Ilmor is an engineering company, specializing in automotive racing projects. Founded in 1983 by Mario Illien and Paul Morgan (with major funding furnished by Roger Penske) its first major project was the creation of an Indy-car engine to compete with the then-dominant Cosworth DFX, a turbocharged variant on the DFV engine popular in Formula One. The company currently supplies engines and consultants to the IndyCar and MotoGP series.
Illien and Morgan were engineers, working at Cosworth on the DFX Indy Car engine. Since at the time Cosworth had a near monopoly on engines for the series, the management was more conservative regarding the development than Illien and Morgan wanted. Eventually the two decided to leave Cosworth, to pursue their own projects.