Dualoverhead

Dualoverhead refers to a specific valve train configuration in internal combustion engines. In a dualoverhead system, there are two overhead camshafts per cylinder head. One camshaft is dedicated to operating the intake valves, and the other is dedicated to operating the exhaust valves. This arrangement is in contrast to a single overhead camshaft (SOHC) engine, where a single camshaft controls both intake and exhaust valves for each cylinder, or a pushrod engine, which uses pushrods to actuate the valves from a camshaft located in the engine block.

The primary advantage of a dualoverhead camshaft (DOHC) design is improved engine performance and efficiency. By having separate camshafts for intake and exhaust valves, the timing and lift of each valve can be optimized independently. This allows for better control over the flow of air and fuel into the combustion chamber and the expulsion of exhaust gases. This independent control can lead to increased horsepower, torque, and fuel economy. DOHC engines are also often capable of operating at higher engine speeds due to reduced valve train inertia and improved breathing characteristics.

Dualoverhead camshafts are a common feature in modern automotive engines, particularly in performance-oriented vehicles and those seeking high fuel efficiency. The complexity of the DOHC design, with its additional camshaft and associated components, can lead to higher manufacturing costs compared to SOHC or pushrod engines. However, the performance and efficiency gains often justify this increased cost for many applications. The physical layout of DOHC engines typically allows for more compact cylinder head designs, which can contribute to overall engine size reduction.