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

Technical Overview#

Unlike Single Overhead Cam (SOHC) configurations, which utilize a single camshaft to actuate both intake and exhaust valves (often via rocker arms), the DOHC design allows for more precise control over valve timing and lift.

• Independent Timing: Intake and exhaust events can be tuned independently, facilitating better volumetric efficiency.
• Valve Placement: DOHC configurations typically allow for a more optimal central spark plug location, which improves combustion efficiency.
• Complexity: The design requires additional components, including a second camshaft, additional cam gears, and a longer timing belt or chain.

Note

DOHC engines are the standard architecture for Honda's high-performance B-series, K-series, and F-series engines.

Comparison to SOHC#

See also: SOHC0