

The temperature is represented by the color of the central pylon. You can leave one running, for example, and it will never explode unless it is receiving power. Stirling Engines will never explode unless the engine itself receives too much power. You can supply this with Redstone or with Red Alloy Wire from RedPower - it may be more effective.

Note that they still require a Redstone signal to run, as do Combustion Engines. Three Stirling Engines can run a quarry at a fairly quick pace. The Stirling Engine can be a great source of power for a Quarry if you are able to gather the coal/charcoal to get it running.

It is not as powerful as a Combustion Engine, but it is more powerful than the Redstone Engine. The Stirling Engine (formerly known as the Steam Engine) is a BuildCraft Engine that runs on Vanilla Minecraft fuels.
