LiquidPiston, Inc., a leading innovator of efficient internal combustion engine technology and hybrid power systems, announced that a fully integrated version of its 25hp XTS-210 heavy-fuel rotary engine (earlier post) has begun testing.

This milestone follows the successful completion of initial dynamometer testing of the engine core and enables parallel development of products powered by the engine, including a compact man-portable 10kW electric generator being developed under a US Army contract awarded to LiquidPiston.

LiquidPiston is moving the XTS-210 from the lab to the real world. Integrating the engine core with the balance of plant components, including the supercharger, fuel and oil pumps, and other ancillary systems marks a major milestone in the development of the engine.

—LiquidPiston co-founder and CEO Alec Shkolnik

The LiquidPiston 10kW genset will be approximately one-quarter the size and weight of the currently fielded Advanced Medium Mobile Power Source (AMMPS) 10kW generator system. Given its smaller footprint and power electronics, LiquidPiston’s genset platform can replace multiple existing generator power classes, greatly simplifying generator procurement and logistics for the U.S. Army and other DoD agencies.

XTS-210-powered 10kW generators will leverage LiquidPiston’s patented High Efficiency Hybrid Thermodynamic Cycle (HEHC) design, offering several key benefits:

• Lightweight – Up to 75% lighter and smaller than the currently-fielded AMMPS.

• Easy to transport – Can be man-portable, instead of requiring a truck, trailer, or forklift.

• Space-efficient – Occupies only ~9 cubic feet of space.

• Heavy- / Multi- fuel capable – Designed for jet fuel, the engines have also been operated on gasoline, diesel, propane and hydrogen.

LiquidPiston’s XTS-210 engine is the result of decades of engine research and development, coupled with more than 10 contracts secured with the US Department of Defense and more than $20 million awarded in development funding, including a $9 million DEVCOM Army Research Laboratory award for a Compact Efficient Rotary Engine announced in November 2022 and an $8.3 million award from DEVCOM C5ISR Center for the development of a Light Weight High Efficiency Generator announced in July 2023.

The XTS-210 is also being integrated into a hybrid eVTOL UAS for an Army demonstration that will occur later this year.