3900919
Connecting Rod Cap Screw
Cummins®

Connecting rod cap screws are integral components in heavy-duty truck engines, ensuring the secure attachment of the connecting rod to the crankshaft. This article focuses on the 3900919 Connecting Rod Cap Screw by Cummins, exploring its role and significance within the engine system.

Basic Concepts

Connecting rod cap screws serve the fundamental purpose of fastening the connecting rod to the crankshaft. This connection is vital for transmitting the force generated by the piston’s movement to the crankshaft, thereby converting linear motion into rotational motion. The secure attachment provided by these screws is crucial for maintaining engine balance and performance, as any instability can lead to vibrations and reduced efficiency ¹.

Purpose and Function

The 3900919 Connecting Rod Cap Screw plays a specific role in the operation of a truck engine. It ensures that the connecting rod remains firmly attached to the crankshaft, allowing for the smooth transfer of power. This screw contributes to the overall efficiency and reliability of the engine by maintaining the integrity of the connection under high stress and varying operational conditions.

Key Features

The 3900919 Connecting Rod Cap Screw is designed with several key features that enhance its performance and durability. These include a high-quality material composition, precise threading, and specific design specifications. The material used is typically a high-strength alloy, which provides the necessary durability and resistance to wear. The threading is designed to ensure a secure fit, while the design specifications are tailored to meet the demanding requirements of heavy-duty truck engines ².

Benefits

The use of the 3900919 Connecting Rod Cap Screw offers several benefits. It contributes to improved engine stability by ensuring a secure connection between the connecting rod and the crankshaft. This stability reduces the likelihood of vibrations and enhances overall engine performance. Additionally, the high-quality material and precise design help to minimize wear and tear, leading to enhanced longevity of engine components ³.

Troubleshooting and Maintenance

Common issues associated with connecting rod cap screws include loosening over time due to engine vibrations and wear on the threading. To troubleshoot these problems, regular inspections should be conducted to check for any signs of loosening or damage. Maintenance practices such as torqueing the screws to the manufacturer’s specifications and replacing them if signs of wear are detected can help ensure the longevity and reliability of the 3900919 model.

About Cummins

Cummins Inc. is a renowned manufacturer in the commercial truck industry, known for its commitment to quality and innovation in engine components. With a rich history and a diverse product range, Cummins has established a strong reputation for producing reliable and high-performance engine parts. The company’s dedication to excellence is evident in its continued investment in research and development, ensuring that its products meet the evolving needs of the industry.

Connecting Rod Cap Screw (Part 3900919) Compatibility with Cummins Engines

The Cummins Connecting Rod Cap Screw, part number 3900919, is a critical component in the assembly of various Cummins engines. This part is designed to securely fasten the connecting rod cap to the connecting rod, ensuring stability and reliability during engine operation. Below is a detailed overview of the engines with which this part is compatible.

Compatible Engines

• 4B3.9
• 6B5.9
• B3.3
• B5.9 G
• B5.9 GAS PLUS CM556
• G5.9
• G5.9 CM558
• ISB CM550
• ISB CM850
• ISB5.9 CM2880 B110
• ISB5.9G CM2180
• ISBE CM800
• QSB3.9 30 CM550
• QSB5.9 30 CM550
• QSB5.9 44 CM550
• QSB5.9 CM2880 B115

Grouping of Compatible Engines

The engines listed above can be grouped based on their model series and specifications. Here is a breakdown of these groups:

• B Series Engines

  • B3.3
  • B5.9 G
  • B5.9 GAS PLUS CM556

• G Series Engines

  • G5.9
  • G5.9 CM558

• ISB Series Engines

  • ISB CM550
  • ISB CM850
  • ISB5.9 CM2880 B110
  • ISB5.9G CM2180
  • ISBE CM800

• QSB Series Engines

  • QSB3.9 30 CM550
  • QSB5.9 30 CM550
  • QSB5.9 44 CM550
  • QSB5.9 CM2880 B115

• Other Engines

  • 4B3.9
  • 6B5.9

Each of these engines, regardless of their specific model or series, relies on the Connecting Rod Cap Screw (part number 3900919) to maintain the integrity of the connecting rod assembly. Proper installation and maintenance of this part are essential for the smooth operation and longevity of the engine.

Role of Part 3900919 Connecting Rod Cap Screw in Engine Systems

The Part 3900919 Connecting Rod Cap Screw is an integral component in the assembly and operation of various engine systems. Its primary function is to secure the connecting rod cap to the connecting rod, ensuring a stable connection between the piston and the crankshaft. This screw plays a significant role in maintaining the integrity and performance of the engine’s internal components.

In the Block 6-B Short, Block Short, and Short Block configurations, the connecting rod cap screw ensures that the connecting rod is firmly attached to the crankshaft. This is essential for the smooth transfer of force from the piston to the crankshaft, which is fundamental for the engine’s operation.

For the Short 4BT, Short 6-BT, and Short 6BT blocks, the screw’s role remains consistent. It secures the connecting rod cap, allowing for efficient power transmission and reducing the risk of mechanical failure.

In the Short E2 Incent and Short E2 215/235 Block configurations, the connecting rod cap screw is vital for maintaining the precision and balance required for high-performance engines. These blocks often demand higher tolerances and greater reliability, making the secure attachment of the connecting rod cap imperative.

The Cylinder Block and Cylinder Head assemblies also benefit from the secure attachment provided by the connecting rod cap screw. This ensures that the reciprocating motion of the piston is effectively translated into rotational motion of the crankshaft, contributing to the overall efficiency and durability of the engine.

In Long Block and Short Block Kit setups, where the engine is partially or fully assembled, the connecting rod cap screw is a key component in ensuring that all moving parts are correctly aligned and securely fastened. This is particularly important in high-stress environments where engine performance and reliability are paramount.

For Performance Parts and Service Blocks, the connecting rod cap screw must meet stringent standards to handle increased loads and stresses. Its role in these applications is to provide a reliable and durable connection that can withstand the demands of enhanced engine performance.

Overall, the Part 3900919 Connecting Rod Cap Screw is a fundamental component in various engine configurations, ensuring the secure and efficient operation of the connecting rod and piston assembly within the engine system.

Conclusion

The 3900919 Connecting Rod Cap Screw by Cummins is a critical component in the operation and maintenance of heavy-duty truck engines. Its role in securing the connecting rod to the crankshaft ensures the efficient transfer of power and maintains engine stability and performance. The high-quality material, precise design, and compatibility with various Cummins engines make this part essential for the longevity and reliability of the engine system. Regular maintenance and proper installation are crucial to maximizing the benefits of this component.