Engine Swap Fundamentals: Trucks

Classic pickup trucks are great candidates for engine swaps for many reasons. For starters, the original motor in any vehicle more than 20 years is bound to be tired and in need of an intensive overhaul if it hasn’t been properly and regularly serviced throughout the years. Enthusiasts who are interested in giving their old truck a new breath of life with a modern engine with far more power, an engine swap is the best way to go given the amount of ready-to-go crate engines and install kits that can make the job doable, and rather affordable too. Whatever the case may be, a new engine can make a world of difference in the experience in building and driving a custom classic truck or vehicle of any type, really. 

New or Used? 

Either way, there’s no losing when replacing that old, whipped engine that’s way past its prime.

Depending on the type of truck you’re working on, there will be plenty of engine options to consider. “New VS. Junkyard Find” will always be a heated battle that will almost always favor a brand new mill given the reliability and warrantied performance at a slightly higher premium when compared to a used engine that would require maintenance and refurbishment before installation. While a good amount of builders will resort to ordering a virgin engine, there is a respectable sect that prefers to scour the junkyards and partake in the thrill of the hunt when looking for that perfect transplant motor that can be had at a fraction of the price. Either way, there’s no losing when replacing that old, whipped engine that’s way past its prime. 

Engine Types

While Coyote 5.0L Mustang engine swaps are trending in classic Ford pickup builds, LS engines have been all the rage in the C10 market for some time now. Since the size is similar to a small-block Chevy (SBC), there is plenty of room to plant one under the hood of just any year classic GM truck.

While there are plenty of other engine SBC V-8 options to select from such as a 350, 327 or 305 models, nowadays the LS platform has taken center stage with a very wide selection of aftermarket kits to assist in the swap of your truck’s new engine. Whichever engine route you decide to take, it will be a drastic change in performance compared to your truck’s dated power plant. 

Adaptability 

While available room isn’t an issue so much when installing a smaller, more modern engine into a classic truck, the matter of properly placing the engine becomes the real factor during a swap. While there are many installation kits available for LS and other engine platforms to pick from, the job itself is anything but plug and play—no matter what you see advertised online. Selecting correct engine mounts is paramount, and luckily, finding the right ones isn’t hard these days.

Aside from getting the new engine to sit in the right place, you’re also going to want to consider swapping out the transmission, driveshaft and all the fixins, especially if you’re going with a more high performance engine. While not necessary at first (but highly recommended), just keep in mind that the OE equipment, especially depending on its age, wasn’t designed to handle the kind of power an LS unit is capable of. Oh, and don’t forget a torque converter. 

Breathing and Cooling Options 

A new engine will require a fresh exhaust system with an emphasis on a proper exhaust manifold and header selection. While there is a range of affordability here to fit any budget swap, you’ll want to take clearance into heavy consideration here. 

A capable radiator is also of utmost importance since heat will definitely not be your new engine’s friend. Depending on the engine you’ve selected to run with, it may be more feasible to go the aftermarket route, maybe even an engine-specific selection, instead of saving a few bucks salvaging one from the scrapyard. 

Gassed 

Let’s say that you went with an LS engine to swap into your old truck. If that’s the case, then you may be ecstatic to ditch a carbureted setup and run with an EFI setup, unless you’re a big, big, BIG fan of the carb. Choosing EFI will make you consider fuel tank and pump options that will vary based on price and level of installation that you’re comfortable with. And if you just can’t stand to stray from a carbureted fuel system, there won’t be as much of an issue, but just be prepared to handle the pros/cons of whichever option you choose. 

Take Control 

It might not click instantly when planting a modern engine underneath the hood of your old truck, but new engines carry with them their own sets of characteristics to take into consideration. Now, when it comes to the ECU (electronic control unit) and wiring harnesses, you’ll have options to choose from to better dial in the installation process. This is where things can get exponentially interesting. Depending on how you plan to drive your truck, you can select an aftermarket ECU controller package that can handle the wiring, as well as enable you to unlock your engine’s true performance capabilities. Builders looking to race their truck or run it through the autocross course will get the most out of topping off the swap with the right ECU package for the job. 

