Tag Archives: Engines

Types of engines and how they work

Engines are machines that convert a source of energy into physical work. If you need something to move around, an engine is just the thing to slap onto it. But not all engines are made the same, and different types of engines definitely don’t work the same.

Jet engine

Image credits Little Visuals / Pixabay.

Probably the most intuitive way to differentiate between them is the type of energy each engine uses for power.

  • Thermal engines
    • Internal combustion engines (IC engines)
    • External combustion engines (EC engines)
    • Reaction engines
  • Electrical engines
  • Physical engines

Thermal engines

In the broadest definition possible, these engines require a source of heat to convert into motion. Depending on how they generate said heat, these can be combustive (that burn stuff) or non-combustive engines. They function either through direct combustion of a propellant or through the transformation of a fluid to generate work. As such, most thermal engines also see some overlap with chemical drive systems. They can be airbreathing engines (that take oxidizer such as oxygen from the atmosphere) or non-airbreathing engines (that have oxidizers chemically tied in the fuel).

Internal combustion engines

Internal combustion engines (IC engines) are pretty ubiquitous today. They power cars, lawnmowers, helicopters, and so on. The biggest IC engine can generate 109,000 HP to power a ship that moves 20,000 containers. IC engines derive energy from fuel burned inside a specialized area of the system called a combustion chamber. The process of combustion generates reaction products (exhaust) with a much greater total volume than that of the reactants combined (fuel and oxidizer). This expansion is the actual bread and butter of IC engines — this is what actually provides the motion. Heat is only a byproduct of combustion and represents a wasted part of the fuel’s energy store, because it doesn’t actually provide any physical work.

An inline, 4-cylinder IC engine.

An inline, 4-cylinder IC engine.
Image credits NASA / Glenn Research Center.

IC engines are differentiated by the number of ‘strokes’ or cycles each piston makes for a full rotation of the crankshaft. Most common today are four-stroke engines, which break down the combustion reaction in four steps:

  1. Induction or injection of a fuel-air mix (the carburate) into the combustion chamber.
  2. Compression of the mix.
  3. Ignition by a spark plug or compression — fuel goes boom.
  4. Emission of the exhaust.

This radial engine looks like the funkiest little man I’ve ever seen.
Image credits Duk / Wikimedia.

For every step, a 4-stroke piston is alternatively pushed down or back up. Ignition is the only step where work is generated in the engine, so for all other steps, each piston relies on energy from external sources (the other pistons, an electric starter, manual cranking, or the crankshaft’s inertia) to move. That’s why you have to pull the chord on your lawnmower, and why your car needs a working battery to start running.

Other criteria for differentiating IC engines are the type of fuel used, the number of cylinders, total displacement (internal volume of cylinders), distribution of cylinders (inline, radial, V-engines, etc.), as well as power and power-to-weight output.

External combustion engines

External combustion engines (EC engines) keep the fuel and exhaust products separately — they burn fuel in one chamber and heat the working fluid inside the engine through a heat exchanger or the engine’s wall. That grand daddy-o of the Industrial Revolution, the steam engine, falls into this category.

In some respects, EC engines function similarly to their IC counterparts — they both require heat which is obtained by burning stuff. There are, however, several differences as well.

EC engines use fluids that undergo thermal dilation-contraction or a shift in phase, but whose chemical composition remains unaltered. The fluid used can either be gaseous (as in the Stirling engine), liquid (the Organic Rankine cycle engine), or undergo a change of phase (as in the steam engine) — for IC engines, the fluid is almost universally a liquid fuel and air mixture that combusts (changes its chemical composition). Finally, the engines can either exhaust the fluid after use like IC engines do (open-cycle engines) or continually use the same fluid (closed-cycle engines).

A Stephenson’s Steam Engine working

Surprisingly, the first steam engines to see industrial use generated work by creating a vacuum rather than pressure. Called ‘atmospheric engines’, these were ponderous machines and highly fuel inefficient. In time, steam engines took on the form and characteristics we expect to see from engines today and became more efficient — with reciprocating steam engines introducing the piston system (still in use by IC engines today) or compound engine systems that re-used the fluid in cylinders at decreasing pressures to generate extra ‘oomph’.

