Double Over Head Cam Engine from a Honda Integra - Copyright © Kevin Hulsey Illustrations, Inc.

The camshaft is located in the cylinder head. The intake and the exhaust valves are both operated from a common camshaft. The valve train may be arranged to operate directly through the lifters as show in Diagram 'A' below, or by rocker arms as show in Diagram 'B' below.This configuration is fairly popular in modern automotive engines and is becoming even more popular.

When the Double Overhead Camshaft is used, the intake and the exhaust valves each operate from separate camshafts directly through the lifters. It provides excellent engine performance and reliability, it used to be used only in more expensive automotive applications, but today it is common to see in many vehicles.