Kick start your sluggish pickup project by tossing the old engine out, and swapping in a brand new crate engine or freshly rebuilt motor in its place. While an engine swap does encourage the replacement of the transmission at the same time, as well as a lot of other key equipment pieces, the job can really update a classic truck in more ways than initially realized. Increase horsepower by the ton, while also delivering a new sense of reliability in the truck you plan on getting real seat time in with whether it be at the track or open stretches of highway. An engine swap isn’t the easiest or cheapest things to do with your truck, but one that will certainly make the biggest impact in the way you enjoy it. 

The 2JZ-GTE: What Cars Have The 2JZ Engine?

There’s no magic behind the success of Toyota’s most popular powerplant, the 2JZ, just sound engineering and a focus on getting the basics right.

Toyota’s 2JZ-GTE is legendary among car enthusiasts for its durability and power potential, capable of reliably delivering 700-plus horsepower without ever touching the factory long block, and four-digit dyno numbers with the right internals. A product of 1990s Japan’s economic boom, saving money on its design and construction was nowhere near the top of the priority list, and the result was an engine fit to be Toyota’s flagship in the secret JDM horsepower war of the era.

It certainly didn’t hurt this engine’s reputation to be paired with the MKIV Supra; a whole generation of enthusiasts grew up with Toyota’s ultimate sports car as an ‘aspirational vehicle’ the same way 80s kids had posters of the Lamborghini Countach on their bedroom walls. A certain movie franchise that will remain unnamed here helped fuel that fire, and even if you didn’t know a wastegate from a blowoff valve, if the 90s were your formative gearhead years  you could recite the factory 2JZ-GTE specs by heart like your older brother could rattle off the Konami code.

While even casual US fans of import performance hold the 2JZ in high esteem, unless you’ve torn one apart and put it back together again, all the details both large and small that earned its bulletproof reputation may not be a part of your knowledge base. To rectify that, we’re going to look at why this twin-turbo inline six became a world-beating engine, starting from the very basics.

Getting That 6-Pack

To begin with, there’s the cylinder layout. Today’s 6-cylinder engines are almost exclusively V-block designs – this layout makes for a very compact engine that is well suited for short engine bays in cars with longitudinal drivetrain designs (where the engine’s crankshaft runs front-to-back) as well as in front wheel drive transverse setups (with the crankshaft running side-to-side). Unfortunately, V6 engines offer significant challenges in terms of firing order, requiring either ‘split’ rod bearings on each of the three pairs of crank throws to even out the timing of each power stroke, or an “odd-fire” crank design with the cylinder pairs sharing a single throw, but the firing events at uneven intervals of crank rotation.

Another option is a flat-6 design, favored by Porsche and Subaru. This also gives a very short engine from the crank snout to the flywheel, but a very wide one. Firing intervals aren’t an issue in what effectively is a V6 engine with a 180 degree cylinder bank angle, but this layout has inherent imbalances in the reciprocating and rotating planes because of the offset of the cylinders.

The 2JZ, however, is a classic inline-six. This engine geometry offers ‘perfect’ primary balance and silky-smooth operation at any speed–an important consideration for a powerplant intended for use in Toyota’s premiere performance cars. The firing order, with evenly-spaced firing intervals and overlapping power strokes, also lends itself to turbocharging as it smooths out pressure delivery to the turbine(s).

Materials Matter

Another critical factor in the 2JZ’s high threshold for abuse is the cast-iron block. While it’s certainly possible to build a durable all-aluminum engine for forced induction, iron is more forgiving of stress, with less thermal expansion and a defined fatigue limit. The latter sounds like a bad thing, but it’s the reason springs are made from steel and not aluminum – when stressed below its fatigue limit, an iron block can handle an effectively unlimited number of load cycles without metal fatigue, while aluminum gets a tiny bit closer to failure every time stress is applied. There is a price to be paid for the 2JZ’s iron block construction, though; it’s one of the major reasons why a fully-dressed engine tips the scales at over 500 pounds.

Speaking of that block, it’s a seven-main-bearing design with a deep skirt at the bottom that extends past the crank centerline. Many engine blocks are designed in such a way that the main part of the structure ends right at the crank midline and the main bearing caps project beneath it. While less expensive to cast and machine, this type of block usually needs reinforcement of the main bearing journals for high performance use. In classic domestic V8 engines, you’ll hear about “four-bolt mains” where each cap has an additional pair of bolts, often splayed at an angle to the primary pair, to cure this weakness.

