Know the Differences in SOHC and DOHC Engines in Cars

 

Car performance is very dependent on the engine technology used. As the technology gets more advanced, it is likely to produce better capabilities as well. Likewise how the engine performs combustion, some use SOHC technology and some DOHC. What's the difference between these types?

Definition of SOHC and DOHC

Single Overhead Camshaft or known as SOHC and Dual Overhead Camshaft abbreviated as DOHC. Inside the engine cylinder, SOHC only has 1 overhead camshaft, while DOHC has 2 camshafts. What is a camshaft? The camshaft is a rotating cylindrical rod. At each rotation, protruding lobes in different positions will push the intake valve so that the air in the cylinder mixes with the fuel. After the air and fuel are mixed, the combustion process occurs and the gas exhaust valve releases the combustion gasses. Modern car engines mostly use DOHC engines with 2 overhead camshafts.

How SOHC and DOHC Work

In general, the way SOHC and DOHC engines work is almost the same. However, on a SOHC engine, 1 overhead camshaft performs two functions at once, namely as an intake and exhaust valve. Meanwhile, in a DOHC engine, 1 camshaft functions as an inlet valve, while the other 1 camshaft acts as an outlet valve. On both engines, the camshaft is above the valves for more accurate performance.

Of course there are details that are the difference between SOCH and DOCH car engines from how they both work. Here's a more complete explanation:

1. How SOHC Works

The camshaft, which is positioned above the cylinder, moves with the help of a drive chain. The camshaft rotates and presses on the rocker arm, the camshaft shaft drives the intake and exhaust valves in the combustion chamber. The work of this machine is simple because there are few components so that the work of the SOHC engine is more stable.

2. How DOHC Works

The piston moves from the dead point above and below, the intake and exhaust valves are closed. Air will be sucked into the engine combustion chamber. Conversely, if the piston moves from the bottom dead center to the top dead center, the combustion gases will be discharged out. The way DOHC works makes the power produced higher, because the process in the combustion chamber is also more complicated.

The Difference Between SOHC and DOHC

The main difference between SOHC and DOHC engines in cars lies in the number of camshafts used. SOHC uses 1 overhead camshaft, while DOHC uses 2 overhead camshafts. Apart from that, here are the differences between SOHC and DOHC:

SOHC	DOHC
1 overhead camshaft	2 overhead camshaft
1 camshaft and 2 valves, the power generated is less	2 camshafts and 4 valves, the power generated is greater
The engine feels lighter while driving but the torque is lower	The engine feels heavier when driving with better torque
RPM rendah, menghasilkan kecepatan maksimal yang tidak terlalu tinggi	Low RPM, resulting in a maximum speed that is not too high
Simple spare parts, tend to be easier to obtain	Parts are more complicated
Easier machine maintenance	Machine maintenance is more complicated
Relatively lower maintenance costs	Higher maintenance costs
More economical fuel consumption	Greater fuel consumption

Advantages of SOHC

The advantage of the SOHC engine is that this engine is lighter than the DOHC, because only 1 camshaft needs to be driven. Light engine effect on more efficient fuel consumption. In addition, in terms of maintenance costs, it is also relatively lower, and the spare parts are simple.

The SOHC engine is capable of producing reliable torque in the middle class. So if you need a car for short travel distances and don't need a lot of power, the DOHC engine can fulfill this need.

Advantages of DOHC

On the other hand, the advantages of DOHC engines have better performance. The power generated is greater, so the maximum speed is higher. Camshaft work is also lighter, because the camshaft is distinguished for entry and exit.

Well, you can also feel the advantages of this DOHC engine at Wuling Alvez. The maximum power produced by this car's DOHC engine reaches 105 hp at 5,800 RPM. Meanwhile, the maximum torque is 143 Nm at 4,000 - 4,600 RPM.

This car has a fuel capacity of 1,485 cc and has an engine that already has Euro 4 emission standards. This means that compared to previous generation engines, this engine is more environmentally friendly due to its more economical fuel consumption. But you don't need to worry about the power, because it is stronger than the previous generation. That's the difference between car engines with DOHC and SOHC technology.