The combustion process inside is fascinating – but it’s also one of the things we never get to see. That’s no longer the case, thanks to this incredible two-stroke engine originally designed by Jan Ridders, then redesigned and constructed by Huib Visser.

Using nothing more than a double-A battery to power the ignition, the engine requires a single pull of the starter cord to start the process, and then we get to witness the plug ignite the white-gas Coleman camp fuel within the cylinder.

Unlike a four-stroke engine, the two-stroke design has the intake and exhaust ports built into the cylinder rather than the cylinder head. As the engine moves downward on the firing stroke, it uncovers the exhaust port, allowing the burnt gases to exit the cylinder.

As the piston continues traveling downward, it quickly uncovers the intake port on the other side of the cylinder and sucks in the fresh intake charge to fill the cylinder again so it can be compressed and fired again – the piston performs the job of the intake valve, the exhaust valve, and the compression all from one unit. The spark plug also fires on every rotation of the crankshaft, unlike in a four-stroke where it fires on every other rotation.

The simplicity of this unit is beautiful. Using a glass cylinder and graphite piston, Visser constructed the engine to show off the combustion process. A flying magnet triggers the miniature spark plug to start combustion, while the single connecting rod and machined crankshaft whir away as the engine runs.

Check out the spark and fire in action!