the article CLEARLY states that the chinese 'found' the design on thingiverse.
In doing so, they 3D printed an entire engine from a design they found on Thingiverse, using nothing but 3D printed parts.
How about actually reading the articles before jumping all over Brian :-)
There'll generally be something else in there you can get him on ;-)
Like this:
Of course these 3D printers aren’t capable yet of printing metal engines,
While technically accurate. There are companies out there who print nylon parts and then electroplate them in metal. The part can actually be strong and durable enough to be used asa metal part would. Saw a guy lecturing on the process at tct last year.
So, technically, with a bit of applied alchemy - you could make a working metal engine model with an fdm printer.