Analyzing SOHC and DOHC Technologies

You may have heard that the Honda CB150R StreetFire uses DOHC technology. Now the question is, do you understand the meaning of the abbreviation? Did you know that besides DOHC, there is also SOHC technology?

Engine technology embedded in two-wheeled vehicles is a significant breakthrough, along with the development of the current era. You can find types of SOHC engines on the Honda motorbikes SH125I.

How SOHC Works

In this type, there are no suppressor rods, so that the reverse movement can be neutralized. The position of the cam is above the cylinder, in the middle, the cam is driven by a drive chain which directly rotates the cam, so the cam presses the rocker arm. Camshaft functions to move the inlet valve (IN) and the exhaust valve (EX), to open and close according to the process that occurs in the engine combustion chamber. This type only has a few components so that the high rotation remains stable. It’s called a single overhead camshaft because it only uses one cam in its design.

How DOHC Works

The first step is the piston moves from the top dead point to the bottom dead point, the position of the inlet valve is open, and the exit valve is closed, causing air or gas to be sucked into the combustion chamber. The process of air or gas before entering the combustion chamber can be seen in the intake system.

Furthermore, the piston moves from the bottom dead point to the upper dead point, the in and out valve is closed, causing the air or gas in the combustion chamber to be compressed. Shortly before the piston arrives at the top dead spot position, the timing ignition occurs in the gasoline engine in the form of a spark plug.

The final process is the piston moving from the bottom dead point, and the upper dead point, the position of the inlet valve is closed. The outlet valve is open, pushing the remaining combustion gas towards the opened exit valve and is forwarded to the drain hole.

Difference between SOHC and DOHC

Basically, the difference between SOHC and DOHC lies in the amount of overhead camshaft in it. SOHC or Single Over Head Camshaft has 1 overhead / noken as in which there are 2 valves (for input gas [intake] and exhaust gas [exhaust]). Whereas DOHC or Double Over Head Camshaft has 2 Noken as each serving 2 valves for intake and exhaust in each Noken.