Now, some of you have probably noticed
we've made a lot of videos about diesel engines, and there are a lot of really cool
diesel engines out there. But the thing is, some of them are better than others and
some of them are unique in their own ways, and with that in mind, I decided to go ahead and
come up with a list of what I consider to be the best diesel engines of all time. Now, keep in mind
this list is not in really any particular order, because I wouldn't think it's fair to officially
say one engine is officially the best as compared to the rest of them. They all have their unique
pros and cons. But regardless, let's get into it. And there's only so much room on the list, so be
sure to drop a comment down below let me know what you think are the best diesel engines ever and
what order that you'd put them. And starting out this list is an engine that we've actually made
a video on recently, and that's the International DT466, and what really makes the DT466 worthy
of being on this list is two things: it's insane reliability and the fact that it completely
changed the medium duty truck market. Throughout its near half century run, in four different
generations, it went through a fair amount of changes, but many aspects also stayed the same.
The best features which built the foundation of the DT466 and never changed include the super
beefy, super heavy cast iron deep skirt block, the wet sleeve cylinder liners, the incredibly
strong connecting rods, and rotating assembly, and the big power capability. The crankcase itself
weighs a ridiculous 400 pounds, with massive bulkhead sections and main bearing surfaces,
and simply put, International built the DT466 to be a big, strong, and hard to break engine.
It's heavier than nearly all of its competitors at the time, while also really not making that
much power, which is a recipe for a bulletproof engine. Unfortunately though, towards the end of
its life, International was forced to add a lot of electronics and emission systems to keep up
with the EPA's demands for cleaner engines, and ultimately those components did sacrifice some of
its reliability. The base engine was still there and it was still reliable, but the electronics
draped on top of it just weren't. Where I think the DT466 really shines is not in stock form and
it's not in tractor trailers, rather it's in high performance tractor racing, where you can see some
of these engines producing over 3,000 horsepower with over 300 pounds of boost, and continuing with
engines that dominate in high performance tractor racing we have the John Deere 50 series, and more
specifically the 6-619 which is the 619 cubic inch version of the 50 series engine. But, in the
tractor world most people just call it the John Deere 619. I know for a lot of you watching this,
you probably haven't even heard of this engine, and I will say, this is probably the most obscure
engine on the list and honestly in dead stock form it's really not that interesting. It's pretty
much just another big tractor engine that can put in decades of work pretty reliably. What makes
this engine so interesting is the racing scene, where the top guys build these things with a
billet block and 600 cubic inches of displacement, with some examples producing upwards of
4200 horsepower at four to five thousand rpm depending on the race, and anywhere from
300 to 400 pounds of boost pressure. In fact, this specific engine is one of the few engines
you'll find at any tractor pulling event that will regularly outrun the aforementioned International
DT466. Like I said, this engine is a little bit obscure compared to some of the other engines on
the list, but the impact that it's had on the pro stock tractor racing world cannot be understated.
Of course, no diesel engine list would be complete without the 6BT Cummins, or the 5.9L, or the 12
valve, whatever you want to call it. And when it was first debuted in 1989, it was an absolute game
changer. Sure, it was stuffed into a very outdated Dodge AD chassis, but it gave new life to the RAM
name and it completely changed the truck market as we know it today. Offering 160 horsepower, the
5.9L Cummins is pretty weak by today's standards, however, at the time of its release, GM's
6.2L diesel produced a mere 130 horsepower and the Navistar International 7.3L in Ford's
trucks output 185 horsepower. This put Cummins right in the middle of its two competitors as
far as horsepower, however, the Cummins output 400 pound-feet of torque while GM's diesel output
240 pound-feet of torque and Ford's at 338lb-ft. The 6BT foundation begins with a sleeveless
cast iron block, with an integrated oil cooler, and oil pump cavity, as well as a camshaft bore
that doesn't call for pressed-in bearings. For increased wear resistance, the forged steel crank
journals were treated to induction hardening and the crank was anchored in place with 14 millimeter
main cap bolts. Underneath the cast iron head, you'll find cast aluminum direct injection pistons
which feature a large bowl for fuel to be injected directly into. Underneath the beefy pistons
you'll find forged steel i-beam connecting rods, which are necessary for coping with the massive
amount of torque this engine produces at very low RPM. These stock connecting rods are capable of
supporting upwards of 2,000 pound feet of torque, so it's safe to say they're pretty overkill for
a stock 5.9L. Depending on the year that you're looking at, the turbocharger and injection system
change a little bit, with the most prized version being equipped with the Bosch 7100 pump, which is
also just known as the p-pump. I think it's also worth mentioning that the 5.9L ISB engine, which
is the 24 valve, is also a really cool engine, and really the only difference between the 12
valve and the 24 valve is obviously the cylinder head having twice the amount of valves, and the
fact that the 24 valve does not have mechanical injection, rather it has electronic injection.
