A Dual Overhead Cam (DOHC) engine configuration utilizes two separate camshafts located in the cylinder head. One camshaft is dedicated exclusively to the operation of the intake valves, while the second camshaft is dedicated to the exhaust valves.

Technical Overview#

In a DOHC design, the camshafts are positioned above the combustion chamber. This configuration allows for:

• Optimized Valve Timing: Independent control of intake and exhaust events.
• Centralized Spark Plug Placement: Improved combustion efficiency due to the space created between the two camshafts.
• Increased Volumetric Efficiency: The ability to utilize four valves per cylinder (multi-valve design) more effectively than SOHC configurations.

Note

DOHC systems are distinct from Single Overhead Cam (SOHC) systems, which utilize a single camshaft to actuate both intake and exhaust valves, often requiring rocker arms or complex geometry to manage valve timing.

Comparison#

See also: SOHC0.