Evan J. Smith
Freelancer
June 2, 2015

Power, we all want it, and Ford is handing over 526 horsepower in a 5.2L package that will power the 2015 and 2016 Shelby GT350. Ford announced it will produce the most powerful naturally aspirated road-going engine in its history. It’s flat-plane crankshaft 5.2-liter V8 will also produce 429 lb-ft of torque in Shelby GT350 Mustang and Shelby GT350R Mustang.

“The Shelby GT350 program began with a clear objective – create the most balanced, nimble and exhilarating production Mustang yet,” said 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 Shelby mill is also rather efficient for its size, as it will generate 102 horsepower per liter of displacement. As speculated, it will be the highest-revving V8 in Ford history – with a redline of 8,250 rpm.

To achieve this level of output, Ford utilized a flat-plane crankshaft more typically found in exotic cars with much smaller displacement and/or in racing applications. Ford arrived at the design after thousands of hours of computer modeling. “We used millions of intake, cam and exhaust configurations before arriving at the optimal combination,” added Hameedi.

“Traditional cross-plane crankshaft V8 engines attach the piston-carrying connecting rods to the crankshaft at 90-degree intervals, creating a “cross” of counterweights when viewed down the axis of the crankshaft. In the all-new Ford 5.2-liter V8, the connecting rods attach to the flat- plane crankshaft at aligned 180-degree intervals – creating what looks like a flat line of counterweights when viewed down the axis of the crankshaft,” he added.

What’s the result? The flat-plane crankshaft improves cylinder exhaust-pulse separation by allowing a firing order that alternates ignition events between cylinder banks in a V8 (or V6) engine. This improves exhaust scavenging and overall breathing, which equals power. In addition, because the crank is much lighter, the engine can typically rev up much quicker.

The 5.2L Voodoo engine also delivers a unique and insanely proud engine note. Peak power comes in 7,500 rpm and 429 lb-ft of torque at 4,750 rpm. Even more impressive is the track-tuned flexibility of the engine’s exceptionally wide powerband. Ford stated that the 5.2L engine produces 90 percent of peak torque from approximately 3,450 rpm through 7,000 rpm, and features a racetrack-friendly spread of nearly 3,000 rpm between its torque and horsepower peaks.

Ford will mate the all-new 5.2-liter to a six-speed manual transmission, we hear it is ultra-smooth shifting. This gearbox is the Tremec TR-3160 six-speed manual that was specifically engineered for less mass and high-rpm in the new Shelby Mustangs.

“One engineer stated it was designed for the application to be shifted butter-smooth right at redline.” The Tremec 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.

To reach the 5.2L displacement, the engine includes a slightly oversquare bore and stroke combination of 94x93 millimeters, and a performance-enhancing 12.0:1 compression ratio! Shelby-specific computer numerical control (CNC)-machined cylinder heads are used along with camshafts that develop a massive 14 millimeters of lift for both the hollow-stem intake valves and sodium-filled exhaust valves.

The GT350 also sports a huge, single-blade, fast-acting 87-millimeter throttle body – the largest ever used for a Ford engine. 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.

Not only will the Shelby produce 526 horsepower, we expect it to rev amazingly fast and scream to redline. We’re anxious to get one on track, and we’ll be the first to report numbers to you. “A new Mustang as exceptional as the Shelby GT350 deserves an equally extraordinary engine,” said Dave Pericak, director, 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.”

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