Regardless though, the 6BT is definitely one of the best diesel engines ever. And as you might
have noticed, so far every single engine on this list is an inline six. And that's for good reason.
We highlighted this in another video, but simply put, the inline six is the best configuration
for a diesel engine, plain and simple. That being said, there are some really good
V8 diesel engines and one of them is the 7.3L Powerstroke from Navistar International, which
was used in Ford's f-series trucks. After Ford and International had seen success working together
to supply engines for Ford's heavy duty trucks with the 6.9L IDI, the 7.3L IDI, and then the 7.3L
IDI Turbo, we ended up with the 7.3L Powerstroke. And when Ford moved from the IDI turbo engines
to the Powerstroke engines, they ditched the mechanically driven injection system in favor
of electronic injection, and this was done for a number of reasons but ultimately it helped them
increase the power output while also decreasing the emissions output. Of course, switching to
electronic injection upset some enthusiasts who love the simplicity of mechanically driven
injection systems, but who cares it had to happen eventually. During its run from 1994.5 to 2003,
the 7.3L Powerstroke was a huge success, with Ford selling more of their diesel power trucks than
ever before. And they delivered everything their customers wanted, with decent power and superb
reliability. By the end of its life in 2003, this engine produced a respectable 275
horsepower and 525 pound-feet of torque, which was miles ahead of the weak IDI turbo engine
before it. But, with Ford dropping the LB7 on the world and Cummins dropping the 5.9L common rail,
Ford was behind the ball on power output compared to their competition. That fact, coupled with
the impending emissions crackdown from the EPA spelled out the death of the 7.3L Powerstroke.
While it's far from the most advanced or the cleanest or the most powerful diesel engine ever,
the 7.3L is without a doubt Ford's most popular diesel engine ever. And yes, the 6.7L Powerstroke
is very good, it's their newest engine and it makes a crazy amount of power, but it'll never
touch the 7.3L as far as being loved by Ford enthusiasts. And that takes us to the third and
final light duty truck engine on this list, which is the 6.6L Duramax, and we could go more specific
and say you know the LB7 or the LBZ or the L5p, but at the end of the day, the 6.6L Duramax hasn't
actually changed that much from generation to generation, so I think it's better that we just
cover the entire thing. There's been effectively zero major changes throughout the history of
the 6.6L Duramax, but there have been lots of small ones. There's been no major changes to the
block, the architect, head design, and pretty much everything else. And like I said, there's been a
lot of small changes which we highlighted in our Duramax guide video, highly recommend you check
that one out. But again, for the fact that it really hasn't changed drastically, it's better to
just highlight the 6.6L as a whole rather than one specific iteration of it. And I know some of you
might be wondering why not the 6.2L or the 6.5L Detroit Diesel that GM used prior to the Duramax?
And I simply didn't choose either of those because they lacked any form of major innovation, they
barely made any power, and they really didn't do anything special at all. With that in mind,
this is the only engine on the entire list that uses aluminum cylinder heads, and it's only
one of two v8s on the list. When it first dropped on the market in the form of the LB7, it had more
power and more torque than any diesel pickup truck had up until that point, and a big part of why
it was able to produce so much more power than anything else is simply because it had a common
rail injection system, which was the quietest, cleanest, and most powerful injection system we
had seen on a pickup engine up until that point. Of course, today common rail injection can be
found on pretty much all diesels, but back then it was a pretty wild thing to see. Another engine
which I think absolutely must be on the list is the Caterpillar 3406, which is arguably the most
influential engine over the last few decades. Throughout the years, we saw a bunch of different
versions of this engine with the 3406a, the 3406b, 3406c, and then finally the 3406e, and depending
who you ask they might claim one is definitely better than the other, and in my opinion the
E is the best of them all, as it combined the best of the simple and reliable base with also
a very reliable electronic injection system, and the addition of the electronic injection system
opened up a massive world of electronic tuning, which also helped the 3406 grow in popularity
even more. This engine features a bore of 5.4 inches and a stroke of 6.5 inches, with a final
displacement of 839 cubic inches, which is a 14.6 liter. Depending on the specific model that you're
looking at, horsepower ranges from 375 horsepower up to 465, with the highest torque rating coming
in at 1850. Before the aforementioned E engine, we had the A and B engines which were both
mechanically injected, which for some people is their preference as there's typically less
parts to break on a mechanically injected engine. But for CAT to keep up with their competition
and more specifically the EPA's requirements for a cleaner engine, they had to introduce the
C engine which was sort of a combination between mechanical and electronic injection. Once they
got their electronic injection system figured out and reliable enough for their liking, we
got the e-engine in 1993. Unlike the DT466 from International which was ultimately ruined when
they introduced electronics, Caterpillar managed to make the electronics on the 3406e incredibly
reliable and while it's no longer in production, it's still being used all over the world, with
many people simply rebuilding theirs when needed rather than upgrading to a newer engine and a
newer truck with more emissions components. That takes us to the next engine on the list, which
is yet another over-the-road truck engine, and it's arguably one of the most reliable semi-truck
engines ever and completely dominated the 1970s and the 1980s, and that's the Cummins 855 Big Cam.
