Complex sentence: They are 12 to 18 foot tall bipedal, armored, single ocupancy military units powered by unusual, but functional piston V-engines based on actual working engines created by students at the University of Colorado.
Split into simpler sentences: They are 12 to 18 foot tall bipedal, armored, single ocupancy military units powered by unusual, but functional piston V-engines. It should be noted this engine is based on an actual working engine created by students at the University of Colorado.