Arfons worked in his father's feed-mill business in Akron, Ohio, before and after service in the U.S. Navy (1943–46), which trained him in diesel mechanics. He began his career as a drag racer in the early 1950s with his brother Walter, with whom he built a series of racing cars, each called the Green Monster; and by 1959 he was involved in car racing full-time. In the early 1960s he designed the ultimate Green Monster, powered by a J-79 jet aircraft engine, which he drove at the Bonneville Salt Flats, Utah. He reached speeds of 434.02 mph (698.34 km/hr) on Oct. 5, 1964; 536.71 mph (863.56 km/hr) on Oct. 27, 1964; and 576.533 mph (927.64 km/hr) on Nov. 7, 1965. The last of these records was broken eight days later by Craig Breedlove's attainment of a speed of 600.601 mph (966.37 km/hr).

Arfons also designed speedboats, using the name Green Monster Cyclops.