Cummins QSB 6.7 Parts - Cylinder Head Section

Cylinder Heads & Related Components for Cummins QSB 6.7 Engines

The Cummins QSB 6.7 engine is a cornerstone in the mid-range diesel lineup, used extensively across construction, agriculture, marine, and power generation markets. Known for its power density, fuel efficiency, and compliance with global emissions standards, the QSB 6.7 requires careful attention to its top-end components to maintain performance and reliability. At Diesel Pro Power, we stock an extensive inventory of new cylinder heads and all associated components required for top-end service on the QSB 6.7 platform.

New Cylinder Head Assemblies for QSB 6.7

Our catalog includes brand-new, fully assembled cylinder heads for Cummins QSB 6.7 engines. These heads arrive ready to install with preloaded intake and exhaust valves and are engineered to OEM specifications to ensure proper fit, flow, and durability.

Key Features:

• Manufactured with high-strength castings for extended durability

• Pre-installed valves to reduce installation time

• Precision-machined for exact combustion sealing

• Ideal for complete top-end overhauls or replacing cracked heads

Replacing a warped or cracked cylinder head is critical to restoring proper compression, eliminating coolant leaks, and preventing loss of engine power. Our new heads help you get back up and running quickly with minimal downtime.

Intake & Exhaust Valves for QSB 6.7

Maintaining proper valve function is critical to the intake and exhaust cycle in a diesel engine. Whether you're rebuilding the head or performing a valve job, we offer a full line of intake and exhaust valves for QSB 6.7 engines.

Cummins Intake Valves:

• Designed for optimal airflow into the combustion chamber

• Heat-treated for high-temperature endurance

• Compatible with ISB and QSB engine platforms

Cummins Exhaust Valves:

• Built to withstand intense heat and pressure

• Include keepers or are available in complete kits with seals

• Matched to QSB 6.7 exhaust flow requirements

Worn or pitted valves can result in poor sealing, blow-by, power loss, and increased oil consumption. Replacing these components during head service is key to restoring peak performance.

Valve Seals, Guides & Inserts

Valve control and longevity are only possible with proper sealing and guidance inside the cylinder head. Diesel Pro Power carries all related components, including:

Valve Seals:

• Prevent oil intrusion into the combustion chamber

• Designed for both intake and exhaust applications

• Require replacement whenever valves are serviced

Valve Guides:

• Support smooth and centered valve movement

• Prevent valve stem wobble and uneven seat wear

• Help reduce oil consumption and ensure accurate valve timing

Valve Inserts:

• Hardened metal rings pressed into the cylinder head

• Provide a seating surface for the intake and exhaust valves

• Protect against seat erosion, especially in high-duty cycles

These components are essential during cylinder head refurbishment and ensure long-term engine health.

Cylinder Head Bolts

Cylinder head bolts for the QSB 6.7 must be replaced any time the head is removed. They are torque-to-yield fasteners, designed to stretch slightly to maintain clamping force across the head and block interface.

Options Available:

• 70mm bolts for earlier Cummins B-series blocks

• 131mm bolts for the QSB 6.7 and related platforms

Installation Tips:

• Always follow the torque and angle sequence in Cummins service literature

• Use clean engine oil or the specified lube on bolt threads and washers

• Inspect bolt holes for debris or damage before installation

Replacing bolts ensures the correct head gasket clamping load and avoids future leaks or failures.

Cylinder Head Gaskets & Upper Gasket Sets

Diesel Pro Power carries complete upper gasket sets specifically for the Cummins QSB 6.7 engine platform. These sets include everything required to reseal the cylinder head and surrounding components:

Included in the Sets:

• Cylinder head gasket

• Valve cover gasket

• Intake and exhaust manifold gaskets

• Thermostat housing and EGR gaskets

• Injector seals and rocker cover seals

The head gasket is engineered to withstand extreme compression and thermal cycling, helping prevent coolant and oil leaks between head and block. These kits are available in variations that match horsepower ratings and emissions configurations.

Valve Springs & Retainers

Valve springs ensure consistent valve closing pressure, preventing valve float and misfires during high-RPM operation. Over time, springs can lose tension due to heat cycling, leading to valve control issues.

Key Features:

• Compatible with QSB, ISB, 4BT, and 6BT engine families

• Matched spring rates for factory valve lift profiles

• Available with matching retainers for complete service

Always inspect valve springs and retainers during cylinder head removal to check for cracks, loss of tension, or abnormal wear.

Intake & Exhaust Valve Inserts

Valve seat inserts play a vital role in heat transfer and sealing. On high-hour engines, worn inserts can lead to valve seat erosion, misfiring, or hot spots.

Applications:

• Intake and exhaust inserts available separately

• Built to resist corrosion and heat damage

• Designed for press-fit installation into cylinder head casting

Replacing these components extends cylinder head life and reduces the risk of catastrophic valve failures.

Valve Cover Gaskets

The valve cover gasket is often overlooked but critical for preventing oil leaks from the top of the engine. Designed to seal the interface between the valve cover and the cylinder head, this gasket helps keep oil in and contaminants out.

Construction:

• Rubber or silicone-based with steel reinforcement

• Designed for thermal expansion resistance

• Easy to install during head or valve cover service

Our gaskets are matched specifically to QSB 6.7 and ISB 6.7 engines, ensuring proper sealing and longevity.

Additional Related Components

In addition to the major parts above, Diesel Pro Power also offers:

Temperature Switches:

• Designed to trigger at 205°F for coolant system alerts

• Compatible with Cummins, Caterpillar, and Detroit Diesel applications

• Threaded for 1/2" NPT ports

These switches are often used in alarm panels or automatic fan systems to prevent overheating—critical to protecting your cylinder head from warping or cracking due to thermal shock.

Why Choose Diesel Pro Power for Cummins QSB 6.7 Cylinder Head Parts?

At Diesel Pro Power, we understand the unique requirements of diesel engine owners, fleet operators, and rebuilders. Our catalog is built around speed, reliability, and accuracy.

Here’s what sets us apart:

• All parts are in stock and ready to ship

• Trusted by over 40,000 satisfied customers worldwide

• Real inventory—no dropshipping delays

• Fast delivery to over 200 countries

• Dedicated diesel experts to assist with fitment and compatibility

We specialize in Cummins diesel engine components, which allows us to maintain deep inventory across every cylinder head component—from gaskets to complete assemblies.

Applications of Cummins QSB 6.7 Cylinder Head Parts

The QSB 6.7 is used in a variety of demanding applications including:

• Agricultural tractors and harvesters

• Wheel loaders and excavators

• Industrial air compressors and pumps

• Marine generators and auxiliary drives

No matter the application, proper cylinder head maintenance ensures optimal engine breathing, compression, and temperature regulation—key to keeping your machine running profitably and efficiently.