Ford’s new 5.0L/5.2L Ti-VCT (Twin Independent Variable Cam Timing) Coyote and 5.2L Voodoo DOHC V-8s can easily be described as the two greatest V-8 engines ever produced in the company’s history. Originally project code named “Coyote” within the company as early as 2007, the Ti-VCT V-8 was developed and engineered to be a true high-performance double overhead cam V-8 conceived specifically for the Mustang. In fact, the Coyote is considered the first “Mustang specific” engine conceived in the marque’s more than half-century history.
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Ford engineers and product planners, led by Mike Harrison, looked at what they liked and didn’t like about the venerable 4.6L and 5.4L overhead cam Modular engine family and applied it to the Coyote’s development. Although the Coyote and Modular engines resemble each other, there is no interchangeability between the two engine families. The Coyote is a totally new DOHC Modular V-8 engine.
When it was in the rumor mill, the 5.0L DOHC Ti-VCT was believed to be the gallant return of the legendary 5.0L engine that made late-model Fox body and SN-95 Mustangs so notorious. There was street chatter about it being a push-rod engine on a par with the classic small-block Ford V-8. However, nothing could have been further from the truth. Ford was moving forward, not backward, with a real purpose-born high-performance double overhead cam V-8.
In 2007, Ford knew it needed to conceive and build a world-class high performance V-8 engine that could compete with tougher world-class competition from not only GM and Chrysler, but Europe and Japan. Ford’s handpicked design and engineering team consisting of racers and manufacturing experts looked closely at how power was made and wasted. Team Coyote looked at thermal and volumetric efficiency along with frictional loss issues. It also looked at the limitations of the 4.6L and 5.4L Modular V-8 architecture to help set a course toward success.
The 5.0L Ti-VCT Coyote engine was born to be a true highperformance V-8, a factory-born racing engine for the street. All the traditional corporate roadblocks were cleared to get an eye-opening DOHC powerhouse to market quickly.
The first step toward the Ti-VCT 5.0L V-8 was the Hurricane engine, which ultimately became the production 6.2L SOHC iron-block Modular for Raptor and F-150 trucks. Though the 6.2L engine provided plenty of torque, it was not suitable for the Mustang in terms of size and power. It really was a completely different standalone Modular engine. Ford had taken the 4.6L, 5.4L, and 6.2L Modular engine family as far as it could.
Though the Coyote design team wanted to create a completely new high-performance overhead cam V-8, the basics of Modular engine architecture had to remain due to cost and factory tooling considerations. The new Modular engine had to be produced from the same production lines and from the same machinery in order to keep cost in line. The 4.6L and 5.4L engines had limited potential for extreme performance. Conceiving the Coyote was an enormous challenge.
Development of Ford’s 5.0L Coyote DOHC V-8 began in earnest in 2008 with Ford’s vision being a true high-performance Mustang engine. Though the Coyote has also arrived in Ford’s popular F-Series trucks, it was originally developed for the Mustang. Ford’s direct injection and Ecoboost turbocharging technology were real considerations for the Ti-VCT V-8, yet not practical or necessary for this engine early in the going. This alone gave the Coyote an economic advantage. Lots of power from a naturally aspirated engine.
The objective was to make the Coyote as compact as possible while keeping block dimensions close to the same size as the 4.6L. The Coyote also had to be an engine that would make at least 400 hp, or 80 hp per liter. These expectations were huge and had to be met to realize the goal of exceeding the capabilities of the 4.6L engine. The Ti-VCT had to do what no Ford production engine had ever been asked to do.
Ford’s goal for the Ti-VCT Coyote was a much stronger block to contain and deliver the kind of power expected. It had to be able to do what the 4.6L and 5.4L engines could do, without a raised deck. It wasn’t just the factory 400/400-hp and torque goal, but also the kind of power enthusiasts wanted once the 2011 Mustang GT hit the streets. The Coyote was going to have to be a 7,000-rpm redline engine right off the production line.
