Just now the European launch of the Mazda MX-8 sports car is in full swing at Rimini in Italy, and we'll soon be seeing copies of it on Irish roads. A rather few copies, granted, but the RX-8 is important for a far more important reason than its numbers sold.

The car is the latest incarnation of a series of sports cars produced by Mazda over the last four decades, powered by an unusual engine, one which was once believed to herald a new dawn in automotive propulsion, was taken up by many carmakers, but Mazda is the only one which has kept faith with Felix Wankel's dream.

Not just his dream, but his dream that became reality.

Felix Wankel didn't have an engineering degree, or even a driver’s licence, but he has a deserved place alongside other automotive engineers like Nicolaus August Otto, Carl Benz, Gottlieb Daimler, Wilhelm Maybach and Rudolf Diesel.

Wankel was fascinated throughout his entire life with machines, even though he did not possess a technical education. He was never an abstract thinker, but an inventor who had a different view of, and kept a certain distance from, mathematics. "I don’t like the formulas," he said. Despite this, he is recognised as the father of the rotary engine.

Several automakers took out licences to build and develop his engine, and one other manufacturer, NSU, actually put one into a production saloon, the Ro80.

But there were problems, as can be expected with any new technology, and the warranty claims on the Ro80 effectively bankrupted NSU, whose name has now disappeared from modern motoring.

No one formulated Wankel’s importance to the automotive industry better than Kenichi Yamamoto, Director of Research and Development, and later Chairman of the Mazda Motor Corporation. "The automotive world lost one of its greatest thinkers," Yamamoto said upon hearing of the death of Felix Wankel on 9 October, 1988. On that day, Mazda Motor Corporation announced that it would continue to develop engines without valves and connecting rods according to the Wankel principle. Mazda kept its word and, since first starting to work on Wankel’s engine in 1961, has built over 1.8 million rotary engines – most of them for the Mazda RX-7.

Today, in the RX-8, Mazda has produced the latest of the Wankel line, the RENESIS. Constructed with twin rotors it is available in two power versions. The entry level engine produces 192ps of power and the flagship engine 231ps, making RENESIS the most powerful non-turbo Mazda rotary engine.

The rotary engine functions in a way that is fundamentally different from conventional internal combustion engines. The piston is in fact a rotor that spins in the centre of a housing that is shaped like an oval pinched slightly in the middle. The rotor has a set of internal gear teeth cut into the centre of one side. These teeth mate with a gear that is fixed to the housing. This gear mating determines the path and direction the rotor takes through the housing.

The eccentric shaft is turned by the rotors in a way similar to a handle turning a winch. With every 360-degree turn of the rotor, the output shaft turns three times. The rotor itself is triangular shaped, and its three points are in constant contact with the housing wall through an apex seal. The shape of the housing ensures that the rotor’s centre point forms a closed circle with every complete turn. The three flanks of the rotor combined with the inner surface of the housing form three working chambers, whose volume constantly changes during a single turn of the rotor. This architecture makes a traditional crankshaft and valves unnecessary. The only moving parts are the rotary piston itself and the eccentric shaft. These characteristics mean that a rotary engine is lighter and more compact than a traditional reciprocating engine.

While a normal four-cycle piston engine needs four cycles to facilitate two turns of the crankshaft, rotary engines achieve all four cycles with only one turn of the rotor. The rotor itself produces the power of the rotary engine and applies it to the eccentric shaft, which fulfils a function comparable to the crankshaft of a traditional piston engine.

RRotary engines with more than a single rotor are characterised by their extreme operating smoothness and low vibration. With a twin-rotor engine the lobes of the eccentric shaft are placed 180 degrees in relation to each other, which ensures an almost perfect balance of mass. A twin-rotor engine operates more smoothly than a six-cylinder piston engine with hardly any vibrations at all.

The rotary engine is also characterised by its uncomplicated architecture, with a minimum of components, which means less weight and a compact size. The extremely compact size of Mazda RX-8’s rotary engine allowed engineers to place it more towards the centre of the vehicle, in a front-midship layout, which meant a 50/50 weight distribution over the front and rear axle. This guarantees excellent handling characteristics.

The name RENESIS stands for "rotary engine (RE) genesis" and is representative of a revolutionary approach to rotary engine technology at Mazda. RENESIS is an elegant combination of high performance potential, on the one hand, and acceptable fuel consumption and low emissions on the other.

Starting point for RENESIS development was the MSP-RE (Multi-Side-Port Rotary Engine), first shown in the concept sports car RX-01 at the Tokyo Motor Show in 1995. Four years later, a refined version of the engine was presented at the 1999 Tokyo Motor Show in the concept vehicle RX- EVOLV. RENESIS as it is now being launched in the new Mazda RX-8, is the final production version of these concept engines, and the product of several years of unbroken development.

RENESIS developers were given three clear goals. The new engine should produce roughly the same power as the twin-turbo 13B engine of the Mazda RX-7, but at the same time use less fuel and produce minimum amounts of emissions. Mazda developers achieved these goals. The result of their effort is RENESIS, a twin-rotor, water-cooled engine with two chambers, each with 654 cm volume capacity. RENESIS comes in two power versions.

