Manley S/D 1.840/+.100 Severe Duty Exhaust Valves (Set of 8)

If you're rebuilding the top end of a high-temperature gasoline engine, especially one that sees a lot of track time or hard use, you need valves that can handle the stress. These Severe Duty exhaust valves from Manley are built from XH-428 material, a proprietary alloy that offers nearly double the tensile strength at 1500°F compared to other common exhaust valve materials. This means they're designed to withstand extreme conditions without failing.

Manley put these valves through some serious testing. In simulated conditions that mimic valve bounce on the seat, which can dramatically increase stress, these exhaust valves endured up to 100 million cycles. For comparison, some competitor valves failed after only 100,000 cycles. They also feature chrome stems and hard tips for added durability, and the under-head areas are swirl-polished to help improve airflow into the cylinder.

This set includes eight exhaust valves, each measuring 1.840 inches in diameter and are +.100 inches oversized. They are specifically designed for high-temperature gasoline applications where valve fatigue is a major concern.