Mercedes-AMG, the high-performance division of Mercedes-Benz, has developed one of the most powerful engines ever to be installed in a production car. The six-liter twin-turbo V12 powers the SL65 AMG roadster, CL65 AMG coupe and S65 AMG sedan.
Developing 604 horsepower, the AMG limited-production V12 models can accelerate from zero to 60 miles per hour in a breathtaking 4.2 seconds, with impressive power all the way to their electronically-limited 186 mph top speeds. Perhaps more important in everyday driving than sheer horsepower is the twin-turbo’s enormous torque of 738 lb.-ft., available from 2,000 all the way to 4,000 rpm.
A Major Boost for Mercedes V12 Power
The standard 5,439-cc Mercedes-Benz V12 engine has been enlarged by installing a special crankshaft that increases the piston stroke from 87 to 93 millimeters. With larger heat-resistant forged pistons as well (up from 80 to 82.6 mm), the AMG 12-cylinder displaces 5,980 cubic centimeters, or about 365 cubic inches. To provide more fuel and air for the larger engine, revised AMG camshafts provide higher intake valve lift and longer opening duration, and fuel injectors with larger openings are used in conjunction with higher fuel pressure – 3.8 bar or 54 pounds per square inch. Larger turbochargers push more air into the engine, with boost set at 1.5 bar or 22 psi.
Hot V12 Engine Stays Cool
Air that’s pressurized by the turbochargers gets hot as a result, so it’s circulated through a special water-cooled intercooler before entering the engine. A dedicated radiator for the intercooler is 70 percent larger than on the standard v12, resulting in intake air temperatures that run about 25 percent cooler than the standard engine. This denser intake air plays a major role in increasing the engine’s horsepower and torque. All the additional power means a lot more heat, so new oil jets in the aluminum block spray more oil onto the underside of each piston. With a larger oil pump, a larger oil cooler circulates more cooling oil throughout the engine.
One Man, One Engine – Individual Hand Craftsmanship
Each new AMG engine is hand-assembled one at a time by an expert technician at Mercedes-AMG in Affalterbach, Germany. Mercedes-AMG follows a philosophy of “one man, one engine,” which means that a single technician – identified by the signature plate affixed to the engine – is responsible for the complete assembly of an AMG high-performance engine from start to finish. With the utmost care, the craftsman installs each and every part – from the crankshaft, connecting rods and pistons to the intake system, wiring harness and oil fill-up. Each engine is bench-tested to ensure consistent quality and maximum performance.
Source: Daimler AG