by Nikola Potrebić
Although diesel engines never found their place under the sun in the US car market, they did play a major role in powering all kinds of trucks over the years. And they still do. Of course, some of them have even made their way into conventional American-made automobiles, but the engines themselves weren’t necessary American as well. Regardless, this time we’re listing the best diesel engines ever offered in domestic cars and trucks, and that’s the only thing that matters. While the engine itself could have been made in Peter Pan’s Neverland for all we care, the application needs to come from one of historical American badges. Of course, all of us have our own favorite powerplants and following 10 aren’t the best for being the most powerful, durable or innovative. It’s more of a combo. All of them, however, have that one special feature that makes them great.
Are These The Best Diesel Engine Units In American Cars?
1982-2000 Detroit Diesel V8
Although it was never part of a standard setup in any civilian vehicle apart from the Hummer H1, Detroit Diesel V8 still managed to create a long lasting legacy. Sort of a sixth man in NBA terminology if you will, it was available as an option in numerous GM application over almost two whole decades. C/K pickups, K5 Blazer, Suburban, Tahoe and Chevrolet Van (later Express) all came with one. If you ended up ticking rather pricey diesel box in options list, that is.
There were couple of displacements available: 379ci 6.2L and 395ci 6.5L. Former was offered until 1993 while latter succeeded it and lasted until Duramax line took over. Although they aren’t around in general population markets any more, Detroit Diesel V8’s are still being produced. At least 6.5L version is. They always served as motivational factors behind AM General’s HMMWV, and they still are today. If 190-horsepower and 380 lb-ft of torque diesel is good enough for the likes of Humvee, it’s good enough for us too. It’s one of the most reliable diesel engine configurations ever, and should be celebrated!
1994-2003 Navistar International 7.3L Power Stroke
There hasn’t been a better fighter for diesel rights since, and I doubt there ever will be another such powerplant in the US than Navistar International’s Power Stroke V8. This is the engine that single-handedly promoted diesels into the mainstream. Electronically controlled, direct injection, turbodiesel V8 engine has found its way to some 2 million satisfied owners. That many people can’t be wrong – can they?
Although performance figures varied over the years and in-between setups, most powerful 7.3L Power Stroke diesel iterations delivered up to 275 horsepower and 525 lb-ft of torque. Ford Econoline vans, Excursion and Ford Super Duty F-Series diesel pickups (Ford F-150, Ford F-250 diesel pickup trucks) were lucky enough to be powered by it and so was the only mass production diesel Bronco ever – the 4-door, 4-wheel drive C-350 Centurion Classic. When 7.3L Power Stroke finally couldn’t keep up with new emissions regulations, International replaced it with smaller 6.0L version of the engine. Sadly, the successor was nowhere near the predecessor in terms of quality.
1984-1998 Cummins B Series
Cummins B Series is cool for multiple reasons. For once, Cummins never used the V angle in any of B Series’ iterations, and they never had more than six cylinders. Family of straight-four and straight-six diesels had, however, motivated some very powerful vehicles in their heyday – most notable of which was the Dodge Ram (and still is).
5.9L version of the engine first appeared in Dodge Ram for 1989 model year, and subsequent installations followed. 24-valve 5.9L ISB Cummins diesel replaced the 12-valve version of the same displacement in 1998, in order to meet the new emission regulations. Similar thing happened when 6.7L mill replaced the mentioned ISB engine in 2007. That same 6.7L 350-horsepower straight-six turbo diesel Cummins B Series mill still powers the RAM trucks while throwing in 610 lb-ft of torque and very good fuel economy figures as a bonus. They weren’t the first diesel power engines offered in pickup trucks, but B Series Cummins mills sure were some of the best thanks to their horsepower and torque, and incredible towing power. If you want to shift a heavy load and enjoy a comfortable ride, this was one of the best diesel trucks for the job.
1983-1991 BMW M21
It’s Bavarian in origin, but it did make its way into one of the most famous American personal luxury cars. I’ll give you a chance to remember which one it was and move straight to the specs. This 2.4L inline-six diesel came either with 84 horsepower and natural aspiration or with Garrett turbocharger which pushed the max output figure to 114 hp. It was a result of almost decade-long engineering process whose ultimate goal was to produce a powerful diesel mill with fuel economy to match. Moreover, the M21 was the first BMW-made diesel engine ever. It also delivered 112 lb-ft of torque in natural aspiration package. Turbo diesel version of the M21 made 155 lb-ft of torque.
