The persistence needed to pull off something like this is mind blowing. Started in 1978, the model was completed in 1992. Wow!
And here's a link to the world's smallest 4 cylinder engine. (I haven't independently verified this claim...). With a 1/4" bore, this monster blows .061 cu/in. That's about one cubic centimeter (or 0.00100 litre).
It takes all kinds