Crankshafts

Crankshafts: Explained

At the heart of every high-performance engine lies a critical component that converts linear motion into rotational motion – the crankshaft. This essential part of your vehicle’s engine plays a pivotal role in driving your car’s performance, durability, and overall efficiency. Whether you’re a seasoned car enthusiast or a beginner in the world of automotive modifications, understanding the importance of a quality crankshaft can significantly enhance your vehicle’s performance.

What is a Crankshaft?

A crankshaft is a mechanical component that transforms the up-and-down motion of the pistons into a rotational motion that drives the vehicle’s wheels. It’s a complex piece of engineering that must withstand high levels of stress and strain, making its quality and durability paramount to your engine’s performance.

Types of Crankshafts

There are several types of crankshafts, each designed to meet specific performance requirements. These include:

Cast Crankshafts: These are made from iron and are typically used in standard production vehicles due to their cost-effectiveness and adequate performance for everyday driving.
Forged Crankshafts: These are made from heated steel and are more durable and stronger than cast crankshafts. They are ideal for high-performance vehicles that require more power and speed.
Billet Crankshafts: These are custom-made from a solid billet of high-grade steel or aluminum. They offer the highest level of strength and durability, making them perfect for racing or high-performance applications.

Why Upgrade Your Crankshaft?

Upgrading your crankshaft can bring several benefits to your vehicle’s performance. These include:

Increased Power: A high-quality crankshaft can handle more power, allowing you to increase your engine’s horsepower and torque.
Improved Durability: Upgraded crankshafts are designed to withstand higher levels of stress, reducing the risk of engine failure and extending the life of your engine.
Enhanced Efficiency: A well-balanced crankshaft can improve your engine’s efficiency, leading to better fuel economy and smoother operation.

Choosing the Right Crankshaft

When choosing a crankshaft, consider your vehicle’s make and model, your driving style, and your performance goals. For daily driving, a cast crankshaft may suffice. However, if you’re into racing or high-performance driving, a forged or billet crankshaft would be a better choice. Always ensure that the crankshaft is compatible with your engine to avoid potential issues.

Conclusion

Investing in a high-quality crankshaft is a smart move for any car enthusiast looking to boost their vehicle’s performance. At Compare.Parts, we offer a wide range of crankshafts from top manufacturers, ensuring you get the best quality and value for your money. Explore our selection today and take your vehicle’s performance to the next level.

Frequently Asked Questions about Crankshafts

What does a higher lift camshaft do?

A higher lift camshaft increases the amount of valve lift, allowing the engine to draw in more air and fuel during the intake stroke. This can lead to improved engine performance in several ways:

Increased Airflow: More air entering the combustion chamber can enhance combustion efficiency.
Higher Power Output: With better airflow, the engine can produce more power, especially at higher RPMs.
Improved Torque: A higher lift can also contribute to increased torque, particularly in performance applications.
Enhanced Throttle Response: The engine may respond more quickly to throttle inputs due to improved airflow dynamics.

However, it is important to consider that a higher lift camshaft may require additional modifications to the engine, such as upgraded valve springs and potentially changes to the engine's tuning.

What makes a cam aggressive?

An aggressive camshaft is characterised by several key features that enhance engine performance. These include:

Increased Lift: Higher lift allows the engine to draw in more air and fuel, improving combustion efficiency.
Longer Duration: A longer duration keeps the intake and exhaust valves open for a greater portion of the engine cycle, allowing for better airflow.
Steeper Ramp Rates: Faster opening and closing of the valves can lead to more power at higher RPMs.
Overlap: Increased overlap between the intake and exhaust valves can enhance performance by improving scavenging of exhaust gases.
Profile Shape: The specific shape of the cam lobes can influence how the engine responds at different RPMs, with aggressive profiles typically favouring high RPM performance.

These characteristics contribute to a camshaft that provides more power and responsiveness, particularly in performance-oriented applications.

What are the cons of camming your car?

