Everything You Ever Wanted to Know About the Shelby GT350 Mustang’s Engine

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“My job is horsepower,” said Adam Christian, engine performance technical expert at Ford. And one glance at the numbers – 102 ponies per liter in particular – and it’s clear he and his team deserve a raise.

Christian is one of many proud parents that helped deliver the new 5.2-liter V8 that will be found under the hoods of Shelby GT350 Mustangs. This exciting powerplant delivers a breathtaking 526 hp, 429 lb-ft of torque and a redline north of eight grand; if you’re wondering, fuel cutoff is 8,250 RPM. “It’s absolutely a high-water mark for us,” he said, and the work it took to deliver these torrid figures is as extensive as it is impressive.

Flat Out: Inside the Shelby GT350 Mustang’s Engine

On the outside it may look like your garden variety 5.0-liter Coyote V8 found in the engine bay of a Mustang GT or F-150, but appearances can be deceiving. “This is a new engine top to bottom,” said Eric Ladner, engine program supervisor at Ford. The list of changes and enhancements compared to the standard five-oh are exhaustive.

2016 Ford Shelby GT350 Crankshaft 02

And as you’ve no doubt heard, the most important update of all is the crankshaft. Engineers eschewed a traditional cross-plane arrangement for one that’s flat. Rather than having the throws arranged at 90-degree intervals the Shelby GT350’s are set 180-degrees apart. Flat-plane cranks are common in supercars like Ferraris where maximum performance is a top concern but this is the first time Ford’s ever offered one and they’ve been mass-producing V8s for more than eight decades, ever since old Henry’s first flathead rolled out of the Rouge foundry in 1932.

Ford Flathead V8

Ladner said, “Flat-plane cranks are inherently lighter than their cross-plane counterparts.” This is because bulky counterweights are not required to balance them. But he also cautioned that crankshafts account for less than 15 percent of an engine’s rotating mass, so this is hardly their only benefit.

SEE ALSO: Listen to the Shelby GT350R at Full Tilt

Beyond all of this, they “[allow] all the cylinders breathe the same,” said Christian, which makes tuning the engine much easier so they can run it closer to the ragged edge and get more power. Additionally, the Shelby GT350’s crank is made from forged steel for extra strength and it’s been “gun-drilled,” meaning holes have been punched through each of its throws to further cut mass. These openings also allow the adjacent bays inside the block to breathe together, further reducing parasitic drag.

Bored and Stoked

2016 Ford Shelby GT350 Engine 09Another major change compared to lesser Coyote V8s is this powerplant’s internal dimensions. Giving it that extra 0.2-liters of lung capacity is a larger bore and longer stroke. The 5.2’s digits clock in at 94 millimeters by 93 millimeters, respectively. If you’re curious, a regular 5.0-liter measures 92.2 by 92.7.

Instead of traditional cylinder liners that are either pressed or cast into place the Shelby’s engine uses a plasma transferred wire-arc technology, which saves a significant amount of mass. Additionally its block is unique to this application but the bore spacing and deck height are identical to a five-oh so the same machine tools can be used. The GT350’s engines will be assembled on Ford’s niche line in Romeo, Michigan; standard Coyotes are built in Windsor, Ontario.

As for the bores themselves, they receive special treatment. Unlike more pedestrian engines, the new 5.2 is deck-plate honed, meaning special jigs are torqued to the block before the cylinders are bored to size. This is an old racing trick that ensures the bores are as round as possible when the head bolts are tightened down. “What that allows us to do is drop the ring tension,” said Christian, which significantly lowers friction, resulting in more power.

2016 Ford Shelby GT350 Engine 08Filling those eight holes in the block are lightweight, forged-aluminum pistons. They have ultra short skirts and appear to be treated with some sort of oxide finish. The connecting rods are manufactured in a similar manner and feature fracture-split big ends.

These rotating components squeeze incoming air and fuel with a frighteningly high 12-to-1 compression ratio and apparently that’s ok. Thanks to exhaustive computer modeling the engine runs just fine on 93 octane pump gas and it doesn’t even have direct injection. According to Ladner this feature “wasn’t necessary to meet our performance targets,” plus DI systems are heavier and add cost.

Moving into the basement, this engine features a composite oil pan that saves more weight, about 20 percent in fact. But it’s hardly just a sump; it also contains an integrated pickup and windage tray, all in one unit. A higher-capacity oil pump ensures there’s plenty of lubrication at all times.

Breathe Deeply

Taking an elevator ride topside, the Shelby engine breathes through an 87-millimeter throttle-body, the largest Ford’s ever fitted, as well as an open-element air filter. Beyond this there’s an all-new intake manifold. Its runners are both longer and larger in diameter than the ones found in the dearly departed Boss 302. This configuration bolsters torque production across the rev range and all told, 90 percent of peak twist is available at just 3,450 RPM.

2016 Ford Shelby GT350 Intake Manifold 01

The cylinder heads are where all the magic happens in modern engines and the 5.2-liter V8’s have received special attention. For starters they’ve been strategically lightened and weigh about 6 percent less than the ones that cap off a standard Coyote block. Beyond this, the engine’s enlarged bores allowed for even bigger valves to help get copious amounts of fuel and air into the cylinders and speedily evacuate spent exhaust gasses once the mixture’s gone off.

2016-Ford-Shelby-GT350-Engine-11“We have large valves, we lift them very high,” said Christian. They pop open up to 14 millimeters. Ford’s twin-independent variable camshaft timing permits each bumpstick to be adjusted individually, which allows the engine to pull like a mule at low speeds and scream like banshee at high RPM. An active exhaust system ensure the GT350 can rip when required yet not drive you insane with droning noises when you’re commuting to work on a Tuesday.

