Manley Chevrolet Small Block Exhaust Valve Kit - 1.600in Head Dia. 5.040in O/A Length, 0.2740in Stem

These Manley exhaust valves are made 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 makes them a solid option for high-temperature gasoline engines, especially those built for demanding use. The valves measure 1.600 inches across the head and are 5.040 inches from end to end, with a 0.2740-inch stem diameter, designed to fit Chevrolet small block engines.

Manley put these Severe Duty® valves through some serious testing. In normal operation, valves can see stress up to 60,000 lbs, especially when bouncing on the seat. These exhaust valves, tested at 40,000 psi and 1400°F, held up for an incredible 100 million cycles. That's about 1000 times longer than some competitor valves that failed after only 100,000 cycles. They also feature chrome stems and hard tips for added wear resistance, and the under-head areas are swirl-polished to help improve airflow into the combustion chamber.

If you're rebuilding the top end of your Chevrolet small block and need exhaust valves that can handle high heat and extreme cycle counts, these Manley valves are a well-built choice. They are designed for improved airflow and combustion efficiency, contributing to better overall engine performance.