Everything looks cooler in slow-mo.
The humble carburetor isn't used much in modern day automobiles. As far as we can tell most manufactures switched to electronic fuel injection in the late '80s, with the goofy Subaru Justy sporting the classic tech until the early 1990s. You certainly won't find one on anything new like a Subaru WRX. They're still used on all manner of lawn equipment and scooters, and using a 28,000 frames-per-second, super slow-mo camera on a transparent version in the following video we can see its inner workings.
Host and engineer Destin Sandlin taps his dad for a primer on the lowly carburetor, as he disassembles one from a tiller to show the bottom half (float), the top half (venturi) and how the throttle and choke work together to get the right amount of air and fuel in the cylinder before combustion. The tech in the little metal carburetor seems comically old, but like we said, they're still used everywhere in your garage. Except for your car. Unless it's old.
Sandlin and what looks to be a team of engineers designed a transparent carburetor using a 3D printer, complete with a plastic throttle and choke, and a perfect viewing window into the bowl and venturi. Sandlin notes that he wants to do another video just on the design of the carb.
Sandlin and dad install the piece on the tiller and fire up the slow-motion camera, which makes literally everything look cooler. We can see the gas squirt into the venturi, with a lot of turbulence down in the bowl. On intake we can see the air/fuel mixture being sucked into the cylinder through the clear walls. Thankfully, nothing explodes, which is certainly a risk when pumping explosive liquid through plastic.
The only problem is the throttle control, which isn't stiff enough to stay closed on the 3D-printed part. Dad Sandlin guesses that if he doesn't hold the throttle closed the engine might tear itself apart. He seems knowledgeable so we're inclined to believe him.
Sandlin gets even tighter on the part with his super camera, and we can see the tiny jet of fuel entering the venturi before it gets sucked away. They discuss surface area and volume and some other science stuff, and then reposition the camera down the throat of the venturi, which yields even cooler results.
Like the see-through oil pan on that Russian Lada, these super-strong transparent parts are the best way to see the inner workings of something like a carburetor. And the slow-motion camera just adds to the intrigue.