Top 10 Greatest Diesel Engines Devised by Human Mind
These diesel engines were game changers
Updated June 26, 2017
Diesel engine is often considered dirty, outdated and/or anemic, but that doesn’t necessarily have to be the case. In fact, it often isn’t nowadays. There have been many great diesel engines produced over 100 or so years during which they’ve been around. This list is here to remind us about those of them we deemed the greatest and/or the coolest in their own way. Unlike this here list of mills ever offered in American cars and trucks, this time we’re only restricted by respective engine’s architecture. In other words, every single engine guzzling fractional distillate of fuel oil is eligible regardless of its application of use, size and power.
1897 Rudolph Diesel’s First Engine
Without it, Diesel engines would have probably ended up being a lot different than they are today. This is why we’ll start with Rudolph Diesel’s first working engine. First working one because he already had couple of prototypes before it. However, engines conceived in 1892 and 1894 respectively, never really worked as they were intended to. Diesel’s first fully autonomous prototype delivered a solid 20 horsepower. It had one cylinder, 19.6L displacement, and 9.84-inch bore and 15.75-inch stroke. More importantly, it achieved efficiency of more than 26%. In other words, that’s the percentage of the fuel heat converted into effective power. Doesn’t look like much today, but back then there were no engines as efficient as Rudolph Diesel’s first mill. Popular steam engines of the time only delivered efficiency of around 10%.
And that’s exactly what Rudolph Diesel’s main goal was. To create a revolutionary substitute to outdated and inefficient steam engines. Although he didn’t live long enough to see his invention hitting it big time, diesels were already starting to take roots in industrial and marine applications. Main manufacturers at the time were the MAN, Sulzer Brothers, Krupp and Adolphus Busch in the US and Canada.
2006-Present Wärtsilä-Sulzer RTA96-C
Rudolph Diesel’s first working engine may have started it all, but Wärtsilä-Sulzer RTA96-C represents a sort of a pinnacle of diesel engine evolution. At least at the moment, it does. This Finnish-built marine powerplant is currently the second largest reciprocating engine in the world. It’s 87 feet long and 44 feet high while weighing 2,300 metric tons which translates to around 4.6 million pounds. It’s power output is equally impressive to say the least. How does a maximum of 108,920 horsepower and 5,608,310 lb-ft of torque sound? With these figures, RTA96-C is by far the most powerful diesel engine out there.
Of course, very few applications can accommodate such a humongous engine. This 25,480-liter and 14-cylinder behemoth is currently powering the Emma Mærsk – once the largest container ship in the world. Wärtsilä-Sulzer also offers smaller versions of the cargo ship hauler like the one with 6 cylinders. Although slightly more petite, it definitely isn’t any less impressive than its big brother. Just look at that thing!
2012-Present Cummins QSK95
Until Cummins puts the QSK120 into the market (which they’ve already announced), we’ll have to take the QSK95 diesel for their largest engine. This 95-liter, 5,700ci V16 generates between 3,600 and 4,400 horsepower depending on the intended application of use. And it has numerous such purposes. It’s intended for freight and commuter locomotives, marine vessels and dump mining trucks alike.
QSK95 features a proven modular common rail fuel system and no less than four turbochargers for clean, quick acceleration. And it’s durable – like any other Cummins engine. Columbus, Indiana-based manufacturer states their largest mill thus far can consume as much as 1.7 million gallons of fuel before mandatory overhaul. Moreover, single-piece, forged-steel pistons are exempt from being expendable goods and can be reused after the major overhaul of the engine. It might not be the most famous of Cummins diesels, but QSK95 certainly is one of the most imposing of the lot.
1974-1991 Mercedes-Benz OM617
To date, Mercedes-Benz 3.0L OM617 straight-five stands for one of the most reliable engines ever created. It was developed using the in-house straight-four OM616 mill as a mule, and it powered numerous W123 series cars among others. OM617-motivated cars were never on the power side of the curve, but then again most of the things in the market back then followed the same pattern. They started with 80 horsepower initially. A figure that would soon rise to 88 horsepower. Furthermore, US market only 300SD Turbo (W116), yielded a healthy 111 to 121 horsepower. Finally, as of late 1982, OM617 diesel started developing 125 ponies.
Apart from being slow, people often complained about OM617’s soot-spawning capabilities. If not maintained and driven properly, your diesel Benz would spew black clouds of soot that could put WWII flak clouds over western Germany to shame. Then again, it is a diesel and diesels tend to do that sometimes. This doesn’t mean they’ll break down anytime soon. Even now, 30 or 40 years after being produced, OM617-powered Mercedes-Benz’s are still going strong. They’ve traversed hundreds of thousands of miles and they don’t show signs of stopping just yet. That’s as good testament of their greatness as any.
1984-2004 Navistar International DT466
Although Navistar International have basically destroyed their reputation by fiddling with already proven formula, their DT466 still remains one of the most reliable and easily maintainable diesel engines ever made. 466ci inline-six is still being produced by Navistar but, as already mentioned, it falls short compared to reliability standards set by its predecessor. MaxForce DT simply can’t compare with old mechanical fuel injection system and even newer HEUI DT466’s.
DT466 first featured Bosch MW style pump until 1992, and P style pump between 1993 and 1995. New, more strict emissions regulations have forced Navistar International to make some alterations and hydraulically actuated electronically controlled unit injector was incorporated. Although modernized, DT466 continued going strong while it was jointly developed by International and Caterpillar. As of 2004, however, that’s changed. Still, 20 solid years have been more than enough to cement DT466’s reputation among diesel application enthusiasts. Take one look outside and you’ll identify a DT466 in every other medium duty application on the road.
