Almost a decade since the last Mazda RX-8 was made, the Wankel rotary engine is fading into obscurity as the Sony Betamax of automobile powertrains. Worshipped by a hardy niche of enthusiasts but mostly forgotten by everyone else, it's hard to believe this technology was once set to rule the world.
Throughout the 1960s, the rotary engine conceptualized by Felix Wankel and developed at vast expense by the small German automaker NSU was kind of the auto industry's darling.
Compact, light, powerful, high-revving yet free of vibrations, and made of very few moving parts, the rotary looked like the future of automobile engines.
To the point that no self-respecting automaker wanted to risk being left behind, including Alfa Romeo, which started its contacts with NSU as early as 1962.
The Milanese company's resources were limited, though, with no more than two engine test rooms and a handful of engineers dedicated to crack the Wankel engine's main engineering challenge: the durability (or lack thereof) of the rotor's apex seals.
These components of the Wankel engine are crucial to maintain compression and burn the fuel mixture efficiently but proved a manufacturing nightmare with the materials and technology available at the time.
By the end of the decade, two production cars were converted into Wankel development mules for road testing. One was a Spider, fitted with a single-rotor 500cc engine good for 65 HP, and a 1750 saloon equipped with a bi-rotor 1000cc engine rated at around 130 HP. Unfortunately, neither car would survive very long after the end of Alfa Romeo's experimental rotary engine program in late 1973.
The twin-rotor engine shown in the video is actually the one that came out of that 1750 saloon, still mated to its Giulia five-speed gearbox and double-choke Weber carburetor.
The Alfa Romeo Wankel engine program never went beyond the experimental stage for several reasons.
First and foremost, the company at the time covered its twin-cam four-cylinder engines with a 100.000 Kms warranty, a distance that had remained out of reach for its Wankel engines.
Then there was the introduction of the first tailpipe emissions regulations in the USA in 1967, which shifted Alfa's development priorities towards fuel injection and electronic engine management systems.
Then, with the company's rotary engine program already on shaky ground, came the Oil Crisis in 1973.
The sudden 400% spike in crude oil prices shook the automobile industry to its core, making the notoriously thirsty rotary engine an unviable proposition.
With that, the Alfa rotary's fate was sealed forever: much like every other automaker bar Mazda, the Milanese company closed the Wankel chapter there and then, without fanfare.