While the 2JZ has two-bolt main caps, they are inset into the block’s thick main web, which gives them extra support without needing an additional pair of bolts. Nissan addressed this issue in the 2JZ’s arch-rival, the RB26DETT, with a ‘girdle’ that incorporates all the main caps into a single structure, and modern V8 engine designs like the GM LS and Ford Modular families use deep-skirt blocks with cross-bolt main caps. Compared to these other fixes, Toyota’s approach is elegant and simple, and hasn’t proven to be an issue even when the 2JZ is pushed far beyond its original horsepower and torque output.

 

A cast cover with a separate small, stamped metal sump for oil control rounds out the bottom end of the 2JZ, with the cover acting as a stressed component of the block rather than simply keeping all the oil from falling out the bottom of the engine. Having a fully “boxed” crankcase is another intentional choice by Toyota to make the block assembly as strong and rigid as possible, without introducing additional complexity or expense.

 

The stock 2JZ crankshaft is another strong point of these engines. Because inline-six cranks are, by necessity, relatively long compared to most other engine layouts, there’s the potential for them to act like torsion bar springs, twisting along their axis and even having issues with destructive feedback if the frequency of the power pulses lines up with the harmonics of the crank. Knowing that this was a potential weak spot, Toyota’s engineers specified a forged, rather than cast crank, with relatively large 62mm main and 52mm connecting rod journals. While aftermarket billet cranks are available, for all but the most extreme builds they’re simply unnecessary–that’s how good the factory crank is.

Heading up the block, you’ll find special GTE-spec rods that are stronger than the ones found in naturally-aspirated 2JZ-GE engines, plus turbo-specific cast pistons with a slight dish to lower compression ratio to a boost-friendly 8.5:1. The underside of the pistons are cooled by oil squirters fed by a gallery at the bottom of the cylinder bores to help prevent detonation caused by hot spots as well.

Getting a Head

Where the block meets the head, the 2JZ uses a ‘closed deck’ design that fully supports the cylinder bores. Compared to an ‘open deck’ block, this leaves less room for coolant passages, but it is a far better way to prevent head-gasket-killing bore shift under boost and maintain the head-to-block seal. Speaking of head gaskets, the stock 2JZ comes with a multi-layer steel gasket of the type typically used as an aftermarket upgrade as another way to prevent combustion leaks. The head is secured with 14 bolts, arranged so that each bore is surrounded by fasteners on all four corners. Replacing these factory parts with upgraded bolts or studs is a relatively inexpensive way to make an already-stout engine just a bit more durable – since the factory fasteners are single-use ‘torque to yield’ bolts they will need to be replaced anyway once the head comes off for any reason, so you might as well upgrade while you have the engine apart.

The bore and stroke are “square” at 86mm each for an actual engine displacement of 2,997cc. The bore diameter leaves plenty of room in the pent-roof combustion chamber for a pair of 33.6mm intake valves and two 29mm exhaust valves. Those valves are activated by a pair of belt-driven cams; while the JDM Aristo and 1998-2002 Supra got VVT-I variable cam timing on the intake side, the 2JZ-GTE in the US-spec MKIV Supra did not. To keep valvetrain mass to a minimum, the cams activate “bucket” tappets that act directly on the valve stem instead of through any kind of rocker, with lash adjusted by shims of variable thickness between the buckets and valves. Though not as quiet or maintenance-free as a valve drive with hydraulic lash adjusters, this system, which is almost universally used in high-performance motorcycle engines, is incredibly reliable and doesn’t require a ton of spring pressure to control valve motion at high RPM, reducing frictional losses. The wide buckets do limit max valve lift and cam lobe design to some extent, but the 2JZ is less sensitive to cam grind limitations than a naturally-aspirated engine would be thanks to forced induction.

Fuel and Spark

Sequential electronic fuel injection was standard, with JDM versions getting 440cc injectors and the US import 2JZ blessed with larger 550cc models. Even with elevated fuel pressure, these can be a bottleneck for power production, but fortunately Toyota used the common top-feed design and aftermarket injectors with much higher flow are common and relatively inexpensive.

