Manley Chevrolet Small Block Exhaust Valve Kit - 1.600in Head Dia. 4.965in O/A Length, 0.3415in Stem

Manley Performance is well-known for making strong internal engine components, especially for racing applications. This exhaust valve kit is a prime example, featuring their Severe Duty? valves designed for Chevrolet Small Block engines. These valves are crafted from XH-428 material, which Manley states has nearly double the ultimate tensile strength at 1500?F compared to other common exhaust valve materials like EV-8.

These valves are built to handle the intense conditions inside a high-temperature gasoline engine. The XH-428 material is put through rigorous fatigue testing, enduring up to 100 million cycles at 40,000 psi and 1400?F, a notable improvement over competitor parts that failed much sooner. They also feature chrome stems and hard tips for added durability, along with swirl-polished under-head areas and fully machined combustion faces to help improve airflow and combustion efficiency.

This kit includes exhaust valves with a 1.600-inch head diameter, a 4.965-inch overall length, and a 0.3415-inch stem diameter. If you're rebuilding the top end of your Chevrolet Small Block and need valves that can withstand high heat and stress, these are a solid option.