cylinder DOHC FWMC that was used as the basis to develop the successful FWMV V8. However, coinciding with the promotion of Peter Windsor Smith as the Chief Engineer (reporting to Walter Hassan) in 1960, Coventry Climax reverted (as in OC and JM engines) to using the metric system for specifying piston and crankshaft sizes, so FWMV was born with 63 mm (2.4803") bore and 60 mm (2.3622") stroke, ending up having almost no parts interchangeability to FWMC despite having an extremely similar design. To streamline production, the 63 mm × 60 mm sizes were later applied back to the 4 cylinder engine to form the 748 cc FWMB with the same cylinder head as the FWMA. FWMV The 1.5-litre FWMV V8, developed from FWMC using a crossplane crankshaft, was designed in 1960 and ran for the first time in May 1961. It produced from 11.5:1 compression ratio and made its debut on Cooper T58 at 1961 German GP in August. Initial developments resulted in at 8500rpm soon after, but Jack Brabham at Cooper and Stirling Moss at Rob Walker Racing Team suffered over-heating problems while enjoying a great amount of power for the rest of the season. The problem was diagnosed to originate in the thermal expansion rate of the cylinder sleeve causing the Cooper Ring in between the block and the head to leak. With this problem solved in the Mk.II 186 bhp version, having a larger 1.35" intake valves (1.30" previously), FWMV started to score GP victories, ending the 1962 season with 3 wins for Lotus, 1 win for Cooper, 5 second places and 4 third places, in addition to 7 pole positions and 6 fastest laps. For 1963, Coventry Climax was able to convince Lucas to supply the cogged belt-driven fuel injection system originally developed for BRM with then-unique sliding throttle plates with four round intake bores cut out. With the larger bore (from 63 mm to 68 mm) and shorter stroke (60 mm to 51.5 mm) compared to Mk.II, notable changes include the increase in conrod length (from 4.2" to 5.1" centre to centre, with a shorter piston crown height) and the switch from crossplane to flat-plane crankshaft, which surprisingly did not increase vibration in the higher RPM range because the longer conrod length counteracted the increase in secondary vibration inherent in flatplane design. The flat-plane crank was adopted partly due to Rob Walker's proposed successor