this combination. It was the only victory for this engine in a world championship race. Lotus built the similar Lotus 42 designed for Indianapolis with a 4.2-litre version of the H16 (2.9375 x 2.36 in, 74.61 x 59.94 mm) but this was never raceworthy; the cars were raced with Ford V8s instead. The H16 engine was redesigned with a narrow-angle four-valve head and magnesium main castings to reduce weight and increase power, but was never raced (it was intended for the 1967 BRM P115) as BRM decided to use the V12 unit which was being sold to other F1 and sports car teams with encouraging results. BRM V12 The H16 was replaced by a V12 (2.9375 x 2.25 in, 74.61 x 57.15 mm) designed by Geoff Johnson. It had been intended for sports car use, but was first used in F1 by the McLaren M5A. Back at the works, the early V12 years were lean ones. In the two-valve layout gave about at 9,000 rpm. In 1968 this had increased to at 9,750 rpm. Geoff Johnson updated the design by adding a four-valve head, based on the H16 485 bhp 4-valve layout; this improved the V12's power output to at 10,500 rpm and eventually to a claimed during 1969. In 1973, Louis Stanley claimed at 11,750 rpm. The design and building of the first V-12 chassis, the P126 was contracted to former Lotus and Eagle designer Len Terry's Transatlantic Automotive Consultants. The cars first appeared during the 1968 Tasman Championship, powered by 2.5 litre versions of the engine, temporary team driver Bruce McLaren winning the fourth round of the series at Teretonga but being generally unimpressed with the car. BRM themselves built further examples of the Terry design, which were designated P133 and 1968 team drivers Mike Spence and Pedro Rodríguez appeared competitive in early season non championship races at Brands Hatch and Silverstone, but then Spence was killed driving the Lotus 56 turbine during qualifying at Indianapolis. Spence's replacement, Richard Attwood, finished a good second to Graham Hill's Lotus at Monaco, but after this results went downhill and the season petered out ignominiously. For 1969 the four valve per cylinder engine was developed and a new slimline car, the P139 was built. John Surtees joined as the team's lead driver backed up by Jack Oliver. Rodríguez was shunted into the semi-works Parnell team. Surtees' time at BRM was not