Assembled Piston & Rod combo is the same used across all engines. 3D Printed nylon piston & rod with 0-80 1/4 socket set screw as the wrist pin.
For those interested in gathering all components individually and a DIY build, 3D printed parts may be purchased from Shapeways. Or, if you have a 3D printer, print your own! STL files for blocks, cranks, pistons, rods, and feet are included here: TurboKeychains_motorparts.zip All other components (motors, gears, wristpins, bearings) are common and readily available on the web.