Last week we were given the full specification of Gordon Murray Automotive’s Cosworth-developed 3.9-litre V12, and now we’re provided with video footage revealing its tone at 8,000rpm. That’s 4,100 revs below that record-breaking limiter, so it’s not quite at maximum pitch. Yet, as you can hear for yourself in the video below, it sounds absolutely fantastic. Like an old Le Mans prototype motor. Just imagine what 12,100rpm will be like.
The video also provides us with another angle of the compact twelve’s beautifully sculpted exhaust manifolds, which flow out from the high-strength aluminium motor beneath an intake bearing four throttle bodies. The 1.66hp per litre engine is being allowed to run without ancillary belts, so it’ll remain this clean and beautiful in the engine bay, if not more.
It’s a teaser, though, given how much further this 178kg engine is capable of going. Don’t forget, it has an idle to redline time of just 0.3 seconds, so it’s barely broken out into a mechanical job on the filmed bench run. Let’s just say we can’t see what shade of orange the pipework turns when the crank’s spun a little faster in the coming months...
Original story: 21.07.2020
Gordon Murray Automotive has confirmed the full specification of the Cosworth V12 and Xtrac manual powertrain that will go into its T.50 hypercar – and to be frank, it's nothing short of phenomenal. This is a setup that’s claimed to be both enormously potent and tremendously visceral, setting new standards for lightness, responsiveness and character, while powering a hypercar that all in weighs a barely believable 980kg. Best get comfortable...
The all-new, bespoke motor is extremely compact for a V12 at 3.9-litres. Its technical setup was inspired by the BMW S70/2 found in the McLaren F1, the Honda RA121E of McLaren’s MP4/6 F1 racer and Murray’s most recent other innovation, the 11,500rpm motor of the Light Car Company’s Rocket, no less. GMA and Cosworth decided it was the optimal capacity to ensure low mass - making it the lightest atmospheric road V12 ever, and the most power dense with 166hp per litre.
The dry-sumped block is made from a high-strength aluminium alloy, the crankshaft is steel and weighs only 13kg, while the connecting rods and valves are made from titanium – along with the clutch housing. As a whole, the mid-mounted motor totals just 178kg, and so featherweight are its internals that it spins up more than three times faster than the F1’s V12 engine. GMA quotes an idle to 12,100rpm (the redline) time of 0.3 seconds. Three tenths. Let that sink in.
You might think that equates to a lot of top-end punch with gutless low-down performance, but of course Cosworth and GMA have ensured that will absolutely not be the case. The 3.9-litre does produce its 663hp peak at 11,500rpm and 344lb ft of torque arrives at 9,000rpm, but we’re told that 71 per cent of that twist (244lb ft) is available from 2,500rpm. This is also a sub-tonne car with a 48v belt driven starter assisting, so we’re expecting it to feel pretty tractable from all starting points.
The V12’s mated to a bespoke H-pattern manual gearbox, too, lending the driver full control with “the best shift action of any road car” thanks to work with renowned transmission firm Xtrac. The ‘box is only 80kg, with an aluminium casing that’s only 2.4mm thick and a selector that’s been honed meticulously for optimal weighting. The lever is said to move through the gate with a short, positive throw from cog to cog, of which there are five close ratios and a longer sixth, for more refined cruising.
You won’t need us to convince you that a 11,500rpm-capable V12 is liable to sound terrific, but GMA does emphasise it with confirmation of the car’s induction setup. The cold air ram intake, which is placed just over the driver’s head, is said to project a low-rev intake growl that “intensifies” into a high rpm scream – as the numbers suggest. The intake’s carbon skin is of varying thicknesses to amplify the tone. Murray said that at high revs, “the V12 will sing like nothing else on the road”.
The motor delivers 100 per cent of its power to the driveline, with none lost through belt driven ancillaries – something Murray wanted from the outset. A positive knock on is the pureness of the engine’s design in the bay; there are no additional parts to spoil its look – something that leaves it looking more thoroughbred racing car than anything else. And a technical achievement with absolutely no roadgoing comparisons – all packaged into a platform of hopefully equal prowess. The full reveal will take place on 4th August.
1 / 2