Today, steam engines have fallen out of widespread use: they’re heavy, bulky things, have a much lower fuel efficiency and power-to-weight ratio than IC engines, and can’t change output as quickly. But if you’re not bothered by their weight, size, and need a steady supply of work, they’re awesome. As such, EC is currently employed with great success as steam turbine engines for naval operations and power plants.

Nuclear power applications have the distinction of being called non-combustive or external thermal engines since they operate on the same principles of EC engines but don’t derive their power from combustion.

Reaction engines

Reaction engines, colloquially known as jet engines, generate thrust by expelling reactionary mass. The basic principle behind a reactionary engine is Newton’s Third Law — basically, if you blow something with enough force through the back end of the engine, it will push the front end forward. And jet engines are really good at doing that.

Mad good at that.
Image credits thund3rbolt / Imgur.

The things we usually refer to as a ‘jet’ engine, the ones strapped to a Boeing passenger plane, are strictly speaking airbreathing jet engines and fall under the turbine-powered class of engines. Ramjet engines, which are usually considered simpler and more reliable as they contain fewer (up to none) moving parts, are also airbreathing jet engines but fall into the ram-powered class. The difference between the two is that ramjets rely on sheer speed to feed air into the engine, whereas turbojets use turbines to draw in and compress air into the combustion chamber. Beyond that, they function largely the same.

In turbojets, air is drawn into the engine chamber and compressed by a rotating turbine. Ramjets draw and compress it by going really fast. Inside the engine, it’s mixed with high-power fuel and ignited. When you concentrate air (and thus oxygen), mix it up with a lot of fuel and detonate it (thus generating exhaust and thermally expanding all the gas), you get a reactionary product that has a huge volume compared to the air drawn in. The only place all this mass of gasses can go through is to the back end of the engine, which it does with extreme force. On the way there, it powers the turbine, drawing in more air and sustaining the reaction. And just to add insult to injury, at the back end of the engine there’s a propelling nozzle.

Hello, I am the propelling nozzle. I will be your guide.

This piece of hardware forces all the gas to pass through an even smaller space than it initially came in by — thus further accelerating it into ‘a jet’ of matter. The exhaust exits the engine at incredible speeds, up to three times the speed of sound, pushing the plane forward.

Non-airbreathing jet engines, or rocket engines, function just like jet engines without the front bit — because they don’t need external material to sustain combustion. We can use them in space because they have all the oxidizer they need, packed up in the fuel. They’re one of the few engine types to consistently use solid fuels.

Heat engines can be ridiculously big, or adorably small. But what if all you have is a socket, and you need to power your stuff? Well, in that case, you need:

Electrical engines

Ah yes, the clean gang. There are three types of classical electrical engines: magnetic, piezoelectric, and electrostatic.

And of course, the Duracell drive.

The magnetic one, like the battery there, is the most commonly used of the three. It relies on the interaction between a magnetic field and electrical flow to generate work. It functions on the same principle a dynamo uses to generate electricity, but in reverse. In fact, you can generate a bit of electrical power if you hand crank an electrical-magnetic motor.

To create a magnetic motor you need some magnets and a wound conductor. When an electrical current is applied to the winding, it induces a magnetic field that interacts with the magnet to create rotation. It’s important to keep these two elements separated, so electrical motors have two major components: the stator, which is the engine’s outer part and remains immobile, a rotor that spins inside it. The two are separated by an air gap. Usually, magnets are embedded into the stator and the conductor is wound around the rotor, but the two are interchangeable. Magnetic motors are also equipped with a commutator to shift electrical flow and modulate the induced magnetic field as the rotor is spinning to maintain rotation.

Piezoelectric drives are types of engines that harness some materials’ property of generating ultrasonic vibrations when subjected to a flow of electricity in order to create work. Electrostatic engines use like-charges to repulse each other and generate rotation in the rotor. Since the first uses expensive materials and the second requires comparatively high voltages to run, they’re not as common as magnetic drives.

Classical electrical engines have some of the highest energy efficiency of all the engines out there, converting up to 90% of energy into work.

Ion drives

Ion drives are kind of a mix between a jet engine and an electrostatic one. This class of drives accelerates ions (plasma) using an electrical charge to generate propulsion. They don’t function if there are ions already around the craft, so they’re useless outside of the vacuum of space.

