As reigning world champion, Cooper was able to secure the supply of the new Coventry Climax V8 engine type FWMV. But with the project taking some time to complete, Bruce McLaren and Jack Brabham had to settle for the old FPF Mk.II, paying around 35bhp to Ferrari. The T55 was a development of the 1960 T53, with a more agile chassis. During 1961 the Coopers often sailed in the mid-table, even struggling with reliability problems. The new Climax V8 was finally ready at the end of July and the team worked hard to adapt the chassis (the car was called T58). However, McLaren continued in the T55 and finished third at Monza and fourth at Watkins Glen. Cooper finished fourth in the constructors' championship, with 14 points, behind Ferrari, Lotus and Porsche.