The 192ps engine reaches maximum torque of 220 Nm at 5,000 rpm. The torque curve climbs quickly, then flattens out to a high plateau-like shape, which means there is plenty of power available over a wide speed range. In fact, 80 percent of peak torque is available at 2,500 rpm with the last 20 percent prior to peak torque at 5,000 rpm achieved gradually over a wide speed range. This characteristic makes everyday driving enjoyable and has definite advantages for city driving.

The 231ps achieves maximum torque of 211 Nm at 5,500 rpm. These figures show how the 231ps version of RENESIS has been modified to be more performance oriented. It develops its power at higher engine speeds. For this reason, the 231ps version has a maximum engine speed of 9,000 rpm, clearly higher than the 192ps version, which reaches maximum engine speed at 7,500 rpm.


A New Chapter

With the launch of the new Mazda RX-8 and its RENESIS engine, Mazda has written a new and successful chapter in the history of vehicles with rotary engines under the bonnet.

Before the launch of the Mazda RX-8 it is worth a look at some of the rotary powered Mazdas over the years and the success of rotary power on the track. The Mazda RX-8 is the product of a long Mazda heritage of manufacturing vehicles with Wankel engines, some of which enjoy cult status among sports car drivers. The most important of these Mazda vehicles include:

Cosmo Sport 110 S

The Cosmo Sport 110 S was launched in 1967 with a 110hp 10A rotary engine. The first car from Mazda with a rotary engine, it was also the first of its kind to go into mass production. By 1972, Mazda had built a total of 1,176 units of the Cosmo Sport. The predecessor of the Mazda RX-7, it made its racing debut at the 72-hour Marathon de la Route, where it finished fourth.

Since the Cosmo Sport 110S, Mazda has produced the following cars powered by the Mazda rotary:

Mazda R100: A two door four seat coupé launched in 1968 and continued through to 1973.

Mazda R130 Coupé: A two door four seat coupé with Italian inspired styling, this was launched in 1969 and continued through to 1972.

Mazda RX2: A high performance coupé with the new 12A rotary, this car was launched in 1970 and ran until 1978.

Mazda RX-3: A sport coupé, this car was powered by the 10A engine, introduced in 1972 and produced for seven years until 1978.

Mazda RX-4: This saloon was launched in 1972 and ran until 1977.

Rotary Pickup: Exclusively sold in North America, it was produced for four years between 1973 and 1977.

Parkway Rotary 26: The world's only rotary powered bus was produced between 1974 and 1976.

Roadpacer AP: The first saloon to be powered by the new 13B RE, this car spent two years in production, 1975 – 1977.

Mazda RX-5: Mazda returned to coupés with this car, powered by a choice of 12A or 13B rotary. It went into production in 1975 and ceased production in 1981.

Mazda 929: Mazda installed its rotary engine in a large luxury car in 1977 and produced the Mazda 929 rotary until 1991.

Mazda RX-7: With 1,094,416 sold units, the Mazda RX-7 is the most popular rotary-engine car in the world. The Mazda RX-7 was refreshed and continuously developed between 1978 and 2002. It is expected that the car – due to its sporty design – will go down in the history of the International Motor Sports Association as the most successful model of its kind in the world.

Mazda Cosmo: 1981 – 1995, the Cosmo was the first to be fitted with a three rotor engine, the 20B REW.

In total Mazda has produced 18 rotary engined cars since the Cosmo Sport 110 S in 1967, the Mazda RX-8 is the 19 th and uses the most advance generation of rotary engines.

The rotary has also taken its place in motor racing history. In April 1969 the Familia Rotary Coupé won the Singapore Grand Prix, finished 5 th at Spa Francorchamps 24-hour race and 5 th in the Marathon de la Route 84-hour race. The following year
Mazda took 8 th place in the British RAC Tourist Trophy race and 4 th in the German Touring Car Grand Prix and finished in a dead heat in 1 st with the BMW team at Spa Francorchamps.

The Savanna RX-3 dominated the Japanese Touring Car Championship in 1972 taking 100 race wins by 1976.

The Mazda RX-7 entered the IMSA championship in 1978 and won the GTU class in the Daytona 24-hour race. Between 1980 and 1987 Mazda never lost a race in the GTU class, a record that has not been broken. Mazda won the GTU class 10 times and by 1990 it had chalked up another record, 100 IMSA wins.

The Mazda RX-7 also won the British Saloon Car Championship, the Belgium Touring Car and the Australian Touring Car Endurance race and in 1992, 1993 and 1994 it won the Bathurst endurance race. In 1981 the Mazda RX-7 won the Spa Francorchamps 24-hour race.

Mazda also entered the world rally stage and in 1985 a Mazda RX-7 finished 3 rd overall in the Acropolis Rally.

Mazda turned its attentions to Le Mans in 1983 with the 717C, but the ultimate endurance prize eluded the Mazda team until 1991 and the 787B. This car was a huge surprise at the 24-Hour of Le Mans in 1991. The car won the race with an average speed of 128.33mph, covering 3077 miles in 24 hours driven by Englishman Johnny Herbert. There was no better way to prove the performance potential and durability of the rotary engine concept than by winning this renowned endurance race.