The V-12 from the Gordon Murray Automotive T.50
"The T.50’s V12 engine is completely bespoke, and has been specified by Murray to a very specific set of goals in construction, capability and design. The 3994cc V12 is built with a 65-degree cylinder-bank angle, with an 81.5mm bore and 63.8mm stroke. It runs at a 14:1 compression ratio, and at its core has been designed for ultimate response as much as for its power figure.
"Peak engine speed is limited to 12,100rpm, but more astonishing is its rev rate per second, gaining a stunning 28.500rpm-per-second, making the engine capable of hitting the red line from idle in just 0.3sec. This is nearly three times faster than the S70/2 V12 in the McLaren F1. To achieve this, the internal moving parts have been shorn of as much weight as possible – the steel crank is just 13kg, the connecting rods and valves are of titanium, all to reduce rotational mass, helping the engine achieve not only those dizzying engine speeds, but the rate of response Murray wanted to achieve.
"This also has a lead-on effect of reducing the V12’s overall weight which is 178kg – a record-low weight figure for a naturally aspirated V12 road car engine, and makes it 28kg less than the V12 Cosworth has built for the Aston Martin Valkyrie. The crank is also a record 80mm from the engine base, lowering all the engine’s internals for the sake of weight distribution. Internal engine lubrication is of a dry sump system, naturally.
"The power and torque figures are almost secondary to these numbers, with a peak power of 654bhp at 11,500rpm, and a 345lb ft torque peak at 9000rpm. This gives the V12 a power density of 166bhp/litre, which is also an improvement on the Valkyrie’s 154bhp/litre figure.
"Almost obsessive measures have been taken in all factors too – there are no belts on the V12, only chains, while a 48V mild-hybrid system and integrated starter motor and generator streamlines the electrical side of things. Murray’s also designed all the V12’s ancillaries to be situated out of sight, making only the headers, exhaust manifolds and intake plenum and trumpets visible from its glazed engine cover. The starter motor and generator also supplement the engine with an extra 49bhp when in VMax powertrain mode.
"The intake is fed via a roof-mounted ram-air scoop that borrows Direct Path Induction Sound tech first seen on the McLaren F1. The system essentially amplifies the intake sound from the roof scoop into the cabin, but runs on the basis of throttle position rather than engine speed, keeping the relative noise down when the driver lifts, but also giving a more varied sound under big throttle applications at low (relative to modern engine) revs.
"The six-speed manual gearbox is another bespoke commission, this time designed and built by XTrac, weighing 80.5kg, which is another road car record. The shift feel has been painstakingly perfected by Murray himself with a short-throw movement on the compact gearlever sprouting from the left of the central driver’s seat."