Overall this engine is lighter than the 5.0-liter V8 on which it’s based and it puts out A LOT more power. And despite spinning beyond 8,000 RPM it has to meet the same durability requirements as any other Ford product. Accordingly it will be backed by the same warranty, so don’t be afraid to tickle that redline.

Priced to Move

2016 Ford Shelby GT350 01With 526 high-winding horses and 429 lb-ft of torque the 2016 Shelby GT350 Mustang should be an easy sell to enthusiasts, especially if it drives as half an nicely as it looks. Perhaps best of all it delivers these figures the old fashioned way, by breathing the same atmosphere we do; there’s cheating here, no forced induction power adders to deal with.

And if there’s not enough to love about the new Shelby Mustang it’s also priced to sell. This car should be available for $49,995 including destination fees; naturally the GT350 R will cost a fair bit more. Still, Ford is bringing supercar performance to a broad spectrum of enthusiasts and they’re planning on building as many as they can sell so there should be no shortage of Shelbys.

Correction: A previous version of this story had one of the engineer’s names spelled incorrectly.

Discuss this story on our Mustang Forum.

  • havasu46

    I want a white strip delete 2014 GT500 and 2016 GT350 just for sh!ts and giggles!

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  • craigcole

    I’m leery of long-term durability and not just because this thing spins past eight grand. It shares the same tight 100-millimeter bore spacing as all modular engines. With a bore of 94 millimeters the meat between each cylinder is getting pretty thin. Still, engineers promised me the block can take a pounding and goes through all the same durability testing of other Ford powerplants.

  • smartacus

    Good stuff!
    i wonder if the 12:1 compression ratio can be further increased to 14:1 for even tighter quench clearance… with the aid of sodium filled valves.

  • X Man

    sodium filled valves are there for weight and other things like aid cooling of the valve and has nothing to do with compression ratio, 14:1 will be possible with E85 not PULP

  • smartacus

    exactly, the better cooling sodium filled valves means less chance of pre-ignition; ergo crank the compression ratio up to 14:1.
    i mean yeah i’d love to see the flatcrank do it the Mazda way (Mazda’s new SkyActiv achieves 14:1 compression because of really long 4-2-1 exhaust header and no E85) but i don’t know if they would clear the fenders in a Stang Engine bay.

  • Kenneth Wright

    Funny how they call the Coyote the ‘lesser’ engine when it can make 500 or more hp at the WHEEL n/a without too much difficulty. One Coyote owner in particular got 520 hp at the wheel on a load bearing dyno even. Youtube video is still up (/watch?v=jfpM9IUoI4k) and you do the math as to what that would be at the crank. This new flat plane 5.2 liter is magnificent so don’t take any of that wrong, just had to stick up for my beloved Coyote! lol

  • Derp

    Uh, it’s simple. It has less horsepower, thus, the lesser engine. Plus of course every GT has the Coyote, derp.

  • Kenneth Wright

    You are correct in that sense but that was not the context of my reply. So not that simple. Context Jeeves.. discernment is a good thing.

  • Derp

    Well, you say the 5.0 is can do 500+ NA, which it can, but not easily at all. You are looking at about 5-6k in mods (even the cams alone will run you about 1500$, as it’s a DOHC motor) and the 5.0 is already a HIGHLY compressed motor. Just sayin, the 5.0 isn’t going to touch this motor unless you just spend the saved money to put a even better engine in there. It’s 130+ over the GT, at 526HP. I’m personally glad it does not have as much HP, or torque, as my ’12 GT-500. Lol. But getting that much HP out of a 5.2l and a red line up to 8.5k, is insane.

  • Kenneth Wright

    Uh oh.. another one of THOSE responders. Again, you utterly and completely missed the context of my op and you are digging yourself a nice big hole. If you insist, please do continue.

  • Derp

    Ok, the Coyote is the lesser engine.

  • Kenneth Wright

    If that makes you feel better….

  • Kenneth Wright

    On a lighter note.. (I’m just having fun here) .. when I said this new 5.2 is magnificent, I meant it and I would definitely not kick it out of my garage. 8.5 k is indeed insane and I’ll admit.. the exhaust note of this engine is intoxicating as well. I look forward to seeing more of this car, and this engine.

  • Steve E Knight

    I’m sticking with pushrods and a carburetor in my mildly modified 351W, and doing just fine. I am pretty close to 500 horse, and building a new shortbock that will more easily withstand more horsepower than that. Oh, and my 1951 Ford pickup only weighs 3000 pounds, not almost 4000.

  • Steve E Knight

    The arbitrary amount of horsepower at which an auto manufacturer positions an engine is inconsequential. Frequently it is an outright lie. The engine in my pickup (351W) was never rated at higher than 290 horse. Getting it to double that amount is neither difficult nor prohibitively expensive. So…dither about the potential, not the insurance company/governmental determined level. Most of the “muscle car” engines of the 1960’s had 100 or more horsepower than their rated power.

  • Derp

    Talking about the 1960s and 70’s is flat out stupid, back then you could LIE about out-put power and get away with it. It ain’t the 60-70’s anymore, and everything is monitored insanely close. Get with the times, no maker bullshits HP, if they can make it to that number, well, due to regulations, it is something to brag about. If you think the 5.0 has more, well, okay, props to you in believing, but it is highly compressed as is, and you can’t beat around that fact, and IMO, needs way more TORQUE.

    Also, since when has “doubling” horse-power not been an issue with wear and tear and longevity? Do you live in a magical realm currently? I’d like to go there.

    Look at a 6.1 HEMI, or 5.7, safe is 530-540 supercharged, past that, done.

    Camaro LS1, or LS3, about, 530-540 super-charged

    Where in the heck are you getting these “Oh it is easy to double the out-put” from in modern cars? Or do you just have an old truck to go on?