Camshaft Vs Crankshaft : The Complete Guide

In your mechanical practice, more so when working with engines and other related systems, you know how vital the shaft is. It is a rotating element with circular cross-section and takes the appearance of a rod. It is used in the transmission of power and the initiation of critical duties within the engine. There are two main shafts under the machine shaft category; the camshaft and the crankshaft. These two seem to be almost similar and bring on the debate of camshaft vs. crankshaft.

The two machine shafts are integral parts of the engines system, and as a mechanic, you need to be in a position to differentiate the two and know how each of them works. On the shaft rods of each, there are attachments on them that ensure there is power transmission or absorption as required.

Let us have a more in-depth look at the two different types of shafts that you can find in the engine system of the various cars under your mechanical practice.


In the engine’s valve system, the camshaft is an essential component in the closing and opening of the valves. It is usually located in the engine, and as an auto expert, you understand that a problem with this system leads to the car stalling or have issues in acceleration.


History Of The Camshaft

The camshaft has been a common element in mechanics for several centuries, with its first use dating back to ancient China. It was a standard feature, most probably in water mechanics sometime in the late 200s AD.  It is also present in the Turkish engineering scene where it found use in water elevation machines and water clocks.

Skip further to the automobile age in the early 1900s, and this system found its way into automobile engineering. In this setting, it took on an essential role in the operation of the internal combustion engine.

Structure And Operation Of The Camshaft

As a mechanic, understanding the camshaft function and structure is essential, especially when it comes to sorting out issues affecting it. The structure of the camshaft consists of a long rod with a set of cams. The cams appear as lobes and take on different angles as they jut from the rod.

The lobes come into contact with the valves of the engine. The movement of the camshaft converts rotational energy to linear though its action on the valves.  In the internal combustion engine, the effect on the valves allows for the entry of fuel and air and release of the exhaustive material. The camshaft is most of the time located atop the engine.

Camshaft vs. crankshaft rotation

The two parts have a connection. It may be through a set of chains, gears, or belts, and the crankshaft transmits rotational motion to the camshaft.

Production Of The Camshaft

During your mechanical practice, you will notice that the camshafts differ from one vehicle to another, even in slight degrees. You may observe that a Chevy camshaft will, in a way, differ from a ford camshaft. Some may be hollow while others are not and depends on the correlation of the weight factor to the operation of the car, mostly to speed and transmission rate. Hollow shafts are conventional in BMW brands.

Factory production banks on a variety of materials to manufacture this essential element of the car. The most common materials in the camshaft manufacturing process are chilled iron castings and billet steel. Chilled iron castings are suitable for large scale production and lend the final product a decent degree of resistance due to the chilling process. The later material is for low scale production, with an eye on quality.

The Camshaft Sensor

You cannot talk about the camshaft without touching on the camshaft sensor. It is an essential element in the shaft system that serves to relay information to the engine control unit. It helps achieve a fine tune in spark timing and the injector pulse. Its location is near the camshaft unit, and they coordinate courtesy of a series of magnets that emit an electrical signal. by clicking here learn more about car sensors 

Symptoms Of A Problem With The Camshaft

The camshaft, like any other element of the car’s engine system, is bound to encounter some issues. The following are symptoms of a problem with the valve shaft system.

  • The car drives differently where stalling, slow acceleration, and a dip in engine power characterize the drive.
  • The car jerks suddenly.
  • In automatic cars, there can be an issue when shifting gears.

The symptoms may point to issues such as worn out lobes or a broken camshaft. Improper lubrication is also a probable cause.

Learn More: Basic Engine Parts Name and Short Descriptions

The Crankshaft

On to the other side of the camshaft vs crankshaft debate, we shift our focus to the crankshaft. It is an equally important element in the engine system and also consists of a rod, embedded with metal protrusions to perform its duty.


History Of The Crankshaft

The use of the crankshaft goes back to ancient times and has been a critical feature in describing ancient Roman technology. The earliest evidence dates back to the second century through its use in a mechanic system dates sometime around the 3rd century AD. It was still in the Roman Empire and was a key feature for their sawmills.

It also featured in an Italian physicists plan for a ship where it featured in the manual control system of the boat. Over the ages, there was some sort of modification as it evolved into its current form, with its use spreading from Europe into the Middle East.

Structure And Function

To have a clear picture of crankshaft and camshaft operation, you need to understand how their structures look and their differences. The main difference comes in the design of the shaft of the crankshaft. It consists of a long rod, similar to the camshafts, though instead of the lobes, it has cranks along its longitude.

