LiquidPiston's "inside-out" rotary X-Engine wins Army research contract

Connecticut-based company LiquidPiston is developing a portable generator for the US Army that uses its X-Engine, a fresh and extremely powerful take on the rotary engine that'll deliver as much power as the Army's current-gen-set at one-fifth the size

https://newatlas.com/military/liquidpiston-rotary-x-engine-army-generator/