It is not a brand but a car model from Chevrolet. It appears at least twice as a homebuilt airplane engine. See Chevrolet.

From Appendix 7: Japan-USA. Suzuki engines (in collaboration with GM Chevrolet) have been used in general aviation and homebuilt.

-This is clearly from the Suzuki Swift car. Now we have another Geo-Metro engine adapted by J.Mullet, a 115 hp, known as "Metro Aircraft Engines". It has horizontally opposed cylinders, perhaps a Corvair.

“The 115 hp Metro-Geo”