What is the difference between 2 valve and 4 valve heads?

In two valve engines there is only one valve for inlet and only one valve for outlet. For four valve engines there will be two for both exhaust and inlet. But in case of four valve system all the valves are of same dimension.

1. Are 2 valves better than 4 valves?
2. What is a 4 valve head?
3. What is the meaning of 4 valves?
4. Does more valves mean more power?
5. What are the advantages of using two intake valves and two exhaust valves?
6. What's the difference between SOHC and DOHC?

Are 2 valves better than 4 valves?

4 valves per cylinder allows for more airflow than 2 valves per cylinder, as there is larger open area when the valves are open. Having a configuration with DOHC and four valves per cylinder means better airflow, especially at high engine speeds, resulting in better top end power.

What is a 4 valve head?

Four-valve cylinder head

This is the most common type of multi-valve head, with two exhaust valves and two similar (or slightly larger) inlet valves.

What is the meaning of 4 valves?

A four-valve setup is more commonly used on modern bikes or performance motorcycles. The configuration comprises of two large intake valves and two small exhaust valves. Generally, a four valve engine requires a DOHC (Double Overhead Camshaft) or two cams setup.

Does more valves mean more power?

More valves equal better airflow and a more efficient engine. Smaller valves are lighter, which means the engine can rev higher, create more power, and in general, look down upon the two-valve engines of the world with a sense of multi-valve satisfaction.

What are the advantages of using two intake valves and two exhaust valves?

Adding multiple smaller valves in place of a single large valve can be costly. Thus, in some cases, manufacturers use two valves for inlet, but only one for exhaust to save on cost. This keeps the engine design relatively simpler, and enhances the engine performance to an extent, without pushing the cost up too much.

What's the difference between SOHC and DOHC?

When a single camshaft governs both intake and exhaust valves, the setup is commonly known as SOHC. On the other hand, when there are two dedicated camshafts, one to push the inlet valves and the other to push the ones which let the gases escape from the cylinder after combustion the setup is called DOHC.