Cummins has a history of producing strong, long-lasting diesel engines, including some of the most popular ones for on-highway applications. Two of their engines in particular, the N14 and the ISX, continue to remain popular diesel choices. So what make the two different from each other? Why did Cummins make the switch from the N14 to the ISX applications? In this article, we dive into the history and the differences between the engines.
Cummins N14 and ISX Development History
The N14
Prior to the release of the N14, the NTC was the workhorse of the Cummins line. For a while, it was really one of the best over-the-road engine applications. It had two versions: a small cam with a diameter of under 2 inches, and a larger cam to help support the increasing injector pressures. They also began putting electronics in the engine, resulting in two different NTC applications with electronic systems—the PT Pacer, which had a cruise control system, and the Pace unit, which included a cruise control system with a PTO setting (this means you could select the engine RPM and it would sustain it no matter the load, up to a certain point).
Cummins eventually got their electronics and parts people together in the same room with the goal of creating a 1,000,000 mile engine. The N14 was the result. It has the same cubic displacement as the NTC, but included more electronics, like the injectors.
After a while, though, the EPA began to release new emissions restrictions and standards that the N14 couldn't meet. Cummins needed to move to an Integrated Management System, which was full electronics. This became the base for the ISX, which would replace the N14 as the Cummins workhorse.
The ISX
In order to meet these increasing restrictions, they really needed to increase pressure to better atomize fuel, which would then result in better emissions. So they worked to improve the electronic fuel controls that would appear in the ISX, allowing the engine to meet the EPA guidelines.
A few years later, though, the EPA came out with even stricter emissions guidelines, and in order for the ISX to continue to meet standards, Cummins really had to control fuel injection, making it more precise. This led to the production of the common rail injectors. The ECM controls the timing of these injectors, leading to more precision, and the rail keeps the pressure constant. This increases efficiency and kept the ISX in line with EPA regulations.
Despite this development, though, the exhaust was still "dirty" and produced a fair amount of soot. They then came out with after treatment (DPF), which acted like a sponge that collects soot. If it cracked, it was easy to tell, as black would begin to leak out.
In 2013, in order to clean exhaust even further, though, diesel exhaust fluid (DEF) was developed. After the exhaust goes through the DPF, the DEF molecularizes it, cleaning it even further. The DPF would heat the catalytic converter. The chemically produced heat of up to 1,200 degrees would burn the carbon to reduce the volume of soot. This helped result in clean stacks—if there's black soot on your stacks, your system is broken.
Differences Between the Engines
Electronics
While the N14 does include some electronic components, the ISX has more. It's name is even based on this (IS stands for Interact System). This move toward more electronic controls is what allowed the ISX to continue to meet the EPA regulations
Size
The two engines are physically different in size. Two versions of the ISX were involved in the phase out of the N14 and the M11 (the little brother of the N14, which was likewise unable to meet emissions standards), the ISX12 and the ISX15.
Components
Because of the shift to electronic controls, the N14 has more valve train components than the ISX. To learn more about valve train components, read our blog post on the topic. This reduction in the amount of components likewise reduced a lot of possible wear. The ISX is more of a direct injection type of device than the N14.
Despite their shared history in the Cummins lineup, the N14 and ISX are very different engines. Both have their pros and cons, though, leading to operators having strong feelings about one or the other.
Need help with parts for your Cummins engine? Our certified technicians can give you a hand! Call them at 844-304-7688, or request a quote online.
