BBC 265cc CNC Alum Heads Magnum 109cc O/P

The AIR FLOW RESEARCH BBC 265cc CNC Aluminum Heads with 109cc chamber represents a precision-engineered solution for Big Block Chevy engines requiring maximum flow and chamber efficiency. These assembled cylinder heads deliver the port velocity and combustion geometry needed for serious street and performance applications where intake charge velocity directly correlates to throttle response and mid-range torque development.

The 265 cubic centimeter intake port volume paired with the 109 cubic centimeter chamber size is engineered to balance high-RPM flow characteristics with low-to-mid range cylinder filling. The 2.190-inch intake and 1.880-inch exhaust valve sizes maximize valve curtain area while the 1.550-inch valve springs provide sufficient seat pressure for sustained high-RPM operation without float. CNC porting precision ensures port wall finish and velocity characteristics are consistent across the entire set. Aluminum construction reduces overall engine weight while maintaining thermal stability under sustained load.

These heads are suited for builders and engine shops developing Big Block Chevy platforms for both street and race duty where chamber volume, port flow, and valve sizing are critical to achieving target compression ratios and power curves. The Magnum street designation signals compatibility with Magnum-series engine packages while the assembled ready-to-install format eliminates valve train assembly time in the shop. A pair of heads is required for complete Big Block Chevy installation.

AIR FLOW RESEARCH has maintained a reputation in the performance engine community for CNC-ported cylinder heads where port design is validated on flow benches and dyno-tested in complete engine configurations. These BBC heads are specified by professional engine builders and OE performance shops where intake port velocity and chamber efficiency directly impact final horsepower and drivability targets.