Mountune was founded in Maldon, Essex UK in 1980 by David Mountain.

Originally focused on developing the British Leyland A series engine for motorsport use, the company expanded quickly backed by the reputation gained from numerous race victories. Ford released the infamous 2.0L YB engine powering the Sierra RS in 1986. David Mountain quickly realized the potential of this twin cam , four valve turbocharged engine and started development for race and rally applications. Mountune's team of engineers worked closely with Ford's own motorsport group based at the infamous Boreham facility in the UK to supply various works teams and 100’s of privateers with Ford YB engines. In 1990, the Mountune powered Ford Sierra RS500 of Rob Gravitt won the British Touring Car Championship resulting in Mountune supplying race winning engines to customers around the world. In the early '90s, Group A rallying was the pinnacle of its sport and the works Escort Cosworth's were all powered by Mountune-built, 2-liter Ford YB engines.