Cummins QSB 6.7 Parts - Camshaft Section

Cummins QSB 6.7 Camshaft Components

The camshaft system in a Cummins QSB 6.7 engine plays a critical role in coordinating valve timing, optimizing combustion, and ensuring peak performance for marine and industrial applications. At Diesel Pro Power, we provide high-quality camshaft components designed to maintain the original performance standards of your QSB 6.7, whether you are performing preventative maintenance, an in-frame rebuild, or a complete overhaul.

Our inventory covers essential camshaft-related parts for the QSB 6.7, including camshaft bushings, valve lifters (tappets), and related hardware. These components are engineered to meet or exceed OEM specifications, ensuring they withstand the rigorous demands of continuous duty cycles in marine and heavy-equipment environments.

Camshaft Bushings for Cummins QSB 6.7

Camshaft bushings are critical for supporting the camshaft within the engine block, allowing smooth rotation while minimizing friction and wear. A worn or damaged camshaft bushing can cause misalignment, increase friction, and lead to premature camshaft wear.

High-quality bushings for the Cummins QSB 6.7 are precision-machined to exact tolerances, ensuring correct oil clearance and stable camshaft operation. When replacing these bushings, proper installation and lubrication are essential to prevent premature failure. In marine and industrial settings, where engines operate under sustained loads, ensuring that bushings are in excellent condition is vital for long-term reliability.

Key benefits of using premium camshaft bushings:

• Maintains correct camshaft alignment for consistent valve timing.
  
  

• Reduces metal-to-metal contact, extending camshaft life.
  
  

• Supports oil film stability to reduce friction.
  
  

• Enhances overall engine smoothness and efficiency.
  
  

Valve Lifters (Tappets) for Cummins QSB 6.7

Valve lifters—also known as tappets—transfer motion from the camshaft lobes to the pushrods and valves. In the QSB 6.7, proper lifter operation is crucial for accurate valve timing and optimal fuel-air mixture control.

We supply lifters designed for both pre-2003 and post-2003 QSB engine configurations. This distinction is important because Cummins modified lifter designs over time to match evolving camshaft profiles and lubrication strategies.

Valve lifter function and importance:

• Ensures smooth transfer of camshaft motion to the valve train.
  
  

• Maintains correct valve lash to prevent excessive wear.
  
  

• Reduces noise and vibration from the valve train.
  
  

• Helps sustain consistent combustion efficiency.
  
  

Why valve lifter replacement matters:
In marine engines like the QSB 6.7, constant operation at mid-to-high load can cause gradual wear on lifter surfaces. Worn or pitted lifters can cause camshaft lobe damage, leading to reduced engine performance and costly repairs. Replacing lifters during an overhaul or when symptoms of wear appear—such as ticking noises, reduced power, or rough idle—is essential to maintaining long-term performance.

Preventive Maintenance for QSB 6.7 Camshaft Systems

The camshaft system is designed for long service life, but it requires proper maintenance to reach its full potential. In a marine environment, QSB 6.7 camshaft components are exposed to sustained load conditions, high operating temperatures, and potential lubrication challenges.

Best practices for camshaft system care:

• Regular oil changes: Use marine-grade oil that meets Cummins specifications to reduce wear on bushings and lifters.
  
  

• Valve lash adjustment: Periodic lash adjustments help prevent excessive stress on camshaft lobes and lifters.
  
  

• Lubrication checks: Ensure proper oil pressure and flow to the camshaft and lifter galleries.
  
  

• Component inspection during rebuilds: Always inspect camshaft lobes, bushing clearances, and lifter faces during in-frame or out-of-frame rebuilds.
  
  

Common Signs of Camshaft or Lifter Wear in the QSB 6.7

Early detection of camshaft or lifter issues can save significant repair costs and prevent unplanned downtime.

Symptoms to watch for:

• Tapping or ticking noises from the valve train area.
  
  

• Drop in engine power or acceleration response.
  
  

• Uneven cylinder compression readings.
  
  

• Excessive metal shavings in the oil filter or sump.
  
  

• Rough idle or misfiring under load.
  
  

When these symptoms appear, it is best to address the problem promptly, as running with damaged camshaft components can result in damage to additional parts, including valves, pushrods, and rocker arms.

Why Choose Diesel Pro Power for QSB 6.7 Camshaft Components

With over 40,000 satisfied customers worldwide, Diesel Pro Power has earned a reputation for providing high-quality marine and industrial diesel engine parts with fast, reliable shipping. Our QSB 6.7 camshaft bushings, valve lifters, and related components are built to withstand the demanding operating conditions found in marine propulsion systems, auxiliary power units, and heavy-duty equipment.

What you get when ordering from Diesel Pro Power:

• Precision-machined components that meet or exceed OEM standards.
  
  

• Expert customer support with deep knowledge of Cummins marine engines.
  
  

• Worldwide shipping to keep vessels and equipment operational.
  
  

• Easy online ordering with in-stock inventory ready to ship.