What does DOHC engine mean?

[RafaelLee]

DOHC engine refers to a double overhead camshaft engine, where the intake valves and exhaust valves are arranged on two separate camshafts. Its advantages include higher performance, better stability, lower noise, and more efficient combustion in multi-valve engines, allowing more fresh air to enter the engine and improving emission efficiency. It can also adjust the opening and closing times of the intake and exhaust valves, providing ample torque at low engine speeds. Since the DOHC engine eliminates the need for valve lifters and rocker arms, power loss is minimized, resulting in greater horsepower. Additionally, the valve overlap angle can be adjusted, enhancing output power. Moreover, the valves can be hydraulically controlled, eliminating the need for valve clearance adjustments, so there's no concern about reduced power output due to changes in valve clearance over increased mileage.