LiquidPiston Rotary Engine Makes Big Power From Small Size (w/Video)

No, it’s not a Wankel. The LiquidPiston rotary engine is an entirely new internal combustion engine that make big power for its size. Its inventors say it is fully scalable from outputs as low as 1 horsepower up to 1,000 horsepower. How does it work? Let’s take a look inside.

Liquid Piston rotary engine

The engine is about 30% smaller than a piston engine with the same power. It can run on gasoline, diesel, natural gas or JP-8 jet fuel. According to Gizmag,

“One of the secrets in the X Engine’s design is the unique rotary cycle. Unlike a Wankel rotary, which uses a triangular center rotor, the X Engine has an oval-shaped rotary which rotates in a cloverleaf-like core. This creates higher compression with better seals and exhaust pressure. It also creates a larger expansion volume than compression volume, similar to the high-efficiency Atkinson Cycle engine used in hybrid vehicles.”

The LiquidPiston rotary engine has three combustion events per rotor revolution, explaining its high power density and balanced operation. The engine is designed to be made with 2-dimensional manufacturing methods, making it simple to build. This also means that it can be easily modified by enthusiasts. In fact, LiquidPiston has already released a developer’s kit for the X Mini.

The LiquidPiston rotary engine is claimed to be 20% more fuel efficient than a conventional 4 stroke engine. Its unique exhaust expansion chamber means it won’t shatter ear drums if it runs without a muffler. There are three combustion chambers, which explains its high specific output for its size.

The design of the X rotary engine also allows for cycle skipping for low output needs and low RPM power. In larger versions of the engine, water can be injected into chambers after the exhaust cycle to cool the engine when under high loads. The engine shown in the video is a 70 cc gasoline version that produces about 3.5 horsepower at 10,000 rpm. LiquidPiston expects to unveil a 5 horsepower version soon.

Watch the video. It’s fun!


Steve Hanley

Closely following the transition from internal combustion to electricity. Whether it's cars, trucks, ships, or airplanes, sustainability is the key. Please follow me on Google + and Twitter.