While the latest engine unveiled by Cosworth hasn’t been designed for racing, it is so extreme that one can anticipate seeing it in competition in future years, be that at the Goodwood Speed Hillclimb or challenging roadcar performance records. This is a naturally aspirated 8.35 litre V16 for the forthcoming Bugatti Tourbillon supercar. Astonishingly, Cosworth reports that it is lighter than the naturally aspirated 6.5 litre V12 it developed for the Aston Martin Valkyrie supercar.
The Valkyrie will contest next year’s World Endurance Championship (WEC), including Le Mans. While, inevitably, the new V16 is longer than the Aston Martin V12 and inherently thirstier, the fact that the WEC is nowadays handicap racing means one cannot discount it powering a future Bugatti LMH or LMDh.
It was 2021 when Cosworth was tasked by Bugatti with producing a clean-sheet successor to the 8.0 litre quad turbo W16 engine that powered the Chiron supercar, which the Tourbillon is replacing. Confined to natural aspiration, the V16 consequently needed to be designed to run to 9000 rpm to reach the target 1000 bhp. Where the Chiron’s turbo-supercharged W16 produces in the region of 1500 bhp, the unblown V16 will be mated to two front and one rear MGUs, in total delivering an additional 800 bhp.
Cosworth reports that it elected for a cross-plane crank design with a 90o bank angle and a dry sump. A total weight of just 252 kg was obtained by taking “steps to optimise weight throughout the engine, including titanium con rods and a carbon-fibre inlet plenum. The overall length of the crankshaft is 900 mm, made from a single billet, with a total engine length just shy of 1 m – demonstrating the scale required to power this incredible car.”
Cosworth’s managing director of powertrain, Bruce Wood, adds: “With the crank and camshafts measuring almost a metre long, we had to employ innovative design technology to overcome the torsional loads. When we first heard it fire up on the dyno and reach maximum revs, we were astounded at the sound. It is a truly unique piece of machinery.”