Curbside Classic: 1974 Mazda RX-4 Rotary Wagon – Still Spinning

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– Posted on March 13, 2012

We can thank Mazda for adding a lot of spice to the automotive landscape. Their compact, smooth and high-revving rotary engine started (and ended) in the most obvious of places: under the hood of sports cars. But during the seventies, they were busy putting the rotary engine into all sorts of other applications, some quite unexpected. There was a rotary pickup truck called the REPU, the compact family sedan Rx-2,  then a compact car with sporty intentions, the Rx-3. But they weren’t done yet.

They even put a rotary engine were it didn’t really seem to make sense, like the engine bay of a big, bulky Holden to create the Roadpacer. Hooking the rotary engine to a three speed gearbox gave it even worse fuel economy than the Holden six it replaced, but the lower displacement did get it into a lower tax rate which was likely the whole point of the exercise. But needless to say it was not a sales success.

Even more bizarre was the Parkway bus which was powered by the same rotary engine with several times the weight. Contemporary ad literature touts the smoothness of the engine as luxury feature but I’d imagine the ride would turn pretty leisurely at even a hint of a hill. Only Lada would top this rotary silliness with a four rotor powered tank.

But back with Mazda: oddly enough, didn’t see fit to produce a pure sports car during this time (until the RX-7 in 1978) even after proving the concept with the Cosmo. The idea of a turbine smooth, high revving rotary engine and a sports car seem to go together naturally, but instead Mazda was mucking around with pickups, buses and even the anti-thesis of sporty – the station wagon.

There surely can’t be too many rotary wagons left in this sort of original condition anymore. Like any semi-affordable sporty sort of car they suffered from enthusiastic drivers who used them right up. Later their numbers were reduced drastically by rust and failed apex seals. Station wagons are quite often the first body style to be turned into parts cars for their more flashy siblings as well. Back even ten years ago it wouldn’t have been worth mucking about rebuilding an engine in one of these. But now that rotary powered 1970s Mazdas are quite desirable with a low number of survivors it is rare to see one in original, driver condition.

Sure, there are a decent number of rusty project level cars kicking around that are still beyond economical restoration and of course plenty of show quality cars. Most of the survivors have been modified as well with bigger wheels, engine swaps, etc. But what we have here appears to be a stock survivor.

The Rx-4 was Mazda’s attempt to add some luxury while retaining the sportiness. Based on the Luce/929 platform, it sported a 110hp 13B rotary engine in the North American market. Other markets started off with the smaller displacement but higher output 12A engine. The Rx-4 was larger than the Rx-2 which itself was larger than the Rx-3. While the engine was quite exotic, they all were quite conventional otherwise with front strut suspension with a live rear axle at the rear. Recirculating ball steering was quite good for what it is, but not as sporty or precise as a rack and pinion set up. Like the Rx-3, the Rx-4 was offered in sedan, coupe and wagon form.

The Rx-4 coupe was even a hardtop befitting its status as the top of the line Mazda.

A wagon like this obviously gained a few pounds over the coupe or sedan (Wikipedia tells me 300lbs more than the coupe) but performance was still very impressive for the era with a 0-60 sprint of just 11.7 seconds. Just the thing to get the kids to soccer practice on time!

This particular example would be a 1974 or 1975 example since it is pre-1976 facelift but sporting the big, battering ram style impact bumpers. I’m leaning towards 1974 as it doesn’t have the bumper over riders. The original front plate (eliminated here in 1991) and AAA sticker on the rear bumper indicate long term ownership. It even has a block heater plug neatly wrapped up in the grill.

The styling works quite well in my opinion if one can look past the bumpers. There are, however, a few areas that could only be ’70s Japanese. Look at those wild door handles. And what the heck is going on with the rub strip on the rear door? I wonder if they were a dealer option as I’ve only seen them on one other example but they cover a little character crease on the door. Or perhaps like stock hub caps on a Datsun 240Z, they were all tossed right away due to excessive ugliness.

How about this oddball, rectangular exhaust tip with the smaller secondary exhaust? The secondary one is for the thermal reactor which is a system for reducing emissions. Basically fresh air is injected into a secondary combustion chamber built into the exhaust manifold. This required the engine to run rich and is partly responsible for the poor fuel economy of the rotary engine.

Here is the set up from a 1980 Mazda Rx-7 which is similar except the injected air is pre-heated to make significant fuel economy gains.

The steering wheel can only be described as different. Almost French different. At the front it has quite an aggressive looking beak to it. Sadly the 1976 facelift neutered it with a more generic Mercedes inspired front end. At the rear, the wagon doesn’t get the rotary specific quad tail lights but instead sticks with the 929 wagon units.

So cheers to the owner of this classic Mazda for keeping it alive all these years. And also for not buggering it up with a set of modern and massive rims. The paint surely isn’t perfect but it wears it well. Perhaps I’m especially fond of it as it seems to be the exact color (of my 808 coupe) and in about the same condition.