Here is a Porsche Carrera Racing Engine model that you can put together in a few hours and keep on your desk to turn heads. This Porsche Type 547 engine (1:3 scale) comes with 300 pieces. You will be able to watch the parts move and listen to the sound of the original engine. The spark in the cylinders are simulated with LEDs.
You get a 120-page manual with this set. You can find out more about it here.