High Performance Pistons & Motorsport Forged Pistons

Introduction to Pistons

At the heart of every internal combustion engine, you’ll find the pistons. These cylindrical metal components play a crucial role in converting the energy produced by the engine’s combustion process into mechanical power. Pistons bear the brunt of the combustion force within the chamber, and through a piston pin, they connect to a rod that powers the crankshaft. Each piston is fitted with three flexible piston rings that create an airtight seal once inside the engine cylinder, ensuring optimal performance and efficiency.

Materials Used in Piston Manufacturing

Pistons are typically made from materials like cast iron, steel, or aluminium alloy. The choice of material depends on the specific requirements of the engine, with each offering unique advantages. For instance, aluminium alloy pistons are lightweight and excellent at heat dissipation, making them ideal for high-performance engines.

Replacement pistons can offer many advantages over stock pistons. They can be made from stronger or denser materials, and they can be specially prepared through processes like forging or heat treatment for higher durability and tolerances. The surface finish of pistons can also vary between manufacturers, affecting factors like friction and heat transfer.

Forging and Billet Pistons

For those seeking to build an engine capable of enduring high load, constant load, or both (think endurance racing like Le Mans 24), forging and billet pistons are excellent upgrade options. Forged pistons are made from a single piece of metal that’s heated and shaped under pressure, resulting in a denser and stronger piston. This increased density allows for higher engine compression, which can increase power output and the available RPM range.

Billet pistons, on the other hand, are machined from a solid block of metal. While they’re more expensive than forged pistons, they offer the highest level of customization and precision, making them a popular choice for high-performance and racing applications.

Increasing Displacement with Pistons

When you’re looking to take your engine’s performance to the next level, modifying the pistons can be a great place to start. One common modification is to increase the engine’s displacement. This can be achieved by creating a wider piston cylinder bore or using a stroker kit to extend the connecting rod for a deeper stroke. Both of these modifications increase the engine’s displacement, which can lead to a significant increase in power output.

Frequently Asked Questions about Pistons

Is it worth fitting a performance air filter?

Fitting a performance air filter can offer several benefits:

Improved Airflow: Performance air filters are designed to increase airflow to the engine, which can enhance performance.
Better Engine Efficiency: With improved airflow, the engine can operate more efficiently, potentially leading to better fuel economy.
Enhanced Throttle Response: Many users report a more responsive throttle, which can improve driving experience.
Longer Lifespan: Performance filters are often reusable and can last longer than standard filters, reducing replacement costs over time.
Potential Power Gains: Some drivers experience a slight increase in horsepower, although this can vary based on the vehicle and filter type.

However, the actual benefits can depend on the specific vehicle and driving conditions.

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.

Pistons