One of the quirks of the 2JZ design is in the ignition. Many people think it’s coil-on-plug, but it’s not. The engine uses what’s known as a ‘wasted spark’ setup where two cylinders that are 360 degrees out of phase in the firing order share a single coil. One cylinder gets the coil perched atop the plug at the center of the pent-roof combustion chamber, while the other spark plug is connected to the same coil by a short high-voltage lead. Both cylinders receive a spark when the piston is just about to get to top dead center; one is on the compression stroke, while the other is on the exhaust stroke, and that spark is ‘wasted.’ It’s a clever way to make three coils do the job for a six cylinder engine, and while it’s possible to replace the entire ignition with an aftermarket setup that has individual coils for each cylinder, experience has proven that the stock coils in good condition provide a spark that’s “hot” enough to reliably prevent misfires even at elevated boost.

It’s worth mentioning that the 2JZ-GTE also employs dual knock sensors, which are transducers screwed directly into the engine block that act like a microphone to detect the first signs of detonation. The ECU can then act to protect the engine from serious damage by pulling ignition timing advance, reducing boost, or both in response.

Making Good Things Even Better

The 2JZ-GTE as implemented in the US MKIV Supra delivered 321 horsepower and 315 pound-feet “at the brochure” and featured a novel sequential twin turbo setup that reduced boost lag by relying on just one unit at low RPM to make the most of available energy in the exhaust stream, then bringing the second identical unit up to speed as the revs climbed to supply sufficient airflow. The result was an amazingly well-balanced power curve, but about an hour after the first Supra was sold in US dealerships, somebody was already pulling off all the intake and exhaust plumbing to install a big single turbo and ditch the dinky side-mount air to air intercooler for a giant FMIC. As the years have passed, pretty much everything you can think of in terms of a turbo setup has been tried on the 2JZ, and hitting an arbitrary horsepower target number is as straightforward as looking to see what’s worked in the past and using that as a blueprint.

It’s a tribute to just how right Toyota got this engine that here, almost 20 years after the last one was produced, people are still building and racing them, parts are widely available, and they pretty much just aren’t wearing out. While newer designs that are lighter, smaller, or cheaper to produce have taken the 2JZ-GTE’s place, it’s doubtful that any of them will earn the same bulletproof reputation or fanbase as Toyota’s legendary twin-turbo inline six.

10 Engines That Changed the World

We take a lot of things for granted today – engines that start with the turn of a key, deliver abundant horsepower from minimal displacement, squeeze every mile possible out of a gallon of gas, and run for a hundred thousand miles and beyond with only routine maintenance. But over the last century or so, there have been some definite turning points where new technology and fresh ideas have radically changed how we drive. Here’s a look at ten of them that deserve recognition.

Ford Model T – 1908

Henry Ford’s car for the masses was one of the few vehicles in history that actually got simpler and cheaper over its long production run, and the basic 144 cubic inch inline-four under the hood, delivering a whopping 20 horsepower, was the perfect powerplant for the job. With a 3.98:1 compression ratio, this side-valve engine wasn’t all that sensitive to fuel quality, which was an important selling point in a world where the availability of highly-refined gasoline was pretty much non-existent.

Everything about the Model T’s engine was simple by design. There was no fuel pump, with the single sidedraft carb relying on gravity feed much like a lawnmower engine, and spark was provided via magneto and four “trembler” coils to step up the voltage. After an initial short run of a few hundred engines equipped with a water pump, Ford switched to a ‘thermosiphon’ cooling system that relied on the natural circulation of hot water. Hand crank starting was supplemented with an optional electric starter in 1919.

Although Model T production ended in 1927, the engine continued to be manufactured all the way up through the fall of 1941 for use in industrial and marine applications to power pumps and generators. 

Ford Flathead V8 – 1932

Though the V8 engine configuration, with two banks of cylinders sharing a single case and crankshaft, dated back to the turn of the 20th century, Ford’s original 221 cubic inch “Flathead” V8 was revolutionary in 1932. Most widely-produced car engines up until that time were either inline four or six cylinder designs, and even luxury cars with powerful (for the time) eight cylinder engines almost always were inline block layouts. The relatively compact Flathead was initially rated at 65 horsepower, then improved via an increased compression ratio to 85, and the design morphed into a number of different displacements ranging all the way up to a 337 cubic inch version and shrunk down to a diminutive 60-horsepower 136CI model.

