How are the Camshaft and Crankshaft different?

I still remember, when I was just diving into the world of Automotive, I came across two words again and again- Camshaft and Crankshaft.

And I had the hardest time understanding the difference. So let’s get that cleared over here!


So, the crankshaft is the main shaft of the engine. It is on this that the connecting rod from the piston is connected to.

They consist of the following main components:

  • Main Journals
  • Crank pin
  • Crank Web
  • Oil Holes
The essential parts!

So, the Crank Pins are the places where the piston’s connecting rod is attached and revolves around it. All the power from the piston is transmitted to the crankshaft which further passes it onto the flywheel.

The main journal passes through the center of the crankshaft and is in-line with the main shaft and the oil holes provide a path for the oil to flow, for the much-required lubrication.

So remember Crankshaft= Main shaft= Main transmission of power.

A realistic crankshaft.


This is the shaft which is placed above the pistons. The camshaft controls the opening and closing of the inlet and exhaust valves.

It consists of the following main parts:

  • Camlobes
  • Main shaft
The inlet and the exhaust camshaft for a 4 cylinder engine.

Hence, it controls the flow of fresh air and exhaust during engine operation. The timing of the camshaft working is very important for efficient working of the engine.

As we can see from the gif below, the cam lobe pushes down the valve against the spring force and opens it.


The profile of the cam lobes decides the opening duration of the valve.

The final setup to sum it all up:


Courtesy: Preview

So next time, don’t get confused between the two! Those are one of the main parts of the engine and require highly accurate manufacturing.


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