What does DOHC engine mean?

[VanAriel]

DOHC (Double Overhead Camshaft) has two overhead camshafts placed on the cylinder block. The first one drives the intake valves, and the second one drives the exhaust valves. Here is a related introduction to DOHC: 1. Function: The camshaft belongs to the valve train of the engine. The valve train ensures that the engine regularly fills the cylinder with fresh combustible mixture during operation and promptly exhausts the burned gases from the cylinder. 2. Composition: It consists of intake valves, exhaust valves, valve pushrods, lifters, rocker arms, camshafts, etc. Among them, the camshaft, whose cross-sectional shape resembles a peach, is also called a peach shaft or eccentric shaft. It is the driving component in the valve train, specifically responsible for opening and closing the valves on time. 3. Position: The structure of camshafts in various vehicle engines is largely similar, with the main differences lying in the installation position, the number of cams, and their shapes and sizes. Particularly, the installation position of the camshaft is considered an important indicator for distinguishing engine construction and performance. Currently, the camshaft installation positions in engines are divided into three types: lower, middle, and overhead.