Camshaft vs Crankshaft – Difference

One notable difference between a Camshaft vs crankshaft is that the camshaft assists to actuate the inlet and exhaust valves, whereas the crankshaft helps to transform the reciprocating action of the piston into rotational motion. Before we get to our main question, let’s go through each of them briefly.

Camshaft

The camshaft helps to open or close the engine intake or the exhaust valves at the exact time. The camshaft gets power from the crankshaft with the help of the timing belt or chain.

Because of the speed reduction in the timing mechanism, the camshaft rotates at half of the speed of the crankshaft.

The cams of the camshaft actuate the rocker arms which are connected further to the inlet and exhaust valves.

The engine can have one or two camshafts. The single camshaft has to handle both inlets as well as exhaust valves while in the case of the engines with two camshafts, the inlet valves and the exhaust valves are operated by separate camshafts.

Crankshaft

The crankshaft is the vital component of the engine that along with the connecting rod helps to convert the reciprocating motion of the piston into rotary motion.

The crankshaft is mounted in the crankcase along with the bearings. The crankshaft takes the power from the piston and transmits it further to rotate the wheels of the vehicle.

Other than this purpose, the power of the crankshaft is also used for the following purposes:

Actuation of valves
Fuel pump
Supercharger
Coolant pump
Compressor of air conditioner.

Camshaft vs Crankshaft: Comparison

No.	Camshaft	Crankshaft
1	The camshaft is used to actuate the intake and exhaust valves.	The crankshaft is used for power transmission purposes.
2	The camshaft is driven by the crankshaft with the help of a timing mechanism.	The crankshaft is driven by the piston with the help of connecting rod.
3	Steel or cast iron is used for the construction of camshafts.	The crankshaft is generally made up of alloy steel.
4	The camshaft is mounted above the engine cylinder.	The crankshaft is mounted in the crankcase below the engine cylinder.
5	The camshaft requires less torque to actuate the valves.	The crankshaft handles a high amount of torque.
6	The camshaft completes single revolutions for each power stroke.	For each power stroke, the crankshaft completes 2 revolutions in a four-stroke engine and one revolution in a two-stroke engine.
7	The engine uses one or two camshafts.	There is only one crankshaft used in the engine.
8	The camshaft is only used in 4 stroke engines.	The crankshaft is used in two-stroke and four-stroke engines.
9	The camshaft uses the rotational motion for reciprocating the valves.	The crankshaft along with the connecting rod converts the reciprocating motion of the piston into rotary motion.