This is a Stirling engine that converts heat energy into mechanical work

A Stirling engine is a heat engine that is operated by the cyclic compression and expansion of air or other gas (the working fluid) between different temperatures, resulting in a net conversion of heat energy to mechanical work. The Stirling engine is a closed-cycle regenerative heat engine, with a permanent gaseous working fluid. Closed-cycle, in this context, means a thermodynamic system in which the working fluid is permanently contained within the system. Regenerative describes the use of a specific type of internal heat exchanger and thermal store, known as the regenerator. Strictly speaking, the inclusion of the regenerator is what differentiates a Stirling engine from other closed-cycle hot air engines.

This 16 Cylinder Hot Air Stirling Engine would make an amazing desk toy

The largest reciprocating engine in the world, the Wärtsilä-Sulzer RTA96-C, produces around 80,080 kilowatts (107,390 HP)

somewhere a tiny victorian gentleman is missing his car engine

It's going to do a lot of good

Although these seem like major advantages to an ordinary engine, they are less practical in most vehicles because they require external heat, rather than internal heat. The external source of hit needs extra time for the heat get the inside of the engines

Who invert it?

Wow 😮

Although these seem like major advantages to an ordinary engine, they are less practical in most vehicles because they require external heat, rather than internal heat. The external source of hit needs extra time for the heat get the inside of the engines