The upcoming Mercedes-AMG GT will be powered by a twin-turbocharged four-valve-per-cylinder 4.0-litre V8 petrol engine, the German car maker has officially confirmed.
In its initial state of tune, the unit will develop 503bhp at 6250rpm and 479lb ft of torque on a band of revs between 1750 and 4750rpm.
The all-new 90-degree quad-cam direct-injection unit, known internally under the codename M178, has been developed from the ground up as a replacement for AMG’s existing naturally aspirated 6.2-litre V8, the M159, which is being phased out after four years, following the end of production of the SLS AMG in both coupé and roadster guises.
AMG’s new sand-cast aluminium block engine, also slated to power the upcoming replacement for the C63 AMG, boasts the same 83mm and 92.0mm bore and stroke measurements as the Mercedes-Benz performance car division’s highly strung 355bhp turbocharged 2.0-litre four-cylinder direct-injection powerplant, as used by the A45 AMG and CLA45 AMG, giving it an overall swept volume of 3982cc.
Boosting induction are a pair of Borg Warner produced turbochargers mounted atop the engine within the space between the two cylinder banks – a layout AMG engine boss, Christian Enderle, says helps make the M178 some 88mm shorter than the M159 engine. The turbochargers, which operate in a parallel state at a maximum pressure of 2.3 bar, are cooled by a water-to-air intercooler.
Other technology included on AMG’s second turbocharged production car engine is a Bosch-supplied piezo injection system, capable of providing up to seven individual injections per cycle, cylinder barrels finished with Mercedes-Benz’s patented Nanoslide friction reducing material, a cylinder head produced from a lightly Zirconium-refined aluminium and dry sump lubrication.