Maybe you already know that I’d made a fiat 126/500 engine before. Which was smaller and easy to print with internal moving parts; pistons, crank, fan etc (It is here).
Later I’ve improved it quite a bit and added space for interior electronics for operating it, a reductor dc motor to power it and volume for leds simulating spark plugs.
There are two versions, the sport and the standard as seen below 😀
The engine models can be hand cranked or ran by a small reductor DC motor located in place of the actual engine’s starter motor. Read more for more information and links.