#1 | |
tcr1016 Rookie Thread Starter Join Date: Jan 2008 Posts: 21 Mentioned: 0 Post(s) Tagged: 0 Thread(s) | I am looking at trucks and mainly looking at the engine that is reliable, easy to maintain, and inexpensive parts. No Kitty Cats for me. I have an RV with a Cummins b-Series and simple to work on since it is a 94 mechanical. The engine/ truck will be from the mid to late 90s. What engine would those of you prefer and had experience with?? I see the injectors alone on the N14 are an arm and a leg. On my B-series Cummins they are expensive too. But how are the Detroits? I do LOVE the sound of the Series 60. Ahh hell I just love diesel sounds, but not Chevy or Ford. |
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heavyhaulerss Senior Board Member Join Date: Jan 2007 Location: north alabama Posts: 1,200 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | ser 60 det!!!!! |
#3 | |
Windwalker Board Icon Join Date: Oct 2005 Location: Been there and gone... Posts: 6,412 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) | The Detroits I've driven spent a lot of time in the shop. They seemed to have an appetite for injectors, as that's what were (seemed like) constantly being replaced. For my own money, I won't buy a Detroit, because when I'm running my own truck, I need to be on the road, not in the shop. The N-14+ (500 hp redhead) I owned had good power, and spent little time in the shop other than oil changes. Yes, I did have a couple of times that it cost me money, but replacing the original air compressor after 800K or replacing the clutch after 750K really doesn't mean there is a weakness in the engine. Yes, I did have to have a front main seal replaced once. By the time I got rid of it, it had over 900K on it. Come to think of it, I did have to replace one injector shortly after I got it. Many times, I've been sorry I don't have it anymore. Who knew how fuel prices were going to go down. Then again, with the EPA regs, maybe it's just as well I don't have it anymore. Compared to the Detroit that the company just got rid of, Just this year, it had been in the shop (and I was off work) a total of 9 weeks. It had 534K on it when they got rid of it. __________________ ( R E T I R E D , and glad of it) |
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allan5oh Senior Board Member Join Date: Aug 2005 Location: jackassville (winnipeg, mb) Posts: 3,280 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | Was it an EGR detroit? I'd avoid those like the plague. Anything EGR for that matter. |
#5 | |
heavyhaulerss Senior Board Member Join Date: Jan 2007 Location: north alabama Posts: 1,200 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | I am just going by my 94 ser 60 1.5 mil & not even an inframe yet. injectors after 1 mil. factory cltuch til 1.1 mil, still org turbo still going everyday. burns & leaks a lil oil, but still has power. 11.1 h.p. |
#6 | |
Copperhead Senior Board Member Join Date: Oct 2007 Location: Kellogg, IA Posts: 534 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | I have been around both engines for several years. The Detroits are pretty good engines overall. They will get better fuel mileage on average than an N-14, but the N-14 beats it out in torque and low RPM lugging power, and usually the engine brake is a lot stronger. Pittsburgh Power will tell you that the N-14 is a more solid engine, but that doesn't mean the Detroit is a slacker either. N-14's will tend to be a little pricier for parts than a Detroit. My choice would be for the N-14, but if the price were good, I would have no problem opting for a good Detroit.... specifically the 12.7 pre egr version. Very reliable engine and when matched with good tranny/rearend specs, really good mpg. Last edited by Copperhead; 08-06-2009 at 02:44 AM. |
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LBF Member Join Date: Jul 2009 Location: Ontario, Canada Posts: 110 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | 1997 S60 DDEC III 470 HP is the year the DD techs I know would own, if they were buying one for themselves. __________________ Ontario, Canada |
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heavyhaulerss Senior Board Member Join Date: Jan 2007 Location: north alabama Posts: 1,200 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | Detroit! It's settled. No more opinions, other than detroit !!! This question is closed to other opinions!! |
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Gearjammin' Penguin Rookie Join Date: Mar 2007 Location: Central AZ Posts: 33 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | Quote: Originally Posted by heavyhaulerss Detroit! It's settled. No more opinions, other than detroit !!! This question is closed to other opinions!! You wish, fool. (flips the bird) (lol) The N14 is the most awesome motor I've ever had. The last Detroit I drove ate its turbo after only 60K miles. The N14 could pull Mount Everest out of the ground without complaint. Even set far below its power threshold, I outran owner/ops uphill at 79,580(at least until 68mph). N14. There is no substitute.
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heavyhaulerss Senior Board Member Join Date: Jan 2007 Location: north alabama Posts: 1,200 Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 1 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) Mentioned: 0 Post(s) Tagged: 0 Thread(s) | Quote: Originally Posted by Gearjammin' Penguin You wish, fool. (flips the bird) (lol) The N14 is the most awesome motor I've ever had. The last Detroit I drove ate its turbo after only 60K miles. The N14 could pull Mount Everest out of the ground without complaint. Even set far below its power threshold, I outran owner/ops uphill at 79,580(at least until 68mph). N14. There is no substitute. I take it, you like the n-14 ? |
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