Apart from powering the E28 and early E34 BMW 5 Series, and E30 BMW 3 Series diesel models, M21 engine, as mentioned above, also motivated none other than the Lincoln Continental Mark VII. It only stuck for two initial model years before disappearing from the lineup, however. This doesn’t mean it wasn’t any good. It simply didn’t have as much power as personal luxury car customers required. It would have been much better fit for mid to full-size family cars of the time but most of them were already promised to Oldsmobile Diesel engines; engines that were less potent and guzzled more fuel in the process.
2014-Present VM Motori L630
A630 version of this Italian 3.0L V6 turbo diesel used to stand behind the likes of Jeep Grand Cherokee and Chrysler 300 in Europe. Moreover, high performance version of the A630 is good enough for the likes of Maserati Ghibli, Quattroporte VI and Levante. That’s the reason why US spec L630 version of the engine has also been good enough fit for domestic Jeep Grand Cherokee and Ram 1500 in 2014.
240 horsepower and 420 lb-ft of torque provided by the engine are just one thing it does admirably. There’s also fuel efficiency to take into account. Furthermore, Gale Banks Engineering manufactures their own version of the engine dubbed the Banks 630T. Banks engine’s primary customers are the military and other specialty application purveyors. But small batch of their VM Motori turbo diesel improvement should also be available to the general public. Their version of the engine also delivers 240 horses, but pushes the maximum torque limit to just shy of 500 lb-ft. And all that from a box that weighs less than 500 pounds. Now you see why VM Motori L630 turbo diesel is actually one of the good Italian engines offered in the US. It certainly has a huge upside even if it doesn’t satisfy all the requirements in its basic form.
1987-2009 Detroit Diesel Series 60
By 1987, Detroit Diesel division’s market share accounted to paltry 3%. All signals suggested it would be an anti-climactic end to the diesel engine market’s creator as they didn’t have the answer to highly reliable Cummins diesel counterparts. Two major events would take place then and turn the tide in Detroit Diesel’s favor. First they introduced the new Series 60 inline-six four stroker on-highway family of engines and then they were bought by Roger Penske who acquired 60% stake in the company. By 1993, Detroit Diesel and Penske Corporation would increase their market share to 33%. Quite a jump compared to 3% from 5 years earlier.
First Series 60 engine was the 677ci 11.1L mill capable of making 350 to 365 horsepower with cruise control on. It was also available with the 775ci 12.7L displacement which would prove to be the most popular Series 60 engine ever made. 12.7L was finally discontinued in 2007 and replaced by even larger 885ci 14L unit. Series 60 was Detroit Diesel’s first ever clean sheet design. Moreover, it was the first fully integrated electronically controlled heavy-duty diesel engine built in the US. At the end of the line, most powerful Series 60 mills generated upward to 525 hp and 1,750 lb-ft of torque. Over 1 million of them have been sold and they still power numerous semis and buses out there – and that’s because it’s the one of the most reliable diesel engine lumps out there.
1984-Present Navistar International DT466
Whenever you notice a medium duty bus or truck out there, know that it’s likely motivated by one of DT466 engines. Navistar International’s most widespread powerplant has been around for more than 30 years and currently goes by the name MaxxForce DT. Its initial name was derived from 466 cubic inch displacement which is still present. Most potent Navistar 466 mills peak at 300 horsepower and 860 feet-pound of torque. They are some of the most reliable and durable diesel engines out there.
When they first arrived, International DT466’s used mechanical fuel injection system and 2 valve per cylinder head design. Bosch MW pump was used until 1992 while Bosch P pump replaced it from 1993 to 1995. Although all subsequent iterations would use hydraulically actuated electronically controlled unit injector and 4 valve per cylinder head design, a few P pump mills would still find their way out of the assembly in 1996 and 1997.
2001-Present 6.6-Liter Duramax Diesel
As already mentioned above, Duramax 6.6L V8 took over the responsibility of powering GM medium duty trucks (Kodiak/TopKick), pickups (Chevy Silverado 2500HD/ GMC Sierra 2500HD) and vans (Express/Savanna) from the 6.5L Detroit Diesel V8. Built by DMAX of Moraine, Ohio which is nothing other than joint venture company of GM and Isuzu, Duramax has helped GM to finally establish themselves as a major name in the US diesel manufacturers’ circles.
