MAZDA AND THE ROTARY ENGINE
THIS YEAR MARKS THE 50 TH ANNIVERSARY OF MAZDA’ S FIRST PRODUCTION CAR TO USE THE ROTARY ENGINE. THE NOW-ICONIC MAZDA COSMOS PORT WAS THE VEHICLE FROM WHICH MAZDA PROPELLED ITS ONGOING USE OF THE WAN K EL ROTARY
CELEBRATING 50 YEARS
Although the basic principles behind rotaryengine dynamics can be traced as far back as the 16th century, it was a 17-year-old German teenager named Felix Wankel who made the dream a reality. Wankel first started toying with the idea of building a different type of engine in 1919. Although he didn’t know much about internal-combustion engines, his determination and fascination led him to continue his studies to develop what would eventually become the rotary power plant.
In 1924, when Wankel was just 22 years old, he established a small engineering laboratory where he was able to further his research and development. During World War II, he managed to continue his work and was supported by the German Ministry of Aviation and other large corporations that saw real promise in his dream.
Wankel formed the Technical Institute of Engineering Study (TES) after the war’s end. There, he continued research on rotary engines and a rotary compressor that was being developed for a wide range of commercial purposes.
It was at this time that a prominent German motorcycle manufacturer — NSU Motorenwerke AG, or NSU — started to take an interest in Wankel’s work. NSU had also had dealings with rotary-engine design, and, in 1957, NSU and Wankel together developed a prototype of the Type DKM, which offered a cocoon-shaped housing that
contained a triangular rotor. This was the birth of the rotary engine as we know it today.
A year later, in 1958, a Type KKM version was built with a fixed housing (the DKM used a rotating housing), which was more practical. The DKM also used a complex water-cooling system on the trochoid housing, and an oil-cooled rotor — NSU was ready to take the rotary engine to the world.
In 1959, after patenting the design, NSU officially announced the engine in the public domain, and started to look for manufacturers to sell licensing agreements to. It received around 100 submissions from companies such as GM Holden, Ford, and Daimler-benz, all of which were interested in furthering the rotary-engine design. A number of Japanese companies were also keen, including Toyota; Nissan; and a small company called Mazda, which, at that time, was only producing three-wheeled motorcycles.
In all, 26 companies obtained manufacturing licences with Nsu/wankel, including Mazda. At that time, its president was Tsuneji Matsuda (the company name ‘Mazda’ being derived from his surname). He negotiated an agreement that joined the two companies by contract in July 1961. Mazda was now in the rotary game and, within only four months, would produce its first prototype rotary engine.
Mazda’s first production rotary engine
Kenichi Yamamoto was the man appointed by Matsuda to head Mazda’s Rotary Engine (RE) Research Department, and start furthering Nsu/wankel’s design. NSU had by now already put a single-rotor engine into production, which, by 1964, had found its way into NSU’S (and the world’s) first rotarypowered production car, the Wankel Spyder.
Mazda’s idea was to experiment with other types of rotary engine that used not one, but two, three, or even four rotors in an effort to increase low-end torque and make the engines perform much like the big six-cylinder production-car units of the day. Mazda’s firstever twin-rotor test engine, the Type L8A (yes, that’s an 8A), featured a 399cc singlechamber volume (times two for the 800cc). It was fitted into a prototype sports vehicle named ‘L402A’ — a car which turned out to be an early prototype for the Cosmo Sport, which would go on sale in 1967.
After successes with that engine, in December 1964, Mazda built its second two-rotor test engine, the Type 3820, which carried extra displacement to take each chamber out to 491cc. This motor would soon be known as the ‘L10A’, and was fitted to 60 Cosmo Sport prototype vehicles to evaluate its reliability, durability, and performance. All 60 vehicles covered more than 600,000km each.
It wasn’t long before Mazda started thinking it was on to something good and investing heavily in custom-made machinery. It began development of three- and four-rotor engines, with the Mazda R16A mid-engined sports car used as the test bed for most of them.
Mazda’s first two-rotor rotary-engined car went on sale on May 30, 1967, with the power plant packaged inside the 110S, or Cosmo Sport. The 10A engine developed 81kw through a side port intake and a twostage four-barrel carburettor. Each rotor was equipped with dual spark plugs for stable combustion. This early technology paved the way for Mazda’s rotary-engine campaign