A Six-Rotor Mazda Cosmo Exists And It's Glorious

Although Mazda stopped at three rotors in its road cars, the modular nature of the Wankel engine means you can keep going further than that if you wish. The Japanese manufacturer itself made the four-rotor ‘26B’ for the screaming 787B racing car, and thusly arranged rotaries are reasonably popular in the aftermarket world. Just look at Rob Dahm’s famed four-rotor RX-7, and the 1200bhp Mazda 3 ‘Mad Mike’ Whiddett will soon be tearing up Pikes Peak with.

Today’s rotary curio, first seen at the recent Tokyo Auto Salon, goes even further. As shown in this video from Alexi aka Japanese car culture aficionado noriyaro, it features six rotors. The beastly engine sits in the front of a Series JC Cosmo, which is probably the only Mazda with a long enough engine to accomodate such a powerplant. However, the stock Cosmo only has a three-rotor unit, so squeezing in something double the size is easier said than done.

For a start, there’s no longer room for a radiator at the front, so that’s now mounted at the rear and plumbed in via pipes running through the cabin, where you’ll also find the remote reservoir for a dry-sump lubrication setup. There is still a boot, however, with the radiator neatly sitting underneath the car.

As for what’s going on at the end, we have a gorgeous row of individual 50mm Borla throttle bodies made from a Porsche flat-six, carbon apex seals, and a custom-made exhaust manifold. The clearance for the latter between the engine and the bodyshell is extremely tight, making fitting/removing everything “like a puzzle”.

It’s early days for the project, but Alexi has pledged to return once the car is running. The endeavour is the work of A-RF (Anniversary Racing Factory) in Saitama Prefecture, which is about 18 miles west of Tokyo. It seems to be a rolling showcase for the company’s components, with elements including the carbon apex seals already on sale.

Although the six-rotor Cosmo is A-RF’s main ‘attraction’, it’s merely one of many items of interest in a treasure trove of rotary goodness. We have rotary Weber carburettor setups, unused 30-40-year-old factory Mazdaspeed peripheral port housings said to be “sold under the table” back in the day, and yes, all sorts of rotary-powered Mazdas. Of particular interest is a 13B-powered Luce the owner successfully raced in the late 1990s.

Looks like a great place to lose a couple of hours, doesn’t it? A-RF should start selling tickets.