sentences:  Although initially slow during practice, gradual tuning and tweaking meant that by the end of qualifying McLaren had managed to put in a lap fast enough to take second place on the grid, splitting the works Porsche 907s.Unfortunately, the Rindt/Spence car had suffered an engine mount failure and failed to qualify.Spence, something of a Brands Hatch specialist, was substituted into the lead car for the race, and was at the wheel, leading the race, when a rubber joint in the transmission failed, putting the car out.