Carrillo BO7040-030 Forged Piston Set for Oldsmobile - 455

The Carrillo BO7040-030 is a high-performance forged piston set engineered specifically for Oldsmobile 455 cubic inch engines. These pistons feature a flat-top design with a -2.5cc dome configuration and 6-degree valve reliefs, optimized for performance engine builds.

Key Specifications:

• Bore Size: 4.155 inches
• Stroke: 4.250 inches
• Compression Height: 1.765 inches (calculated for 6.735-inch connecting rod)
• Valve Relief Angle: 6 degrees (Oldsmobile configuration)
• Dome Volume: -2.5cc (flat top design)
• Material: Forged aluminum alloy construction

Carrillo pistons are precision-machined from aerospace-grade forged aluminum billets, providing superior strength and durability for high-performance and racing applications. The flat-top design with minimal valve reliefs allows for excellent compression ratios while maintaining proper valve clearance in modified Oldsmobile 455 engines. This piston set is designed to work with 6.735-inch connecting rods and the 4.250-inch stroke crankshaft commonly used in Olds 455 performance builds.

Each piston is manufactured to exact tolerances and includes precision-machined ring grooves for optimal ring seal and longevity. The lightweight forged construction reduces reciprocating mass while maintaining the structural integrity needed for high-RPM and forced induction applications.