The most significant footprint of rotary engines may be in Mazda’s sports vehicles, yet a recent installment of “Jay Leno’s Garage” explores the engine’s antecedents.
Long before Mazda popularized the rotary engine, German automobile manufacturer NSU—which eventually became part of Audi—introduced the technology to the mass market. The NSU Spider debuted in 1964, a full three years prior to Mazda’s release of its inaugural rotary car, the Cosmo 110S. An early model of the NSU Spider is presently housed in Jay Leno’s own collection of vintage cars.
Invented by German engineer Felix Wankel and subsequently licensed to automotive companies, the rotary engine distinguishes itself through its unique operational principles. Unlike traditional piston engines, the rotary engine employs the rotational energy generated from the combustion of fuel and oxygen to turn a rotor. Later renditions by Mazda even utilized dual rotors.
This rotor has a triangular configuration and is placed within a roughly cylindrical housing. The apices of the triangle are engineered to form a seal against the housing. This complex sealing task proved to be a significant engineering challenge. The empty spaces created between the sides of the rotor and the housing serve as combustion chambers, where a fuel-air mixture is ignited. In the case of the NSU Spider, a single spark plug suffices to initiate combustion, which imparts rotational force to the rotor.
One of the rotary engine’s most prominent advantages is its smooth operation coupled with its diminutive size. The NSU Spider’s engine is so compact that it resides beneath the rear luggage compartment, thereby offering both a traditional trunk and a “frunk” (front trunk), compensating for the car’s small dimensions. The air intake for the engine is cleverly positioned on the rear trunk lid and channeled to the engine via a trunk-based duct.
However, there are drawbacks, such as higher oil consumption compared to standard piston engines and an inherent propensity for high-revving, which can prematurely degrade the rotor’s seals. Jay Leno mentions that while the NSU can easily rev to 8,000 rpm, doing so can lead to wear and tear on these seals. The vehicle’s tachometer has a green zone that tops out at around 5,500 rpm, promoting more cautious driving.
Monetarily, the NSU Spider was a significant investment during its time, priced at approximately $3,500 in 1964. This made it costlier than some other small sports cars like the MGB, despite offering only 54 horsepower transmitted to the rear wheels via a four-speed manual gearbox. With a curb weight of approximately 1,500 pounds, the NSU Spider necessitated a patient approach to driving.
The Rotary Engine’s Ongoing Legacy
Post-development of another rotary sedan, the R080, NSU became part of the Volkswagen Group in the late 1960s and was amalgamated into what is now known as Audi. However, the legacy of rotary engines persisted. Companies like General Motors and Mercedes-Benz explored this technology in the 1970s, while Mazda continued to incorporate it in iconic models like the RX-7 and RX-8. In a landmark achievement, Mazda’s rotary-engine-equipped 787B became the first Japanese automobile to win the 24 Hours of Le Mans in 1991. Alas, production of Mazda rotary engines ceased in 2012.
Recent announcements suggest a revival of rotary engines, at least in a limited capacity. Earlier this year, Mazda revealed plans to use the rotary engine as a range extender in a new R-EV version of the MX-30 electric crossover. While this particular model won’t be available in the U.S., Mazda did showcase an electric rotary concept named the Iconic SP at the 2023 Tokyo Auto Show, fueling optimism for the reemergence of rotary-powered sports cars.
Frequently Asked Questions (FAQs) about Rotary Engines
What is the main focus of the article?
The article offers a comprehensive examination of rotary engines, detailing their history, mechanics, advantages, and disadvantages. It draws upon insights from a recent episode of “Jay Leno’s Garage” as well as technical specifications and historical data.
Who invented the rotary engine?
The rotary engine was invented by German engineer Felix Wankel and was subsequently licensed to various automakers.
Which automaker first popularized the rotary engine?
Mazda is most commonly associated with popularizing the rotary engine, particularly through its sports cars like the RX-7 and RX-8.
What was the first car to use a rotary engine?
The NSU Spider, produced by German automaker NSU, was the first car to enter production with a rotary engine in 1964.
What are the advantages of a rotary engine?
Rotary engines are known for their smooth operation and compact size. For example, the NSU Spider’s engine was small enough to be placed beneath the rear luggage compartment, thus offering both a conventional trunk and a front trunk.
What are the disadvantages of a rotary engine?
The downsides include higher oil consumption compared to standard piston engines and an inherent tendency to rev high, which can lead to premature wear of the rotor’s seals.
What is the current status of rotary engines in the automotive industry?
Mazda announced the return of the rotary engine as a range extender for its new R-EV version of the MX-30 electric crossover. Although this model won’t be available in the U.S., Mazda showcased an electric rotary concept at the 2023 Tokyo Auto Show, suggesting a possible reemergence of rotary-powered sports cars.
What role does Jay Leno play in the article?
Jay Leno, a renowned collector of vintage cars, offers insights into the history and mechanics of the rotary engine through his platform, “Jay Leno’s Garage.” An early NSU rotary car is part of his collection, serving as a focal point for the article.
More about Rotary Engines
- Jay Leno’s Garage Episode on Rotary Engines
- History of Rotary Engines
- Mazda’s Rotary Engine Milestones
- NSU Spider: The First Rotary-Engined Car
- Mechanical Engineering Behind Rotary Engines
- 2023 Tokyo Auto Show: Mazda’s Electric Rotary Concept
- Technical Analysis of Rotary Engines
- Mazda MX-30 R-EV Announcement
- 24 Hours of Le Mans and Mazda 787B