Machinery & Truck PartsThe Cummins ISC is an 8.3-liter inline-six diesel built for medium-duty trucks and demanding vocational applications. It combines a heavy-duty wet-liner block with electronic controls and was offered in multiple emissions and fuel-system generations, so horsepower, torque, injection system, and aftertreatment vary by model year. Machinery and Truck Parts stocks tested used Cummins ISC engines, each identified by stock number and backed by warranty coverage. Call (800) 696-5459 with the engine serial number or CPL and your truck information so we can help confirm fit and quote freight.
Cummins ISC 8.3L Engine Specifications
| Displacement | 8.3 L (505 cu in) |
| Configuration | Inline-6, 4-stroke turbodiesel |
| Bore x Stroke | 114 mm x 135 mm (4.49 in x 5.31 in) |
| Cylinder design | Replaceable wet liners |
| Aspiration | Turbocharged and charge-air cooled |
| Horsepower | Common truck ratings about 240 to 350 hp; some applications reach about 380 hp |
| Peak torque | Typically about 660 to 1,050 lb-ft, depending on rating |
| Governed speed | Commonly about 2,200 rpm |
| Fuel system | Varies by year: CAPS on many early engines; high-pressure common rail on later versions |
| Applications | Medium-duty truck, school bus, fire and emergency, motorhome, and vocational |
| Engine family | ISC / ISC8.3 |
What Trucks and Equipment Use the Cummins ISC
The Cummins ISC powered medium-duty and vocational trucks from manufacturers including Freightliner, International, Kenworth, Peterbilt, Sterling, and other chassis builders. It was also widely used in transit and school buses, fire and emergency apparatus, motorhomes, refuse and utility trucks, and selected construction or industrial applications. Ratings and installation hardware differ by duty cycle, chassis, and emissions year, so confirm the engine serial number, CPL, ECM calibration, and accessory arrangement before purchase.
Cummins ISC 8.3L vs. Cummins ISB 5.9L
The ISC 8.3L is the larger, heavier-duty choice compared with the Cummins ISB 5.9L. The ISC generally offers more torque, replaceable wet liners, and greater vocational capacity, while the ISB is lighter and commonly used in lower gross-vehicle-weight applications. Neither model name alone confirms compatibility: compare the engine serial number, CPL, electronics, emissions generation, mounts, flywheel housing, and accessory drives.
Common Cummins ISC Problems and What to Check When Buying Used
Identify the fuel-system generation first. On CAPS-equipped engines, ask about lift-pump supply, hot-start behavior, fault history, and injection-pump operation; low fuel supply pressure can shorten pump life. On later common-rail engines, review rail-pressure and injector information. Across all versions, check cold starts, blow-by, oil pressure, coolant condition, turbo play, charge-air leaks, ECM connectors, front and rear seals, and signs of overheating. For emissions-era engines, confirm which EGR and aftertreatment components are included and compatible with the receiving chassis.
Cummins ISC Engines In Stock
Cummins ISC Engine FAQ
What size engine is the Cummins ISC?
The Cummins ISC is an 8.3-liter (505-cubic-inch) inline-six diesel with a 114 mm bore and 135 mm stroke.
How much horsepower does a Cummins ISC make?
Ratings vary by application and emissions year. Common truck versions are roughly 240 to 350 horsepower, while some fire, emergency, and motorhome ratings reach about 380 horsepower.
How much torque does a Cummins ISC produce?
Depending on rating and application, Cummins ISC engines commonly produce about 660 to 1,050 lb-ft of peak torque.
What trucks use a Cummins ISC engine?
The ISC was used in medium-duty and vocational Freightliner, International, Kenworth, Peterbilt, Sterling, bus, fire and emergency, motorhome, refuse, and utility applications.
Does the Cummins ISC have wet sleeves?
Yes. The ISC 8.3 uses replaceable wet cylinder liners, a heavy-duty feature that supports in-frame service and overhaul work.
What is the difference between Cummins ISC and ISB?
The ISC is an 8.3-liter wet-liner engine with higher typical torque and vocational capacity. The ISB 5.9 is smaller and lighter and is common in lower-GVW medium-duty applications.
What should I check before buying a used Cummins ISC?
Confirm the engine serial number, CPL, horsepower rating, fuel-system and emissions generation, ECM calibration, mounts, flywheel housing, accessory layout, included components, test results, and warranty terms.
How do I order a Cummins ISC engine?
Choose an in-stock engine above and call (800) 696-5459 with its stock number, your truck year, make, model, engine serial number or CPL, and delivery ZIP code.