How does a Rotary Engine actually work?
Suck, squeeze, bang and blow, that's how an engine works.
Specifically, the engine sucks in a mixture of fuel and air, then squeezes it together (compresses it), then it burns / explodes combined with a bang, and then finally it blows out the exhaust.
However, way back in the 1920s a German man named Felix Wankel decided that this suck squeeze bang and blow strategy could be improved upon. He came upon the basic concept of a rotary engine, one in which there would be no pistons, but rather a triangular piece of metal spinning inside of an O-shaped chamber.
Being busy with warmongering on behalf of the Nazi party, however, he didn't get the chance to develop his engine too far until 1951, when the German automaker NSU invited him to design a prototype.
The engine which resulted was unlike anything else before it, with no cylinders to be heard of it could get up to previously unheard of RPMs, at least for a little while. Because as the engineers soon realized that despite its amazing performance this engine was beyond unreliable, it would simply shred itself to pieces after just a few minutes.
However, a few years later Mazda and NSU formed a partnership, one in which the Rotary flourished. The engine quickly developed into what we now know to be Mazda's most iconic engine of all time.
But how does work?
Put simply a rotary engine is a barrel-shaped internal combustion engine, one which consists of two or three rounded triangular rotors, which simultaneously spin around a shaft through the hollow barrel. Fuel and air are pumped into the spaces between the rotors' sides and interior walls of the barrel, where they ignite. The rapid expansion of exploding gases turns the rotors.
This brings with it two inherent upsides, first, the engine is significantly lighter than a typical combustion engine of the same displacement, while producing the same amount of power due to the simply nutty rotational speeds these rotors can achieve.
However, rather famously the Rotary Engine at its very core had one Achilles Heel, the apex seals-thin strips of metal between the spinning rotors' tips and the rotor housings. These problematic seals had may different variations, however, unlike NSU who chose to go with a three layers, which caused irregular wear that made them grenade; Mazda figured out a way to make apex seals by using just one layer, and introduced its new Wankel engine in the simply gorgeous 1967 Cosmo sports car.
The rotary went onto be a great engine, although it was never famed for its reliability, Mazda famously put it into the RX7 sports-coupe, a car which still remains as an icon to this day. However, the problematic apex seals never truly left the car alone, as they would often grenade the engine after 80,000-100,000 miles.
But who cares!
Wankel's engine showed us that there is indeed an alternative to the more conventional suck, squeeze, bang, and blow, and we have to love him for that.