The BIGGEST And Most POWERFUL Australian Diesel Engines Ever Used - This Is INSANE!

Somewhere in the Western Australian outback right now, a single diesel engine is dragging more than 200 tons of steel, fuel, and cargo across a road with no painted lines, no phone signal, and nowhere to stop for 400 kilometers. One Australian prime mover once pulled a road train so long it stretched further than 14 football fields laid end-to-end, hauling roughly the same weight as three fully loaded jumbo jets using one engine bolted behind a single cab. Most diesel engines built for ordinary highways would not survive a single afternoon out here, but the five on this list did not just survive, they became legends. By the end of this video you will know exactly which engine's badge ended up attached to that record-breaking run and why the other four earned their place on the same list. Every list like this has to start somewhere, and this one starts with the sound that outback drivers still imitate around campfires 40 years later. Stand next to a running 12V71 and you do not hear a diesel engine, you hear something closer to a jet engine having an argument with a chainsaw. General Motors built this two-stroke V12 from the 1960s through the 1980s and it found its way into Australian Kenworths hauling ore, cattle, and general freight long before anyone had heard the words emissions standard. Two-stroke means the engine fires a power stroke on every single downward movement of the piston instead of every second one like a normal engine, which is why it screams instead of rumbles, and why drivers on both sides of the Pacific nicknamed the whole Detroit two-stroke family the Screaming Jimmy. This version displaced close to 14 liters across 12 cylinders and produced up to 475 horsepower in its strongest highway tune, staggering output for its era. Picture seven small car engines bolted together into a single block and you are close. How does an engine built in the 1960s end up feared and loved in equal measure on the other side of the planet decades later? In the American Midwest, one owner-operator running double trailers on Interstate 90 through the 1970s said the engine's torque was so brutal it burned through a set of drive tires roughly every two months, turning good rubber into scrap long before it wore out normally. If you ever change drive tires on a Jimmy-powered rig more often than you change the oil, you already know exactly what that felt like. The trade-off for all that scream was thirst, since a two-stroke diesel burns oil along with fuel, and by the 1990s, tightening emissions rules finally forced the last Screaming Jimmys out of new trucks for good. Here is the kicker. The final Series 71 engine rolled off the line in 1995, which means some of these things worked outback road trains for three solid decades before retirement. It was not the most powerful engine on this list, and it was not the most modern, but it might be the loudest argument ever made for the idea that character beats a spec sheet. The next engine on this list took that same brute force philosophy and wrapped it in 18 liters of pure stubbornness, and it earned a reputation that outlasted almost every other big diesel of its era. Number four, the Caterpillar 3408. 18 liters, eight cylinders, a reputation for outliving the trucks it was bolted into. Walk up to a Kenworth or Western Star fitted with this engine, and the first thing you notice is how much room it takes up under the hood. A solid iron V8 built when Caterpillar believed bigger was simply better. Caterpillar built the 3408 from 1975 to 1985, marketing it as the big brother to their far more popular six-cylinder 3406. It never became the sales leader Caterpillar hoped for, but the operators who did run it treated it less like a truck engine and more like a family heirloom. On the highway it produced between 425 and 550 horsepower, and it weighed as much as 3,700 pounds, roughly the same as the sedan sitting in your own driveway. Except this sedan is a single engine block. Its reputation rests on a rating still repeated by mechanics today, a documented life expectancy of up to a million miles or 20,000 hours before a full rebuild was even considered necessary. What kind of engine earns a nickname like the million mile motor decades after it stopped being built? In one documented case, mechanics working on a 1983 3408 sitting in a glider kit, Peter built, with 1.8 million miles on the odometer, still recorded nearly 700 horsepower at the crank. On a chassis dynamometer with only mild tuning, numbers that would embarrass plenty of engines a quarter of its age. If you have ever kept an old 3408 running well past the point anyone expected it to, you already know exactly why people still argue over this ranking. The catch was fuel. All that iron and displacement drank diesel faster than smaller. More modern engines could match, and its sheer weight ate directly into payload on every single load, which is exactly why fleets slowly drifted toward the lighter 3406 instead. Pretty wild, right? An engine considered a commercial disappointment in its own showroom, still has diesel mechanics chasing used examples decades after Caterpillar stopped building it. This is an engine that lost the sales war and won almost every argument that happened after it. That engine at least had some breathing room under the bonnet. The one coming up next was built to be tuned harder than Caterpillar ever intended, and in Australian hands, that is exactly what happened to it. Number 3. The Caterpillar. 