1/4 Scale Running Model Offenhauser (Offy) Engine By Ron Colonna

I'm still amazed by these miniature engines.  "1/4 scale" means one quarter inch equals one foot.  What imagination goes into them!  Solving a thousand "little" problems of metal working and engineering!  The parts are usually made from scratch.  These guys sit around the basement for years grinding tiny valves, making tiny springs and bolts.  And they run! 

We are a very capable race, we humans, we can do amazing things.  Why anyone would take on such a challenge is beyond me, but it's somehow reassuring that some do.