma moly, chrome, and phosphate finishes to support consistent wear characteristics in compatible classic V8 rebuilds.