Cummins 6B Engine Parts – Camshaft & Related Components

The camshaft system is the heart of the Cummins 6B’s valvetrain, controlling the precise timing and movement of the engine’s intake and exhaust valves. A properly maintained camshaft assembly ensures that your engine breathes efficiently, delivers strong torque across the power band, and maintains its legendary reputation for reliability in marine and industrial applications.

In this section, we detail all major camshaft-related components for the Cummins 6B engine, including the camshaft bushings, valve lifters (tappets), and push rods. These parts work in harmony to translate the rotational movement of the crankshaft into smooth, accurate valve actuation—ensuring peak performance and long service life.

Camshaft Function in the Cummins 6B Engine

The camshaft in the Cummins 6B is designed for optimal durability and precise operation, even under heavy-duty workloads. As the crankshaft rotates, it drives the camshaft via a timing gear or timing belt, depending on the engine configuration. The camshaft lobes push on valve lifters, which then transfer motion through push rods to rocker arms, opening the valves at exactly the right moment for efficient combustion.

Key benefits of a well-maintained camshaft include:

• Consistent valve timing for improved fuel efficiency.

• Smooth engine operation with reduced noise and vibration.

• Maximized power output across various RPM ranges.

• Reduced wear on related components, extending overall engine life.

Camshaft Bushings for Cummins 6B

Purpose of Camshaft Bushings

Camshaft bushings provide a stable, low-friction surface for the camshaft journals to rotate in. By maintaining proper alignment and minimizing metal-to-metal contact, these bushings prevent premature wear on both the camshaft and the engine block.

Features of High-Quality Bushings

• Precision-machined surfaces for exact fit and optimal oil film retention.

• Hardened alloy construction for extended wear resistance.

• Oil channeling design to ensure constant lubrication of the camshaft journals.

When to Replace Camshaft Bushings

Over time, bushings can wear due to insufficient lubrication, contamination, or high operating loads. Common signs of worn bushings include:

• Excessive camshaft endplay or lateral movement.

• Abnormal valvetrain noise.

• Metal shavings found in engine oil.

Routine inspection during overhauls helps prevent costly damage to the camshaft and surrounding components.

Valve Lifters (Tappets) for Cummins 6B

Role in the Valvetrain

Valve lifters, also known as tappets, transfer motion from the camshaft lobes to the push rods. They must operate smoothly to ensure consistent valve lift and duration. In the Cummins 6B, solid lifters are used for durability and high-precision valve operation.

Features & Benefits

• Hardened contact surfaces to resist cam lobe wear.

• Precision-ground faces for consistent camshaft contact.

• Oil passage designs that promote lubrication to critical contact points.

Signs of Worn Valve Lifters

• Tapping or clicking noises from the engine.

• Uneven engine idle or reduced performance.

• Premature camshaft lobe wear.

Replacing worn lifters is crucial, as continued use can damage both the camshaft and push rods.

Push Rods for Cummins 6B

Function & Importance

Push rods transmit the upward motion from the valve lifters to the rocker arms, which then pivot to open the valves. Proper push rod geometry ensures that valves open fully and close completely, maintaining compression and combustion efficiency.

Construction Features

• Hollow steel or alloy tubes for light weight and strength.

• Precision ball ends for smooth seating in lifters and rocker arms.

• Oil passage capability in certain designs for added lubrication.

Replacement Guidelines

Push rods should be inspected for straightness, tip wear, and surface pitting. Bent or damaged push rods can cause valve timing errors, reduced engine performance, and even catastrophic engine failure if left unaddressed.

Maintaining the Camshaft Assembly in a Cummins 6B

Proper maintenance of the camshaft system extends the engine’s lifespan and ensures optimal efficiency. Best practices include:

• Using the correct grade of engine oil and changing it at recommended intervals.

• Inspecting camshaft lobes, lifters, and push rods during major services.

• Ensuring proper oil pressure to maintain lubrication.

• Checking valve lash periodically to prevent excessive load on camshaft lobes.

Why Choose Diesel Pro Power for Cummins 6B Camshaft Components

With over 40,000+ satisfied customers worldwide, Diesel Pro Power is a trusted source for Cummins 6B camshaft parts and related valvetrain components. All parts are built to meet or exceed OEM specifications, ensuring reliable performance in demanding marine and industrial environments.

Whether you’re replacing a single camshaft bushing, upgrading your valve lifters, or performing a full top-end rebuild, you can count on:

• Expert customer service from diesel specialists.

• Fast worldwide shipping to minimize downtime.

• High-quality parts backed by decades of experience.