How Many Crankshafts Are In A V8?

Internal combustion engines have undergone continuous development throughout the history of automobiles. As a result, they have seen significant technological advancement in layout and power efficiency. And one of the most popular layouts is the V8 engine. A V8 engine is an internal combustion engine with eight cylinders mounted on the crankcase in two banks of four cylinders, in most cases set at an angle to each other. This arrangement creates a “V” shape while the eight pistons that ignite the engine’s fuel reflect the number eight in the V8.

How Many Crankshafts Are In A V8 1 How Many Crankshafts Are In A V8?

Table of Contents

How many crankshafts are in a V8 engine?

Given the many cylinders and pistons, you might ask how many crankshafts are in a V8. Most V8 engines have only one crankshaft. Because of the limited space in the V8 engine’s structure, only one crankshaft can connect to the cylinders and pistons.

Aside from the V8 limited space, internal combustion has no relation to the number of cylinders and needs one crankshaft. There is no need for several crankshafts to serve the same motion because the crankshaft of a V8 engine helps convert linear motion into a rotational motion.

To learn more about the role of a single crankshaft in a V8 engine, continue reading!

What Is a Crankshaft?

A crankshaft is a mechanical part of an engine that can perform a conversion between reciprocating and rotational motions. 

It is used in internal combustion engines and other machines that use rotational power. Crankshafts are steel and can withstand high pressure while driving pistons up and down during operation.

In the V8 engine, the crankshaft transforms reciprocating motion into rotational motion. It is positioned at the bottom end of your car’s engine.

The crankshaft is attached to the engine’s pistons through the connecting rods. A crank mechanism made up of numerous cranks and crankpins drives the crankshaft.

How Does a Crankshaft Work in a V8 Engine?

How Many Crankshafts Are In A V8 1 1 How Many Crankshafts Are In A V8?

The connecting rods connect each piston with its crankpin on the crankshaft axis. This allows the pistons to move simultaneously inside their respective cylinder chambers.

The connecting rods transmit the motion of the engine piston’s downward stroke to the crankshaft in the V8 engine.

The crankshaft subsequently converts the piston’s linear motion into a rotational motion, which is ultimately sent to the camshaft.

When the camshaft receives the rotational motion, it will open the inlet valve, which enables a mixture of fuel and air to enter the combustion chamber. This mixture will then be compressed, causing ignition and eventually releasing heat.

The heat generated will cause the piston to continue its downward motion, sending the crankshaft back into rotation. This motion is then transferred and stored to the flywheel, eventually powering the vehicle’s wheels.

What Are the Common Issues in V8 Engine Crankshafts?

Though the crankshaft can withstand high amounts of pressure, it will eventually wear out over time.

Some contributing factors that cause the wearing of the crankshaft are worn bearings, bent connecting rods, and worn crankshaft pulleys.

Additionally, a broken crankshaft may result from the engine running out of oil or transmission and clutch failures that impart a counter-force on the crankshaft.

Problems with the crankshaft are frequently indicated by engine vibrations, excessive engine revving, and odd engine noise.

Types of Crankshafts in V8 Engine

Even though a V8 engine only needs one crankshaft, two kinds of crankshafts are employed in various V8 engine cars. Let’s see what makes each type unique and how they work to keep your engine running smoothly.

Flat-plane Crankshaft

A flat-plane crank is also known as a single-plane crankshaft. When looking at a flat plane crankshaft, you will notice that they usually have just one crankpin and do not depend on large counterweights to handle their mass and momentum. 

This type of crankshaft typically completes cycles rapidly, but this has the drawback of causing secondary vibrations in the crankshafts.

Most hypercar and supercar designs use flat plane cranks because they have advantages over other types. 

The advantages are improved airflow past the cylinders for faster combustion speeds, smoother operation, and enhanced firing order, making it easier for manufacturers to tune vehicles for better performance.

Flat plane crankshafts are good at delivering power when the engine is at high RPM or revolutions per minute. 

With a flat plane crankshaft, each cylinder’s connecting rod will be at an angle of 90 degrees from the piston motion, which means power can be delivered at its highest point to help keep the engine running smoothly.

Some famous sports cars with flat-plane cranks are Lotus, Porsche, Ferrari, and McLaren.

Cross-plane Crankshaft

Cross-plane crankshafts are also known as the two-plane crankshaft. This is one of the most popular hot rod engine variants designs because it has a 90-degree angle between each. This makes it easier to balance an engine and provides a greater power output.

Because of this innovation, cross-plane crankshafts have four crankpins positioned on two levels and balanced by a 90-degree angle giving the crank its name.

These engines are often found in V8 machines used for racing or high-performance purposes that want more power out of their cars or trucks, like muscle cars, drag racers, and sports car enthusiasts.

The cross-plane crank delivers power at an angle between 90 and 180 degrees, which means that each cylinder’s connecting rod is oriented to intersect with the rotation of another piston’s connecting rod. This arrangement allows for more excellent torque production on lower RPM ranges.

American muscle cars like Ford, Mercedes, and Dodge use cross-plane crankshafts in their V8 engines.

Conclusion

In a nutshell, the crankshaft is an essential part of the engine and transforms the action of the engine piston into a rotating motion, which gives your car its motion. Since there is only so much room in the engine’s structure, only one crankshaft is used in V8 engines, as explained in this article.

Two types of crankshafts are employed in different V8 engine cars: the Flat-plane Crankshaft and the Cross-plane Crankshaft. Each of these types of crankshafts has certain advantages and disadvantages, which is why V8 engines use a specific type to cover every possible aspect of the vehicle’s performance.