Former ace race-car driver Louis Chevrolet began building competition cars under the Frontenac name in 1914. He was not a remarkable designer himself, but he knew how to pick men who were. He chose Cornelius van Ranst to design the 4-cylinder Monroe Frontenac, one of which Louis' brother Gaston drove to win the "Indianapolis 500" in 1920. Before van Ranst designed the straight-eight that won at the Indy Speedway the following year, he drew up a high-performance pushrod head for the side-valve Model T Ford.
The Chevrolet Brothers Manufacturing Company was created on April 5th, 1921, for its production and marketing, headed by Louis and Arthur, Gaston having died at the wheel of a Fronty on the Beverly Hill Board Speedway six months after his victory on the Indy bricks.