The cranks connect to a set of pistons, which are part of the connection which transmits circular motion to the wheels. The piston’s linear motion gets transferred to the crankshaft, which converts it into a rotational movement. A flywheel at the end of the shaft maintains some level of consistency in the rotation of the shaft. The power form the piston is usually robust, and hence most crankshaft must be of heavy-duty quality to operate efficiently.

Types of Crankshafts

There are two types of crankshafts, with their differentiating factor being their construction. They are the monolithic crankshaft and the assembled one. The monolithic consists of one large crank that connects to the piston while the assembled consists if a series of cranks in alternating positions connected to the pistons.

The Crankshaft and Camshaft

As earlier hinted, these two components are connected either by series of gears or a belt. They move in tandem, though the camshaft vs. crankshaft speed may differ with the crankshaft being faster and the camshaft going for half the rate of the former. If you check up the crankshaft and camshaft animation, then you will get a clear picture of their operation in the engine system.

Bearings on The Crankshaft

As a mechanic, you know the importance of unrestricted movement, especially when it comes to movable parts in the automobile engines. To beat friction in the system, there is a set of bearings to provide ample flow along the shaft’s longitude. The bearings are not only at the ends of the shaft; rather at convenient points.

It is a primary factor of consideration, especially when dealing with large and powerful engines such as those from Toyota, among others.

Symptoms Of A Bad Crankshaft

During your stint working as a mechanic, you need to be on the knowledge of signs pointing to a bad crankshaft. The problem is usually severe and compels immediate replacement of the shaft system in question.

Below are some signs of a bad crankshaft.

  • Problem starting the car.
  • Constant stalling.
  • Irregularities during acceleration.
  • Rough idling.
  • Reduction in gas mileage.

Frequently Asked Questions

Question: what is the difference between the crankshaft and camshaft?

Answer: the two are essential parts of the car’s internal combustion engine though they are different. They, however, work in tandem and are connected via a belt, gears or chains. They are also a structural connection between them.

In the engine system, the camshaft controls the opening and closing of the valves courtesy of the action of the cams. The opening and closing of the valves allow for the intake of fuel, it’s burning, and the release of the exhaust gas. The effect of burning the fuel causes the pistons located at the bottom of the cylinders to move. The motions of the pistons then translate to the movement of the crankshaft, which converts the linear motion of the pistons to circular motion, which subsequently drives the wheels of the car.

Question: How are camshaft and crankshaft connected?

Answer:  The camshaft and crankshaft establish a connection, either via a set of gears, chains, or a belt, which is known as the timing belt.

Question: What spins faster, camshaft, or crankshaft?

Answer: On the issue of the camshaft vs. crankshaft speed, the crankshaft spins the fastest. Its rate is twice that of the camshaft if it is in a proper working condition.

Question: How many times does the crankshaft rotate compared to the camshaft?

Answer: The crankshaft spins the fastest and goes for two rotations per one from the camshaft.

Question: What happens when your camshaft goes bad?

Answer: The camshaft is prone to get damaged, just like any other car part. If it is damaged, you need to be on the lookout for the following signs.

  • Frequent engine stalling.
  • An issue in acceleration.
  • Reduced engine power.
  • The engine light comes on, indicating an issue with the system.
  • You may also notice that the car jerks during motion.
  • Rough idling.
  • The vehicle will not start in some instances or have trouble doing so.

Once you identify the issue, you need to use your mechanical know-how to deal with the problem. Most of the time, replacement is the way to go.

Question: How many types of crankshafts are there?

Answer: There are two types of crankshafts you need to know about during your stint as an auto-mechanic. There is the monolithic crankshaft consisting of a large crank that joins to the piston. The other is the assembled crankshaft, which comprises of a series of cranks joining a set of pistons in the engine.

Question: What are some of the camshaft and crankshaft sensor symptoms indicating a faulty system?

Answer: Most of the time, a problem with the sensor is indicative of an issue of either of the shafts. A common symptom is the check engine light coming on. There will also be noticeable problems in the handling of the car with stall and low engine power being common symptoms.


The camshaft vs. camshaft debate finalizes with the knowledge of each part from its structure, positioning, and functioning. Both of them are integral parts of the internal combustion engine and are connected via a set of gears.

The camshaft controls the valve system and has a set of cams that control the opening and closing of the valves during fuel combustion. The crankshaft is located under the engine and has a connection to the pistons. It converts linear motion from the piston to the circular motion, boosted and conserved by the flywheel connected at one end of the shaft.

Knowing the difference between the two is helpful in your mechanical practice, especially when it comes to their repairs and tuning.

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