External Combustion Engine

Steam & Stirling Engine Kits for Adults

This category encompasses all engines where combustion occurs outside the working cylinder. While it includes Stirling and Steam engines, we specifically highlight the unique Vacuum Engine (also known as the "Flame Licker") here. These are fascinating low-pressure engines that are safe, visually distinct, and a joy to watch in operation.

Classification & Types

Beyond standard steam/Stirling, the primary classification here is for Vacuum Engines:

• Vacuum / Flame Licker Engines: Characterized by a valve that opens to physically suck a flame into the cylinder.

• Cooling Method: Air-cooled (with fins) or Water-cooled (with a hopper) to maintain the temperature difference needed for the vacuum.
  

How it Works (Vacuum Engine Principle)

Unlike an explosion pushing the piston out, this engine works by suction. A valve opens, drawing a hot flame into the cylinder. The valve closes, and the hot air is rapidly cooled by the cylinder walls. This cooling causes the air to contract, creating a partial vacuum. The atmospheric pressure outside the engine then pushes the piston back into the cylinder, creating power.