Revolutionary Spin: Unraveling the Mystique of Rotary Engines

by AutoExpert   |  29 January, 2024

Share :

Ever wondered how a rotary engine works? It's not your typical engine setup. Picture something spinning around a center axis, like a triangular rotor whizzing around an output shaft. This is the heart of a rotary engine, which, by the way, only shares the internal combustion part with traditional piston engines.

The rest? Totally different. Rotary engines are pretty simple, consisting of a barrel-shaped housing, a triangular rotor, and the output shaft along with other bits like the intake and outlet port and spark plugs, but these three are the main players. This simplicity is actually a big part of why they're so cool.

Rotary Engines

So, how does this thing work? Imagine a barrel with a couple of triangular rotors inside. These rotors create chambers between them and the housing. Add some fuel and air, plus a spark from the spark plug, and boom – the rotors start spinning around the output shaft, which then powers the wheels. Unlike other engines with their pistons and crankshafts, rotary engines keep it neat and tidy.

Rotary Engines

As for specs, rotary engines are small but mighty. Mazda RX-8, the last car to rock a rotary engine, had a 1.3-liter engine dishing out 232 horsepower at 8,500 rpm and 159 lb-ft of torque at 5,500 rpm. And all this without any turbo or supercharger help. Rotary engines usually come with two or three of those triangular rotors. The Mazda RX-7 and RX-8, for example, had a 2-rotor layout.

There were some more rotors in some special racing builds, but those were rare. Cooling these engines is a whole other story. They use oil cooling, which means they guzzle a lot more oil than your average engine due to high friction. Some engines use air to cool the rotors, either through induction air or a separate port blowing ambient air directly onto them. Either way, it's a bit of an oil fiesta in there.

Felix Wankel designed the first rotary engine back in 1951; this is the reason why they're also called Wankel motors. His design was super high-revving but too complex for mass production. Hanns Dieter Paschke came along and made it simpler, focusing on making it more practical. Both guys worked for NSU Motorenwerke, who then licensed the design to big names like Nissan, Porsche, and Mercedes-Benz. Mazda was, however, the one that really ran with it for a long time.

Rotary Engines

Mazda Cosmo 1105, the carmaker's first rotary car, was not a huge success as expected and it got soon dismissed. Later, Mazda EX-7 twin-turbocharged 3rd gen model became a hit. The car's a legend now, but it wasn't so back then. The RX-8 tried to keep the rotary dream going, but despite its high-rev fun and sharp handling, it was a nightmare when it came to maintenance.

So, what about rotary engines today? Well, they're pretty much history. Mazda's moved on to other engine types and is even going electric. If you're into rotary engines, the choices are slim. Some cool concept cars played around with them, like the Audi A1 e-tron and the Mercedes-Benz C111, but nothing really stuck.

So, rotary versus piston engines – which is better? Depends on what you're after. Rotary engines are high-revving speed demons but fall short on torque and are pretty thirsty. Piston engines are more efficient and easier to maintain.

Rotary Engines

And the sound? Rotary engines are like angry vacuum cleaners, with lots of pops and bangs thanks to all that unburnt fuel. In the end, rotary engines had their moment, but they just couldn't keep up with the times. Who knows, maybe they'll make a comeback one day, but for now, they're a cool piece of automotive history.

Recomended:

BMW Teases New M5: Illuminated Dual Grille Shines In Latest Video - Photo
Car News
BMW Teases New M5: Illuminated Dual Grille Shines In Latest Video

The promotional campaign for the new iteration of the BMW M5 performance model is in full swing. Even though we expect the official launch this summer, the Bavarians are still releasing teasers of the

AutoExpert
BMW Celebrates 25 Years Of The X5 With Exclusive Silver Anniversary Edition - Photo
Car News
BMW Celebrates 25 Years Of The X5 With Exclusive Silver Anniversary Edition

25 years have passed since the first X5 of the E53 generation left the production line at BMW's South Carolina plant, on September 1, 1999. With the Silver Anniversary Edition, built on top of the

AutoExpert
McLaren's New SUV Project: A 'Shared Performance' Model Set To Challenge Ferrari - Photo
Car News
McLaren's New SUV Project: A 'Shared Performance' Model Set To Challenge Ferrari

A "Shared Performance" vehicle is in the works at McLaren, according to CEO Michael Leiters, and it will be competing head-on with the Ferrari Purosangue. Piers Scott, Head of Global Communi

AutoExpert
BMW Accelerates EV Revolution With Neue Klasse Platform And Upcoming i3 And iX3 Models - Photo
Car News
BMW Accelerates EV Revolution With Neue Klasse Platform And Upcoming i3 And iX3 Models

By launching the Neue Klasse platform, BMW is speeding up its transition to electric vehicles, which is part of the company's strategy to move toward digital mobility. The flagship models of this

AutoExpert
Kimera K39 Is A Contemporary Homage To Classic Racing - Photo
Car News
Kimera K39 Is A Contemporary Homage To Classic Racing

The iconic Lancia 037 served as inspiration for Kimera Automobili's latest model, the K39. Specifically, last year's announcement of the Kimera K39 included a 1:5 scale prototype and

AutoExpert
Bugatti's Tourbillon Redefines Speed With 1,775 HP And A Hybrid V16 Engine - Photo
Car News
Bugatti's Tourbillon Redefines Speed With 1,775 HP And A Hybrid V16 Engine

Meet the new Bugatti Tourbillon, which is lighter, stronger, and quicker. First things first. Every model since the 2004 Veyron has used the 8.0-liter W16; however, Bugatti has discontinued it. I

AutoExpert
Bertone Celebrates 110 Years With Groundbreaking GB110 Supercar - Photo
Car News
Bertone Celebrates 110 Years With Groundbreaking GB110 Supercar

 At this month's Top Marques Monaco, Bertone unveiled their new GB110 supercar for the first time in person. Bertone, a legendary automobile design business, declared bankruptcy in 20

AutoExpert
Bentley Showcases The Mulliner Istanbul Silhouette Collection In Black Sapphire - Photo
Car News
Bentley Showcases The Mulliner Istanbul Silhouette Collection In Black Sapphire

Bentley's Istanbul dealer has announced the exclusive sale of three limited-edition vehicles. Featuring the Continental GT, Flying Spur, and Bentayga in Azure specification with V8 engines, the Be

AutoExpert
Manhart Transforms BMW X3 M Competition Into A 650 HP Beast - Photo
Tuning
Manhart Transforms BMW X3 M Competition Into A 650 HP Beast

In its factory configuration, the BMW X3 M Competition produces 510 hp (380 kW) and 479 lb-ft (650 Nm) of torque. The guys from Manhart wanted to build something even more spectacular because it was

AutoExpert
Maserati MC20 Cielo Gets A Novitec Makeover With 701 HP And Advanced Aerodynamics - Photo
Tuning
Maserati MC20 Cielo Gets A Novitec Makeover With 701 HP And Advanced Aerodynamics

Even though Novitec has been improving the Maserati MC20 coupe for over two years, they have now expanded their effort to include the topless MC20 Cielo. The carbon fiber accessories attached to the M

AutoExpert