VALVE ROCKER INLET 8970746140 Suitable for NPR models fitted with 4HF1 4HE1 4HG1 engines

Design Philosophy

Precision-engineered intake rocker arm designed for Isuzu 4HF1/4HE1/4HG1/6HE1T/6HH1 engines. Made from durable steel, it serves as a double-arm lever with the rocker shaft as its fulcrum. The short arm features a threaded hole for the valve lash adjusting screw, while the long arm has a curved working face that pushes the intake valve.

How It Works

Mounted on the rocker shaft and driven by the camshaft. When the cam lobe pushes the rocker arm, the arm pivots on the shaft, and its long curved face presses down on the intake valve stem to open the valve. When the cam releases, the valve spring pushes the valve closed, and the rocker arm returns to its resting position.

Problems It Solves

Fixes valve timing errors, engine ticking noise, power loss, and increased fuel consumption caused by a worn or bent intake rocker arm. Restores precise intake valve actuation and ensures reliable engine performance in NPR / NPR66 / NQR70 / NQR71 trucks.