Cummins ISB 6.7 Exhaust System Parts Catalog

The Cummins ISB 6.7L diesel engine is widely used in both marine and industrial applications, requiring a reliable exhaust system to handle high temperatures, control emissions, and optimize back pressure for peak performance. Diesel Pro Power supplies a full range of exhaust components for the ISB 6.7, from manifold gaskets to industrial mufflers, engineered for long service life and maximum efficiency. With over 40,000+ satisfied customers, we deliver OEM-quality parts that ensure your Cummins engine stays compliant, efficient, and dependable.

Intake Manifold Cover Gasket for Cummins ISB 6.7

The intake manifold cover gasket seals the top of the intake manifold, preventing air leaks that can disrupt fuel-air mixture balance and reduce performance. A properly fitted gasket also keeps contaminants out of the intake path, protecting cylinders from wear.

• Function: Maintains intake manifold air tightness, prevents unmetered air entry.

• Material: High-temperature composite for diesel application.

• Installation Tip: Always clean both sealing surfaces thoroughly and torque bolts in a crisscross pattern to manufacturer specifications.

• Applications: Marine propulsion, industrial generator sets, auxiliary power units.

Exhaust Manifold Insulation Tape – 3" Wide x 100' Long

High-temperature exhaust manifold insulation tape helps maintain exhaust gas velocity by retaining heat in the manifold and piping. This reduces heat soak into surrounding components, increases turbocharger efficiency, and improves operator safety.

• Dimensions: 3 inches wide, 100 feet long, 1/8" thick.

• Heat Resistance: Designed for extreme diesel exhaust temperatures.

• Benefits:

• Reduces engine compartment heat load.

• Protects wiring, hoses, and nearby components from radiant heat damage.

• Improves turbo spool time by keeping exhaust gases hot.

• Installation Tip: Overlap each wrap by 1/4 to 1/2 inch for best coverage.

Exhaust Manifold Insulation Tape – 4" Wide x 100' Long

Similar to the 3-inch tape, the 4-inch version provides broader coverage per wrap, ideal for large-diameter exhaust piping or wide manifold runners.

• Dimensions: 4 inches wide, 100 feet long, 1/8" thick.

• Applications: Often used on large industrial exhaust headers or marine wet exhaust elbows.

• Material: Fiberglass-based thermal wrap with reinforced weave for durability.

• Performance Benefit: Helps preserve exhaust system efficiency and prolongs paint or coating life on exhaust components.

Flange for Industrial Exhaust Manifold – 4" Inside Diameter

This heavy-duty flange connects the Cummins ISB 6.7 exhaust manifold outlet to the downstream exhaust piping.

• Material: Precision-machined steel for a secure, leak-free connection.

• Size: 4-inch inside diameter.

• Benefits:

• Provides a strong mechanical junction for high-vibration environments.

• Compatible with marine-grade stainless exhaust piping.

• Maintenance Tip: Inspect flange faces for warping before reassembly to ensure gasket sealing.

Gasket for 4" Manifold Flange

The flange gasket provides a gas-tight seal between the exhaust manifold flange and the connected pipe or muffler inlet.

• Size Compatibility: For 4-inch inside diameter flanges.

• Material: High-temp graphite or composite blend to withstand diesel exhaust heat cycles.

• Role in Performance: Prevents exhaust leaks that can cause power loss, turbo inefficiency, and excessive noise.

Muffler for Industrial Cummins ISB 6.7 Applications – 4" NPT Inlet & Outlet

This industrial-grade muffler is engineered to quiet exhaust noise while maintaining low back pressure for optimal ISB 6.7 performance.

• Inlet/Outlet: 4-inch National Pipe Thread.

• Construction: Heavy-gauge steel with corrosion-resistant coating for marine or industrial environments.

• Performance Benefits:

• Reduces operator fatigue from prolonged noise exposure.

• Helps maintain compliance with local sound ordinances.

• Sizing Note: Always verify muffler dimensions against available mounting space before purchase.

Muffler End Caps for Cummins ISB 6.7 Exhaust Systems

End caps protect muffler openings from debris, moisture intrusion, and environmental damage when engines are inactive.

3" Muffler Cap

• Outside Diameter: ~2.99 inches (7.59 cm).

• Use Case: Small outlet mufflers or auxiliary exhaust ports.

3.5" Muffler Cap

• Outside Diameter: 3.50 inches (8.89 cm).

• Use Case: Medium-sized muffler systems in industrial or marine gensets.

4.5" Muffler Cap

• Outside Diameter: 4.49 inches (11.40 cm).

• Use Case: Large exhaust ports requiring full coverage against salt spray or dirt.

5" Muffler Cap

• Outside Diameter: 5 inches (12.7 cm).

• Use Case: Heavy-duty marine or stationary applications with wide exhaust outlets.

Installation Tip: Always measure pipe outside diameter before selecting a cap size to ensure a secure fit.

Exhaust System Maintenance for the Cummins ISB 6.7

A healthy exhaust system ensures the ISB 6.7 operates efficiently and within emissions compliance. Common signs of exhaust wear include:

• Increased exhaust noise.

• Visible soot around joints or flanges.

• Reduced turbo response.

• Overheating in nearby components due to failed insulation.

Preventive Practices:

• Replace gaskets whenever the exhaust system is disassembled.

• Rewrap insulation tape every few years, especially in marine environments.

• Inspect mufflers for internal baffle deterioration.

• Use corrosion-resistant hardware in coastal operations.