Manley Chevrolet Big Block Exhaust Valve Kit - 1.880in Head Dia. 5.522in O/A Length, 0.3415in Stem

Manley Performance is well-known for making strong engine components, especially for racing applications. This exhaust valve kit is a prime example, built for Chevrolet Big Block engines. These aren't just any valves; they are constructed from XH-428 material, which Manley states is unmatched globally for exhaust applications, offering nearly double the tensile strength at high temperatures compared to other materials like EV-8. This means they can handle the extreme conditions inside a high-temperature gasoline engine much better than standard valves.

You can expect improved airflow and combustion efficiency thanks to the swirl-polished under-head areas and fully machined combustion faces. What really sets these apart is their durability under stress. Manley subjected these valves to rigorous fatigue tests, simulating normal operation and valve bouncing on the seat. While competitors failed after about 100,000 cycles, these Manley valves impressively endured up to 100 million cycles at 40,000 psi and 1400?F. They also feature chrome stems and hard tips for added wear resistance, contributing to their overall longevity.

This kit is designed for serious performance and reliability, especially if you're rebuilding or upgrading the top end of your Chevrolet Big Block. The specific dimensions are a 1.880-inch head diameter, 5.522-inch overall length, and a 0.3415-inch stem diameter, ensuring a precise fit for compatible applications.