Project planners knew they had to look far ahead into this engine’s future at not only what performance enthusiasts would do with it, but also what Ford had planned in terms of direct injection and turbocharging. The objective was to engineer the block to a satisfactory point so that the engineers didn’t have to come back and do it again later.
Where the Ti-VCT Coyote V-8 shines is its completely new cylinder head design and function; it has maximum flow into each cylinder and greatly reduced valvetrain friction and weight. Larger cylinder head bolts and improved sealing technology help contain much higher 11.0:1 compression.
Because the Coyote development timeline was tight, the team had to fast track this engine through development, prototyping, testingcertification, and into production. The traditional three-year development window to get this thing turning and burning was not an option. Existing Modular mule engines had to be used to work and test Coyote engine parts for durability. A lot of scrap that didn’t measure up went into the recycle bin.
To get the Ti-VCT where Team Coyote wanted it necessitated a lot of back and forth between hardware people in engine building and dyno rooms and software geeks who compared information and made adjustments as necessary. It was a great combination of hard-core seat-of-the-pants engine experimentation and high-tech computer design. Engines were thrashed, tortured, and trashed via hundreds of hours of dyno lab testing. Any weak links were revised or eliminated.
By January 2009, Ti-VCT engine dyno testing was in full swing with those first prototype mule engines going under unspeakable loads at high RPM and throttled until they were worn out. Ford engineers disassembled used-up mules and inspected them for wear. Much to their amazement, the Ti-VCT held up very well with minimal abnormal wear issues.
Engine testing transcends hard full-throttle pulls on a dyno and in test vehicles. It must also pass tough corporate muster and federal emissions standards. Those first few prototype engines made it through testing and certification with very few changes. Field-testing in mule vehicles in extreme heat and cold was the final frontier where the Ti-VCT proved its worth. It performed flawlessly.
By the time the Coyote reached mass production in 2010, it had been tested, tortured, and abused unlike any Ford engine before. It was put through greater extremes than any Ford engine ever had to ascertain its integrity. The team wanted an engine that would deliver fuel efficiency, durability, and longevity. It wanted an engine that could handle both the daily commute and the racetrack without complaint.
The Ti-VCT Coyote was conceived during one of the most trying financial times in modern automotive history. Faced with a potential Ford bankruptcy, Ford CEO Alan Mulally saw the value in investing in product and people, and without government assistance. It paid off handsomely in a new generation of vehicles and powertrains. Mustang was among the first carlines to witness the payoff with the most advanced V-8 in its half-century production history.
The gold nugget in the Coyote was and still is its wonderful simplicity. It is an easy engine to understand and build because it is produced in only one North American plant (Essex, Ontario, Canada) with basically one block and head casting type, although I fully expect more variations in the future as this engine grows to meet demand. The confusion of two engine plants with different approaches and parts that existed with the 4.6L and 5.4L engines is gone.
The Coyote’s firing order is different from the 4.6L and 5.4L V-8’s at 1-5-4-8-6-3-7-2. Compression ratio reminds me of the 1960s at 11.0:1, making the most of its lower displacement and carefully executed valve timing, despite having port fuel injection instead of direct injection. Imagine being able to do this with 87-octane fuel, although 91-octane is preferable. This innovation comes of Ti-VCT, which enables each cam to adjust valve timing based on input from the powertrain control module (PCM).
What makes the Coyote Ti-VCT different from the 4.6L and 5.4L engines are great innovations that make it a user-friendly engine. And if you’re considering a Modular engine swap, the 5.0L Ti-VCT double overhead “cammer” is the best way to go if you’re going to go to all that trouble and expense.
