3940123
Valve Collet
Cummins®

The Cummins 3940123 Valve Collet is a component designed for use in heavy-duty truck engines. It serves a specific function within the engine’s valve train, contributing to the overall performance and reliability of the engine. Understanding its purpose and significance is key to maintaining and optimizing the operation of heavy-duty trucks.

Basic Concepts of Valve Collet

A Valve Collet is a mechanical device used in internal combustion engines to secure the valve stem within the valve guide. Its function is to ensure that the valve operates correctly by maintaining proper alignment and allowing for efficient sealing of the combustion chamber. The collet operates by clamping onto the valve stem, which helps in transmitting the motion from the camshaft to the valve, ensuring it opens and closes at the correct times ¹.

Purpose of the 3940123 Valve Collet

This Cummins part plays a role in the operation of a truck engine by securing the valve stem in the valve guide. This ensures that the valve moves smoothly and precisely in response to the camshaft’s actions. Its interaction with other engine components, such as the camshaft and valve springs, is crucial for maintaining the engine’s efficiency and performance.

Key Features

The 3940123 Valve Collet is characterized by its design and material composition, which are tailored to withstand the high stresses and temperatures within an engine. It is made from durable materials that offer resistance to wear and corrosion, ensuring longevity and reliable performance. Unique attributes such as its precise fit and robust construction enhance its functionality within the engine.

Benefits

The advantages provided by the 3940123 Valve Collet include improved engine efficiency, durability, and reliability. By ensuring proper valve operation, it contributes to the engine’s overall performance, allowing for smoother operation and potentially extending the engine’s lifespan. Its durable construction also means it can withstand the demanding conditions of heavy-duty truck operation.

Installation Process

Installing the 3940123 Valve Collet requires careful attention to ensure it is correctly fitted. The process involves placing the collet onto the valve stem and securing it within the valve guide. Tools such as valve collet pliers may be required. It is important to follow best practices, such as lubricating the collet and valve stem to facilitate easy installation and ensure a proper fit.

Common Issues and Troubleshooting

Common problems associated with the 3940123 Valve Collet may include wear and tear or malfunction due to improper installation. Symptoms of issues can include engine misfires or decreased performance. Troubleshooting methods may involve inspecting the collet for signs of damage or wear, ensuring it is correctly installed, and replacing it if necessary.

Maintenance Tips

To prolong the lifespan of the 3940123 Valve Collet, regular maintenance practices are recommended. This includes periodic inspection for signs of wear or damage and adhering to manufacturer guidelines for replacement intervals. Keeping the engine clean and well-maintained can also contribute to the collet’s longevity and performance.

Cummins Overview

Cummins Inc. is a global power leader that designs, manufactures, and distributes engines, filtration, and power generation products. With a history spanning over a century, Cummins has established a reputation for quality and reliability in the commercial truck industry. Its product range includes a variety of engines and components designed to meet the demanding requirements of heavy-duty applications.

Valve Collet 3940123 Compatibility with Cummins Engines

The Valve Collet 3940123, manufactured by Cummins, is a critical component used in various Cummins engine models. This part is essential for maintaining the integrity and functionality of the engine’s valve train system. Below is a detailed description of its compatibility with different Cummins engines:

B Series Engines

• B4.5 CM2350 B129B
• B4.5 RGT
• B5.6 CM2670 B152B
• B6.7 CM2350 B135B
• B6.7 CM2670 B153B
• B6.7 CM2670 B164C
• B6.7 G CMOH6.0 B125

The Valve Collet 3940123 is designed to fit seamlessly with the B series engines, ensuring proper valve retention and minimizing the risk of valve failure. These engines are known for their robust performance and reliability, making the correct valve components crucial for their operation.

F Series Engines

• F3.8 CM2350 F120B
• F3.8 CM2350 F128C
• F3.8 CM2620 F137B
• F3.8 F102
• F4.5 CM2620 F139B
• F4.5 CM2620 F141C

The F series engines also benefit from the Valve Collet 3940123. This part is engineered to provide a secure fit, which is vital for the high-performance demands of these engines. The compatibility ensures that the valve train operates smoothly, contributing to the overall efficiency and longevity of the engine.

