Cummins QSC Parts - Cylinder Head Section

Cylinder Heads & Related Components for Cummins QSC

The Cummins QSC engine series is part of the Quantum System family of electronically controlled diesel engines, commonly used in commercial marine, construction, agricultural, and industrial equipment. Known for its fuel efficiency, low emissions, and high performance in heavy-duty applications, the QSC engine benefits significantly from a robust and well-maintained cylinder head system.

At Diesel Pro Power, we carry a full range of cylinder heads and related components for Cummins QSC engines. Whether you’re performing a top-end overhaul or simply replacing key valvetrain components, our parts meet or exceed OEM standards and are trusted by over 40,000 satisfied customers worldwide.

Complete Cylinder Head Assembly for Cummins QSC

We offer a brand-new cylinder head for the Cummins QSC engine that includes both valves and valve springs pre-installed. This complete assembly is ideal for customers performing a full cylinder head replacement and looking to minimize downtime. The fully assembled head eliminates the need for additional machine work or parts installation.

This head is also compatible with many QSL engine configurations, especially those sharing the CM850 electronic control module platform. The casting quality and component metallurgy ensure long service life, resistance to cracking under thermal stress, and excellent sealing between the head and the block.

Exhaust Valves for Cummins QSC

The exhaust valves in your QSC engine play a vital role in channeling hot gases out of the combustion chamber. We offer premium exhaust valves that are heat-treated for high-temperature applications and engineered to resist warping and erosion. These valves are a direct-fit replacement for the QSC, ISC, and compatible ISL platforms.

Routine inspection and timely replacement of exhaust valves can help prevent issues like backfiring, poor engine performance, or cylinder head overheating. If you're rebuilding the top end, it's strongly recommended to replace both intake and exhaust valves together.

Intake Valve Kit for Cummins QSC

Our intake valve kit is a high-quality solution designed to ensure optimal airflow into the combustion chamber. The kit includes the intake valve, and is precision-manufactured to maintain tight tolerances and proper seating inside the cylinder head. For QSC engines using the CM850 control module and HPCR fuel systems, these intake valves help maintain peak fuel efficiency and engine responsiveness.

Cylinder Head Bolts for Cummins QSC Engines

Cylinder head bolts are responsible for securing the head to the engine block and maintaining the pressure seal necessary for combustion. We offer high-strength cylinder head bolts suitable for the ISC and QSC models. These bolts are built to handle the high clamp loads generated during operation, especially in electronically controlled QSC engines.

For best results, always use new head bolts during reassembly and follow the torque sequence and specifications outlined in the Cummins service manual. Reusing old bolts can lead to uneven torque and blown head gaskets.

Gasket Sets for QSC Engine Cylinder Head Rebuilds

Upper Gasket Sets for Multiple Fuel Systems

We carry several upper gasket sets designed for different QSC engine configurations. These sets include the cylinder head gasket, intake and exhaust manifold gaskets, valve cover gaskets, and injector seals.

For CM554 / CAPS Fuel System

This upper gasket set supports QSC and ISC engines running the CAPS (Cummins Accumulator Pump System). These engines were common in earlier production models and require specific gasket material compositions.

For CM850 / HPCR Fuel System

High Pressure Common Rail systems found in newer QSC variants (often labeled CM850) demand gaskets that can withstand higher injection pressures and thermal cycling. Our sets meet these demands for durability and performance.

For EGR-Compatible Engines

We also offer gaskets tailored for engines equipped with Exhaust Gas Recirculation systems. These require enhanced sealing around the EGR ports to prevent gas leakage and ensure compliance with emission standards.

Lower Gasket Set for QSC Engines

For a more complete overhaul, we offer the lower gasket set for the QSC engine, which includes oil pan gaskets, crankshaft seals, and front/rear cover gaskets. This is ideal when performing both top and bottom-end rebuilds. Especially for engines with the CM850 Control Module, it’s crucial to use the correct lower gasket material to prevent oil and coolant cross-contamination.

Valve Train Components for Cummins QSC

Valve Springs & Spring Retainers

Our QSC valve springs are engineered for both intake and exhaust valve assemblies and are compatible across the ISC, ISL, and QSL engine families. Designed for high-tensile strength and consistent spring pressure, these springs ensure valves return to their seat at the proper time during the engine cycle.

Pair these with our heavy-duty valve spring retainers, manufactured from hardened steel, to ensure reliability under high-RPM and high-load conditions.

Valve Seats (Inserts) – Intake & Exhaust

Valve inserts (also called seats) are a critical interface between the valve and the cylinder head. We supply both intake and exhaust valve inserts for QSC engines, made of hardened alloy to withstand impact and thermal cycling. Proper valve seat replacement is crucial during a cylinder head rebuild, particularly if the head has experienced valve recession or pitting.

Valve Guides & Seals

Valve guides provide lateral support for the valve stem and help maintain alignment during operation. Over time, guides may wear, leading to excessive valve movement, oil consumption, or valve misalignment. We offer precision-machined guides that match OEM tolerances and restore factory specifications.

Valve guide seals—often overlooked—are just as essential. Our QSC-compatible seals are made from high-temperature rubber and polymer blends to prevent oil from seeping into the combustion chamber. Replacing valve seals during a top-end rebuild can significantly reduce oil burn and improve compression.

Intake Connection Gasket

The intake connection gasket provides a reliable seal between the intake manifold and the cylinder head. This gasket ensures air entering the combustion chamber is not disrupted by vacuum leaks, which can affect fuel mapping and throttle response in electronically managed QSC engines.

Additional Components Supporting QSC Cylinder Head Maintenance

Rocker Arm Gaskets and Valve Cover Gaskets

A complete cylinder head rebuild isn’t finished without a fresh valve cover gasket. Our valve cover gaskets are compatible with 5-bolt and 8-bolt cover designs and are designed to withstand oil splash and engine vibrations without degrading over time.

We also offer the rocker housing gasket, which provides a seal between the rocker assembly and the head. These gaskets are especially important when using synthetic oils, which tend to seep past older gasket materials.

Cylinder Head Installation Tips for Cummins QSC

• Always use new head bolts and torque in the proper sequence. QSC engines rely on exact clamping force to maintain cylinder pressure.

• Inspect the head for flatness before installation. Warped heads can cause gasket failure.

• Use OEM-spec gasket material that is compatible with your fuel system (CAPS, HPCR) and emission configuration (EGR vs. non-EGR).

• Replace all wearable components together—this includes valves, springs, retainers, guides, seals, and gaskets—to ensure consistent performance and longevity.

• Flush the cooling system thoroughly before restarting the engine to prevent contamination buildup.

Temperature Switch for Cummins & Detroit Diesel Engines

We also carry a high-quality temperature switch that fits Cummins, Detroit Diesel, and Caterpillar engines. This temperature sensor activates engine fans or warning systems at a calibrated threshold and is compatible with QSC engine setups using mechanical or digital temperature readouts. Threaded to 1/2" NPT, it installs easily in standard sensor ports and adds an extra layer of protection during demanding applications.

Trust Diesel Pro Power for Cummins QSC Cylinder Head Parts

Whether you're performing preventative maintenance or a full top-end rebuild, Diesel Pro Power has the cylinder head components you need—backed by fast shipping and expert support. Every part we offer for the Cummins QSC engine is selected for quality, durability, and compatibility with both marine and industrial duty cycles.

With 40,000+ satisfied customers, Diesel Pro Power is a name you can trust for Cummins parts. We’re proud to offer not only premium replacement parts, but also peace of mind.