VALVE SPRING EXHAUST 8972106820 Suitable for 700P models fitted with 4HK1 6HK1 engines

Design Philosophy

Precision-engineered exhaust valve spring designed for Isuzu 4HK1/6HK1 engines. Made from high-grade alloy spring steel with a red paint mark for identification, it is engineered to provide the correct spring tension and fatigue resistance needed to ensure reliable exhaust valve closure under high-cycle thermal and mechanical loads in commercial diesel engines.

How It Works

Installed between the cylinder head and the valve spring retainer. It maintains constant pressure on the exhaust valve, forcing it to close tightly against the valve seat after the cam lobe releases. The spring absorbs the inertial forces generated during high-speed valve opening and closing, ensuring proper sealing and preventing compression loss.

Problems It Solves

Fixes valve float, compression loss, and exhaust valve sealing failure caused by weak, broken, or fatigued valve springs. Restores proper valve closing force and prevents misfire and power loss in 700P / NPR75 / NQR75 / NQR90 / FSR90 / FVR34 trucks.