The Hall Thruster.
Image credits NASA / JPL-Caltech.

They also have a very limited power output. However, since they only use electricity and individual particles of gas as fuel, they’ve been studied extensively for use in spaceships. Deep Space 1 and Dawn have successfully used ion drives. Still, the technology seems best suited for small craft and satellites since the electron trail left by these drives negatively impacts their overall performance.

EM/Cannae drives 

EM/Cannae drives use electromagnetic radiation contained in a microwave cavity to generate trust. It’s probably the most peculiar among all types of engines. It’s even been referred to as the ‘impossible’ drive since it’s a nonreactionary drive — meaning it doesn’t produce any discharge to generate thrust, seemingly bypassing the Third Law.

“Instead of fuel, it uses microwaves bouncing off a carefully tuned set of reflectors to achieve small amounts of force and therefore achieve propellant-free thrust,” Andrei reported on the drive.

There was a lot of debate on whether this type of engine actually works or not, but NASA tests have confirmed it’s functionally sound. It’s even getting an upgrade in the future. Since it uses only electrical power to generate thrust, albeit in tiny amounts, it seems to be the best-suited drive for space exploration.

But that’s in the future. Let’s take a look at how it all started. Let’s take a look at:

Physical engines

These engines rely on stored mechanical energy to function. Clockwork engines, pneumatic, and hydraulic engines are all physical drives.

A model of Le Plongeour, showing the huge air tanks.
Image credits Musée national de la Marine.

They’re not terribly efficient. They usually can’t call upon large energy reserves either. Clockwork engines for example store elastic energy in springs, and need to be wound each day. Pneumatic and hydraulic types of engines have to carry hefty tubes of compressed fluids around, which generally don’t last very long. For example, the Plongeur, the world’s first mechanically powered submarine built in France between 1860 and 1863, carried a reciprocating air engine supplied by 23 tanks at 12.5 bars. They took up a huge amount of space (153 cubic m / 5,403 cubic ft) and were only enough to power the craft for 5 nautical miles (9 km / 5.6 mi) at 4 knots.

Still, physical drives were probably the first ever used. Catapults, trebuchets, or battering rams all rely on this type of engines. So too are man or beast powered cranes — all of which have been in use long before any other kind of engines.


This is by no means a complete list of all the engines man has made. Not to mention that biology has produced drives too  — and they’re among the most efficient we’ve ever seen. But if you read all of this, I’m pretty sure yours are running out of fuel by this point. So rest, relax, and the next time you come across an engine, get your hands and your nose all greased up exploring through it — we’ve told you the basics.

These are the fastest production cars of every decade

Cars have revolutionized the world we live in, and fast cars have fascinated people since the very beginning — often times for no real reason other than fame and glory. Let’s be honest — how often will you get to drive your car at 300 km/h, even if it’s able to go that fast? No matter the reason, we like fast cars, so let’s learn a bit more about them. Here’s a list of the fastest cars, decade by decade.

1880-1889 | Horse carriage | 10-30 mph (16-48 km/h)

Mercedes Benz

Image via E Mercedes Benz.

I know, I know, this is not a car, it’s a horse-drawn carriage — but we needed a reference point. This is the Benz Motorwagen, one of the sleekest carriages ever made. There’s no definite maximum speed for carriages, but since specially-bred horses can reach some 40 mph free, it seems safe to say that 30 mph should be the top speed with the weight of the carriage and the passengers. It’s a real piece of art and history, but let’s move on to some real cars!

1890-1899 | Stanley Runabout | 35 mph (56 km/h)

Image via Flickr user Glenlster.

Oh yeah, now we’re talking! F.E. and F.O. Stanley were twins born in Kingsland, Maine, on June 1, 1849. They operated a dry-plate photographic business in Massachusetts until they entered the car industry in 1896 with a splash. They developed this magnificent car with a steam engine, the best option considering the available technology at the time. Steam engines often have fewer than 25 moving parts, so this powerful engine for its time was quite simple in essence, though its complexity was impressive.

In 1897 the duo began producing automobiles in Massachusetts, selling over 200 by the fall of 1897.

1900-1909 | Mercedes-Simplex 60HP | 73 mph (117 km/h)

The Mercedes Simplex was an automobile produced from 1902 to 1909 by the Daimler Motoren Gesellschaft (DMG, Daimler Motor Society, a predecessor of Daimler-Benz and Daimler-Chrysler). It continued the use of the Mercedes name as the brand of DMG, rather than Daimler.

