The $29.99 all-metal desktop Stirling engine kit is one of the simplest. It can be assembled in 15 minutes and is recommended for ages 14 and up. Also for $29.99 is the Exploring Kid Steam Engine Kit.

Tamiya’s Mini 4WD toy line primarily consists of small ... but we’d love to see a competition series using steam powered racers. We don’t see a whole lot of steam hacks around here, but ...