Next-generation rotary engine could get laser ignition

Mazda’s next rotary engine will have a “special kind of ignition system” that will not make use of traditional spark plugs, according to a senior engineer with the manufacturer. It is believed the alternative could involve using laser beams to ignite the fuel/air mixture inside the engine.

Mazda, which has refused to give up on development of the rotary engine, started work on the next-generation 16X Renesis unit in 2007, 40 years after it first introduced its innovative new power source to the industry.

Read more on why the last RX-8 was axed

The 16X’s capacity has been raised from 1304cc to 1600cc, and it is also physically smaller and partly built from aluminium. The changes are designed to improve two of the biggest issues with rotary engine performance: fuel economy and torque delivery.

However, increasingly stringent emissions regulations are hampering future progress. The Mazda RX-8 was withdrawn from Europe because its rotary engine could not meet Euro 5 emissions regulations, and future upgrades of the existing engine may not meet Euro 6 laws.

The Mazda source said the new engine “needed a smaller hole on the wall [of the combustion chamber]” as a result of eliminating the space-hungry normal spark plug. He also admitted to Autocar that the use of laser ignition “was absolutely possible”.

Read more on Mazda's Sky Activ tech

Recent advances in Japan have created high-power lasers made from ceramics that measure just 9mm in diameter and 11mm in length, easily small enough to fit into a car engine.

Using lasers to ignite the fuel/air mix would allow an engine to run leaner. It would also make it possible to much more closely control the timing and the point of ignition, reducing emissions and improving economy.

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