The first Big Cam engines were introduced in 1976 and they were designed to replace the Small Cam
855 engines that needed to be phased out thanks to the US Government regulations regarding noise
pollution and the Clean Air Act of 1976. Although it's kind of forced to market due to government
restrictions, it actually ended up being super fuel efficient, super reliable, incredibly
durable, and more powerful than nearly all of its competition, which is what led it to becoming so
popular. This 855 cubic inch Big Cam engine uses a 5.5 inch bore and a 5.98 inch stroke, and most
versions were available with power ratings ranging from 250 horsepower up to 400 horsepower, however
there were some rated as high as 605 horsepower in gen set form. The first three versions of
the 855 Big Cam used the Cummins pressure time fuel system, which was unique from other
mechanical injection systems in the fact that it allowed for mechanically variable timing, which
simply meant more power, better fuel efficiency, and reduced emissions output. But, when the Big
Cam 4 was introduced it honestly wasn't as good and most people prefer the first three versions
of the Big Cam, which is fine because the fourth version didn't really last that long and it was
quickly replaced with the Cummins M14. Throughout the years, we saw upgrades including a demand
flow cooling system and pulse exhaust manifold that debuted in the Big Cam 2 engine in 1979, a
pressed steel oil pan and Holset ht3b turbocharger was added to the Big Cam 3 in 1983, and a
revised cylinder head and pulse exhaust manifold for the Big Cam 4 in 1985. But, before we saw any
electronic injection systems really take over the market and be adopted by all other companies, we
had one engine that did it first, and that's the Detroit Diesel Series 60, which was the first
ever heavy duty truck engine ever, plain and simple ever, to bring electronic injection to the
market and it came out in 1987. Think about it, most American cars were still carbureted at this
time or using weird sorts of electronic throttle body injection, so to see this from a heavy
duty diesel truck engine at the time was quite literally unheard of. With the 60 series, Detroit
developed two sizes: an 11.1 liter and a 12.7 liter, and both of them were instant successes.
Really, before either of these engines dropped, Detroit Diesel was losing market share and they
probably would have been out of business at the rate that they were going, so you can credit the
60 series with not only saving Detroit Diesel but also becoming their single most successful
engine series ever. By 1992, a short five years after it was launched, it was already the single
most popular heavy duty truck engine in all of North America, with applications ranging from
trucks, boats, generators, emergency vehicles, and much more. Supposedly, Detroit Diesel worked
with John Deere in the mid-1980s to fix their dying engine programs, but it's unclear how much
John Deere actually helped with the development of the series 60. Compared to the 50 series, they
pretty much solved every issue and then some. By the time the 2000s rolled around, we saw a new 14
liter version of this engine which lasted all the way until 2011, when the series 60 was phased out
and replaced by the DD15. So, that's some of the best diesel engines of all time, and I think there
are some honorable mentions I want to bring up, including the 6.7 liter Cummins, the KTA Cummins,
the Mack e7, the 1.9 liter tdi from Volkswagen, the Detroit Diesel series 71, and much much more.
Like I said at the beginning, this list is in no particular order and there's only so many engines
I could put on the list if I wanted to keep this video relatively short. So, be sure to drop a
comment down below letting me know what engines you think deserve to be on the best diesel engines
of all time list. If you guys enjoyed the video, be sure to smash the thumbs up button, get
subscribed so you don't miss out on future videos, check out some of the other stuff on the channel,
like I said drop a comment down below let me know what you think, and what other engines you'd add
to the list and i'll see you guys in the next one.
