Mazda is working on the biggest rethink ever of its signature Wankel rotary engine, with a ‘stroker’ version under development. A new eccentric shaft would increase engine diameter, but could help improve the engine’s fuel efficiency. Senior engineers add that some Sky-G piston engine technologies are applicable to the rotary, and could also help cut its thirst and exhaust emissions.
“You could call it ‘Sky-Rotary’,” says Seita Kanai, Mazda’s R&D and program management director. But the Sky name will only be applied if the improvements are similar to those of the Sky-G petrol piston engines over Mazda’s current engines.
The new rotary engine, codenamed 16X, is currently under development. Engineers have been struggling to find the sweet spot containing optimum power with low fuel consumption, emissions, and oil consumption that has hindered development thus far. If Mazda’s Sky-G technology is adaptable, it could give Mazda the efficiency and cleanliness it needs to break out from prototype to production.
Those worried that Mazda may give up on the rotary altogether needn’t be. “The rotary is like a jewel or a treasure for Mazda,” Kanai says, adding that Mazda is the only company that knows how to polish something so valuable.
But where could it find a home? Over at Mazda’s design studios there’s at least one guy itching to do another RX-7. Speedy Maeda is the son of the designer of the very first RX-7, and he would love to follow in his father’s footsteps. But before the design boss is commissioned to create a new RX-7 there must be strong demand for the rotary-engined icon’s return. “Please ask Mazda to do a new sports car, please…” begs Maeda.
Meanwhile, the RX-8 is ending its last year of production for the U.S., leaving Mazda without a rotary engine in its North American lineup for the first time since 2002.