Coaker was trained as an accountant and mechanical engineer,[1] and had been a keen amateur Formula Three competitor during the mid- to late-1960s.

During this time he became friendly with fellow racers Max Mosley and Alan Rees, and racing car designer Robin Herd.

The four created March Engineering in mid-1969, the name of the team being derived from their initials: Max Mosley, Alan Rees, Graham Coaker, and Robin Herd.

Coaker was responsible for the workshop and manufacturing side of the new company, drawing on many years of experience as general manager of one of Hawker Siddeley's automotive subsidiaries,[1] and was the driving force behind March's move into the customer-car market.

Unfortunately for him, Coaker died that April from sepsis caused by injuries sustained when he crashed the car during practice for a Formule Libre race at Silverstone Circuit.