Initial code LB7 Duramax engines have been known to suffer from numerous issues. After all, they featured an experimental composite design cylinder head. Severe overheating and even blown head gaskets were much too common early on and they continued for some time. At least LLY code units introduced mid-2004 featured easily removable valve covers which significantly simplified the repair process. Current Duramax engines have no such issues. They’re highly capable and reliable diesel workhorse engines able to yield as much as 400 hp and 765 lb-ft of torque.
1938-1995 Detroit Diesel Series 71
Almost 60 years of production, and myriad of different versions, configs and displacements have made Detroit Diesel Series 71 two-strokers some of the most versatile diesel engines ever devised. Their fields of use were practically limitless. They appeared in everything from farm tractors to medium tanks like the M4A2 Sherman. However, they were most common in all kinds of medium-duty trucks including most of the common fire trucks.
At first, Series 71 featured inline cylinder configuration. One, two, three, four and six cylinder configs to be more precise. V-block versions would make their debut in 1957. They came with six, eight, 12, 16 and 24 cylinders. Apart from being some of the most versatile engines ever made, Series 71 diesels were also highly durable and laughably easy to maintain. Some grease and good kick with the hammer were often enough to make them start buzzing again. Inline models also earned numerous nicknames over the years. Screaming Jimmy, Green Leaker and Driptroit Diesel are only some of them. They sure did leak from all directions all right. V-block versions had nicknames of their own. Detroit Diesel Series 71 V12 was called Buzzin Dozen due to its sound with the exhaust brake on.
1978-1985 Oldsmobile Diesel
Olds Diesel? Really? I know what you’re thinking, but hear me out first. I remember entering a wacky hairstyle competition when I was 10 or so. There were only two more guys lined up against me so I thought why bother? I just messed up my hair a little bit and figured out I’d be heading home with the third place plaque. And what did the jurors do? They only handed out prizes for the first two spots (the bastards). Do you believe that!? Little did I know then that Oldsmobile Diesel was watching and giving me the attaboy. For Olds Diesel can relate to that turn of events. Although intended as gasoline emission standards immune counterpart to choked out petrol engines of the day, Olds Diesel was neither particularly efficient nor powerful. It ended up being lazy, slacking, good for nothing POS just like yours truly in that competition.
However, Oldsmobile Diesel was also the only American diesel engine offered in domestic passenger cars at the time. And that makes it a candidate for this list. 4.3L V6 and 4.3L V8 were rarer of the three versions with 350ci 5.7L V8 being the flagship model. Code-named LF9, it served as driving force behind applications such as the Buick Riviera, Cadillac Eldorado, Chevy Impala, Pontiac Grand Prix and Olds Toronado, among others. It produced 120 horsepower at first. A figure which would sink down to 105 hp later on. Same thing happened with the maximum torque which downgraded from 220 lb-ft to 205 lb-ft.
Anemic and unreliable as they were, it’s safe to say Oldsmobile Diesel engines were a flop. They weren’t thoroughly thought out since GM division’s engineers used the same 10-bolt head design as in petrol engines. However, diesel engines are subject to much higher compression ratios and higher temperatures which, in turn, lead to head-gasket failures and severe engine damage. Moreover, lack of water separator lead to fuel system’s corrosion. And the problems mounted on. V6 version of the engine was, however, much more reliable as it included reinforced head bolts. But the damage was already done and V6 only accounted for fraction of the market.
So, what was Oldsmobile Diesel good for? Well, we have Olds Diesel to thank for the lemon law. Plus, its reinforced blocks have found their new purpose in many a race car’s petrol engines.
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 turbo diesel 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, the 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.
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.
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.
What About A Bonus 10 Crazy Diesel Engine Swaps?
Despite the best efforts of many automakers, the North American market has never truly accepted the diesel engine in much of anything other than trucks. Even then, the diesel engine has more of a cult following than a true sales base.
With diesel cars and trucks accounting for less than two percent of all new vehicle sales, most people are not interested in reading about the ho-hum, everyday diesel engine that can be found at the local dealership. However, we know that regular visitors to this site want to hear about superpowered engine swaps(hell, any interesting engine swap for that matter) whether it is a diesel engine swap or any other fuel type. So, with that in mind, we scoured the internet with beady eyes and a greedy grin to bring you these ten diesel engine swaps that will make you think.