This car featured powerful engines, with power ranging from 40 (at 1300 rpm) to 60 horsepower. It used a magneto-electric spark ignition system, with a single spray-nozzle carburetor. It represented quite a step forward at the time, being quite unlike any other vehicle in its day. Because of this, the Simplex quickly became popular with royalty, nobility, and the other creme de la creme of the day. Needless to say, this car cemented the dominance of Mercedes in the field of automobiles, a legacy the company carries to this day.

1910-1919 | Austro-Daimler Prince Henry | 85 mph (136 km/h)

Image via Wikipedia.

In 1911 Austro-Daimler began producing the Prinz Heinrich (in English: Prince Henry) model; this car featured an overhead cam 5,714-cc four-cylinder engine. The car’s production figures suffered during the First World War as the 4,500 workers of Austro-Daimler contributed in large numbers to wartime production. Unfortunately, soon after that, the company began collapsing. Still, this car remains an epitome of the luxury and technological prowess of its time.

1920-1929 | Duesenberg Model J | 119 mph (191 km/h)

Image via Auto Evolution.

The Duesenberg Model J is a luxury automobile made by Duesenberg. Created in 1928, the car was meant to compete with the most powerful and elegant cars of the time, and it did an amazing job at that. Unfortunately for the company, the car was introduced just a few years before the stock market crash that led to the Great Depression and was sold only until 1937. Although smaller than other engines of the time, it generated 265 hp. This made the car amazingly fast for its time. It was dominant and had all you could want in a high-end car. It could have become a staple, cherished to this day, if not for the circumstances of the time.

1930-1939 | Duesenberg Model SJ | 140 mph (225 km/h)

Image via Wikipedia.

You’re probably starting to notice a trend for these last few cars. The Duesenberg J was so dominant at its time that the company did what every respectable car company would do — they pimped it out. The SJ had a  320 hp, inline, eight-cylinder engine with a centrifugal supercharger, a three-speed manual transmission, beam-type front, live rear axles with semi-elliptic leaf springs, and four-wheel vacuum-assisted hydraulic drum brakes. Interestingly enough, the car was initially designed for Mae West, who ultimately declined the design. Joke’s on her, right?

1940-1949 | Jaguar XK 120 | 132 mph (214 km/h)


Image via Wikipedia.

Perhaps the best testament to how dominant the Duesenberg was at its time is that for the next decade, no one could create a faster car — although, in all fairness, no one really cared about that during WWII. After the war, it was time for the Jaguar to rise to prominence. The XK was sold between 1948 and 1954. It was Jaguar’s first sports car since the SS 100, which ceased production in 1940. For high speeds, the windshield had to be folded down, which must have given riders quite a thrill.

1950-1959 | Aston Martin DB4 GT | 153 mph (246 km/h)

Image via Wikipedia.

High speed and high class seem to go hand in hand, and the Aston Martin DB4 GT was the epitome of both. With supreme class and luxury, it was the undisputed ruler of the highways, and even today, they are sold at lavish auctions for dazzling prices. Due to the huge popularity, huge price tag, great look, and rarity of the DB4 GT, many replica cars have been constructed, and even those replicas sell extremely well.

1960-1969 | Ferrari 365 GTB/4 “Daytona” | 174 mph (280 km/h)

Image via Wikipedia.

Of course, no “Fastest” list would be complete without at least one Ferrari.

Better known as the Ferrari Daytona, The Ferrari 365 GTB/4 was a traditional front-engined, rear drive car. The car achieved fame not only for being the fastest of its decade but also for being driven by Dan Gurney and Brock Yates in the inaugural Cannonball Baker Sea-To-Shining-Sea Memorial Trophy Dash. The event showcased not only the car’s maximum speed but also its capacity to maintain high speeds over long periods of time. The duo won with an average speed of 80.1 miles per hour (129 km/h), completing the distance from New York to L.A. in 35 hours 54 minutes (2,876 miles (4,628 km)).

1970-1979 | Ferrari GT4 Berlinetta Boxer | 175 mph (281 km/h)

Image via F Wallpapers.

