Manley Chevrolet Small Block Exhaust Valve Kit - 1.600in Head Dia. 5.640in O/A Length, 0.3110in Stem

If you're rebuilding the top end of your Chevrolet Small Block engine, especially for high-temperature gasoline applications, these Manley Severe Duty? exhaust valves are a solid choice. They're designed to handle the intense heat and stress that can occur during normal operation and especially when valves bounce on the seat, offering a significant improvement over standard components.

Manley crafts these exhaust valves from XH-428 material, which has nearly double the tensile strength at 1500°F compared to other common exhaust valve materials like EV-8. They've also undergone rigorous fatigue testing, enduring up to 100 million cycles at 40,000 psi and 1400°F, which is a notable improvement over many competitor valves that fail much sooner. The valves feature chrome stems and hard tips for added durability, and the under-head areas are swirl-polished to help improve airflow into the combustion chamber.

This kit includes exhaust valves with a 1.600-inch head diameter and a 5.640-inch overall length, featuring a 0.3110-inch stem diameter. They are well-built to support demanding engine builds.