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What Is the Relationship Between the Number of Motorcycle Engine Valves and Performance?

Mar. 02, 2020

What is the difference between two-valve and four-valve engines for motorcycle engines? Are two valves better or four valves better?

The number of valves per cylinder of a motorcycle engine generally has two-, three-, four-, or even five-valve designs. Here we will discuss the differences between single-cylinder two-valve and four-valve. Engine valve exporter shares with you.

Intake And Exhaust Valve For Motorcycle

We all know that the valve is the part that manages the intake and exhaust of the engine when it is working. When the engine is working, it is like a person running. The more the number of valves, the smoother the breathing, and the more efficient the one-time inhalation and exhaust. Therefore, it also makes it easier for the engine to reach high speed, and high speed is the only way for the engine to improve its power data. Therefore, the engine uses a four-valve design. Compared with the two-valve design, its high-speed performance is often better.

But compared to the two-valve, the four-valve design does not help the low-torque output at low and medium speeds. For engines with the same displacement, the two-valve design will be smoother and more powerful at low and medium speeds.

But not every four-valve engine is necessarily better than a two-valve engine. This is not absolute. The power of the engine is generally closely related to the displacement, the number of cylinders, the cylinder bore ratio, the compression ratio, and the maximum power output speed. The number of valves mainly affects the last factor-the maximum power output speed. The four-valve design makes the engine more efficient in intake and exhaust, and it is easier to reach high speeds.

Engines with four-valve designs often breathe smoothly, more suitable for the needs of high-speed engines, and better high-speed performance, but the valve noise is often larger, the structure is more complicated, the cylinder head volume will be larger, and the cost will be higher. The low-torque response of the two-valve engine is more timely, and it can provide better power feedback at low and medium speeds. The engine noise is relatively low, the fuel consumption is relatively low, the structure is simple and the cost is low, but the high-speed performance is generally inferior to that of the four-valve engine.

Our company provides intake and exhaust valve for motorcycle.