A Tiny Engine Aims to Redefine Two-Stroke Power: INNengine's e-Rex
INNengine’s e-Rex (and Rex-B) are ultra-compact, four-cylinder engines with eight opposing pistons on thrust plates, marketed as “1Stroke” even though the cycle operates as a two-stroke—combustion/exhaust in one pass, intake/compression in the other. The design aims for high power density, smooth balance, no traditional valve train or oil burning, and on-the-fly variable compression. INNengine claims about 120 hp from a 500cc unit and has tested it in a Mazda Miata, envisioning it as a range-extender rather than a replacement for conventional engines.
