3941253
Push Rod
Cummins®

The Cummins 3941253 Push Rod is a component designed for use in Cummins engines, specifically tailored for heavy-duty truck applications. Its purpose is to facilitate the operation of the engine’s valve system, ensuring efficient and reliable performance under demanding conditions.

Basic Concepts of Push Rods

Push rods are mechanical components used in overhead valve (OHV) engines to transfer motion from the camshaft to the valves. They play a role in the engine’s valve operation by connecting the camshaft’s lobes to the rocker arms, which then actuate the valves. This mechanism allows for precise control over the timing and duration of valve opening and closing, which is crucial for engine performance and efficiency ¹.

Purpose and Role of the 3941253 Push Rod

The 3941253 Push Rod is specifically engineered for Cummins engines, where it serves to transmit motion from the camshaft to the rocker arms. This transmission is vital for actuating the valves, which control the intake and exhaust of air and fuel in the combustion process. The push rod’s role in valve actuation directly influences the engine’s overall performance, including its power output, fuel efficiency, and durability ².

Key Features

The 3941253 Push Rod is characterized by several key features that enhance its functionality and durability. It is constructed from high-quality materials, ensuring resistance to wear and fatigue under the high stress and temperatures of engine operation. Its design specifications include precise dimensions and tolerances to ensure optimal fitment and performance within the engine. Additionally, any unique attributes, such as surface treatments or specific design elements, contribute to its reliability and longevity ³.

Benefits of Using the 3941253 Push Rod

Incorporating the 3941253 Push Rod into Cummins engines offers several advantages. It contributes to improved engine efficiency by ensuring precise valve operation, which is critical for optimal combustion. The push rod’s reliability and durability enhance the engine’s overall longevity, reducing the need for frequent replacements. Furthermore, its design may offer performance enhancements, such as reduced friction or improved heat dissipation, contributing to the engine’s efficiency and power output ⁴.

Troubleshooting and Maintenance

Common issues associated with push rods include wear, bending, or failure due to fatigue. Diagnostic procedures for identifying problems with push rods may involve visual inspection, measurement of clearances, and assessment of engine performance symptoms such as misfires or loss of power. Maintenance practices to ensure optimal performance and longevity of the 3941253 Push Rod include regular inspection for signs of wear or damage, proper lubrication, and timely replacement when necessary ⁵.

Installation and Replacement

Installing or replacing the 3941253 Push Rod requires careful attention to detail to ensure proper fitment and functionality. The process involves removing the old push rod, inspecting the camshaft and rocker arm for any damage, and installing the new push rod with the correct orientation and clearance. Necessary tools include wrenches, sockets, and possibly a push rod alignment tool. Precautions include ensuring the engine is cool before beginning work and following the manufacturer’s specifications for torque and clearances. Best practices involve double-checking all connections and clearances after installation to prevent future issues ⁶.

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, reliability, and innovation in the automotive industry, particularly in the realm of heavy-duty truck components. The company’s product offerings include a wide range of engines and components designed to meet the demanding requirements of commercial and industrial applications.

Cummins Push Rod 3941253 Compatibility

The Cummins Push Rod part number 3941253 is a critical component in various Cummins engine models, ensuring the proper operation of the valve train system. This push rod is designed to fit seamlessly within the architecture of several Cummins engine series, providing durability and reliability in demanding applications.

B Series Engines

• 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

These B series engines, ranging from 4.5 to 6.7 liters, utilize the 3941253 push rod to maintain the precise movement of the valves. The push rod’s design is compatible with the camshaft and valve mechanisms in these engines, ensuring smooth operation and longevity.

ISB Series Engines

• ISB (Chrysler)
• ISB CM2150
• ISB CM550
• ISB CM850
• ISB/ISD4.5 CM2150 B119
• ISB/ISD6.7 CM2150 SN
• ISB5.9 CM2880 B110
• ISB5.9 CM2880 B140
• ISB5.9 CM2880 B149
• ISB6.7 CM2250
• ISB6.7 CM2350 B101
• ISB6.7 G CM2180 B118

The ISB series engines, which include both 4.5 and 6.7 liter variants, are designed to work with the 3941253 push rod. This part is engineered to fit within the valve train of these engines, ensuring the valves open and close at the correct times, which is crucial for performance and efficiency.

ISBE Series Engines

• ISBE CM2150
• ISBE CM800
• ISBE4 CM850

The ISBE series engines also benefit from the 3941253 push rod. This part is compatible with the specific design of these engines, providing the necessary support and movement for the valves.

ISD Series Engines

• ISD4.5 CM2220 D108

The 3941253 push rod is also suitable for the ISD4.5 CM2220 D108 engine. This part ensures the valves operate correctly, maintaining the engine’s performance and reliability.

QSB Series Engines

• QSB4.5 CM2250 EC
• QSB4.5 CM850(CM2850)

The QSB series engines, including the 4.5-liter variants, are designed to use the 3941253 push rod. This component is integral to the valve train system, ensuring the valves function as intended.

The Cummins Push Rod 3941253 is a versatile and essential part that fits into various Cummins engine models, providing the necessary support and movement for the valve train system. Its compatibility across different engine series highlights its importance in maintaining engine performance and reliability.

Role of Part 3941253 Push Rod in Engine Systems

The Part 3941253 Push Rod is an integral component in the operation of various engine systems, facilitating the transfer of motion from the camshaft to the valve train. Its primary function is to transmit the rotational motion of the camshaft into linear motion, which is essential for the opening and closing of engine valves.

Interaction with the Rocker Lever

In engine systems equipped with overhead valve (OHV) configurations, the Push Rod interfaces directly with the Rocker Lever. The Rocker Lever, in turn, amplifies the motion transmitted by the Push Rod. This amplification ensures that the valve opens sufficiently to allow the necessary airflow into the combustion chamber. The precise movement of the Rocker Lever, guided by the Push Rod, is vital for maintaining engine efficiency and performance ⁷.

Integration with the Long Block

When considering the Long Block—an engine assembly that includes the cylinder block, crankshaft, pistons, and often the camshaft—the Push Rod plays a supporting yet significant role. It ensures that the camshaft’s motion is effectively translated to the valve train, allowing for the proper timing of valve operations. This timing is essential for the engine’s combustion process, directly influencing power output and fuel efficiency ⁸.

Functionality in the Long Block Kit

In a Long Block Kit, which typically includes all components of the Long Block along with additional parts like gaskets and seals, the Push Rod remains a key element. It ensures that once the engine is assembled, the valve train operates smoothly and efficiently. The Push Rod’s role in this setup is to maintain the integrity of the valve timing, which is crucial for the engine’s overall performance and longevity ⁹.

Coordination with the Rocker

The coordination between the Push Rod and the Rocker is fundamental in overhead cam (OHC) engine systems as well. Although the camshaft is closer to the valves in OHC engines, the Push Rod still plays a role in certain designs, particularly in systems where additional leverage is required for valve actuation. The Rocker, in this case, works in tandem with the Push Rod to ensure that the valves open and close with the precision needed for optimal engine function ¹⁰.

Conclusion

In summary, the Part 3941253 Push Rod is a vital link in the chain of components that make up an engine’s valve train. Its interaction with the Lever, Rocker, Long Block, and Long Block Kit underscores its importance in ensuring that the engine operates efficiently and effectively.