What are the difference between Crankshaft And Camshaft?

Table of Contents

I. Introduction

A. Explanation of crankshafts and camshafts

The crankshaft and the camshaft are major components of the engine. The crankshaft is located at the base of the engine and is responsible for converting the reciprocal movement of the piston to rotary movement. The camshaft on the other hand is on top of the engine. The camshaft controls valves to regulate air-fuel mixture entry into the cylinder and exhaust gasses exiting from the engine. Crankshafts and camshafts must be precisely engineered and machined for maximum performance and longevity; typically made of high-strength steel or other durable materials, their design and placement can significantly affect an engine’s power output, fuel efficiency, and overall performance.

B. Importance of understanding the functions and components of crankshafts and camshafts

Understanding the functions and components of crankshafts and camshafts is fundamental in automotive engineering, mechanical engineering, and manufacturing. The crankshaft converts piston vertical motion into rotary motion while the camshaft controls valve opening/closing action. By understanding how these parts function together efficiently, designers can create efficient designs with improved engine performance, fuel economy, reliability; as well as diagnosing/repairing any issues related to these components for maintenance & safety purposes.

II. What Is a Crankshaft?

A. Definition and explanation

The crankshaft is forged from steel and is responsible for converting the up-and-down movement of the pistons to rotary motion producing the power of the engine. It consists of several journals, counterweights, and throws which have been precisely machined for balance and durability. When the pistons move up and down, the exert a force which is transferred to the crankshaft. The crankshaft is designed to turn this up and down force into rotary motions which produces the power of the engine.

B. Function and purpose

The crankshaft converts piston reciprocating motion into rotary movement, which is then transmitted to the transmission and ultimately wheels – propulsion that propels your vehicle forward. It does this using connecting rods attached to it; designed so piston up-and-down movement turns it on its axis. Furthermore, counterweights help balance out piston reciprocating motion which reduces vibration while increasing engine durability and longevity.

C. Different types of crankshafts

Single-Plane Crankshaft: Common in many four and some six cylinder engines, this crankshaft features all its throws on one plane for a compact and lightweight design.

Crossplane Crankshaft: Common in V8 engines, this type of crankshaft features two throws per cylinder bank offset by 90 degrees for smoother engine operation and an attractive exhaust note.

Flat plane Crankshaft: Used in some high-performance engines, this type of crankshaft features all throws on one plane but the cylinder banks are spaced farther apart for improved breathing and higher revving capabilities.

III. Components of a Crankshaft

A. Main journals

Journals are what attach the crankshaft to an engine, running parallel to each other for smooth rotation while reducing friction and wear on both components. They feature bearings which ensure smooth running of both components by reducing friction and wear during normal operation.

B. Crank pins

Crank pins act as the connecting link between main journals and throws, offset from each other to provide attachment points for connecting rods that transfer piston motion onto the crankshaft.

C. Crank webs

Cranks webs refer to the sections that are located between the main journals and the throws of the crankshaft. They help to distribute the force generated by the pistons evenly and provide rigidity to the crankshaft.

D. Flywheel/force transfer

The flywheel is a large, heavy wheel made from cast iron attached at the end of the crankshaft. It acts as an energy storage device to help regulate engine power delivery while also transmitting energy from the engine to the transmission – enabling vehicles to move.

E. Oil bore

This passage runs the length of the crankshaft and supplies oil to various bearings and surfaces to keep them lubricated and cooled, thus reducing friction and wear.

F. Counterweights

Counterweights are weights attached to the crankshaft in order to balance its throw weight, reducing engine vibration and friction wear.

IV. What Is a Camshaft?

A. Definition and explanation

A camshaft is an integral component of an engine that controls valve openings and closing to let air-fuel mixture enter and exhaust gasses escape. It regulates precise timing and duration for these openings, controlling how much mixture enters or leaves the engine and how much exhaust comes out.

B. Function and purpose

The primary function of the camshaft is to regulate valve opening/closing timing, which affects combustion process, power output, and fuel efficiency. To do this, cam lobes are designed and positioned so they push on valve lifters or followers at precisely the correct time with enough force – providing optimal valve open/close timing tailored specifically for your engine requirements.

