A “twin-cam” engine is a term used to refer to a double overhead camshaft or DOHC, which defines the valve train layout. While saying you have a twin-cam engine sounds cool, it isn’t a precise term.

How it works

Two camshafts are inside the cylinder head. One camshaft is responsible for operating the intake valves and the other one takes care of exhaust valves. The DOHC engine has several features unique to its design. For instance, the rocker arms are smaller or may not even be present at all. A wider angle is seen between the two types of valves than what you would see on a single overhead camshaft or SOHC.

Many DOHC engines have multiple valves on each cylinder, even though it isn’t necessary for the engine to work. More valves improve the output of the engine without increasing the volume of the airflow.

Benefits of a twin-cam

The design of a DOHC allows for less restricted airflow at higher speeds. If the engine also has a multi-valve design, it also experiences improved combustion for better efficiency because of the placement of the spark plug.

What this means for you as the driver is that your vehicle will have more torque at higher speeds for faster acceleration. You will also enjoy improved efficiency, which translates into more money saved at the gas station while enjoying the faster, more powerful engine. In addition, a DOHC generally runs quieter.

If you’re looking for a vehicle with more power and the ability to drive at faster speeds, a twin-cam engine is going to give you what you want.

This article originally appeared on YourMechanic.com as What Does "Twin-Cam" Mean? and was authored by Joyce Morse.


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