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Cummins N14 Engine

Cummins N14 Engines For Sale

Black Remanufactured Cummins N14 Engine for Sale Side View

The Cummins N14 is an inline, six-cylinder engine capable of producing 310 to 525 hp. it was originally rolled out in 1987, but officially began production in 1990, for the ’91 model year. The N14 replaced the popular 855 Big Cam that practically owned the Class 8 engine segment in the late 1970s to mid 1980s.

An “855” With Electronics

With more stringent particulate matter (PM) regulations taking effect in 1991, the N14 was Cummins’ answer for cleaner emissions. Externally and internally, the N14 looked like a spitting image of the outgoing 855. It featured the same bore and stroke (5.50-inch x 6.00-inch), made use of wet cylinder liners, modular 4-valve cylinder heads, retained a unit injection system, and even came equipped with the same oil pan. The key difference was the N14’s utilization of electronics, which not only afforded Cummins the ability to meet tighter emissions standards, but produce more horsepower and torque.

“Like” A New, Improved Version Of The Coveted 855

Of course, using the same basic architecture of the 855 Big Cam wasn’t enough. Cummins performed subtle changes where necessary—all of which were geared toward retaining the platform’s reputation for million-mile durability. The diameter of the rod journals was increased to accommodate larger bearings, independent rocker shafts simplified the valvetrain and the engine’s water manifold was incorporated into the rocker boxes, the camshaft rollers were made wider, and the N14 also gained an air-to-air intercooler.

Everyone’s Favorite N14: The Celect Plus

In 1996, Cummins released the Celect Plus N14 which, with its advanced electronic controls, could produce as much as 525 hp. Celect Plus models could also turn out 1,850 lb-ft of torque at a low, 1,200 rpm—perfect for getting loads moving while also optimizing fuel efficiency. It goes without saying that this version is a favorite among Class 8 drivers. The Cummins N14 Celect Plus is instantly recognizable by the red top valve covers it wears, as well as the diagonal bolt arrangement it uses to mount the exhaust manifold.

N14 Engine Applications and Uses

  • On road trucks
  • Construction
  • Industrial
  • Military

Common N14 Engine Problems & Failures

Some of the more common N14 problems and failures we come across at Big Bear Engine Company are listed here. Most of the issues below occur on higher mile engines and, unfortunately, some of them can lead to the engine being unsalvageable. However, if some of these issues are discovered early enough, the engine can be saved.Logo of AERA Engine Builders Association

  • Spun Crankshaft Bearings
  • Cracked Cylinder Head(s)
  • Scored Pistons and Liners
  • Over Fueling
  • Lack of oil or oil pressure
  • Extreme Blow By
  • Dropped Valves
  • Camshaft Failure
  • Crankshaft Failure
  • Lifter/Roller Failure
  • Connecting Rod Failure

Cummins N14 Engine Replacement Options

Depending on which kind of failure your N14 faces, complete engine replacement may be your only option. However, other scenarios may only require the replacement of certain parts or components. In high mile applications, your engine might just need a new lease of life—in the form of a refresh. Of course, cost, downtime, and availability will factor into any decision you have to make. Below, we’ll detail our comprehensive remanufacturing process for the Cummins N14.

*Note that you can also consider the compatible Cummins ISX15 in cases where complete N14 engine replacement is necessary.

Replacement Options for Remanufactured Cummins N14 Engine for Sale

The Big Bear Remanufacturing Process

A remanufactured Cummins N14 long block is a perfect replacement option for the customer who’s experienced a catastrophic internal engine failure but that still has good, re-useable external components from the original engine. Long blocks are another logical alternative when you’re trying to cut down on some of the costs associated with a new engine.

Our team of machinists and engine builders perform a full core tear down, cleaning, and inspection, followed by machining of the engine before it leaves our facility. This ensures the N14 is built to perfection each and every time.

However, it’s important to mention that all of our Cummins N14 remanufactured long blocks are built with a combination of both remanufactured and new parts. We do not recondition or refurbish old engine parts but rather completely rebuild your old N14 back to OEM specs.

Thorough Cleaning

Every Cummins N14 is completely stripped. The block, heads, rods, crankshaft and camshaft are all carefully cleaned in a chemical jet wash or hot tank to remove impurities that could facilitate both early component and engine failure later on.


