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2011 Mustang GT's 5.0L Engine - Return Of The 5-Liter Mustang
Ford Turns To A Classic Nameplate For It's Latest Mustang V-8-The Result Is 412 HP And 390 LB-Ft Of Torque.
For dyed-in-the-wool late-model Mustang enthusiasts, or even Mustang newbies, Ford's new 412hp, four-cam 5.0L is a dream come true.
Simply stated, the "5.0" engine encompasses great meaning to many Mustang fans, both old and young. When the Fox-body Mustang hit the streets in 1979, the V-8 powerplant featured 8.4:1 compressio and a two-barrel carburetor, and produced a wild 140 hp. By 1987 the 5.0 H.O. was fuel injected and making 225 hp. It was a player in the performance war, going head-to-head with GM and Chrysler's best.
Real performance was on the comeback and the 5.0L Mustang offered the best bang for the buck. It was cheaper than either F-body, the Corvette, or the powerful GN, and in the right hands could do amazing things. Early 5.0 pioneers like Steve Collison, Tony DeFeo, Neil van Oppre, Lee Rutter, Nitrous Pete Misinsky, Brian Wolfe, and Stormin' Norman (to name a few) pushed 5.0L Mustangs past what anyone thought was possible. They ran 12s, 11s, and then 10s with basic bolt-ons and tuning-and they did so at the time when 11s and 10s were reserved for racecars or big-block muscle.
Frankly, 5.0L Stangs exceeded the performance limits of what production cars were "supposed" to do. An amazing feat considering many thought the funky EFI setup meant the end of hot rodding altogether.
Magazines like Cars Illustrated and then MM&FF dedicated page after page to 5.0L performance, focusing on new technology, fresh parts, and real-world dragstrip testing. We reported feverishly on those LX and GT models that proved to be fast, reliable, (save for the T-5) and ultimately, limitless in performance.
Sadly, the 5.0 era came to an end in 1996 when Ford switched to the modular Two-Valve 4.6L engine. Due to lacking performance, some appeal slipped away, but thankfully Ford eventually turned the 4.6L into a winner, making over 300 hp. The last variant will go to bed in 315hp form in the 2010 GT.
Nevertheless, Mustang enthusiasts crave more, and for 2011 Ford will deliver the goods with an all-new 5.0L V-8. More than just a beefed 4.6L modular, the "new" 412hp 5.0 features a fresh design with a slew of technological advancements that will produce an efficient 82 hp per liter and at least 25 mpg-and it makes as much torque as a Terminator! Important features include 11.0:1 compression, variable cams that help produce a broad torque curve, a new composite intake, 80mm throttle body, and tubular headers.
In the spring of 2007, Bob Fascetti, director of Large Gas and Diesel Engine Technology, chose Mike Harrison, a chief engineer, to be in charge of the new 5.0L engine for the Mustang. After some initial research, Harrison reported back to Fascetti that his team could build an engine to produce 370-380 hp. Fascetti told Harrison to make it 400 hp and the normal time to undergo such a project was going to be cut by a whole year. So Harrison assembled a team of engineers, who are also enthusiasts, for the race against the clock. With the two main characteristics of the engine already decided, 5.0L and 400 hp, the goal was to build an exciting, affordable, and fuel-efficient engine around those parameters.
Though all of the components of any engine are parallel and work in harmony, the cylinder heads were the first major design project. Todd Brewer and John Reigger lead the way. The team agreed that the heads had to be a Four-Valve, DOHC design.
Once a prototype of the new compact Four-Valve head was built, the team tried the new cylinder heads on surrogate engines using existing FRPP camshafts to test for power output and torque curves. The end result is said to outflow GT500 heads by 4 percent. After studying what camshaft profile worked best for the new head design, a set of prototype cams was computer-designed by Kevin Shinners and John Carter, and cut for testing. "For the first time ever, we only ground one set of cams," said Adam Christian, ICE engineer (Intake, Combustion, and Exhaust). It usually takes dozens of prototype cams to find the right combination.
With the geometry of the major components set, prototype assemblies began to be produced. Members of the engineering team were working 70-plus hours a week, channeling all of their energy into this project. "We've got a lot of emotion behind it," Mike Harrison told us of the personal touch everyone contributed.
The all-aluminum block, though it features 100mm bore spacing, bears little resemblance to its predecessor. Cast-iron four-bolt main-bearing caps with side bolts hold the forged steel crankshaft steady, even at 7,000 rpm. Large oil passages are built into the block to allow the oil to flow back to the pan faster and with less restriction. The coolant crossover is now built into the block, eliminating coolant passages in the intake manifold. This is good for performance because the hot coolant doesn't heat up the incoming air charge. The rods are a familiar forged powder metal with a floating pin, and the pistons are hypereutectic aluminum, but there are oil squirters to cool the pistons and help resist detonation. Compression ratio is a stout 11:1.
Though some would argue an aluminum intake manifold is preferable, the team opted for a composite plastic design. "The plastic is smoother, more consistent, and heat transfer is lower," remarked Adam Christian. Not only is the plastic intake lighter and less expensive to manufacture, it makes 1 to 2 percent more power than an aluminum version.
