Turbo

Turbochargers & Related Components for Cummins 4BT Engines

The Cummins 4BT turbo system plays a vital role in the performance and efficiency of your engine. Whether you're working with a marine generator, industrial pump, or equipment application, proper boost and airflow are critical to keep your Cummins 4BT running at peak efficiency. At Diesel Pro Power, we stock a complete selection of turbochargers and supporting components designed to match the unique specifications of the Cummins 4BT engine.

Explore genuine and aftermarket options below, all backed by our fast shipping and support from a team trusted by 40,000+ customers worldwide.

Complete Turbocharger Assemblies

Cummins 4BT Turbocharger Assembly

Our premium-quality Cummins 4BT turbocharger is a direct-fit replacement engineered for standard single turbo setups. This unit is ideal for restoring factory boost pressure and ensuring your engine maintains proper combustion temperatures, power output, and fuel efficiency.

• Designed for 4BT 3.9L engines with single turbo configuration

• Precision-balanced turbine and compressor wheels

• Durable cast construction with high-nickel alloy housings

• Ideal for marine, agricultural, and industrial 4BT applications

• Backed by Diesel Pro Power’s fast shipping and customer support

Compatible CPLs: While specific CPL numbers vary, this turbo fits most standard 4BT CPLs using single turbo configurations.

Turbo Hardware & Connection Components

Hump Hose – 3.5" to 3" Turbo Inlet Reducer

Boost piping often requires adapting between mismatched diameters—our high-quality hump hose makes this easy. This flexible silicone coupling allows for vibration isolation and secure fitment when adapting a 3.5-inch turbo outlet to a 3-inch intake or intercooler inlet.

• Heavy-duty construction rated for high-boost applications

• Excellent resistance to heat and oil mist

• Ideal for 4BT intercooler retrofits or turbo upgrades

Use this part when retrofitting or maintaining charge air systems where turbo piping diameters vary from the stock configuration.

Turbo Mounting Studs – Set of 4

Reliable turbo mounting hardware is essential. This OEM-grade turbo stud fits the Cummins 4BT and comes in a set of four—the exact number required to mount a standard turbocharger to the exhaust manifold.

• Threaded for precise fitment with minimal vibration

• Corrosion-resistant coating for marine and harsh environments

• Ensures consistent torque and safe operation

Note: Always replace turbo studs during turbocharger replacement to avoid future failures due to thermal cycling or fatigue.

Air Management Components

Cummins AirSep System – Single Turbo Setup

The Cummins AirSep system is an advanced crankcase ventilation solution designed for marine and stationary Cummins 4BT engines using a single turbo. This unit helps eliminate oil mist, reduce blow-by, and ensure clean intake air.

• Fits Cummins 4BT 3.9L engines with single turbo

• 3-inch throat diameter for clean air flow

• Combines crankcase filtration with intake filtration in one system

• Ideal for high-hour or emissions-regulated installations

Applications: Marine vessels, standby generators, water pumps, and more.

Intake Manifold Gasket for Cummins 4BT

A clean, leak-free intake manifold is essential for turbocharged engine performance. This gasket forms a precise seal between the intake manifold and the cylinder head on the 4BT engine.

• Durable composite material resists high temperatures

• Maintains intake boost pressure integrity

• Prevents unmetered air from entering the engine

Always inspect and replace this gasket when servicing the intake or turbo system.

Turbo Oil & Coolant System Components

Turbo Oil Drain Gasket – Cummins 4BT

This small but critical gasket ensures a proper seal at the turbocharger’s oil drain outlet. A failed gasket can lead to oil leaks, turbo contamination, and poor lubrication.

• Compatible with Cummins 4BT, 6BT, ISB, and QSB turbochargers

• Heat-resistant materials suitable for sustained high temps

• Easy drop-in replacement

Recommended to replace this gasket any time the turbo is removed or replaced.

Aftercooler O-Ring for Cummins 4BT and Related Engines

This high-quality O-ring is used to seal aftercooler joints across multiple Cummins engine platforms including the 4BT, 4BTA, 6BT, 6BTA, ISB4.5, ISB6.7, QSB4.5, and QSB6.7.

• Premium elastomer formulation resists oil, heat, and pressure

• Ensures charge air cooling system operates at full efficiency

• Helps maintain consistent boost and intake air temps

Proper aftercooler sealing is especially critical in marine environments, where air-cooled charge air systems are often exposed to salt-laden atmospheres.

Sealant for Turbo Mounting

762 Hi-Temperature Jointing Compound

Turbocharger systems operate under extreme temperature conditions. The 762 compound is a premium jointing material designed to create gas-tight seals on turbo flanges, exhaust manifolds, and other high-heat joints.

• Withstands up to 760°C (1,400°F)

• Compatible with Cummins and Detroit Diesel turbos

• 225-gram tube ideal for multiple applications

• Remains pliable over time to resist vibration cracking

Perfect for sealing metal-to-metal joints in turbo systems where traditional gaskets may fail or are not used.

Why Diesel Pro Power is the Best Choice for Cummins 4BT Turbo Parts

Whether you're maintaining an existing turbo system or upgrading to improve performance and durability, Diesel Pro Power is your trusted source for Cummins 4BT turbocharger components. With over 40,000 satisfied customers, we deliver parts that meet or exceed OEM standards and provide unmatched customer support.

What You Can Expect:

• All Components In Stock – Ready to ship fast

• Worldwide Shipping – Trusted by marine and industrial operations globally

• Dedicated Engine Experts – Support staff who actually know your engine

• Secure Checkout – Easy, fast, and encrypted transactions

• No Guesswork – We help you find the right part the first time

Installation Tips for Cummins 4BT Turbochargers

• Pre-lube the turbo: Always pour clean engine oil into the oil inlet before startup.

• Check shaft play: Slight radial play is normal, but axial play is a red flag.

• Inspect exhaust manifold and oil lines: Replace gaskets, studs, and clamps as needed.

• Boost leak test: After installation, check your charge air system for leaks to prevent power loss.

• Don’t forget the drain gasket: It's a cheap part that can prevent costly oil messes.

Common Applications for Cummins 4BT Turbo Components

• Marine propulsion and genset engines

• Stationary pumps and compressors

• Construction machinery and forklifts

• Industrial equipment and retrofit conversions

• Off-road and agriculture vehicles using 4BT powerplants