There is not really any one inventer of the gas engine, many people throughout history contributed to it. To illustrate here are some examples. Christian Huygens designed the first internal combustion engine in 1618 but never built it. In 1824 Samuel Brown modified an old seam engine. 1883 Edouard Delamare built the first four stroke engine. 1886 Karl Benz received patent for a gas powered car. And lastly 1890 saw the first four cylinder, four-stroke engine, invented by Wilhelm Maybach.