Manley Chevrolet Big Block Exhaust Valve Kit - 1.900in Head Dia. 5.464in O/A Length, 0.3715in Stem

Manley's Severe Duty? exhaust valves are crafted from XH-428 material, a choice that offers nearly double the ultimate tensile strength at 1500?F compared to other common exhaust valve materials like EV-8. This means they can handle the intense heat and stress found in high-temperature gasoline engines, especially those built for performance or racing applications.

These valves are designed for improved airflow and combustion efficiency, featuring swirl-polished under-head areas and fully machined combustion faces. The chrome stems and hard tips add to their durability, ensuring a long service life. Rigorous fatigue testing shows these valves can endure up to 100 million cycles at 40,000 psi and 1400?F, a notable improvement over many competitor parts that fail much sooner. This kit includes exhaust valves with a 1.900-inch head diameter and a 5.464-inch overall length, featuring a 0.3715-inch stem diameter.