Last fall, Mazda brought its stunning Vision concept to the Tokyo auto show and lit the flame of hope for all of us who have ever owned an RX-7. Those of us who did can never get the thrill of its nearly vibration free rotary engine spinning up to 8,000 rpm and beyond. That engine made a satisfying growl like no other. It was music to the ears of plenty of gearheads, myself included.
Yeah, it was thirsty. And yeah, it burned a little oil. But that was one sweet motor. By comparison, the pushrod lump in my MGB felt like it was from the Stone Age. The last time Mazda sold a car with a rotary engine in America was in 2011. Since then, fuel economy and emissions challenges have kept it out of production. Gone but not forgotten, it seems.
Mazda has just filed a patent application for a modified rotary engine design. According to AutoBlog, this one places the intake ports as the bottom of the engine and the exhaust ports at the top. The changes are said to allow the engine to sit lower in the chassis of the car it is mated to. A lower center of gravity leads to better handling.
The top mounted exhaust is also supposed to make it easier to turbocharge the engine — something that would be necessary in order to help the little screamer meet upcoming emissions standards. The short distance from engine to turbo should make the old bugaboo of turbo lag nothing more than a memory.
The new engine design uses port fuel injection. According to the patent filing, it has a triangular rotor that covers part of the exhaust port which allows for different exhaust flow characteristics. The filing claims that that two of the four possible orientations allow for less airflow resistance in the exhaust port. That would also boost turbo performance.
The Mazda Vision is one of the sexiest designs this side of the original Jaguar XK-E, before it got crapped up with federalize headlights and bumpers. Will a rotary equipped Vision ever see production? The odds, frankly, aren’t that good. It is unlikely that Mazda will ever be able to tame the Wankel engine to meet modern regulatory constraints.
But if it does, and I was forced to choose between a rotary powered Vision and an autonomous transportation pod like the Tesla Model 3, I’m pretty certain my love of sports cars with real engines and transmissions that have to be stirred by hand would carry the day.