‘The Bruce & Denny Show’ rolled relentlessly through the calendar, taking eight 1-2 sweeps, winning the other three races and suffering only three retirements, two of them through engine problems. Michigan even saw a 1-2-3 when Dan Gurney started from the back of the grid in the spare works M8B and sliced through the field to finish third.
The M8B was dramatically different from the M8A in only one respect: it sprouted a tall rear wing mounted on struts which bore down directly on to the rear hub carriers, a configuration permissible in Can-Am but outlawed in F1. Less significant, but another M8B distinguishing feature, was the creation of large scallops behind the front wheels for improved streamlining and brake cooling. Otherwise, the new car was so similar that the spare works M8B for 1969, in fact, was Denny’s M8A suitably modified. Even Bruce’s regular M8B used some components from his 1968 M8A – one was the rear suspension lower wishbone which fatigued at Riverside and pitched him into a rare high-speed accident.
The engines, still assembled at Colnbrook but now under George Bolthoff’s care, grew slightly in size when Chevrolet came up with the 7.1 litre ‘430’ which peaked at around 650bhp and could rev safely to 8000rpm. Can-Am gossip held that McLaren was using huge engines, perhaps as big as ‘480’ but this was not so – one ‘465’ was used in practice but never raced.
"The M8Bs were the nicest cars we ever built," remembers Teddy Mayer. "Mounting the wing on the rear uprights was the proper way to do it, because this put the load straight into the tyres rather than the chassis. This made it a really easy car to set up, and Bruce and Denny always said it had lovely handling because there were no pitch sensitivity problems – but we were only allowed to do it in 1969. Our Can-Am cars, to be honest, never handled as well after this."
With the F1A having forced stricter wing rules on the liberal Can-Am organisers, the 1970 works cars – leaping to the M8D designation because M8C was used for Trojan’s customer build – were designed within a tighter aerodynamic envelope. Since aerodynamic devices could not be tied directly to the suspension and the wing could set no more than 80cm above the base of the chassis, the M8D featured a chunky tail section with the wing mounted between upswept tail fins. The suspension was also modified to give a 4in wider track front and rear, and more strength at the rear. To deal with Bruce’s observation that the M8B had tended to shudder when accelerating hard out of slow corners, bracing was installed from each side of the engine to the monocoque.
Bruce’s tragic death while testing the prototype M8D at Goodwood on 2 June was caused by these revised aerodynamics. The new wing’s powerful downforce, accentuated by the venturi effect of the rear deck ahead of it, caused the huge bodywork tail section to tear away from its mountings.
It was a despondent team which packed two new M8Ds for the flight to America only a week later. Bruce was gone, and Denny was still nursing tender new skin on hands which had been badly burned at Indianapolis. Dan Gurney filled the void as Denny’s team-mate for the first three races. He won the Canadian openers at Mosport and St. Jovite, but then had to step down because of a conflict between his personal Castrol sponsorship and McLaren’s Gulf backing. Peter Gethin competently took his place, scoring one victory and a pair of second places.
But it was Denny’s season, ‘The Bear’ taking his second Can-Am title with six wins from a run of eight races once he was back to full fitness. The results don’t paint the whole picture, for McLaren’s supremacy was now being threatened by Lola and Chaparral. The M8Ds no longer had such an overwhelming advantage, and actually posted slower lap times than the M8Bs at a few circuits.
The M8F arrived for 1971, when Peter Revson replaced Gethin in the team. Although the monocoque was strengthened and lengthened to give a wheelbase stretch of 3in in the interests of more stable handling through fast corners, the car looked much the same apart from the addition of full-length aerodynamic fences along either side of the body to keep air channelled to the rear wing. There was much more power, around 740bhp, from the engines, now prepared once again by Knutson, thanks to even bigger capacity (8.1 litres) and special linerless cylinder blocks cast by sponsor Reynolds in its new 390 silicon-aluminium alloy.
The McLaren steamroller continued in 1971 with eight wins from 10 starts, but the competition was still hotting up. Jackie Stewart’s Lola T260 turned out to be a serious, but less reliable rival as he steered it to the other two victories. Revson scored five wins to Denny’s three to take his first – and McLaren’s fifth – Can-Am title.