The crankshaft is precision machined to exact tolerances, polished, and then magnafluxed. After that, the crank is thoroughly inspected by our quality control department.

Cylinder Heads

Heads are resurfaced to guarantee a proper sealing surface with the block, as well as to provide a finish that’s compatible with today's new gasket materials. Valve height is mic-d and every head is vacuum tested to assure correct valve seating.

Cylinder Blocks

Regarding the block, we use magnetic particle to inspect for both cracks and imperfections. Cylinders are bored and honed to precise tolerances, and then inspected. On certain N14 engines, torque plate honing is performed to rule out the possibility of cylinder head distortion after the head has been bolted (and torqued) to the block. This process eliminates a major cause of engine blow-by.


The camshaft is inspected and precisely machined to provide correct lift. All cam lobes are measured with a micrometer to make sure OEM tolerances are met.

Connecting Rods

Connecting rods are cleaned, then machined to OEM specifications. From there, they’re honed to the standard diameter of original equipment for even distribution of stress on the rod bearings. New bushings are fitted and machined in all bushed rods. Each rod is also carefully inspected for bend and twist.

New N14 Parts

Our N14 long block engines receive a standard set of new parts such as pistons and piston rings, bearings, gaskets and seals, and liners. New parts assure dependable performance and reliability throughout the life of your engine. All new parts are a combination of OEM and aftermarket when available.

Request a Quote

Please fill out the form below with your information and request. A member of our staff will be with you shortly.

Remanufactured Engines Standards

To remanufacture is to make as close to new as possible. Wearable parts are automatically replaced. All N14 core material is thoroughly inspected and examined against original equipment specifications for correct dimensional tolerances, and replacement parts are new or requalified. If new, parts are made using the same production processes as original equipment. Testing is also performed to manufacturer specifications and original production standards.

Reman N14 Long Block Parts List:

Black Remanufactured Cummins N14 Engine for Sale Wrapped on a Plastic

  • Block
  • Complete, Loaded Cylinder Head
  • Crankshaft
  • Connecting Rods
  • Intermediate Cover
  • Timed Front Gear Group
  • New Upper and Lower Gasket Set
  • Camshaft
  • Followers/Lifters
  • Pistons
  • Piston Rings
  • Liners
  • **1 Year Warranty

*Note: We can provide a new oil pump, oil cooler, water pump, turbo, injectors and fuel pump for additional cost with the long block, but these components will not come assembled on the engine.

**First 6 Months Parts & Labor, Second 6 Months Parts Replacement Only. Ask your sales representative for a full copy of our remanufactured long block warranty.

Cummins N14 Engine Specs

Engine Data

ApplicationsClass 7/8 on-highway trucks
Engine Type/ ModelsFour-stroke, direct injection, turbodiesel / N14, N14 Celect, N14 Celect Plus
ConfigurationInline 6 Cylinder
Displacement855 ci, 14.0 L
Firing Order1 - 5 - 3 - 6 - 2 - 4
Bore5.5 in (140 mm)
Stroke6.0 in (152 mm)
Compression Ratio14.0 to 17.0:1 (depending on model)
ValvetrainOverhead Valve (OHV), 4 Valves per Cylinder
Minimum Oil Pressure10 psi at low idle; 35 - 45 psi at governed speed, no load
Engine Oil Capacity11.0 gal (most common for applications with a bypass filter, oil capacity may vary depending on model)
 Rated Horsepower310 - 525 hp (at 1,800 to 2,100 rpm, depending on model)
Rated Torque1,250 - 1,850 lb-ft at 1,200 rpm
Engine Weight (Approx)2,550 - 2,625 lbs. dry |

2,650 - 2,750 lbs. wet

Cylinder Head MaterialCast Iron
Engine Block MaterialCast Iron with Wet Cylinder Liners

Give us a call today at 844-340-4114 for immediate sales and support for the Cummins 4BT, Cummins 6BT, 6CT, ISC, 855, QSB 4.5 L or CAT 3306. If you have any questions check out our FAQ Page. We are always ready to help or just listen to your crazy off-roading adventures!

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