Retooling the Essex, Ontario, engine plant for the 5.0L Ti-VCT was simple because it remained within the parameters of the Modularengine family. The Coyote block shares the same bore spacing (3.937 inches or 100 mm), deck height (8.937 inches), bellhousing bolt pattern, and external dimensions as the 4.6L SOHC and DOHC engines. Bore size increased to 3.629 inches (92.2 mm) along with an increased stroke of 3.649 inches (92.8 mm), which is still a “square” engine design with identical bore and stroke. It differs in block design, which is entirely new, with heavier webbing and other internal improvements intended to support greater power output from modest displacement.
The Coyote engine has a rugged aluminum block with paper-thin ductile iron cylinder liners. Because the Coyote’s iron cylinder liners are quite thin, this block must be sleeved with thicker liners for all-out racing in the 1,000 to 1,500-hp range. Modular Motorsports, as one example, offers racers the Pro Mod Coyote block with extra thick ductile iron cylinder liners that ensure block integrity. You can build one of these Pro Mod engines for the street if you’re an avid weekend racer. Bores can be taken as high as 3.700 inches to achieve 5.2L.
Improved block architecture holds this engine together. The main bearing webs are thicker and heavier, which allows for performance extremes from enthusiasts and Ford product planners. This means the Coyote block can stand up to naturally aspirated performance demands, supercharging, nitrous, and direct injection. It can be said with great confidence that this block will withstand more than 1,500 hp sleeved with the thicker ductile iron cylinder liners mentioned earlier.
The Coyote block brings advances in crankcase ventilation known as “bay-to-bay” breathing. Ford engineers located venting in the main webs designed to allow the freedom of air scavenging without hurting power. These vents are known as chimneys. The result is a more positive piston ring seal, which helps efficiency and power.
The Modular V-8’s cooling tube down the middle of the valley is not present on the Coyote. Instead, coolant is routed through the front of the block, leaving plenty of room for exotic induction systems and superchargers. Any way you view the Coyote block, it is a vast improvement over the Modular.
Because this is a 7,000-rpm engine, the Coyote is fitted with an induction-hardened, fully counterweighted crankshaft that’s virtually indestructible, featuring an eight-hole flange. Team Coyote elected to stay with the 4.6L engine’s main and rod journal dimensions because they have been a proven success in nearly two decades of production in every application imaginable. In addition, aluminum bearings were borrowed directly from the 4.6L engine instead of tri-metal bearings because they have worked successfully.
The Coyote engine shares the same connecting rod dimensions with the 4.6L engine at 5.933 inches center to center; yet it is not the same rod. It is a stronger rod with 12-point bolt heads. Rod ratio is 1.62:1 for excellent dwell time at each end of the bore. The Coyote’s 5.933-inch cracked rod is a sintered metal I-beam piece engineered for extreme street and weekend race duty. However, it is not a rod that stands up to the severe punishment of supercharging and nitrous. If you’re planning a supercharger or nitrous induction, Manley H-beam rods are mandatory over the stock 5.933-inch rod. The stock rod takes a lot of punishment. However, you’re pushing your luck if you use anything less than a heavy-duty forged-steel I-beam or H-beam rod if you plan to push it above 600 hp.
The Coyote is fitted with lightweight hypereutectic pistons with coated skirts for reduced friction and wear. Ford engineers weighed the benefits of forged versus hypereutectic and hypereutectic won for its weight and expansion properties. Forged pistons are noisy when they are cold due to excessive piston to cylinder wall clearances, which generate plenty of complaints with 4.6L and 5.4L engines. Hypereutectic pistons run quieter because you can run tighter tolerances without noise when they are cold. The Coyote piston tolerates the extremes of street and weekend race duty and offers durability. However, if you intend to supercharge or use nitrous you’re better off with a forged and coated piston for best results.
Another reason Ford opted for a hypereutectic piston is the oil cooling jets that keep the pistons cooler, which improves piston life. This approach also allows for faster warm up because oil is in direct contact with one of the hottest parts of the engine right from the start. Ford engineers proved that the crankshaft runs roughly 25 degrees F cooler with the oil jets, which enables this engine to operate on 87-octane fuel and survive (although 91-octane is optimum).