1994-2000 Caterpillar 3406E
Although Caterpillar holds a large chunk of the diesel engines market share, their mills aren’t without issues. 3406E, however, isn’t one of them. It’s as good as semi truck diesel mill can be, and has proven its reliability over the years. It came in 14.6L (1994-1998) and 15.8L (1997-2000) variations before evolving into C15 and C16 engines. With horsepower ratings between 375 and 465 ponies, and with up to 1,850 lb-ft of torque, Cat 3406E was capable of powering most heavy duty rigs out there. And it did. Pretty much any Peterbilt truck from the nineties and early two thousands had one of them inside it.
Furthermore, Cat 3406E has an integrated engine control module, and it was one of the first such engines done right. ECM allowed for numerous power upgrades which made 3406E popular with hot rodders as well. And it isn’t all that hard to work with which is always a plus. Caterpillar yellow doesn’t necessarily have to be the warranty of for quality and durability, but that certainly is the case with 3406E.
2014-Present MAN B&W 12S90ME-C Mark 9.2
It’s not the most powerful diesel engine in the world. That honor, as we’ve already seen, belongs to Wärtsilä-Sulzer RTA96-C. It’s not even the second most powerful being beaten by in-house MAN 12K98MC-C which powers CSCL Star container ship. However, with the height of 56 feet and the length of 193.5 feet, MAN B&W 12S90ME-C Mark 9.2 is definitely the largest engine in the world – period. One such can be found below the deck of the world’s second largest cargo ship – CSCL Globe.
MAN B&W 12S90ME-C Mark 9.2 produces a total of 98,000 horsepower at 84 rpm. Low-speed two-stroke 12-cylinder diesel behemoth weighs a whopping 4,160,000 pounds. Only its 76-feet long crankshaft weighs 930,000 pounds. By listing it here, we’ve included both the largest and the most powerful (Wärtsilä-Sulzer) marine engine currently in production. There are more from whence they came, but MAN and Sulzer are the most popular brands among cargo ship builders, and there’s no need digging any deeper than this.
1988-2002 Mack E7
We simply couldn’t have compiled a list of greatest diesel engines ever made without including arguably the most durable class 8 diesel out there. 12L inline-six Mack E7 is the backbone of the company’s Bulldog fleet. It delivers between 250 and 454 horsepower with maximum torque figures between 975 and 1,660 lb-ft. With such high power output, E7 can easily compete with competition’s higher displacement mills. And it’s also lighter than most of them.
They were first introduced in 1988 but you’ll be hard-pressed to find first two production year engines out there. These early units were air-cooled, while all post 1990 units are water-cooled. Moreover, water-cooled E7 Macks also come with Econovance variable injection timing system which increases fuel economy. That’s the main reason older mills have been replaced – not their unreliability. But reliability isn’t their only advantage. Mack E7 diesels have a simple design which makes maintenance easier. Moreover, average E7 engine will require oil change at around 25,000 miles – almost twice the mileage of competitive engines. Every great engine has its strong point or two, and Mack E7 just keeps piling them.
1983-1991 BMW M21
It isn’t the most efficient BMW inline-six engine to date, nor is it the most powerful. It did, however, start the trend, being Bavarian maker’s first ever diesel mill. Germans took almost a whole decade developing it. The process started in 1975 and was prompted by the 1973 oil crisis. BMW simply needed a more efficient way to power their luxury cars, and they saw diesel as the answer. M21’s were supposed to be powerful and efficient at the same time, and they have. Sort of, at least. Compared to today’s standards, natural 84 or turbo 114 horsepower aren’t actually considered powerful. But that was just enough back then.
Among the applications motivated by the M21, you could have found the likes of BMW 3 Series (E30), BMW 5 Series (E28 and E34), and the Lincoln Continental Mark VII. In 1991, 2.4L M21 was replaced by 2.5L M51. Same engine would later be replaced by the M57, N57 and finally B57 – all of which are still active today. M21’s influence has also spread to 4-cylinder units. First BMW diesel was responsible for spawning the M41, M47, N47 and B47 – last two of which are still being produced today. Last but not the least, BMW also produced the B37 diesel – a 1.5L straight-three mill.
1987-2009 Detroit Diesel Series 60
Detroit Diesel Series 60 is more or less the king of class 8 diesel engines. And like many great things before it, Series 60 too was spawned out of dire necessity. It’s the engine series that had put Detroit Diesel back on the map. Company that’s had a major 40% market share during the early seventies had fallen on hard times in the eighties. Their major diesel engines market share melted away and by the time Series 60 had made its debut, it amounted to paltry 3%.Inline-six family of four-strokers started out as 11.1L mills but soon switched to 12.7L displacement. 12.7L version would remain active until 2007 when it was de facto replaced by larger 14L units.
Apart from being Detroit Diesel’s savior, Series 60 is also their first clean sheet design. Moreover, it was the first American electronically controlled heavy-duty diesel engine. Detroit Diesel Engine Control technology or simply DDEC system went through four stages (I through IV). During the DDEC II reign (until 1992), strongest Series 60 engines were capable of putting up 525 hp and 1,750 lb-ft of torque. Latest 14L DDEC IV units have pushed these figures to 575 hp and 1,850 lb-ft of torque. Detroit Diesel Series 60 have ultimately managed to save and revive the company thanks to their limitless open source possibilities. By the time DDEC III was introduced in 1993, Detroit Diesel once again held 33% heavy-duty diesel engine market share in their hands.