Despite having cooling issues stemming from the necessity of routing exhaust passages through the block, and the general inefficiency of the valve-in-block cylinder head design, it’s impossible to understate just how important the Flathead was as an automotive powerplant. It was the engine that spawned the original hot rod movement, and countless aftermarket performance parts, up to and including overhead valve “Ardun” cylinder head conversions. Eventually overshadowed by more modern V8 engine designs, the Flathead still remained in production (albeit in highly-modified form) all the way up until the mid-1960s, and it continues to be popular with hot rod builders interested in retro or period-correct power.

Volkswagen Flat Four – 1936

Designed during the era of German nationalism that metastasized into the Nazi Reich, the horizontally-opposed, air-cooled flat-four engine from the “people’s car” ended up powering decades’ worth of vehicles that became synonymous with peace and love, and remained in factory production for more than 50 years, eventually spawning a water-cooled successor and laying the groundwork for Porsche’s legendary aircooled 6-cylinder “boxer” engines.

Despite its uber-simple design, which utilized a horizontally opposed layout to make it as compact as possible and fan-driven air cooling to eliminate the need for complex castings incorporating passages for liquid coolant as well as the weight of a water pump and radiator, the VW flat-four featured some remarkably sophisticated engineering for the era. The heads were manufactured from aluminum, while the finned cylinders were cast iron, and the crankcase was made from lightweight but strong magnesium.

With displacements ranging from 1.0 to 2.0 liters, and horsepower ranging between 24 and 99+ in factory trim, the VW flat-four found its way into a lot of vehicles other than the iconic Beetle – vans, the mid-engine Porsche 914 and “entry level” 912, countless dune buggies and kit cars, and even aircraft. As a matter of fact, its similarity to the widely-used Continental and Lycoming horizontally-opposed air cooled aircraft engines led not only to conversions for experimental kit planes, but even certified versions for aviation use. Its simplicity, durability, and tuner-friendly nature mean that the VW aircooled four will be popular for as long as internal combustion engines still exist.

Jaguar XK6 – 1948

There were inline-six engines before the Jaguar XK, and there were dual overhead cam engines before it as well. But the 3.4L engine that first appeared in the Jaguar XK120 sports car (their first sporting model since the unpleasantness on the Continent ended production of the SS100 in 1939) was the engine that all subsequent I6 designs and all DOHC powerplants of any cylinder count worth mentioning can claim as an ancestor.

When Nissan, Toyota, and even BMW set out to build their own I6 powered sports cars, the XK6 provided the archetype, so if you are a fan of the RB, 2JZ, or M30, you owe a debt of gratitude to this seminal design.

The XK6’s iron block was topped by an aluminum cylinder head; the material had been selected not only for light weight but also for its ability to efficiently move combustion heat into the cooling system, which allowed a higher compression ratio without detonation (and took advantage of the massive increases in fuel knock resistance that the war had brought). Widely-spaced, large valves and ports designed to increase intake charge swirl let it breathe, and the XK6 quickly went from a rated 160 horsepower to 210, then 250.

The Jag 6 was the result of a generation of engineers who had been pushed hard for a decade to defeat an existential threat to their nation turning their now-razor-sharp skills on making the best auto engine they possibly could, and between 1948 and the end of its run in 1992, the design in all its variations and displacements made its way into dozens of different Jaguar models, and even powered the Scorpion and Scimitar armored fighting vehicles.

When Nissan, Toyota, and even BMW set out to build their own I6 powered sports cars, the XK6 provided the archetype, so if you are a fan of the RB, 2JZ, or M30, you owe a debt of gratitude to this seminal design.

BMC A-Series – 1951

The Austin Mini holds pride-of-place as the car that first put together all the elements of the modern automotive transportation appliance in the same package: All the bulky mechanical parts out ahead of the passenger compartment, with a transaxle powering the front wheels driven by a transverse inline-four engine. The diminutive car required a similarly-tiny engine, and the BMC A-Series, ranging in displacement from 0.8 to a whopping 1.275 liters, was the perfect companion.

While outside of Japan’s Kei sub-sub-compacts, almost every other FWD car is huge compared to the original Mini, but they all draw inspiration from it. Nissan’s CA family can show a direct engineering family tree to the BMC A-Series, having been built around a licensed version of the little Austin’s blueprints. The A-Series inline four wasn’t anything particularly revolutionary in terms of performance or mechanical engineering, but it led the way in how engines would be packaged in the future to free up maximum space for people and things on the inside of the vehicle, making an impact on the automotive world that was as enormous as the engine itself was small.

