BBM Shaft Rocker Arm Kit 1.70/1.70 Ratio

The T and D Machine BBM Shaft Rocker Arm Kit with 1.70/1.70 ratio delivers the precision valve actuation required for serious marine engine performance. This shaft-mount rocker arm assembly is engineered for Mopar RB-series engines found in high-performance marine applications, providing consistent lift and duration control across the full RPM range. Built for reliability under sustained throttle and demanding water conditions, this kit represents a core upgrade for builders targeting increased horsepower and optimized valve timing in offshore and freshwater powerplants.

The 1.70 ratio specification means each rocker arm provides a 1.70-to-1 mechanical advantage, translating camshaft lobe lift directly into increased valve lift for enhanced fuel-air mixture control and exhaust scavenging. The full roller design minimizes friction and heat generation during repeated valve cycles, critical when running sustained high RPM offshore. Constructed from aluminum with natural finish, the kit resists corrosion while maintaining the lightweight properties necessary for balanced engine dynamics. This assembly integrates with Brodix B1 original cylinder head designs, ensuring fitment compatibility and maintaining OEM-level assembly standards.

Builders upgrading Mopar RB-series marine engines—whether for performance fishing boats, vintage cruisers, or custom restoration projects—turn to this rocker arm kit when camshaft selection and intake/exhaust modifications demand precision valve actuation. The shaft-mount design provides superior valve control compared to stud-mount alternatives, making it the preferred choice for engine combinations where valve float prevention and consistent performance across varying water temperatures are priorities. Part number 8013-170/170 represents the exact specification needed for builds requiring symmetrical lift ratios and proven Brodix compatibility.