the V8 engine was sold to privateers and appeared in a number of other chassis during the 1.5 L formula, particularly in private Lotus chassis and in smaller marques such as BRP. A number of privateers acquired 1961 and 1962 BRMs during this period, including Maurice Trintignant and Scuderia Centro Sud; these cars continued to race for many years. The monocoque BRM P261 V8 car was soon developed and these ran on through the 1.5-litre formula and performed useful service in the early races of the subsequent 3.0-litre formula. In 1965 Jackie Stewart was signed to partner Hill; he took his first grand prix win at Monza in his debut season, and won the first world championship race of the new three-litre formula with a car fitted with a Tasman two-litre V8; once again BRM were not ready for the start of a new formula and the old cars continued to be used, even on occasion after the H16 was ready. BRM H16 For , the engine regulations changed to permit three-litre atmospheric (or 1.5-litre supercharged) engines. BRM refused Peter Berthon and Aubrey Woods's proposal to build a V12, and instead built an ingenious but very complicated engine, designed by Tony Rudd and Geoff Johnson, the H16 (BRM P75), which essentially used two flat-eight engines (derived from their 1.5L V8) one above the other, with the crankshafts geared together. BRM found the H16 (2.75 x 1.925 in, 69.85 x 48.895 mm) attractive because it was initially planned to share design elements and components with the successful 1.5-litre V8. While the engine was powerful, it was also heavy and unreliable - Rudd claimed that his drawings were not followed accurately and many of the castings were much thicker and heavier than he had specified (when Lotus took delivery of their first H16 it took six men to carry it from the van to the workshop). At that time, BRM earned the nickname of "British Racing Misery". BRM, Lotus, and various privateers had been using enlarged versions of the BRM 1.5 V8 of up to 2.1 litres in 1966, as competitive three-litre engines were in short supply in the first year of the new regulations. Lotus also took up the H16 as an interim measure until the Cosworth DFV was ready, building the Lotus 43 to house it, and Jim Clark managed to win the US Grand Prix at Watkins Glen with