Which feature is described by tapered runners angled toward the cylinder head to improve high-RPM airflow?

• A. Plenum
• B. Tunnel ram
• C. Side-draft
• D. Cross-ram

Answer: (B)

The feature is about optimizing air delivery at high engine speeds by using short, smoothly tapered runners that are directed straight toward each cylinder’s intake port. When RPM is high, air must rush into the cylinders with minimal resistance, so runners that narrow slightly (taper) and angle toward the head provide a straighter, less turbulent path and help maintain air velocity as it enters the port. This design is the hallmark of a tunnel-ram intake, which feeds each cylinder from a shared high-rise plenum with short, direct runners to maximize horsepower at high RPM. By contrast, a simple plenum just stores air and doesn’t address how it’s delivered to the ports; side-draft and cross-ram configurations use different routing that emphasize other rpm ranges and flow characteristics, not the same direct, high-RPM-driven taper and angle into the ports.