Most important to remember is clearance issues. Heavy-duty I-beam and H-beam connecting rods don’t always clear the tight confines of the Coyote block. You must first do a mock-up and make sure everything clears by at least .060 to .100 inch throughout 360 degrees of crank rotation with all rods and pistons (without rings) installed. Pay close attention to piston skirt to crank counterweight clearances, which can become very tight and prohibit the Coyote from accepting any more than a 3.649-inch (92.5-mm) stroke. Another area of consideration should be connecting rod interference issues with the piston cooling jets, which has happened in some builds.
Ford’s Ti-VCT Coyote has a new cylinder head design that makes the engine less bulky while providing extraordinary high-RPM breathing. The Ti-VCT’s intake ports are free from restrictive tendencies, outflowing even some of the most legendary racing cylinder heads in the industry. Intake flow numbers are in excess of 300 cfm. Because the Coyote’s top end was designed more as a package than just individual heads, cams, and induction, it produces numbers never seen before in a factory Mustang engine. These heads flow very well without specialized port work, which leaves the door wide open for even more power if you decide to do port work.
Ford’s Ti-VCT design team, specifically Todd Brewer and John Reigger, understood it would have to spend a lot of time to come up with a cylinder head that could do everything. First, they had to perform basic hotrodding tricks to achieve greater flow; then, these seasoned engineers had to jump into areas that they had never ventured into before. Although the Coyote cylinder head appears to be a derivative of the GT500 head, it isn’t. A lot was learned from the GT500 head, yet none of it was carried over.
Engineers had to focus on aspects of port design that had never been considered, such as the distance between the four valves, valve angle, valveseat revisions, and more. Valve angle had to change to improve valve to piston clearances and air flow. Thanks to advanced computer technology, engineers were able to come up with a new cylinder head quickly. It took extensive development work for six months at seven days a week to create a new, more innovative head.
Cams and Valvetrain
When Team Coyote was finished with basic cylinder head casting development, it had to go back and look at cam profile along with valvetrain size and weight. Think of high-revving motorcycle engines; this is what Ford was faced with in developing the Coyote. Rocker arms and valvesprings had to be much smaller to improve both efficiency and performance. There had to be less reciprocating weight to enable these high revs. Put the 4.6L/5.4L and 5.0L rocker arms side by side and you see the difference in size. The 5.0L engine does it with less mass and weight. In addition, it enabled Ford to reduce cylinder head size and width, which reduced overall engine width.
The Coyote’s valvetrain system is the most complex cam and valvetrain package ever installed in a Mustang, and it is designed to optimize all driving conditions. This task went to Kevin Shinners and Adam Christian, engineers who developed the camshafts and valvetrain. “Ti-VCT” means “Twin Independent Variable Cam Timing,” which in turn means that the intake and exhaust cams work independent of each other based on driving demands. Each camshaft is indexed or phased around its centerline by oil pressure. Oil pressure is metered electronically via solenoids and phasers to control cam indexing as required.
Ti-VCT enables the Coyote to deliver an incredibly wide power band across RPM ranges while giving you the bonus of high-end horsepower, which was not previously easy to achieve. What makes the Coyote’s Ti-VCT different from the rest of the Ford line is cam torque actuation, which uses valvespring energy to advance and retard timing more quickly depending on engine RPM and driving demands. Instead of a complex electronically controlled shuttle valve and oiling system routing, the Coyote’s Ti-VCT is a simple on/off solenoid; cam torque does the rest.
Ti-VCT can advance/retard valve timing by as much as 50 degrees, and do it in .2 second. This approach offers you modest valve timing on the way to work and more aggressive valve timing when it’s time to get the heat on. For the environmentally conscious, the Coyote doesn’t need EGR (exhaust gas recirculation) because valve overlap is increased in certain types of driving, especially deceleration, which reduces hydrocarbon emissions.