Chrysler Hemi – 1951

Born from an experimental aircraft engine design that reached maturity just a bit too late to contribute to the Allied war effort in 1945, Chrysler’s hemispherical cylinder head concept was, at heart, the engineering solution to the problem of fitting the biggest possible pair of valves into any given cylinder bore diameter. Once civilian car production re-started, the company took what they had learned in developing that engine and applied it to their FirePower 331 cubic inch V8 that debuted in 1951, delivering between 180 and 300 rated horsepower depending on configuration.

Thanks to the design’s wide bore spacing, displacement grew throughout the decade, and DeSoto Fire Dome and Dodge Red Ram and Power Dome versions of the same architecture were introduced. But the second-gen Hemi, introduced in 1964 and displacing 426 cubic inches, was what put the name on the performance map. The over-the-counter version available to the driving public from 1965 to 1971 was rated at 425 horsepower (gross, with no accessories like a water pump drive or alternator to put parasitic drag on the engine) and 490 pound-feet of torque. In competition, NASCAR and professional drag racing teams embraced the enormous (and enormously powerful) Hemi, and there are still traces of the original 1964 Hemi DNA in today’s nitromethane-burning supercharged Top Fuel and Funny Car engines.

While the name was revived (rendered in all caps – “HEMI” – don’t you forget it!) for a third generation in 2003 that continues in production today, the engine bears little resemblance to its forebearers – a true hemispherical combustion chamber as seen in the second-gen engines, while allowing very large valves, ends up with a “squish” space that looks like an orange peel. This makes the design sensitive to fuel quality and ignition timing to make sure that large, thin volume of compressed gas and air burns smoothly and completely. Modern multi-valve “pent roof” cylinder heads with four facets for a pair of intake and exhaust valves, plus a fifth for the spark plug, achieve the same airflow advantages of a two-valve Hemi head while allowing more efficient combustion chamber shapes. Nevertheless, Chrysler’s Hemi remains as an iconic turning point in performance engine design.

Small Block Chevy – 1954

Arguably the most popular engine of all time, the original “small block” Chevy V8, first introduced in the 1955 model year Corvette and Bel Air, caught lightning in a bottle, and its descendants continue to be manufactured today for use in cars like the mid-rear-engine C8 Corvette. Unlike the Flathead, Chevy’s V8 utilized an overhead-valve cylinder head that allowed for higher compression, a more efficient combustion chamber design, and improved cooling.

 

The original 265 cubic inch design eventually grew into 400CI factory engines with the same bore spacing, and the SBC was one of the first production engines to deliver more than one horsepower per cubic inch of displacement. Over five separate generations, there have been countless changes to the original Chevy V8, including various mixes of cast iron and aluminum blocks and cylinder heads, distributor-fired and coil-per-plug ignition, carburetors, mechanical fuel injection, and EFI, and even cylinder deactivation for “displacement on demand” and variable valve timing.

Through all these changes, from the original 162 horsepower Gen I in 1955 to today’s naturally aspirated Gen V LT2 rated at 490 horsepower in the 2020 Stingray and the 638-horse supercharged Gen IV LS9, the SBC has retained one archaic design feature (with the exception of the unique Lotus-designed DOHC 1989-1995 LT5) – a single cam located in the center of the vee, with pushrod valvetrain actuation. In a world dominated by overhead cam designs, GM’s venerable cam-in-block design continues to prosper in everything from trucks to sports cars.

Wankel Rotary – 1964

Out of all the engines on our list, the Wankel is definitely the most revolutionary (pun intended). Forgoing the conventional piston-engine layout, the design originally conceived by Felix Wankel and patented way back in 1929 is a graduate-level education in geometry and physics. Instead of reciprocating, all the internal components in a rotary spin in the same direction, and although it operates in the same general way a four-stroke piston engine does, it has the power delivery characteristics of a two-stroke, with one power “event” per turn of the output shaft for each rotor assembly.

…but whenever there’s a need to pack a huge amount of horsepower in a high-RPM engine the size of a pony keg, the Wankel is ready to answer the call.