The 10-liter manifold features long, shaped runners and an 83mm round inlet with "whoosh fingers" to direct airflow and control whistling at part throttle. It utilizes an 80mm round throttle body, which "flows better for its size than a twin," according to Christian. Intake specialists Dave Born and Nolan Dickey designed the intake with a front-mounted inlet, which required a new location for the alternator. As simple as that may seem, relocating the alternator was one of the greatest challenges.
The finished aluminum cylinder heads house two 37mm (1.46-inch) intake valves and two 31mm (1.22-inch) exhaust valves, compact roller fingers, and vertical 193cc intake ports. Port and Combustion Chamber Engineer Jim Froling perfected the chamber and runner design, complete with round exhaust ports, absent from the Three-Valve.
A new firing order forced the team to create a new design for the exhaust manifold. The team wanted to create a tubular header, but power loss, due to paired cylinders on each bank, disallowed use of a tri-Y design like conventional performance headers. With only two weeks left before tubular headers were scratched for cast manifolds, Christian thought of the idea of using a twin-T design. "I gave him a bunch of bent tubing, and he built the prototypes over the weekend in his garage," said Harrison. Though they look inefficient, we project long-tubes will only yield about 15 hp over these stock units.
The ballet of performance (power and driveability) and economy (emissions and cost) is not more prevalent than in the camshafts and Ti VCT, or twin-independent variable camshaft timing. The camshaft profiles, though not revolutionary, are completely optimized in efficiency. The new cam phasers use uneven torsional energy of the camshafts to index the cams, and the cam sprocket is machined in. Oil does flow through the new cam phasers, but only for cooling and lubrication duties. They are very quick to react, and can operate their full range of motion in one engine revolution. This infinitely adjusting timing and lobe separation (from 81 degrees to 131 degrees) is what makes this engine the animal that it is. Instead of waiting for 4,000 rpm to reach impressive torque numbers, "It pulls from 2,000 rpm all the way up to 7,000 rpm," Harrison says.
Aesthetically, the photos speak for themselves. The partial engine cover allows the intake to peek through but covers things like the wiring harness and injectors.
When asked about the most important aspect of the engine, 5.0L Engine Chief Engineer Mike Harrison replied, "volumetric efficiency." From 3,750 rpm to 6,500 rpm, it is over 100 percent efficient. At peak torque it's 110 percent efficient, while even the greatest [naturally aspirated] racing engines peak at 120 percent, and most other engines max out at less than 100 percent. The pumping efficiency of this powerplant puts it on the cutting edge of technology.
To meet the performance and economic needs of the new engine, new automatic and manual transmissions will be standard on the 2011 Mustang GT. The 6R80 six-speed automatic has a wider ratio span, can handle a higher torque output, and allows for 3-5 percent better fuel economy over the 5R55. The MT82 manual transmission features low shift effort, a new fully synthetic oil, and is more durable and efficient than the current TH3650.
Another important feature is EPAS (electronic power-assist steering). Gone are the power steering pump, hoses, and fluid. An electric booster is built into the steering rack and is controlled by the PCM. Steering feel will be improved greatly, without compromising steering assist or adding parasitic loss.
The last, and probably most simple, standard feature on the '11 is the new "5.0" badge. Found on the engine cover and fenders, it takes a new spin on the original. The red decimal looks almost identical, only slightly larger, and the font of the numbers is reminiscent, yet modern. It's big enough for the larger S197, but not gaudy.
Brembo brakes will now be available for the GT, along with other options like the Track Pack and larger wheels.
Gone is the Three-Valve modular; in its place we have an attractive and balanced specimen that far exceeds our expectations. Overall weight is within a few pounds of the Three-Valve, thanks to a smaller and lighter valvetrain, but power output has been increased by roughly 100 hp. We smell 12-second quarter-mile e.t.s right out of the box.
Once again, Ford Motor Company nailed the exercise, and now all that's left for us is to drive one.
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|2011 MUSTANG GT SPECIFICATIONS|
|TYPE||90-degree all-aluminum DOHC V-8|
|DISPLACEMENT||5.0L (302 ci/4951 cc)|
|BORE/STROKE||92.2 mm (3.63 in)/92.7 mm (3.65 in)|
|BLOCK||Aluminum, four-bolt cast-iron main bearing caps with side bolts, 100mm bore spacing|
|CONNECTING RODS||Forged powder metal with floating pin|
|CYLINDER HEADS||Aluminum Four-Valve with Ti VCT (twin-independent variable cam timing)|
|VALVE DIAMETER (intake/exhaust)||37 mm (1.46 in)/31 mm (1.22 in)|
|CAMSHAFT LIFT (intake/exhaust)||12 mm (0.472 in)/11 mm (0.433 in)|
|CAMSHAFT DURATION (intake/exhaust)||260 degrees/263 degrees|
|LOBE SEPARATION||81 to 131 degrees, Ti VTC-controlled|
|OIL PAN||8-quart with built-in windage tray|
|INTAKE MANIFOLD||Composite scroll design with front-mounted 83mm inlet|
|FIRING ORDER||1, 5, 4, 8, 6, 3, 7, 2|
|EXHAUST MANIFOLDS||Tubular headers|
|MAXIMUM RPM:||7,000, computer-limited|
|OUTPUT||412 hp at 6,500 rpm/ 390 lb-ft at 4,250 rpm|