ISB Series Engines

• ISB (Chrysler)
• ISB CM2150
• ISB CM550
• ISB CM850
• ISB/ISD4.5 CM2150 B119
• ISB/ISD6.7 CM2150 SN
• ISB4.5 CM2350 B104
• ISB5.9 CM2880 B110
• ISB5.9 CM2880 B140

The ISB series engines, including both the ISB and ISD variants, are designed for heavy-duty applications. The Valve Collet 3940123 is specifically crafted to meet the stringent requirements of these engines. Its compatibility ensures that the valve train can withstand the high stresses and demands of heavy-duty operations, providing reliable performance and durability.

Each of these engines relies on the precise fit and function of the Valve Collet 3940123 to maintain optimal performance and prevent potential failures. Cummins’ engineering expertise ensures that this part is compatible with the specified engine models, offering a reliable solution for maintaining the integrity of the valve train system.

Role of Part 3940123 Valve Collet in Engine Systems

The part 3940123 Valve Collet is an essential component in the orchestration of various engine systems, ensuring the seamless operation of the engine’s valve train. Its primary function is to secure the valve stem within the valve guide, allowing for precise control over the valve’s opening and closing. This, in turn, facilitates the efficient intake of air-fuel mixture and the expulsion of exhaust gases.

Integration with Key Engine Components

• Camshaft: The Valve Collet works in conjunction with the camshaft to maintain the valve’s alignment and stability. As the camshaft lobes push against the valve, the collet ensures that the valve stem remains centered within the guide, preventing any lateral movement that could lead to wear or failure.

• Cylinder Head and Cylinder 6B Head: These components house the valve train assembly. The Valve Collet’s role is pivotal in ensuring that the valves operate within the specified tolerances, contributing to the overall integrity and performance of the cylinder head.

• Intake Valve Kit and Exhaust Valve Kit: The Valve Collet is instrumental in the proper functioning of both intake and exhaust valves. It ensures that these valves open and close at the correct times and with the appropriate force, which is essential for optimal engine performance.

• Injector and Injector Plumbing: Efficient combustion requires precise timing and quantity of fuel delivery. The Valve Collet, by ensuring proper valve operation, indirectly supports the injector’s function by maintaining the engine’s combustion cycle.

• Upper Engine Gasket Kit and Full Engine Gasket Set: These gaskets seal various engine components, including the cylinder head. The Valve Collet’s role in maintaining valve integrity helps prevent any undue stress on these gaskets, which could otherwise lead to leaks or failure.

• Long Block and Long Block Kit: In a long block assembly, which includes the cylinder block, crankshaft, pistons, and often the camshaft, the Valve Collet is a small yet significant part that ensures the valve train’s reliability and performance.

• Overhaul Kit: When performing an engine overhaul, the Valve Collet is often replaced to ensure that the valve train starts afresh with components that meet the engine’s specifications.

• Connecting Rod and Piston: Although not directly connected, the Valve Collet’s role in the valve train affects the engine’s overall performance, which in turn impacts the operation of the connecting rod and piston.

• Water Pump Drive: Efficient engine cooling is vital for performance and longevity. While the Valve Collet does not directly interact with the water pump drive, its role in maintaining engine efficiency indirectly supports the cooling system’s effectiveness.

In summary, the part 3940123 Valve Collet is a fundamental component in the valve train, ensuring the precise operation of valves within the engine. Its integration with various engine systems underscores its importance in maintaining engine performance, efficiency, and longevity.

Conclusion

The Cummins 3940123 Valve Collet is a critical component in heavy-duty truck engines, ensuring the precise operation of the valve train. Its role in securing the valve stem within the valve guide contributes to the engine’s overall performance, efficiency, and reliability. Proper installation, maintenance, and understanding of its function are essential for optimizing engine operation and longevity.