In order to do the complex work of Ti-VCT and other critical functions, Ford’s EEC (Electronic Engine Control) was asked to do more than it ever had in its history. This system is known as “Copperhead.” It is a new multi-channel system designed to control every aspect of engine and driveline including Ti-VCT. Instead of a simple on/off system of cam modulation, Ti-VCT advances and retards valve timing on each cam. Electronic control monitors and controls oil pressure to the cam phasers.
Ti-VCT isn’t something you need to worry about maintaining or tuning. It is a life-of-the-engine system. If the cam phasers fail, all you have to do is remove the cam cover, align the timing marks, and replace the phasers. The Coyote’s cam position sensor is located at the opposite end of the cam than on the 3V Modular, and this accounts for the difference in phaser function between the Coyote and 3V Modular.
The Coyote’s induction system is a composite design, which is mainstream today because it is both lighter and a great heat insulator. It stays cool and keeps the intake charge cooler. It is also easier and cheaper to manufacture.
Induction design and tuning has changed considerably thanks to computer-aided design (CAD) and a lot of engineering time. The Coyote’s intake manifold, also known as a plenum, is single plane with long intake runners for a broad torque curve. These are long 16.9-inch (430 mm) runners with gentle turns for improved flow. They are carved deep into the valley to allow for a lower vehicle hoodline. Because Ford has eliminated the coolant tube in the valley, there’s more room for induction. The 80-mm throttle body is centered at the front of the engine on top. Another great evolution is a digital mass air sensor for extremes of fine-tuning as you drive.
The 5.0L Ti-VCT’s induction system for 2015–up also includes Charge Motion Control Valve (CMCV) assemblies. The CMCVs (which are actually flaps on the Coyote) close upon start-up; they give this engine a smoother idle and better low- to mid-range torque. When it’s time to get it on, these vacuum-controlled charge motion control flaps move out of the way to improve high-RPM induction flow.
The Coyote continues with traditional port injection because Ford engineers felt it didn’t need direct injection at this time. A lot of development work is yet to be done if you’re considering direct injection. The Coyote’s cylinder head castings have a provision for direct injection. The block is strong enough to support direct injection. Ford just isn’t there yet.
The Coyote’s exhaust system is just as critical to power and efficiency as the rest of the package. Headers might not seem important in the big picture, but they are important and were a great area of focus for Team Coyote. The Coyote has short tri-Y headers that were thought out painstakingly and well executed. Engineering had to fight for them. Bean counters didn’t want them because they cost twice as much to produce as cast-iron exhaust manifolds, yet they were crucial to emissions, power, and fuel economy.
Because the Coyote’s factory shorty header is extremely unique in its approach, it has enabled the Ti-VCT to produce more than 400 ft-lbs of torque. Try that with your 5.0L pushrod small-block. You can get horsepower all day long. Torque is another story and a huge challenge.
The Ti-VCT Coyote was conceived for high revs, and with that dynamic comes huge oiling system demands. The Coyote must sustain sufficient lubrication to 7,000 rpm and beyond and under extreme driving conditions. Ford opted for an 8-quart oil pan and a suitable windage tray/pan gasket combination. This is all good for keeping oil pressure and volume on target. It also created the huge challenge of oil drainback because oil arrives at moving parts in abundance. Ford solved this problem, and others, with crankcase breathing chimneys. These PCV chimneys improve both drainback and crankcase ventilation.
Close attention was paid to the Coyote’s cooling system, which focuses on exhaust valve cooling along with other extremely hot areas of the engine. Ford calls this cross-flow cooling, which is different from the conventional cooling that the 4.6L and 5.4L Modulars employ. Cross-flow cooling routes coolant upward through the block where it enters cylinder heads at the exhaust valves 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.
The 5.2L Voodoo
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.
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 x 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.
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.
Ford Performance 5.2L Coyote
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.
Improving on a Winner
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.
Written by Jim Smart and Posted with Permission of CarTechBooks