What is the difference between SOHC and DOHC engines?
2 Answers
The difference between SOHC and DOHC engines: An SOHC engine refers to an intake system that uses a single overhead camshaft, meaning one intake valve and one exhaust valve; a DOHC engine refers to an intake system that uses dual overhead camshafts, typically with multiple valves per cylinder, commonly four valves. Multi-valve engines allow for more complete combustion, enabling more fresh air to enter the engine, resulting in better emission efficiency. The automotive ignition system is designed for spark-ignition engines to operate properly by supplying the spark plugs with sufficiently high-energy high-voltage electricity in the correct firing order for each cylinder, ensuring the spark plugs generate strong enough sparks to ignite the combustible air-fuel mixture.
I'm always fascinated by engine mechanics, and the biggest difference between SOHC and DOHC lies in their structural design. SOHC stands for Single Overhead Camshaft, where one shaft controls all valve operations - simple and reliable like a diligent worker. DOHC means Double Overhead Camshaft, with two shafts having clear division of labor: one dedicated to intake valves and the other to exhaust valves. This design difference directly impacts performance - DOHC delivers more power at high RPMs with quicker valve response and snappier acceleration, though at higher manufacturing costs. My old Honda with SOHC works just fine for city commuting, being fuel-efficient and easy to maintain. But if you're buying a sporty car, DOHC is definitely the way to go.