German manufacturer NSU was the first to bring a semi-practical design to mass production, but it took Mazda to really embrace the Wankel, licensing the patents and working out many of the unique challenges posed by the design, which included developing combustion seals for the rotor apexes and between the rotors and housing sides that would be durable enough to compete with piston engine technology that had several decades’ head start. Legendary Mazda cars like the Cosmo, RX-2, -3, -4, -7, and -8, and even a compact pickup (which was singularly unsuitable for rotary power in practical terms, but an awesome example of Mazda’s “Wankel all the things!” enthusiasm) featured rotary power, and many US manufacturers considered using variations of the design for everything from subcompacts to Corvette concepts.

Unfortunately, some inherent drawbacks remained hard to overcome – apex seal lubrication required a small, but continuous consumption of oil as there was no crankcase to separate lube from the combustion process, and although Wankel rotaries are very compact and mechanically simple compared to piston engines that deliver the same power, they’re also thirsty thanks to the thermodynamic inefficiency of their continuously variable combustion space. In the end, even Mazda more or less gave up on rotary engines for production vehicles, but whenever there’s a need to pack a huge amount of horsepower in a high-RPM engine the size of a pony keg, the Wankel is ready to answer the call.

Honda B-Series – 1988

Where would a list of the Ten Engines that Changed the World be without the Honda B-series? For one thing, the author would be risking violence at the hands of a pitchfork and torch wielding mob of Honda fans, but this particular inline four earns its place on merit. It’s arguably the most-popular modern inline four in history, and it combined all the features and technology we take for granted in high-tech engines today. Although it was never intended for turbo– or supercharging, it proved itself to be readily adaptable to boost, and there’s no small-displacement engine family that can boast as much aftermarket support as Honda’s killer B.

With displacements ranging from 1.6 to 2.0 liters in factory trim and rated horsepower from 126 to 190, there were a wide range of variations in both short and tall deck versions, with a panoply of different details like cylinder head design. But the big thing Honda gave the world with the B-series was the widespread introduction of VTEC, their term for a system to switch cam profiles through the use of a hydraulically-actuated cam follower setup. Activated by a signal from the ECU, VTEC allowed the engine to flip between valve timing, lift, duration, and overlap optimized for fuel economy to higher performance and back again, foreshadowing all the current variable valve control technology incorporated into state of the art engines today.

Like the Ford Flathead and classic Small Block Chevy, the Honda B-series has become a favorite of racers and enthusiasts due to the broad availability of performance parts and the extensive tuning knowledge gained over the past thirty years (has it really been that long?)

Nissan VC-Turbo / Mazda Skyactiv / Hyundai Cvvd – Today

It might seem like a bit of a cheat to give the last spot in our top ten list to a whole group of modern engines, but there are so many new technologies being introduced to production internal combustion engines that we can’t simply ignore their effect on the landscape. Gasoline direct injection (GDI) was the first to become relatively commonplace, offering both performance and fuel efficiency increases, but compared to what’s come after, it seems almost quaint – after all, Diesel engines have more or less always been direct-injection.

Nissan’s recently-released VC-Turbo engine uses a multi-link connecting rod assembly to provide a continuously variable “static” compression ratio, from 8:1 for turbocharged operation under boost to a miserly 14:1 under low load and atmospheric intake pressure for maximum efficiency.

Mazda introduced a whole range of new technology under their “SkyActiv” trademark, from the aforementioned GDI to a low-compression (14:1) advanced diesel with two-stage turbocharging to eliminate a large percentage of the particulate and NOx emissions normally associated with compression-ignition engines. They’ve even rolled out a gasoline “SkyActiv-X” engine with two-stage direct fuel injection and variable spark or spark-plus-compression ignition that promises 20-30% greater fuel efficiency.

The “camless” engine has been the holy grail of powerplant design since the middle of the last century, and while certain exotic-but-impractical designs have been proposed or used for pure race engines, and some production engines like BMW’s N55 have implemented systems that can dynamically control cam phasing and variable lift, Hyundai’s Continuously Variable Valve Duration (CVVD) technology comes as close as we’ve seen so far to offering complete control over when and how much a conventional tappet valve opens. While it still relies on mechanical contact between a cam lobe and a follower, it’s a good compromise between practicality and theoretical “perfect” control of valve motion.

We’ve done our best to pick the most significant engine designs without prejudice or favoritism, but we’ve undoubtedly left some of you scratching your heads as to why we overlooked your personal selection in our Top Ten. Make your case in the comments below, and we might just revisit the topic in a future article to mend the error in our ways…