"I've seen a few other Kinner related posts before and took the time to do a little research. They were not around long, but at one time were the largest aircraft engine manufacturer on the west coast."
This was a somewhat misleading claim. The two other west coast manufacturers were Axelson of Los Angeles (who also made machine tools, mostly metal lathes), who made one model of 7-cylinder air-cooled radial engine, and Menasco Motors, which made its name building small, inverted inline, air-cooled engines mostly for racing. It certified a few models for production aircraft, the most successful of which was the C-4. This was a four-cylinder engine that powered the production versions of the Ryan Sport Trainer. Neither company had significant production, with Axelson selling very few engines and Menasco focused on racing.