to develop a 2-Litre version of FWMV so that Lotus, who built one Lotus 33 chassis specifically for FWMW, and were counting on using FWMW's anticipated 3-Litre successor, could avoid missing the first races of the 1966 season. Neither the old 4 cylinder FPF nor the 8 cylinder FWMV could be enlarged to 3 Litres, and the 11 years old 2.5-Litre FPE parts had been sold off in their entirety and were in the hands of Paul Emery, who was in the process of enlarging FPE to 3-Litres as described in the above FPE section. Partly because of this project's grand scale failure, and partly because of Jaguar's take over in 1963, Coventry Climax could not develop a 3-Litre successor to FWMW, and announced its withdrawal from the F1 engine business, with its reputation and the long-standing relationship with Lotus seriously tarnished. Jaguar V12 Having designed and developed the successful Jaguar XK engine under the guidance of William Heynes at SS Cars Ltd, Walter Hassan and the team were tasked to develop a Jaguar 5.0 L DOHC V12 engine when Coventry Climax was purchased by Jaguar in 1963. It was about this time when Walter Hassan convinced Harry Mundy, who had left to become the Technical Editor of The Autocar magazine in 1955 (while there he also designed the Lotus-Ford Twin Cam for Colin Chapman), to rejoin the team, which now included the Jaguar engineer, Claude Bailey, who always worked under William Heynes from the days of XK engine development. William Heynes was the executive in charge of the team, who retired in July 1969. This engine was initially conceived in 1954 for the Le Mans 24 Hour Race by combining two Jaguar XK cylinder heads on a common 60 degree block. The first prototype was assembled in 1964 with LM8 aluminium alloy sand cast block and flanged cast iron liners, EN4A forged and nitrided 7 main bearing crankshaft for 4994 cc (87 mm × 70 mm). This racing engine, with its intake ports in between the intake and the exhaust camshafts, came out to be the fuel-injected 5L DOHC Jaguar XJ13 engine in 1966, but more importantly, it was further developed by the same team into the series-production 5.3 L SOHC V12 engine. This engine, with characteristically long intake tracts connecting the four carburetors on the outside of cam covers to the intake ports inside the V angle, came