Ernest Henry (engineer)

Ernest Henry (1885 in Geneva, Switzerland – 1950 in Paris, France) was a mechanical engineer. He developed auto racing engines, and is especially well known for his work for Peugeot and Ballot, who dominated Grand Prix auto racing from 1912 to 1921. His engine design directly influenced Sunbeam Racing cars as early as 1914; the 1921 Grand Prix Sunbeams owe much to his work with Ballot and the 1922 Grand Prix Sunbeams were designed by him.

His engine operational architecture was the precursor of modern engines. One biographer called him "perhaps the most brilliant engine designer ever"; another described one of his designs as "so technically advanced it could have landed from outer space". Henry's "theory, design and execution" of twin-cam engines was to guide engine development in Europe and then around the world for the next century.