The rotary engine may come back, but not in the way you expect

Felix Wankel, a young German mechanical engineer got an idea to build a new type of internal combustion engine in 1919, at only 17 years old. He worked in a machine shop with his friends and had a dream to build a “Half turbine, half reciprocating” engine. The new system for this engine would be a lot less complicated then the common piston engine with less moving parts. He began designing it by 24 years old but didn’t start building it until 1951

The rotary engine would go on to win one of the most prestigious races ever, the 24 Hours of Le Mans. Enthusiasts would eventually turn some of these engines in to speed demons, with some coming to 1000 horsepower out of small 1.3L engines.

Not to be confused with the rotary piston engine, the rotary uses a spinning triangle in an oval housing which completes intake, combustion, and exhaust strokes in less time than a traditional piston engine, while taking up less space.

With the help of the Japanese auto manufacturer Mazda, the first prototype was completed by 1957. This engine was refined for another ten years until it was put in its first car, the Mazda Cosmo Sport 110S. This car was the first with this new engine, as well as the first sports car Mazda made. The small 1.2L engine brought the car up to 110 horsepower, which was very good considering how small it was.

Over the next 30 years, the engine evolved incredibly quickly, going from 100 horsepower to almost 300 horsepower. Mazda was testing out what type of car best suited an engine that produced this much consistent power, and in 1978, the engine was put in a pickup truck. The size was increased to 1.3L which brought it to 130 horsepower. The engine size would stay the same until 2012, when it was discontinued, but the horsepower would drastically increase over time, especially after turbocharging.

Mazda ultimately decided that this was a sporty engine that belonged in an equally sporty car, therefore the next car that Mazda would put the engine into would be the RX-7. This car is a Japanese legend, and many say this is because of the rotary. The turbocharged 1.3L engine had 280 horsepower. The RX-7 would be discontinued in 2002, with its next model, the RX-8 coming out. The RX-7 is one of the biggest reasons the rotary got to where it is. The RX-8 had a naturally aspirated (non-turbocharged) 1.3L engine with 230 horsepower. This disappointed many as the car was made slower and a lot less reliable, but there were reasons for this.

Emissions restrictions were getting more and more strict as the years went on. Manufacturers had to make their vehicles more efficient than ever. This was a problem, as the rotary wasn’t known for being efficient. As the laws got more and more strict, the rotary’s end was near, and in 2012 it was discontinued along with the Mazda RX-8. This left many enthusiasts upset, and Mazda knew it, but at the time, there just wasn’t a way for the rotary to pass emissions tests. Some dedicated fans would let it live on, with some shops developing that specialized in rotary engines.

One of the biggest reasons for the huge fan base of this engine is its performance at the legendary 24 hours of Le Mans. The first time the Mazda race team entered was in 1982, where they placed 14th, which was good, but not good enough. Mazda would keep improving the engine and keep getting better and better, but they were still struggling to get the win. Mazda made one more, groundbreaking engine to get the win. This engine was known as the R26B and it made 930 horsepower out of a 2.6L engine. In 1991, with the new engine, Mazda was able to take the win with the legendary car, the 787B. Mazda was the first Japanese car Manufacturer to win the race and held that title for another 27 years. This would be the last time the rotary would race at Le Mans, as in 1992 it got banned by the International Automobile Federation from racing in its group, mandating 3.5L engines like in F1 cars. The win from the race is one of the biggest reasons fans love this engine so much, as it was improved so much in attempts to get 1st place and finally managed to win after almost 10 years of trying.

The rotary engine remained mostly a historical footnote until recently, when Mazda started noticing that fans missed the rotary, and have been trying to find a way to bring back the legendary engine while also passing emissions tests.

Mazda revealed the RX-9 concept car at the 2017 Tokyo Auto Show and it is supposed to be available by 2020. The only thing we don’t know is what’s under the hood. Some theories say Mazda managed to flip the engine and make it efficient enough to pass emissions. They claim it’s done by adding new fuel injectors that are closer to the combustion chamber. The other theory out there is the new car will come as a hybrid. The latter is most likely in my opinion as the technology has evolved enough where the Mazda won’t lose much power, but will still pass emissions. The only thing that has been confirmed is that the new car will have a rotary, we just don’t know what configuration it will be in.

Whatever happens regarding this engine, after winning extremely tough races, it has developed a loyal fan base who will always keep it running. The rotary has come of legendary status, and as we all know, legends never die.

Image Credit: YouTube, Matt Rittman