Low-Cost Piston Engine of the Future Could Be Doomed by Lack of Interest

Despite paying lip service to the growing — but still minuscule — electric vehicle market, automakers do love piston engines. The companies that built their current empires around internal combustion engines take comfort in the technology, finding stability and solace in the seemingly timeless act of burning fuel in exchange for power.

Batteries and electric motors? We understand those too, the companies claim. It’s not a new thing, after all.

What automakers don’t particularly trust is a new type of engine that could squeeze record mileage out of a tank of gas, for less cost, while still using a moving piston with fuel injectors, intake valves and exhaust valves.

An Israeli company claims it could double the range of vehicles for little cost, if only automakers would adopt its technology. According to Agence France-Presse (via phys.org), the Tel Aviv-based Aquaris Engines is in talks with Renault after developing a horizontally oriented single-piston combustion engine that does away with all the hardware one normally sees below the piston head.

No crankshaft or flywheel. No mechanical connection to the drive wheels. Just power produced twice as efficiently as a conventional engine thanks to a “free” piston system.

“It is the highest efficiency you will probably meet,” Aquarius co-founder Gal Fridman told AFP. “It has the lowest emissions and the highest power-to-weight ratio.”

The engine Fridman describes sounds an awful lot like a version of the free piston engine “linear generator” under development by Toyota. Word first leaked out about that automaker’s efforts two years ago. Featuring a magnet-wrapped piston connected to a gas spring chamber, the piston generates electric current by moving up and down inside a linear coil. Powering the piston is a simple two-stroke combustion chamber with associated fuel delivery and exhaust hardware.

Used in a plug-in hybrid vehicle, the unit would be a simpler alternative to the repurposed multi-cylinder engines that currently act as generators. The unit’s lighter weight, longer range, and lower cost could give automakers a leg up on their plug-in competitors. There’s also a chance that, if used en masse, the technology could stave off the need for automakers to invest in expensive battery electric vehicles.

Of course, this assumes the engine works as designed, with no drawbacks. Aquarius says it does, with the company currently seeking a third round of funding (to the tune of $40 or $50 million). It’s also in talks with French automaker Renault, which confirmed the conversations without mentioning any “obligation or a specific project.”

While Renault seems to have at least a mild interest in Aquarius’ engine technology, don’t expect a revolution in the industry — at least not for a long time, even if the free piston design becomes accepted as a reliable generator.

John German, senior fellow at the International Council on Clean Transportation, told AFP that the generator’s “radical” design — as well as the changes needed to install the technology — could prompt cautious automakers to stick with what they know, and what they already manufacture.

Ana Nicholls of the Economist Intelligence Unit claims a widespread adoption of the generator design isn’t likely. The industry shift is from gasoline-powered vehicles to pure electric vehicles, she said, and automakers aren’t likely to tap into R&D budgets to test unproven technology.

For Fridman, the predicted electric car revolution is more hype than anything else.

“A lot depends on the path the electric vehicle revolution takes,” he said. “If pure battery electrics sell well then there probably isn’t much need for this kind of engine. But if people balk at the long recharge time and high costs of battery-only cars, then systems like these might be the future.”