3-4-0-6-E. This is where the list stops being about brute size, and starts being about how far an engine can be pushed past what the factory ever signed off on. It does not look dramatic sitting in a bay, a straight six with none of the visual drama of a V8 or a screaming two-stroke, but that plain exterior hides one of the most modified diesel engines in trucking history. Caterpillar introduced the 3-4-0-6-E in the early 1990s and kept building it into the 2000s, right at the exact moment diesel engines were shifting from mechanical injection to electronic control. This was Caterpillar's first fully electronic unit injection engine, meaning a computer, not a mechanical pump. Decided exactly how much fuel went into each cylinder and exactly when, and that computer turned out to be surprisingly easy for owner-operators to talk their way around. Stock highway ratings ran from around 425 horsepower up to roughly 600 horsepower in the toughest factory trims, with peak torque above 1800 pound feet, more twisting force than five stock pickup trucks combined. So what happens when you hand an entire generation of Australian owner-operators an engine with a tunable computer and a reputation for taking abuse? One owner interviewed by a parts supplier put it bluntly, saying his 550 horsepower 3-4-0-6-E would out-accelerate brand new 600 horsepower electronic engines away from a stoplight, purely because the old mechanical-style throttle response had no turbo lag and no computer hesitation to fight through. And if you ran a tuned 3-4-0-6-E through the Pilbara or across the Nullarbor and you think we have not guessed how far your particular engine was pushed, drop the real number in the comments, because everyone who has run one insists theirs was the strongest example ever built. How far did some operators actually push it? Far enough that documented power ratings for this general engine platform have been recorded as high as 800 horsepower in its most aggressive commercial tunes, nearly double where the engine started its life. That flexibility came at a cost. Push an engine designed around a specific factory torque curve well past its intended limits for years at a time, hauling road train weight through outback heat that regularly passes 50 degrees and something eventually gives, whether it is a cracked piston, a cooked turbo charger, or a cylinder liner that was never built to see that kind of sustained pressure. Caterpillar never approved these aggressive tunes, which meant when something failed under warranty, operators were entirely on their own. A trade-off plenty of drivers accepted without a second thought, because the extra power was worth the risk. Here is something most people do not know. Caterpillar eventually built its own successor engine specifically because keeping the 3406E's mechanical feeling durability while closing the tuning loophole had become impossible. This engine did not just get modified by its owners, it got redesigned by its own manufacturer specifically to stop people from doing what made it famous in the first place. The real question about what comes next is not how much horsepower it made, it is how a European manufacturer that had never built for Australian conditions decided to try anyway. And the answer changed the horsepower conversation in Australian trucking forever. Before we get to the final two engines on this list, including the truck that once held the title of the most powerful production truck in the world, and the badge that ended up attached to the longest road train ever pulled by a single prime mover, there is something worth knowing. If you want to keep seeing videos like this one, subscribe so you never miss what is coming next. Number 2. The Scania 730 By 2011, Europe had already crowned a horsepower king for road-going trucks, and a Swedish manufacturer decided the crown needed to change hands. The truck itself looks almost understated for what it carries, a cab over European design. With none of the towering hood or bull-bar drama Australian drivers usually expect from something built to survive the outback. Scania introduced the 730 in Europe around 2011 and brought it to Australia not long after, aiming it directly at the road train and heavy haulage market. Under the cab sits a 16.4 liter V8, and to hit 730 horsepower Scania had to rebuild the engine's internal structure using compacted graphite iron, a metal alloy that means stronger and lighter at the same time, letting the block survive dramatically higher pressures without adding much weight. That engine produces 3,500 newton meters of torque, which converts to roughly 2,581 foot pounds, more than six times what a modern pickup truck makes. Delivered as low as 1,000 revolutions per minute so the truck can lug a heavy load without constantly hunting for gears. How much fuel pressure does it actually take to force diesel through an injector fast enough to feed an engine like that? The system runs at pressures up to 34,000 pounds per square inch, which is roughly 700 times the pressure coming out of a garden hose. In Western Australia's Pilbara region, senior driver Richard Skurta ran a 730 horsepower Scania twin-steer prime mover for fusion contracting, hauling iron ore on a nightly run of nearly 800 kilometers with a gross train weight of 171 tons spread across 18 axles. If you have ever sat in the cab of a 730 pulling a quad road train through the Pilbara at 3 in the morning, tell us in the comments whether the comfort actually