Car Engine

What Is Different Between Camshaft vs Crankshaft?

Mike Cross
Updated Oct 18, 2020
Camshaft vs Crankshaft

There are two words that seem to get thrown around often when talking about vehicles - camshaft and crankshaft. Many times, these words are almost used interchangeably.

What do these two terms actually mean and can they really be used interchangeably?  Let us take a closer look at each word and how it relates to vehicles. After all, the better we understand our car, the better we can take care of it.

Camshaft vs Crankshaft
Camshaft vs Crankshaft

Are there similarities to a camshaft and a crankshaft?

Both a camshaft and a crankshaft are essential parts of a 4-stroke engine. They both need to function together so that the gear, shafts and rods in the engine are working perfectly.

These two distinct shafts are essential for starting the engine cycle and then transmitting the torque created by the combustion down to the transmission.

The Camshaft

Let’s start with the camshaft. They are made from either steel or cast iron and are located in the head of an engine, above the cylinders. There are two distinct ways that camshafts are incorporated into a car: SOHC (single overhead cam) or DOHC (double overhead cam).

How Does It Work?

There are lobes that sit at angles alongside the camshaft. They are designed and positioned so that when the camshaft is rotated, they connect with the rocker arms. The arms are responsible for opening up the valves of the engine. They will also open up the valves during specific times in the engine cycle. This allows for an optimal mix of air and fuel to enter the cylinder, and for the exhaust gas to be expelled at the right time.

The valves are spring loaded. This ensures that lobe lets go of the valve, it should automatically close back up.

To help assist in this process, a cambelt is needed. The cambelt, also called a timing belt, helps to synchronize the movement of the crankshaft. This regulates the valves opening at the proper time with the engine cycle. This is key for avoiding any valve or cylinder damage that can occur when mistiming happens.

A SOHC is responsible for both the intake and exhaust valve operations.

A DOHC has both an intake camshaft and an exhaust camshaft.

Camshafts and valve in oil on the car engine
Camshafts and valve in oil on the car engine

The Crankshaft

Usually constructed from steel, the crankshaft can be found sitting in the engine block below the cylinders and pistons. The purpose of the crankshaft is to take the vertical movement from the pistons, rotate it, and then transfer it to the flywheel and then into the transmission. There are pins (crank pins) that are designed to line up horizontally with the pistons.

The crank pins are specifically designed to help each cylinder mover from top center to bottom center and back. This action helps to transmit movement for the shaft’s rotation. There are rods that connect the pins and the pistons.

The crankshaft is needed to complete the torque conversion coming from the internal combustion that happens in the cylinders.

Where are you more likely to have a problem?

It is interesting to note that the majority of an engine’s power loss will be through the crankshaft. This power loss can happen for a variety of reasons: heat, vibration, noise and friction are just a few reasons.

You need to realize that the crankshaft is under a lot of stress since there are multidirectional forces that are being applied to it from the pistons. It is for this reason that engineers try to keep the length of the crankshaft to a minimum.

What are some signs that I need to have my camshaft sensor checked?

The camshaft sensor is an important part of the whole process. It is a magnetic device that helps to send and receive info regarding the camshaft’s speed. This information is used to calculate the timing of the ignition and the timing of the fuel injection.

Over time, this sensor can weaken due to wear and tear. When this happens, the car’s computer does not get the right information and signals. This will negatively affect the way your car runs.

1.You notice the Check Engine light comes on.

This is often a first and early sign that there is an issue. Getting it taken care of right away is crucial since at this stage there is still time for you to have it changed without too many other issues or expenses. Then you need the best obd2 scanner to find the code and fix your problem.

2.Driving Disruptions

If you start to have problems while driving, this is another clue to a camshaft sensor problem. Issues such as stalling, poor idling, abnormal acceleration, etc. all point to the camshaft sensor. Anytime you notice these issues it is important to see your mechanic immediately. If you wait too long your car may not start at all.

3.Igition Trouble

The biggest sign of camshaft sensor trouble is ignition troubles. Once your sensor has completely deteriorated, it will no longer be able to send signals to engine. Once this signal is lost, your car will not start.


The camshaft and the crankshaft are two distinct parts of the engine of your car. They are also both essential for your car to run.

The camshaft is responsible for opening up valves during specific times in the engine cycle. It helps to ensure that there is the right mix of fuel and air entering the cylinder and then the right amount of gas exhaust is expelled. The camshaft can be found at the head of the engine.

The crankshaft is located in the engine block, sitting below the cylinders and pistons.

It is necessary to complete the torque conversion coming from the internal combustion that happens in the cylinders.

Final Thoughts

Your car’s engine is a well-designed machine and all parts are necessary for it to run successfully. Proper maintenance is key. In addition, anytime that you notice your car is driving a little off or the check engine light comes on, you need to get it checked immediately. You may not think it is a big deal, but it may prevent a bigger problem down the road.

Mike Cross
Life is too short to drive with stock audio

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