eksosventilene

Eksosventilene, or exhaust valves, are components of internal combustion engines that open to vent exhaust gases from the combustion chamber after combustion. They sit in the cylinder head and seal against a valve seat when closed. Activated by the camshaft through lifters, pushrods, or rocker arms, exhaust valves work in concert with intake valves to manage gas flow and engine breathing. Most engines have at least one exhaust valve per cylinder; some use two or more to improve exhaust flow and performance.

Materials and design: Exhaust valves must withstand high temperatures and corrosive gases. They are usually made from heat-resistant steel alloys; high-performance valves may use nickel-based superalloys and special coatings. Some valves feature a hollow stem with a sodium-filled design to improve heat transfer and reduce valve seat recession.

Operation and timing: Valve opening is controlled by cam events. In fixed-timing designs, exhaust valves open and close at set crank angles; modern engines frequently use variable valve timing to optimize scavenging, efficiency, and emissions across operating conditions.

Maintenance and failure: Common issues include burning, warping, or seat recession from overheating, carbon buildup, or aggressive combustion. Regular maintenance (valve lash checks, seat inspection, and occasional grinding or replacement) helps preserve compression and performance. Severe wear can lead to loss of power, higher emissions, or engine damage.

Impact and variants: Increasing exhaust flow and reducing backpressure improve power and efficiency, while advanced coatings and designs extend valve life. In some engines, multiple exhaust valves per cylinder or specialized stems (e.g., sodium-filled) are used to manage heat more effectively.