YouTuber Warped Perception built a transparent Wankel rotary engine in his shop, and the resulting footage of the combustion process is absolutely stunning.
Rotary engines are one of many mechanical fascinations of mine, so being able to see the innards of one while it’s running is just flat-out cool. The host of this video describes the tiny motor as a “Wankel rotary model aircraft engine,” and while it looks very much like a toy, there’s nothing toy-like about the classic, rotary-smooth, high-pitched sound coming from the spinning Dorito:
The video clearly shows how the rotor—spinning on an eccentric shaft—pulls in air through an intake port by increasing the chamber volume and thus creating a low pressure. The chamber volume then reduces as the rotor continues spinning, squeezing the air charge, and then igniting it (via a glow plug in this case, though automotive applications usually use a couple of spark plugs). After ignition, during the power or “expansion” stroke, the chamber expands, and then finally, the chamber contracts again to squeeze out the spent gases through the exhaust port.
Keeping in mind that the carburetor/intake is on the bottom left of the image, the ignition source is on the right side, and the exhaust is at the top right, here are some visuals showing the engine’s combustion process, starting with the intake of fuel and air:
The rotor then spins on the eccentric shaft and compresses that intake charge:
An ignition source (or two spark plugs, as is the case in many Wankel engines) begins the combustion process:
That combustion of fuel and air spins the rotor during the power stroke:
And eventually, the burned fuel exits through the exhaust:
That .gif at the top of this post is going to become my new screensaver, because the rotary really is one of the coolest engines in all of automobile-dom.