C. Different types of camshafts

Flat tappet camshafts: The flat tappets are flat as the name suggests and they ride on a lifter which opens and closes the valves as the camshaft rotates. They are simple in design and commonly used in standard engines.

Hydraulic – The hydraulic camshafts use hydraulic lifters to open and

close the valves. The hydraulic oil compensates for the engine temperature and


Solid – These camshafts use solid lifters to operate the valves but require

regular adjustment of the valve lush. They are mostly used in high-performance


Variable valve timing camshafts (VVT) – These camshafts have valve timing

technology to optimize engine performance and fuel consumption.

V. Components of a Camshaft

A. Journals

These cylindrical areas allow the camshaft to rotate within an engine block, so their precision requires precise measuring and milling for accurate fitment with the block, usually made out of hardened steel or other durable materials.

B. Lobes

These egg-shaped projections on the surface of a camshaft interact with an engine’s valve lifters or followers to open and close intake and exhaust valves. The shape and positioning of these cam lobes determine when valve openings take place, which plays an integral role in engine performance and efficiency.

C. Ends

The camshaft has two ends, front and rear. Depending on the engine and manufacturer, these may feature different features like a sprocket or gear to connect it to the timing chain or belt, while the rear end may have a keyway connecting it to an oil pump drive or distributor.

D. Cam bearings

These cylindrical metal inserts fit into the engine block and support the camshaft, helping reduce friction and wear on it. To match up properly with the size and shape of a camshaft journal, these bearings may be constructed from various materials like brass, steel or aluminum alloy and are usually press-fitted into place within the engine block.

VI. Differences Between a Crankshaft and a Camshaft

A. Location

Crankshafts are located at the bottom of an engine block, connecting pistons via connecting rods. On the other hand, camshafts reside at the top of an engine and control valve opening/closing action.

B. Mode of operation

The crankshaft is rotated by piston force, while the camshaft is turned by a timing belt connected to the crankshaft and running at half its speed. It uses its lobes to push on valve lifters or followers so valves open and close precisely at their intended times.

C. Make

Crankshafts are usually constructed of forged steel due to their high tensile strength to support piston weight, while camshafts may be made from cast iron, steel, or other strong steel alloys.

Camshafts may receive specialized heat treatments or coatings to increase wear resistance and longevity, since they operate at higher speeds with greater strain than their crankshaft counterparts.


A. What is common with both the crankshaft and camshaft?

Both are components of an engine and work in synergy to ensure everything runs optimally.

B. What are the signs of a malfunctioning crankshaft?

Some possible symptoms include engine vibration, knocking or tapping sounds, decreased fuel efficiency, difficulty starting the engine or engine stalling.

C. What is the main function of the camshaft?

The primary function of a camshaft is to regulate valve opening and closing timing on an engine, allowing it to inhale air, fuel, and exhaust gases at precisely the correct intervals.

D. Which turns faster, the crankshaft or the camshaft?

The crankshaft runs faster due to its increased load from pistons. Conversely, the camshaft rotates at half its maximum speed and is controlled by a timing belt.

E. What is the main function of a crankshaft?

A crankshaft’s primary function is to transform linear motion from pistons into rotational motion that drives wheels, by using its offset journals to convert up-and-down piston motion into circular movement.

VIII. Conclusion

Crankshafts and camshafts are essential components for internal combustion engines. They are manufactured through various processes such as mold manufacturing, CNC machining, and rapid prototyping. Modern manufacturing techniques enable high precision and accuracy when producing these components, guaranteeing their reliable and efficient operation in engines of all types. Because of this, intricate mold designs are used to produce precise molds of the crankshaft and the camshaft.

Additionally, ongoing research and development efforts push the limits of crankshaft and camshaft design, creating more powerful, efficient, and reliable engines than ever before. As the automotive industry develops, crankshafts will remain at the forefront of innovation – propelling technology that powers our world forward.


Gary Liao

Gary Liao

Gary Liao is the Engineering Manager of TDL Company and has more than 20 years of mold design experience.

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