BBC Roller Cam - 4 & 7 Swap 47S318RXD-14

The COMP Cams BBC Roller Cam — 4 & 7 Swap 47S318RXD-14 is a mechanical roller camshaft engineered for high-performance drag racing applications in big block Chevrolet engines. This is a dedicated race component designed to deliver maximum lift and aggressive valve timing for engines built to operate in the 5000–9000 RPM range. The 4/7 swap designation indicates compatibility with engine block configurations requiring this specific valve train geometry, making it essential for builders matching vintage and modified big block platforms.

The camshaft specifications reveal its race-focused character: 0.824-inch intake lift and 0.800-inch exhaust lift, combined with 318-degree intake duration and 338-degree exhaust duration, generate the aggressive overlap and dwell profiles required for naturally aspirated drag engines. The 114-degree lobe separation angle (LSA) positions the intake and exhaust events to optimize cylinder filling and scavenging at elevated RPM. Mechanical roller followers eliminate the friction penalties of flat-tappet designs, improving reliability and reducing parasitic losses during sustained high-RPM operation. This profile demands a properly tuned fuel system, ignition timing, and exhaust system to realize its full potential.

This camshaft is purpose-built for drag racing teams and engine builders committed to big block Chevrolet competition engines. Serious bracket racers, heads-up competitors, and vintage muscle car restoration specialists select roller cam profiles like this when stock or street-oriented camshaft designs no longer meet their performance targets. Installation requires precision valve train setup, including pushrods, rocker arms, and lifters matched to this camshaft's lift specifications and roller profile geometry. Buyers should verify compatibility with their specific block, head configuration, and intended fuel and ignition system before purchase.

COMP Cams has maintained its position as a leading manufacturer of racing camshafts and valve train components for over four decades. The BBC roller cam line is known for consistent grind quality and performance delivery in competition environments where reliability under stress is non-negotiable.