One of our readers just sent in two videos of the amazing functional paper V8 engine in action -- previously featured on TechEBlog. Just to recap, it features many moving parts which include "a compound crankshaft, a rapid cooling fan, 8 rods, 8 pistons and a complex compound gearbox etc.". The engine is powered by 2x1.5V D Batteries and weighs 2.98kg. From start to finish this model took one year to design and construct. Videos after the jump.