Episode 154 | Efficient Engine | LiquidPiston
The common piston engine has been hard to beat. With few exceptions, it has dominated all forms of locomotion for the last 100 years.
Connecticut-based LiquidPiston hopes to change that. They have a new take on the rotary engine, also known as the Wankel engine. My guest, founder and CEO Alec Shkolnik, says the engine was always built around the thermodynamic cycle, not the engine. His father, Nikolay, first conceived of the engine around 2003. The first concept was literally a liquid piston—gas pushing around a liquid, no pistons. Alec joined the company following his Ph.D. work at MIT in 2011.
Wankels had success under the hood of some Mazda sports cars from 1967-2012. According to Alec, those engines had few moving parts, low vibration, high power density, and were very responsive. But he says they also had issues with sealing, cooling, efficiency, emissions, and durability.
“It’s like a new operating system for the engine. We turned the old Wankel engine inside out,” says Alec. Whereas a typical Wankel is best described as a triangular rotor inside a peanut-shaped housing, LiquidPiston is opposite, a peanut-shaped rotor inside a tri-lobed housing.
Alec says this solved all the previous challenges. He says their “X Engine” is simple, small, and strong. The motor contains just two moving parts. Right now they believe they can be about 30% more efficient than a gasoline engine and three times as efficient as a small turbine. They can be ten times smaller than a diesel engine at the same efficiency. He says the engine has operated on Gasoline, kerosene, jet fuels, diesel fuels, propane, and hydrogen.
Some critics might argue that a new mechanical engine in 2022 is too late. We’re moving on to battery electric vehicles now. Alec believes a hybrid battery/X Engine vehicle would be better. “We’ve moved the emissions off the [EV] and put it somewhere else,” he says. “A hybrid solution means you can use smaller, lighter, cheaper batteries and still keep all the benefits of electrification.”
Alec points out that the automotive industry has traditionally been conservative about adopting a new engine. For now, the company is focused on developing its engine for the Department of Defense. Alec says the X Engine’s size and efficiency were key to an organization that may spend up to 100 gallons of fuel to get one gallon of fuel to the front lines.
“We think this is going to be the first domino,” he says. “Rather than going into the automotive world directly, we’re starting by going to our friends at the DOD, solving their immediate problem that they have, and then the dominos can fall from there.”
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