Camming your car can enhance performance, but it also comes with several drawbacks:

Increased Engine Wear: A camshaft can put additional stress on engine components, leading to faster wear and potential failure.
Reduced Fuel Efficiency: Performance cams often result in lower fuel economy due to altered air-fuel mixtures.
Compromised Driveability: Cams can affect low-end torque, making the car less responsive at lower RPMs.
Noise Levels: Performance cams can increase engine noise, which may not be desirable for all drivers.
Potential Emissions Issues: Altered engine performance can lead to higher emissions, potentially causing issues with regulations.
Cost of Installation: Upgrading to a performance camshaft can be expensive, including parts and labour.
Compatibility Issues: Not all engines are compatible with aftermarket cams, which can limit options.

Do camshafts change engine sound?

Yes, camshafts can change the engine sound. The design and specifications of a camshaft influence the timing and duration of valve openings, which affects the engine's performance and acoustics. Factors that contribute to changes in engine sound include:

Lift and Duration: Higher lift and longer duration can create a more aggressive sound.
Profile: Different camshaft profiles can alter the exhaust note.
Engine RPM: Camshafts designed for higher RPMs may produce a different sound compared to those for lower RPMs.
Engine Type: The overall engine configuration (e.g., V8, inline) also affects how camshaft changes impact sound.

Why do cammed cars sound choppy?

Cammed cars sound choppy primarily due to the characteristics of the camshaft profile. Here are the main reasons:

Lift and Duration: A camshaft with higher lift and longer duration allows more air and fuel into the engine, creating a more aggressive sound.
Overlap: Increased overlap between the intake and exhaust valves can lead to a rougher idle, contributing to the choppy sound.
Idle Speed: Cams designed for performance often require a higher idle speed, which can accentuate the choppy noise.
Exhaust Note: The changes in exhaust flow dynamics due to the cam profile can alter the exhaust note, making it sound more aggressive and choppy.

Does camshaft affect acceleration?

Yes, the camshaft does affect acceleration. The camshaft controls the timing and duration of the engine's valve openings, which directly influences engine performance. Key factors include:

Valve Timing: Proper timing allows for optimal air-fuel mixture intake and exhaust gas expulsion, enhancing engine efficiency.
Lift and Duration: Higher lift and longer duration can improve power output at higher RPMs, which can lead to better acceleration.
Engine Tuning: A camshaft designed for performance can shift the power band, affecting how quickly the engine accelerates.

In summary, the design and specifications of the camshaft play a crucial role in determining how effectively an engine can accelerate.

Does camming a car make it louder?

Camming a car typically involves installing a performance camshaft, which can indeed make the engine louder. This increase in noise is due to several factors:

Increased Airflow: A performance camshaft allows for greater airflow into and out of the engine, which can enhance the exhaust note.
Higher RPMs: Cams designed for performance often operate at higher RPMs, producing a more aggressive sound.
Exhaust System Interaction: The camshaft can change the way exhaust gases exit the engine, potentially amplifying the sound through the exhaust system.

Overall, while camming a car can lead to a louder engine sound, the extent of the increase will depend on the specific camshaft used and the overall setup of the vehicle.

How much does it cost to replace a camshaft?

The cost to replace a camshaft can vary significantly based on several factors, including the make and model of the vehicle, labour costs, and whether you choose an original equipment manufacturer (OEM) part or an aftermarket part. Typical costs include:

Parts: £200 to £1,000
Labour: £300 to £800

Overall, the total cost for camshaft replacement can range from approximately £500 to £1,800. Always consult with a mechanic for a precise estimate based on your specific vehicle.

Do camshafts increase horsepower?

Yes, camshafts can increase horsepower. They play a crucial role in controlling the timing and duration of the engine's intake and exhaust valves. Upgrading to a performance camshaft can enhance airflow, improve engine efficiency, and increase power output. Benefits of a performance camshaft include:

Improved airflow into and out of the engine
Increased torque and horsepower at higher RPMs
Better throttle response
Optimised engine performance for specific driving conditions

However, the extent of the horsepower increase depends on various factors, including the engine type, other modifications, and tuning.

How much lift should my cam have?

The amount of lift your cam should have depends on several factors, including your engine type, intended use, and performance goals. Here are some general guidelines:

Stock Engines: Typically, stock camshafts have lift values ranging from 0.350 to 0.450 inches.
Performance Engines: For mild performance upgrades, aim for lift between 0.450 to 0.550 inches.
High-Performance Engines: For racing or high-performance applications, lift can exceed 0.600 inches.
Engine Specifications: Always refer to your engine's specifications and consult with a professional for optimal lift based on your setup.