Mazda RX3

A Rare Japanese Classic

When all is said and done, there are not too many classic and collectable Japanese cars from the early 1970's. But there is one exception, and that is for anything that came standard with a Rotary engine.

The good folks at Mazda have proven to be rather adept at manufacturing extrodinarily exciting cars - today's RX8 and MX5 both being brilliant cars to drive while remaining relatively affordable. And back in 1972 the affordable pocket rockets were undoubtedly the Mazda RX2 and RX3.

The RX3 was first released to the Japanese domestic market in March that year, and was initially powered by the 10A Roraty engine, while a higher spec GT came with the 12A engine and 5 speed manual. This engine, taken from the RX2, was fitted to all RX3's sold outside of Japan and Australia.

The 1972 RX-3 was powered by the 10A in Japan, Australia, and Europe, while other markets got the larger 12A from the RX-2. The 1972 RX-3 was the first rotary-powered station wagon. 10A Engine output was 105 hp (78 kW) and 100 lb·ft (135 Nm). 0-60 mph (0–97 km/h) time was 10.8 seconds, and the car ran a 17.6 second quarter-mile (400 m)(16.3 for the RX-2).

Mazda RX3 Series 2

A year later Mazda released the Series 2 in Japan, the designers having re-styled the entire front end, while at the rear there was a new tail light set-up that featured twin brake lights. Inside there were only a few changes, most obvious being the re-calibration of the speedo to 200 km/h.

Externally the entire front end sheet metal was revamped and a different set of taillights with twin brake lights were included (commonly known as Savanna tail lights in Australia). The Series 2 RX-3 hit Australia in March of 1974 powered by the 12A single distributor (12B). Earlier 12A engines featured dual distributors. The starter motor was also relocated in the later engines from the top of the engine to the left hand rear side.

Other internal 12A changes included moving from dual row side seals to single row and significant changes to apex seal design. The Series 2 was slower than the 10A series 1 down the quarter mile even with the 1,146 cc 12A's greater capacity and 15 percent more power. The Rotary Engine Anti Pollution System (REAPS) hurt torque. As a result, the Series 2 was slow off the mark but had a better top speed. The loss of torque plus a 44-kilo weight increase slowed the series 2 to a 17.8 second quarter mile.

Additional exterior colors for the Series 2 like Bottle Green and Alexandria gold added appeal. Interior changes were minor and included a change from the km/h/mph speedometer to a 200 km/h speedometer (180 km/h for the 808), an exhaust overhead light, a 50 amp/our ammeter gauge (up from 30ah) plus design changes to the trims and seat belts. Notably the radio antenna was enhanced by a twin post (rather than single) design. The 1974 model kept the three spoke plastic wood grain steering wheel; the '75 received a fake leather wheel with slots cut into its three spokes.

12A Engine output was 130 hp (97 kW) and 115 lb·ft (156 Nm). 0-60 mph (0–97 km/h) time was 10.8 seconds, and the car ran a 17.8 second quarter-mile (400 m). The Savanna was updated in June 1973 for 1974. Mazda put the new 12A "AP" single-distributor engine in the RX-3. The body was also updated. It was refreshed again in 1975 with a "REAPS-5" engine. In 1976 the Series 3 RX-3 was released in America and Japan but not Australia or New Zealand. There weren't as many changes this time around, but the few made were significant. The nose cone wore a new lower spoiler-type lip, the gimmick rotor badges were replaced with a simple Mazda badge on the grille.

The RX-3 was finally dropped in 1978 to make room for the new Mazda RX-7. Of all the pre-RX-7 rotary vehicles Mazda built (930,000 in total), the RX-3 was by far the most popular. Of all the RX-3's built, the coupe exceeded 50 percent of total sale - all facts which influenced the design profile of the RX-7. Here in Australia the RX-3 was not available after 1976.

It would have made sense to continue with the rotary powered sedan, however Mazda were moving over 50% of their RX3's as coupe's, meaning the sedan version would not be able to account for sufficient sales, and it was not viable to have two 2-door rotary coupes occupying the same showroom floor.

Mazda 808 Conversion

When production ended the iconic rotary sedan was sorely missed, which prompted many to convert the more humble Mazda 808 sedan into an RX3 copy. Fortunately, there are a few ways to recognize a copy. The 1300 cc 808's had a very small diff centre compared to the standard RX-3 diff; however the SN3A diff is RX-sized.

If you are looking at a Series 2, look for a cut-out in the front bumper that provided for the oil cooler airflow. All RX fuel tanks were stamped with the letter 'L' and had a capacity of around 60 litres to accommodate the extra thirst of the rotary engine. The standard Mazda 808 however was only fitted with a 45 litre tank.
Again, if you are looking at a Series 2 RX3, check for emission control relays in the cars computer.

The engine bay wiring should have a choke control and an ignition relay. The best distinguishing trait is the exhaust overheat thermo-sensor. Located in the right corner of the boot near the shock tower, this device would short out and illuminate the dash-mounted light when the REAPS (Rotary Engine Anti Pollution System) rear muffler heated up 'beyond safe limits'.

If the sensor isn't there, look for the mounting holes and/or the plug in the wiring loom. If there is no evidence of this ever being installed on the car, it is likely you are looking at an RX-808. The REAPS-5 engine was fitted from 1975. Unfortunately for enthusiasts today, many RX3's found their way onto the racetrack, and so their numbers have dwindled.