1. 1970 Plymouth Cuda “Torc”
When the 1970 Plymouth Barracuda hit the market, America was in the throes of muscle car mania. Every automaker was building horsepower monsters. Many of them still appeal to die-hard gearheads. In 1970, a ‘Cuda would have set you back a tad over $3,000 and could have been equipped with a 426 cu.in. Hemi V8 engine capable of 425 hp. Damned impressive for the time.
Well, the guys at Weaver Customs thought it would be a lot of fun to do a 6.7-liter Cummins diesel engine swap. The result of the project is a 1,500 hp monster aptly named the ”Torc.” As all gearheads know, ponies are not the most impressive aspect of diesel engine swaps; the torque is. The Torc thrusts 3,000 lb-ft of the stuff to the pavement.
2. 2004 Chevrolet Silverado 2500
Pop the hood and you can see where the magic begins. Staring you in the face is a Duramax that hosts so many aftermarket parts that you need a secretary to read the build sheet while you drool over the powerplant. At the wheels, this Duramax creates 1,100 hp. To get there the crew at DTS added an ATI damper, Howard’s connecting rods, and ARP 12mm main studs. As your secretary continues to read, you will find Pro Gram main caps and high performance Mahle racing pistons.
The DTS boys didn’t stop there. They added a custom-built cam as well as specialty valvesprings and rocker arm bridges. The pushrods are another special order item and DTS did a complete porting job on the cylinder heads. Along with all of the custom material already mentioned, DTS needed to be able to move a lot of air and fuel to get their truck to finish the quarter mile in 10.41 seconds at 128 mph. DTS looked to Garrett ball-bearing turbochargers. To wit, a 75.8mm GTX4202R manifold turbo and a 106mm GT5541 turbo. With the airflow issue conquered, DTS decided to use a PPE Dual Fueler kit and a twin set of Stage 2 CP3 pumps built by Wicked Diesel Motorsports.
3. 1969 Chevrolet C10
Brett Deutsch’s 1969 Chevy C10 started its life powered by a gasoline engine just as every other C10 on the block did. In a plot twist, Brett’s grandfather dropped a three-cylinder Detroit Diesel into this C10 shortly after buying it. As any diesel fan knows, that engine is not impressive nor something to build upon. Brett found a way around those limitations, though.
Taking an interesting approach, Brett and his father decided to use a bus engine, transmission, and chassis for their build. A Duramax Diesel/Allison combo to be exact. The final result is a diesel engine swap that features Carrillo rods, performance main caps with a girdle, a SoCal Diesel 3388 camshaft, Stage I heads, and a 72mm VGT turbo. Toss in injectors that are 175 percent over and you get a 1969 Chevy C10 that Dynos 1,002 hp at the rear wheels and does the quarter in 9.99 seconds at 142 mph. After a few changes to his set up and some weight reduction, Brett managed 1,106 hp and a best run of 9.43 at 148 mph.
4. Demented Mustang
The Ford Mustang is a pretty popular car for diesel engine swaps, but no one has taken the same approach as Mark Kubik. His version is powered by a 7.3L Power Stroke, giving the Demented Mustang more power than most drivers could ever hope to handle.
The 7.3L powerplant you see under the hood is capable of 1,700 hp. To get there this superpowered diesel engine swap required a lot of aftermarket parts. Out went the HEUI injection system, in came a mechanical setup that uses a Bosch P-pump. Also coming in were forged connecting rods, low-compression pistons, and a camshaft from Hypermax. Approximately 100 psi of boost comes from a 98 mm Garrett GTX5533R Gen II turbo. Even the crankcase had to be swapped out in order to handle all of that power, so it was back to Hypermax for a compacted graphite iron (CGI) block. The quickest run the Demented Mustang has made is 5.24 seconds at 134 mph through the 660.
5. 1966 Chevrolet Nova II
Ryan Milliken of Hardway Performance built this 1966 Chevrolet Nova II specifically to drag race. Dubbed the Green Reaper, this car makes our list of diesel engine swaps with an eighth-mile time of 4.88 seconds at 150 mph.
A time like that requires a lot of work. The base car had been run by Mickey Tessneer, but Milliken swapped in an inline six built by Freedom Racing Engines. The powerplant boasts such amenities as a Hamilton Cams cast-iron block, billet steel rods, and a Wagler Competition billet-aluminum head. Inside, there are Diamond Racing pistons and 400 percent over injectors supplied by an 88 mm Garrett GTX5533R providing 65 psi of boost.
