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Fordâs all-new V8 is the highest revving in its history
New flat-plane crankshaft 5.2-liter V8 for Shelby GT350 and GT350R Mustang is the most powerful naturally aspirated engine in OEM’s history
Ford has announced the most powerful naturally aspirated road-going engine in its history. The all-new Ford 5.2-liter flat-plane crankshaft V8 will produce 533ps and 582Nm of torque in the Shelby GT350 Mustang and Shelby GT350R Mustang – an engine unique to the two models set to go on sale this fall. [Click here to see the Ford V8 in action]
“The Shelby GT350 program began with a clear objective – create the most balanced, nimble and exhilarating production Mustang yet,” says Jamal Hameedi, Ford Performance chief engineer. “Every change we made to this car was driven by the functional requirements of a powerful, responsive powerplant.The high-revving, naturally aspirated 5.2-liter flat-plane V8 delivers on every target we set – high horsepower, broad torque curve, aggressive throttle response and light weight.”
The new 5.2-liter V8 is not only Ford’s most powerful naturally aspirated engine ever, but is also its most efficient in terms of specific output. Without turbocharging or supercharging, the flat-plane crankshaft V8 produces 103ps per liter of displacement. The new engine is also the highest-revving V8 in Ford history – with a redline of 8,250rpm.
Unlike traditional V8 engines, the 5.2-liter uses a flat-plane crankshaft more typically found in a Ferrari sports car or racing applications. The design of this new engine for the Shelby GT350 was optimized using computer-aided engineering and fully digital performance simulations. Millions of intake, cam and exhaust configurations were iterated before arriving at the optimal combination.
Traditional cross-plane crankshaft V8 engines attach the piston-carrying connecting rods to the crankshaft at 90° intervals, creating a ‘cross’ of counterweights when viewed down the axis of the crankshaft.
In the new V8, the connecting rods attach to the flat-plane crankshaft at aligned 180° intervals, creating what looks like a flat line of counterweights when viewed down the axis of the crankshaft.
Beyond a change in the characteristic sound of an American V8, the flat-plane crankshaft helps improve cylinder exhaust-pulse separation by allowing a firing order that alternates ignition events between the V8’s two cylinder banks. This can vastly improve engine breathing, and subsequently allow the engine to make more power.
The result in the new 5.2-liter V8 – in addition to a unique engine note – is 533ps at 7,500rpm and 582Nm of torque at 4,750rpm.
Even more impressive is the track-tuned flexibility of the engine’s exceptionally wide powerband. It produces 90% of peak torque from approximately 3,450rpm through 7,000rpm, and features a racetrack-friendly spread of nearly 3,000rpm between its torque and horsepower peaks.
In both the Shelby GT350 and Shelby GT350R, the new 5.2-liter will be paired with a 6-speed manual transmission as the only gearbox option. The Tremec TR-3160 6-speed manual is specifically engineered for less mass and high-rpm application in the new Shelby Mustangs. The 6-speed features a lightweight, die-cast aluminum case and clutch housing for increased overall powertrain stiffness. Gear cross-sections, the dual-mass flywheel and dual-disc clutch are all optimized for an overall reduction in inertia and weight.
Other aspects of the new 5.2-liter V8 (actual displacement is 5,163cc) include a slightly oversquare bore and stroke of 94 x 93mm, and a performance-enhancing 12.0:1 compression ratio.
Computer numerical control-machined cylinder heads house camshafts that develop a massive 14mm of lift for both the hollow-stem intake valves and sodium-filled exhaust valves. A single, fast-acting 87mm throttle body – the largest ever used for a Ford engine – feeds air to the engine, allowing for a simpler, lighter intake.
Further reducing engine weight is a unique new aluminum engine block featuring Ford’s patented plasma transferred wire arc cylinder-liner technology. This process eliminates typical heavy iron cylinder liners with an electroplate coating. The forged-steel flat-plane crankshaft is ‘gun drilled’ to reduce total engine weight and to improve bay-to-bay cylinder breathing. A lightweight, high-capacity composite oil pan contains baffling designed for sustained high-speed cornering and hard braking.
“A new Mustang as exceptional as the Shelby GT350 deserves an equally extraordinary engine,” says Dave Pericak, director of Ford Performance. “The all-new naturally aspirated 5.2-liter V8 perfectly fits the balanced dynamics of the Shelby GT350, and we believe this new engine will become a performance legend.”
Click here to see the all new V8 in action
June 11, 2015