Crankshaft and Camshaft Connection: Precision In Motion
The crankshaft and camshaft are engine components that depend on each other for an engine’s four-stroke cycle to work. These two components have to be in sync with one another because timing is everything in engine combustion.
The camshaft helps the lungs of the engine. It is how the engine breathes in order for combustion to take place. Once the process of combustion is in play the crankshaft is what keeps that process going. In turn, it helps the camshafts do their job in one beautiful choreography of a self-powering system.
What you will learn About :
What is a crankshaft?
A crankshaft is a specifically shaped balancing shaft that sits in the lower part of an engine block called the crankcase. The Crankshaft helps convert the forces of combustion into rotational force that ultimately creates mechanical power. Crankshafts are made from cast iron or steel through either casting or forging techniques. A Crankshaft has something called journals. Journals are the circular parts of the crankshaft where rotating happens. There are two types of Journals. Main Journals and rod journals.
The main journals are the main supporting parts that the crankshaft rotates on. The main journals are what make contact in the engine block and are locked in with journal-bearing caps. The rod journals are the parts that the connecting rods attach to which rotate and ultimately support the piston’s linear movements. Each journal has holes inside which act as a pathway for engine oil. Keeping the journals lubricated prevents metal-to-metal contacts and provides ease of rotating for engine performance. All journals are connected to one another by crankshaft webs.
How does a crankshaft work?
A crankshaft’s job is to help process the forces of combustion into rotational force while keeping balance in the engine. Most engine’s combustion processes are in a 4-stroke cycle. This Four stroke cycle is referred to as Suck, Squeeze, Bang, Blow (S.S.B.B). This is exactly the process that happens in the combustion chamber. This process requires the pistons to move up and down in the cylinder. This up-and-down motion is supported by the crankshaft. Think of it like riding a bike.
It is the relationship between your legs and the pedals that best explains the crankshaft’s job in the engine. The crankshaft are the pedals and the pistons are your legs. Each time you pedal on the bike the pedals rotate in a circular motion while your legs move up and down. The same motions happen in the engine. While it is the muscle in your legs that drives the pedals forward it is the combustion process that drives the crankshaft in an engine. Each time you pedal down on one side you help the other side go up, just as when some pistons move downward in an engine the others go up.
However, and engine’s crankshaft is making much much faster revolutions than you can ever pedal. This creates much stronger rotational forces along with combustion forces and reciprocating forces. All of these forces create a lot of shaking in the engine which needs to be countered. The crankshaft has built-in counterweights which are the webs that connect the journals. These counterweights counter the forces at one end by being on the other side providing a smooth rotation on the crankshaft. The design of a crankshaft also allows for an even firing order of combustions and piston position optimal piston position for further balancing of the engine.
What is a camshaft?
A camshaft is a shaft that sits in the cylinder head or the cylinder block of an engine that influences how the engine breathes. In an engine timing is everything. The camshaft Allows the intake of air or air-fuel mixture, the compression and combustion of the air-fuel mixture, and the exhaust from combustion to happen at specific times. Camshafts are made from steel or cast iron and have very specific shapes along the shafts called cam lobes. The shape of these cam lobes greatly determines the performance of your engine. They dictate how much air your engine breaths and for how long.
How does a camshaft work?
Camshafts are either located in the engine block or cylinder head of an engine and are vital parts of an engine’s valve train. Where the camshaft is located will change the shape and design of a cylinder head. The camshafts rotate and the rotation of the cam lobes affects the opening and closing of the valves. These cam lobes are egg-shaped, where one end is more rounded than the other end. When the camshaft rotates the less rounded more protruding end makes contact with tappets/lifters essentially opening intake and exhaust valves at specific times. As the camshaft rotates back to the more rounded side it allows space for the valves to close by the valve springs. Think of it like using a spring-loaded door. You can push a spring-loaded door open and then it closes on its own once you remove the pressure from your hands. In this scenario, your hands play the role of the camshafts. Camshaft designs vary depending on the type of camshafts set up an engine has.
How does crankshaft and camshafts work together?
Both the crankshaft and camshaft play vital roles in the engine’s combustion process and the timing of it all. The crankshaft and the camshaft are both connected through a timing mechanism using gears, chains, or belts. The rotational forces of the crankshaft transfer through the gears, chains, or belts (timing mechanism) influencing the rotation of the camshaft. The timing mechanism keeps both the crankshaft and camshaft in sync with each other. When the crankshaft rotates for a piston intake stroke the camshaft has to open the intake valves at the same time for this to work. For the compression stroke, both valves have to stay shut and for the exhaust stroke, the exhaust valves open. This process gets completed thousands of times at high rates of speed, which is why the timing between the crankshaft and camshaft is crucial.
Signs you need a new timing device
The timing device is the connection between the crankshaft and the camshaft. The crankshaft and camshaft facilitate the proper function of combustion, so faulty timing devices would trigger a few things leading to a decrease in engine performance. A few signs that you may need new parts for the timing mechanism are:
- Check engine light
- Cylinder misfire
- Rough idle / Vibrating or shaking
- Engine overheating
- Trouble turning over the engine (Engine starting)
- Squealing and rubbing noises from timing belts
- Possible oil leaks
- Ticking Noises coming from the engine
Conclusion
Now we know that the time managers of the engine are the crankshaft and camshaft, we also understand how vital they are to the process of engine combustion and performance. The way these engine components are designed has a great effect on your engine power. We hope to have given you another IQ boost about your car engine and the way it works. So the next time you pop open the engine bay you know what you’re looking at.
FAQ’s
What are two types of crankshafts?
The two main types of crankshafts are flat-plane crank and cross-plane crank. In the flat-plane crankshaft, the rod journals exist in one plane whereas in the cross-plane crankshaft, the rod journals exist in two planes 90 degrees from one another.
Types of camshaft setup?
Different types of camshaft setups are Single Over Head Cam (SOHC), Dual Over Head CAM (DOHC), and Over Head Valve (OHV).
What’s the difference between a crankshaft and a camshaft?
The Difference between the crankshaft and the camshaft is that the crankshaft is the main shaft of the engine responsible for turning the piston’s linear forces into rotational forces. The camshaft/camshafts are responsible for how the engine breathes.
How much does a crankshaft cost?
The cost of either repairing or replacing a crankshaft can range from $300 – to $3000, depending on engine make and model, parts, and labor included.
How much does a camshaft cost?
The cost of repairing or replacing a camshaft can range from 2k-3k depending on engine make and model, parts, and labor included.
How many times does a camshaft turn to a crankshaft?
The camshaft makes one revolution every two revolutions of the crankshaft. This is a 1:2 ratio connection between the crankshaft and camshaft.