matched the reputation, because plenty of drivers who switched from American iron say the ride alone justified the badge. Was all that power actually necessary, or was it simply about winning a horsepower race most customers would never fully use? Fusion Contracting's owner John Edwards admitted the decision to trial the 730 was not taken lightly, because most of the trucks Scania sold worldwide were never expected to handle multiple trailer combinations in outback conditions at all. They were built primarily for European drivers hauling far lighter single trailers. Getting genuine reliability data for extreme Australian road train use meant operators were essentially running their own live experiment at their own financial risk on one of the most demanding freight applications on the planet, and that is not a small number. The same fleet reported burning between 630 and 650 liters of diesel on a single trip, comparable fuel use to a 600 horsepower Mac pulling a noticeably lighter load. This was never just a truck engine, it was Europe's answer to a question Australia had been asking for years, whether anyone could outmuscle American iron on its own home turf. If you thought the horsepower race ended with that badge, wait until you hear what a much older, much simpler V8 was already doing decades earlier, and its badge is still the single most recognizable symbol in Australian trucking history. Number one, the Mac E9. Every engine on this list earned respect, only one of them earned a religion. You hear a Mac Super Liner before you see it, a distinctive bop idle followed by an air start system that fires the engine awake with a blast of compressed air loud enough to turn heads across an entire truck stop. Mac Trucks Australia introduced the Super Liner in 1980, powered by a 16.4 liter E9 V8 producing 400 horsepower, and by the time the Super Liner II arrived in 1986, that number had climbed to 500 horsepower standard with a gross combination mass rating up to 200 tons. Displacement wise, the E9 measured 998 cubic inches, built as a V8 sharing early engineering roots with Scania's own V8 family through a technical partnership between the two companies, which explains why two brands on opposite sides of this list technically share ancestry. By 1992, the Econodyne version reached 525 horsepower, and the fully electronic Australian only EA9 variant of the mid to late 1990s pushed past 610 horsepower with over 2,000 pound feet of output that outmuscled every rival on the Australian market at the time, including Caterpillar's own big block C16. How does one V8 built by an American company end up becoming the single most emotionally loaded engine badge in an entire country's trucking culture? The clearest proof of just how far the E9 could be pushed came from a 1984 Super Liner in the United States nicknamed the Buckeye Bulldog, campaigned by national tractor pulling champion Ray Collins, whose E9 powered pulling truck was documented producing over 2,500 horsepower reliably. Word of that build reached Mack enthusiasts in Australia, and through direct contact with Mack Trucks International's own Hagerstown Engine Factory, a similarly built engine capable of over 2,000 horsepower was constructed for an Australian project. Proof that the same production block underpinning ordinary road train prime movers could be pushed into territory most manufacturers would call fiction. If you ran an E9 powered Super Liner on straight pipes, and you think no engine on this entire list ever sounded as good, you are not alone, and you are welcome to say so loudly in the comments. So what happens when you take that reputation for reliability, under absurd abuse, and put it to work on the single hardest freight application on the planet? The E9 was not perfect. It was heavy. It was thirsty compared to newer inline engines. And when Volvo acquired Mack in the early 2000s, the E9 was discontinued entirely by 1999, replaced first by a Cummins signature engine, and eventually by Mack's own 16 liter MP10. Parts, rebuilds, and specialist knowledge became harder to find every year, and an entire generation of drivers had to watch the engine that defined outback trucking slowly disappear from new truck lineups for good. Let that land for a moment. On the 18th of February 2006 in Clifton, Queensland, a tri-drive Mack Titan carrying the same bulldog badge that the E9 made famous pulled 113 semi-trailers weighing 1,300 tons across a distance of 1,474.3 meters, longer than 14 football fields laid end-to-end, driven by 70-year-old John Atkinson, and it remains the longest road train ever pulled by a single prime mover in recorded history. The E9 did not just power trucks across the outback. It built the reputation that made a later Mack capable of doing something no other manufacturer's badge has matched before or since. Five engines, five completely different philosophies, and one continent that tested every single one of them harder than anywhere else on earth ever could. Which one do you think actually deserves the top spot? The screaming two-stroke that started it all? The tuned 3406E that Caterpillar had to redesign an engine to stop? Or the bulldog badge that ended up attached to the longest road train ever pulled? And if you have actually driven one of these five across the Nullarbor or through the Pilbara yourself, we want to hear which one you would trust with your own life on that road. If you want more videos like this one, subscribe so you never miss what is coming next. See you in the next one.