6. 2003 Chevrolet Silverado 2500
What do you do when your diesel truck has two blown head gaskets, bad injectors, and 350,000 miles on it? If you’re Tyler Rabbage, you do an engine swap. Where most owner’s do diesel engine swaps and stay with the same type, i.e, putting a General Motors product back into a GM truck, Rabbage chose to go with a 5.9L Cummins instead of a Duramax.
Rabbage’s truck didn’t make our list of diesel engine swaps because of its raw power. It made the list because the swap was done in just eight days. That includes rebuilding the Cummins, pairing it with a beefed up Dodge 47RH, and getting the truck back on the streets. Granted he had help from Outlaw Diesel. Even though a Cummins 5.9L is one of the most common diesel engine swaps around, eight days is still pretty impressive.
7. Dodge Ram 3500
The Dodge Ram 3500 dually is already a great truck whether it is equipped with a diesel engine or not. The available 6.7L Cummins is a very efficient engine, but not the most powerful diesel on the market. So, what do you do if you want more power? Well, if you are Calibrated Power Solutions(CPS), you swap in a commercial QSL9. QSL9 diesel engine swaps into a pickup truck are not common because of space limitations in the engine bay. After some careful work with a shoehorn, CPS was able to make it happen.
The bulk of the QSL9 was increased further by a threesome of BorgWarner S591 turbos and all of the necessary pipes. Once room was made for the new powerplant, CPS went to work beefing up the QSL9 beyond adding the turbos. First up was a new gearbox to handle the massive amount of low-end torque envisioned. The new one is a Competition Stage 3 47RE built by Firepunk Diesel replete with manual valvebody and TCI Automotive pistol-grip shifter. The QSL9 had an original displacement of 8.9L. After some serious boring and stroking, that was increased to 10.4L. The flow from the fuel system was increased with dual Exergy Performance 14 mm CP3 injection pumps. The air/fuel mixture is completed by the 100 psi of boost created by the BorgWarners. Today, the Dodge Ram 3500 is one of the best used diesel trucks you can buy.
8. 1967 Ford Falcon XR
In 1967, buyers had six engine options to choose from when buying a Ford Falcon. None of them were diesels. In addition to being the only Falcon we have ever heard about with a diesel engine swap, this build makes our list of diesel engine swaps because it was built using 100 percent recycled parts. Dubbed Zero’d by its builder Mark Faber, the car was billed as the world’s first ”elite eco-friendly custom-built muscle car.”
Starting with a 7.3L Ford Powerstroke diesel engine, the Australian custom builder upped the output to 600 hp at the wheels. That may not be massive, but it was achieved running B20, a blend with 20 percent biodiesel included. Faber stressed the ”green” aspects of the car to the point of reusing fenders, installing custom seats that were stitched together with hide scraps, and using old nuts and bolts. The only new parts he used were rubber, glass, and a custom-built radiator and intercooler.
9. 1963 Chevrolet Nova II
The power coming from the standard engines offered in a 1963 Chevrolet Nova II is anything but spectacular. How do you improve on the base output? Well, to make our list of diesel engine swaps, you have to choose an oil burner of some type. John Fyffe went with a Duramax.
John turned to diesel performance experts at Fleece Performance Engineering to turn his LB7 Duramax into a seven second drag car. Fleece installed a great Wagler Competition water-to-air intake, parallel 63 mm BorgWarner turbos, and a Chrysler 47RH gearbox with a manual valve body to handle the torque. Output is north of 1,200 hp at the rear tires.
10. 1949 WillysA 1949 Willys truck is not a vehicle commonly associated with great diesel engine swaps. Off-roading, yes; not diesel engine swaps. Despite that, Gerry Rommel, pictured above with his truck, had a vision.
That vision involved a engine bay stuffed with an inline four 4BT Cummins. Hey, we didn’t say the Willys was on our list of diesel engine swaps for its amazing power. It does hit the interesting factor pretty hard, though.
Gerry’s build includes a 3.9L 4BT equipped with a rotary Bosch VE injection pump. There is no intercooler to be found under the cowl, but you will see a Fluidyne radiator. The 4BT is paired to a durable Turbo 400 automatic. As you can see in the image, this is a raised off-roader. To that end, Rommel installed a tough NP205 transfer case, a Dana 44 front axle, and a Dana 60 rear. Both axles have 3.55 gears.