for excellent heat transfer and reduced operating temperatures. Coolant runs through a long manifold cast into the cylinder head at the exhaust valveseats. This keeps detonation issues to a minimum and durability high.
Ford’s 5.2L DOHC flat-plane crank V-8 is billed as the highest-revving factory V-8 in American automotive history, with 526 hp and 429 ft-lbs of torque on tap. It spins to 8,250 rpm but shuts off at 8,000 rpm. The sound of the 5.2L Voodoo is clearly different from the sound of the Coyote Ti-VCT V-8 it is spawned from. With flat-plane crank technology the Voodoo makes a snarly, raspy bark from its tailpipes. At high RPM it emits a goose bump–inspiring scream unlike any American V-8. On the surface, the 5.2L Voodoo looks like its smaller sibling, the 5.0L Coyote. Beneath the aesthetics it is a different animal entirely.
The 5.2L Voodoo has been conceived for the Shelby GT350 to make it a breed apart from anything else on the road. Jamal Hameedi, chief engineer at Ford Performance, describes the 5.2L flat-plane V-8 as a product for which every single performance target has been met, including a broad torque curve, crisp throttle response, and no weight increase.
The flat-plane crankshaft approach is nothing new, especially when it comes to exotic high-end European sports cars. However, it is surely a fresh idea for Detroit. When you look at more traditional cross-plane–crank American V-8s with 90-degree reciprocating intervals opposite the counterweights, the flat-plane approach puts pistons and rods exactly 180 degrees opposite the counterweights instead of the traditional 90 degrees. The result is a completely different sound from the traditional V-8 roar that you are used to hearing. The difference in sound comes from exhaust pulses, which happen at different intervals than with a cross-plane–crank V-8. Cylinder banks fire alternately creating a buzzy exhaust harmony on a par with European exotics. At wide-open throttle at high RPM, it sounds like a Ferrari.
This is the 5.2L Voodoo engine in a 2015 Shelby GT350. Although the 5.2L engine is based on the 5.0L Ti-VCT Coyote, it is not the same engine by any means. Its flat-plane crank design is only the beginning of what makes this engine different from any other American V-8. Traditional V-8s have a cross-plane crank with huge counterweights surrounding rod journals at a 90-degree angle. This makes for smoother operation, but a heavier crankshaft. The 5.2L’s flat-plane crank weighs less and gives this engine a snarly buzz at high RPM, like European exotics. This comes from rod journals being 180 degrees opposite of where the crank looks flat, hence the term “flat-plane” crank.
What flat-plane technology means for you at your backside is better exhaust scavenging and a notable increase in power. Even more, it enables Ford to produce a lighter crankshaft with a crisp, snappy throttle response that allows a 7,500-rpm top out, with peak torque coming in at 4,750 rpm. Redline (fuel shutoff) comes at 8,000 rpm.
The flat-plane 5.2L engine really is a racing mill that you can enjoy on the street because it delivers excellent fuel economy on the open road with a 3,000-rpm torque curve. Yet it makes 526 hp at wide-open throttle. What this means for you on the track is brute torque coming out of turns with an incredible blast of power coming down the straights. This is an engine that loves to rev.
Ford says torque begins to come on strong at 3,750 rpm with peak at 4,750. To achieve 5.2L, Ford infused a slightly oversquare bore and stroke ratio at 94.0 × 92.7 mm. This author wound up behind one of the 5.2L Voodoo Mustang engineering prototypes at a traffic light in suburban Phoenix, Arizona, for an intimate experience with the 5.2L Voodoo’s exhaust tips.
Here’s the 5.2L Voodoo head on. Although, at a glance, the Voodoo resembles the Coyote, there are many differences, including a more advanced induction system, GT350-specific cylinder heads, a Voodoo specific block, and more. (Photo Courtesy Ford Performance Parts)
The Voodoo is clearly a different experience because it is buzzy like a European exotic at high RPM. However, through the revs it resembles an American V-8. It is very Jekyll and Hyde as it makes its way to 8,000 rpm. At peak horsepower, it makes a European V-6/V-12 buzz like you’ve never heard in a Mustang. Compression ratio is an astonishing 12.0:1.
Even though there are positives to flat-plane technology, there are also negatives. If you’re married to the traditional sound of a cross-plane–crank V-8 engine, the flat-plane–crank pulse will seem foreign to you. Harmonics issues also exist to some degree with flat-plane–crank engines when displacement rises above 4.5L. Low-end torque also suffers with flat-plane–crank engines. The 5.2L Voodoo isn’t big on low-end torque. However, this isn’t an engine designed or engineered for low-end torque. It is a race-bred high-end street/track engine that does its best work at mid- to high RPM.
The 5.2L “flat-plane” V-8’s induction system is completely different from its 5.0L sibling’s. This is an engine designed for high-RPM operation, which makes low- to mid-range torque rather lackluster. But who cares? This is an ultra-high-performance V-8 developed for the racetrack and canyon cutting, not grocery getting. However, if your plan is to buy groceries, this guy does it quickly.
A nice surprise at press time is Ford Performance’s announcement of a 5.2L Coyote engine and parts for the enthusiast. Ford Performance begins with a production 5.2L Coyote block, heads, and valvetrain. By September 2016 Ford Performance expects to have a complete 5.2L Coyote cross-plane–crank crate engine available. Although a flat-plane crank in the Ford Performance inventory would be a welcome addition, it is not currently on the production schedule.
In back, the 5.2L Voodoo has a dual-mass flywheel, charge motion actuators, and a more advanced induction system. This is easily the most advanced intake manifold in Ford history, with the focus being high-RPM operation. Low-end torque isn’t what this engine is about. It is race bred and born for Mustang. (Photo Courtesy Ford Performance Parts)
It seems that the Coyote engine yields little room for improvement, but exactly the opposite is true. If you’re comfortable with box stock performance and 400 to 430 hp, the factory original Coyote offers excellent performance and fuel economy. However, the Coyote’s bones also enable you to weave in more power and still maintain durability. I’ve learned on the dyno that you can grow this engine to 500 to 600 hp without consequence. In the JGM Performance Engineering dyno room, I pushed the Ford Performance test mule to 7,600 rpm and there was room to take it to 8,000. Horsepower continued to rise at 7,600 rpm. Although this would probably not be a good idea for your Coyote Mustang or F-150, it demonstrates the durability on which you can build power.
The Voodoo’s side profile reveals a block that’s a cut above the Coyote. This is the block you want if your goal is increased displacement and strength. Its cylinder heads are also more advanced than the Coyote’s; they simply flow better. Note the high-capacity oil pan designed specifically for racing. (Photo Courtesy Ford Performance Parts)
