The internal combustion engine is a fascinating thing because precisely machined pieces of metal combine to become something capable of moving an automobile at high speeds. This video from the JohnnyQ90 YouTube channel highlights this intricacy by showing the manufacturing of a tiny, two-rotor Wankel powerplant. The completed mill is small enough to hold in your hand.

This is the latest video in a series showing the creation of this little, rotary engine. At this point, the mill is largely complete, including having the rotors and combustion chambers done. This clip starts with the creation of the eccentric shaft that runs through the centre of the powerplant and transmits the power to the flywheel.

Unfortunately, there's a problem because the builder grinds the piece too much, resulting in the eccentric shaft not fitting properly. To make things work, the creator manufactures a bushing that allows everything to slot together.

Next, he fits together all of the internal pieces. It's neat to see how few components are inside a Wankel engine.

Things aren't done, yet. The builder machines the flywheel, intake, and exhaust. He wires glow plugs to ignite the fuel when the engine is running.

The first attempt at starting the little rotary engine is a failure and results in the powerplant seizing. The single-inlet intake causes the powerplant to run too lean, so it can't get going.

The solution to this is swapping to a dual-carb setup. This change finally lets the engine get running. The sound it makes is similar to a small displacement, two-stroke motorcycle, or a weed trimmer.

A digital tachometer shows the little Wankel idling at around 4,000 rpm. With the throttle wide open, it spins at about 14,000 rpm.

At the end, the rear counterweight breaks. This is a replaceable part, and the homemade rotary engine is now back together.

The video indicates the future of the powerplant is for an RC car. Judging by the contents of the YouTube channel, this builder gets as much joy from machining these tiny engines as installing them into a scale model and going for a drive.