Cosworth reveals how the T.50, Valkyrie and Bugatti Tourbillon engines differ

Cosworth V12 supercars: T.50 and Valkyrie

How do you prevent two modern greats of the V12 supercar world from overlapping when you are responsible for both of their engines? To find out, we spoke with Chris Willoughby, commercial director at Cosworth’s Northampton headquarters. He is well placed to answer: Cosworth created the engines for the T.50 and the Valkyrie.

“The customer always has a vision for their vehicle, and the engine specification flows down from that vision. With Gordon Murray, he wanted high engine speed and small capacity. Plus, lightweight and compact. The power-per-litre of the DFV engine, in its earliest guise, isn’t that much different to the T.50. And yet the GMA is emissions-compliant; you can start it on an icy morning or in 50-degree heat and go touring around Europe with it.

“It may have 664bhp, but the thing you never really get when you’re working on the dyno is, subjectively, how easy the engine is to drive. I think people expected, because it’s a high-speed engine, that driving it around town would be like riding a two-stroke motorbike where it would cough and bang and then light up at 6,000rpm and go. But that hasn’t been the case.”

Different engineering priorities for the Valkyrie

The Aston Martin Valkyrie had initially been intended to make 950bhp. However, its engineering ultimately exceeded that target. Once the first development engines arrived on the dynamometer, Cosworth identified areas for optimisation. With Aston’s consent, output was raised to 1,000bhp - substantially more than the T.50 produces.

“The Valkyrie was originally meant to produce 950bhp, but we ended up over-engineering it. When we first got the development engines on the dyno, we saw there were areas where it could be optimised. So, with Aston’s approval, we cranked it up to 1,000 - far more than the T.50 has.”

Weight was approached very differently for the two V12 supercars. The T.50’s engine comes in at only 178kg, against the Valkyrie engine’s 206kg. Nothing within the GMA engine could be there without a purpose, meaning virtually every part was examined to eliminate unnecessary mass.

“But the T50’s engine weighs just 178kg (compared to the Valkyrie’s 206kg), so the approach is completely different. We couldn’t have any components in there that are just along for the ride. Everything has to be functional, so we analyse pretty much every component to make sure we aren’t carrying excess weight. A lot of people think these two cars share engines, and I’m sure there might be a screw or two that’s the same, but in reality everything else is different.”

Willoughby added that Murray had wanted to “not compete with the Valkyrie” from the outset, seeking instead to deliver a wholly distinct type of experience. The Valkyrie is more focused and visceral, while the T.50 has a broader range of abilities - less Didier Drogba, more Frank Lampard. Murray also chose a smaller 3.9-litre capacity as a tribute to the Lamborghini Miura; the Valkyrie’s 12-cylinder engine, by comparison, displaces a substantial 6.5 litres.

Bugatti Tourbillon and Cosworth’s 8.3-litre V16

Cosworth’s other recent heavyweight project is the Bugatti Tourbillon, powered by a naturally aspirated 8.3-litre V16. Discussing Mate Rimac’s brief for the hypercar, Willoughby explained that refinement was Bugatti’s overriding requirement.

“The Tourbillon engine is far different to what we usually make, because Bugatti wanted refinement above all else.

“It didn’t want a 12,000rpm screamer, but the envelope it’s pushed instead is engine length. Crankshafts can wind up like a piece of rubber, and the longer they get, and the more cylinders you attach, the more lively they wind up. The Tourbillon’s crankshaft is a metre long for some perspective, and one of the main challenges we had here was managing the torsional vibrations and making sure they didn’t become disruptive to the other components. So we’ve stuffed in a load of dampers to control it.”

Those additional four cylinders also bring considerably more power than either of the other two engines: precisely 1,775bhp. That naturally raised the question of how much additional power could theoretically be unlocked.

“Old engines have a lot of headroom, that’s why you can put a stronger cylinder head on a Ford Anglia and find an extra 150bhp. It’s not quite that simple these days with modern engines. It’s a hard question to give an easy answer to, but we do need to have a development mindset with our engines. Everything can always be improved. There isn’t a washer or any other feature you couldn’t change that might make the engine more powerful.”

Perhaps the answer will emerge over the next few years. In the meantime, here is an entertaining, if entirely useless, car fact: if an object were subjected continuously to the peak acceleration of a T.50 piston, it would reach the Moon in 20 seconds. That equates to 238,855 miles in 20 seconds, or roughly 11,942 miles per second. If Willoughby is right, a T.50 piston can accelerate to just under 43 million miles per hour. Completely pointless, perhaps, but still staggering.