Ferrari continued to assert its dominance over the next decade as well. Amidst hotter and hotter competition, in which Lamborghini said its Countach could do 200 mph (and it couldn’t), it was again Ferrari who took the crown. It’s worth noting that no BB was ever originally sold in North America, as Enzo did not believe it to be worth the cost of complying with the extra environmental and safety regulations. Today, he’d probably sell it only in the US.

1980-1989 | Ferrari F40 | 202 mph (325 km/h)

Image via Imgur.

Its direct competitor, the Porsche 959, was almost just as fast at 200 mph, but Ferrari again took the crown. An endless debate emerged between which one was better, and that debate still hasn’t been answered today; but in terms of speed, the Ferrari F40 takes the crown.

1990-1999 | McLaren F1 | 240 mph (386 km/h)

Image via Wikipedia

An emblematic car, the McLaren F1’s speed was only limited by its engine rpm — it was so aerodynamic that wind resistance was almost negligible. It was so amazingly fast that it won the LeMans not only in its class but also in the prototype class, something which was unheard of for a streetcar — to this date, this is considered one of the most incredible feats in motorsports. In 1994, the British car magazine Autocar stated in a road test regarding the F1, that “the McLaren F1 is the finest driving machine yet built for the public road” and that it “will be remembered as one of the great events in the history of the car, and it may possibly be the fastest production road car the world will ever see.”

But it wasn’t.

2000-2009 | Shelby Super Cars (SSC) Aero | 257 mph (414 km/h)

Image via Ride Lust.

The SSC Aero came with a bang, and to this day, it lost the title of ‘fastest production car’ by just a scratch. The SSC Ultimate Aero held the title of the fastest production car in the world from 2007 until the Bugatti Veyron came out in 2010. Simulation and testing at NASA’s Virginia facility had shown the Ultimate Aero TT theoretically capable of attaining approximately 273 mph (439 km/h), enough to surpass the production car record-holding Bugatti Veyron’s 253.7 mph (408.3 km/h).

2010 – today | Bugatti Veyron 16.4 Super Sport | 268 mph (431 km/h)

Image via HD Car Wallpapers.

The original version had a top speed of 407 km/h (253 mph), but the superspeed version went even further. The current Super Sport version of the Veyron is recognized by Guinness World Records as the fastest street-legal production car in the world. The Veyron features an 8.0-liter, quad-turbocharged, W16 cylinder engine, equivalent to two narrow-angle V8 engines bolted together. Each cylinder has four valves (for a total of 64), but the VR8 configuration of each bank allows two overhead camshafts to drive two banks of cylinders so only four camshafts are needed. It’s a monumental car, and a spectacular engineering achievement by all standards.

An honorable mention goes to the Hennessey Venom GT, which recorded a top speed of 270.49 mph (435.31 km/h) — but only in one direction (runs in both directions need to be achieved to compensate for the wind speed) and only 16 cars have been ever sold — too little to be considered a production car.

As far as the fastest cars in general, not just production ones, we have two modern-day contenders worth taking a look at:

2011 – 2015 | Hennessey Venom GT | 270 mph (434 km/h)

Hennessey Venom GT.

Image via Wikipedia.

Only 12 of these cars were ever produced, which definitely disqualifies them from being considered a ‘production’ vehicle. However, its characteristics are definitely worth its $1.2 million price tag.

Powered by a 1,200 horsepower, twin-turbocharged V8 engine, the Hennessey Venom GT achieved a top speed of 270.49 mph at the Kennedy Space Center on February 14, 2014. At the time, this made it the fastest car in the world, overtaking the Bugatti Veyron Super Sport by two miles per hour. The car goes from zero to 60 mph in 2.7 seconds.

2015 – today | Koenigsegg Agera RS | 278 mph (447 km/h)

Koenigsegg Agera RS.

Image via Wikimedia.

The Agera RS was unveiled at the 2015 Geneva Motor Show, gathering quite a fair share of attention — and for good reason.

This is the fastest car in the world today. The company tweeted back in November 2017 that the model achieved a world record of 277.9 mph, documenting the moment on video. All this performance comes from its twin-turbo V8, 1176 horsepower engine. It goes from 0 to 60 mph in 2.9 seconds, and from 0 to 249 mph in 33.29 seconds.