When Team Coyote was finished with cylinder head casting development, it had to go back and look at cam profile and the very size and weight of valvetrain components. Ford had to improve mechanical advantage between the camshaft and valvesprings by reducing load. Reduced load came from larger cam lobes, which was a nuance that began with the 4.6L SOHC engine a quarter-century ago.
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A lot of research and development went into these heads to get them where Ford engineers wanted them in terms of size. Consider high-revving motorcycle engines: This is what Ford was faced with in developing the Coyote. Coyote heads and parts had to get smaller, as did valvetrain components. Rocker arms had to be smaller to improve both efficiency and performance. Less reciprocating weight on top meant freedom of speed at higher-RPM ranges.
Put the 4.6L DOHC and 5.0L Ti-VCT DOHC rocker arms side by side and you see the obvious difference in size. The Coyote’s rocker arms are smaller. The 5.0L Coyote engine does it with less mass and weight. Furthermore, it enabled Ford to reduce cylinder head size and width, reducing overall engine width. The result has been a higher-revving engine with less mass from shoulder to shoulder. In fact, the Coyote is small enough to fit into a 1979–1993 Fox Mustang or the 1994–2004 SN-95 thanks to this overall reduction in size.
The Coyote’s valvetrain system is the most complex ever installed in a Mustang or F-Series truck and it is designed to optimize all driving conditions. Remember that “Ti-VCT” stands for “Twin Independent Variable Cam Timing.” This means intake and exhaust cams work independent of each other based on driving demands. The system advances cam timing on each side as necessary based on conditions and throttle position. 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 a wide power band across the RPM while giving you the bonus of high-end horsepower, which was never easy to achieve before with conventional methods. Cam torque actuation, which uses valvespring energy to retard timing more quickly depending on engine RPM and driving demands, is the feature that sets the Coyote’s Ti-VCT apart from the rest of the Ford line. Instead of a complex electronically controlled shuttle valve and oiling system routing, the Coyote’s Ti-VCT is a simple on/off solenoid to advance valve timing; cam torque from valvespring pressure does the retarding. Oil pressure advances cam timing and cam torque from spring pressure retards timing.
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 it 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. It became known as the Copperhead system, 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 valve timing on each cam for fine-tuned operation. Electronic control monitors and controls oil pressure to the cam phasers. It isn’t just advance/retard; it actually modulates both elements in degrees based on driving demands.
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, they’re easily replaced by removing the cam and timing covers, aligning timing marks, and replacing the phasers. What makes the Coyote’s phasers different from the 3V Modular’s is cam position sensor location, which is at the opposite end of the cam on the Coyote.
Improving the Coyote Valvetrain System
What can you do to improve the Coyote’s valvetrain system? The Coyote’s rocker arms are petite, stamped-steel, heavy-duty rollers that can stand up to the punishing abuse of the most aggressive cam profiles. At present, the aftermarket isn’t producing a roller rocker for the Coyote. As cam profile aggressiveness increases, however, valvespring pressure must increase accordingly. The key to durability and performance is matched components from the aftermarket. Ideally, you buy camshafts and springs as a set. Your cam manufacturer can advise you on which spring, retainers, and keeper to choose.
Unless you are going racing or are on a steady diet of street/track it makes little sense to lock in cam timing. If you opt for a hotter cam you’re going to need to install cam phaser limiters or adjustable sprockets for more controlled valve timing.
You may opt for a more aggressive cam profile from Comp Camsor Ford Performance Parts and wind up with a user-friendly valve action program that infuses more power into your Coyote. Cam swaps are easy on the Coyote. Even valvespring replacement is straightforward if you have the right tools. You can do a cam and/or valvespring swap without pulling the heads. And if you have to pull heads for something like CNC port work, cylinder head removal and replacement is straightforward whether you have a Mustang or F-Series truck.
When you are performing topend work on your Ti-VCT Coyote, you’re going to need the head swap kit (M-6067-M50) from Ford Performance Parts. Cometic and Fel-Pro cylinder head gaskets are another viable option available from your local auto parts store or Summit Racing Equipment. Always replace cylinder head and cam journal bolts, which are torque-to-yield and can only be used once. Once torque-to-yield bolts have stretched one time they’re basically a throwaway and should not be used again.
Ford did a good job of camming the Ti-VCT Coyote from the factory, including the BOSS 302 sticks. However, Comp Cams has undertaken a lot of research and development time with the Coyote and come up with aggressive cam profiles engineered to meet some of the toughest street and strip requirements.
Comp Cams claims that its billet hydraulic roller cams for the Coyote unlock a lot of hidden power, which I have proven via dyno testing at JGM Performance Engineering for this book. Cams are available for naturally aspirated and blown applications with three cam profiles each from Comp. Each is dynamic balanced for smooth operation in the Coyote. Comp Cams says the XFI NSR (191160) cam can produce as much as 417 hp and 382 ft-lbs of torque at the rear wheels with long-tube headers and a JLT induction system, based on in-house testing.
We have dyno tested a 2011–2014 crate Coyote from Ford Performance at JGM Performance Engineering and experienced in excess of 500 hp at the crank from both the Ford Performance BOSS 302 cams and the Comp Cams 191160 with BOSS 302 and Cobra Jet induction. With the Comp 191160 grind and Cobra Jet induction it came in just shy of 600 hp.
Ford Performance BOSS Cam
The 2012–2013 BOSS 302 camshaft set (M-6550-M50EXT and M-6550-M50BINT) offers more lift and duration for improved performance without having to use cam phaser locks. These cams were used in both the BOSS 302 Coyote and the Cobra Jet. They are good cams for the money with few modifications required.
Chains and Guides
The 5.0L Ti-VCT Coyote has a series of timing chains and guides similar to the 4.6L DOHC engine. Chain tensioners are oil pressure modulated just like the 4.6L/5.4L engines. Chains travel through plastic guides between the crank and camshaft sprockets. The installation and proper timing of these chains and sprockets is simple if you take your time and pay close attention to what you’re doing. It can be said with confidence that the stock Ford chain guides take tremendous amounts of abuse. They are “life-of-the-engine” pieces engineered to last 100,000 to 200,000 miles in normal use.
Note: The 2015–up Coyote engines do not require modified cylinder heads or changes to cam phasers. The CR Series cams for 2015–up have revised lobe centers and more lift yet work with stock valvesprings and Ford mid-lock phasers. Two upgrade spring kits are available if you desire greater spring pressures.
If you’re concerned about failure issues, you can step up to hardened crankshaft gears from Modular Motorsports Racing or Ford Performance Parts. Modular Motorsports Racing (MMR) has billet chain guides for your Coyote project if you’re going racing. The MMR pieces can be found in a lot of racing Coyotes, be they drag or road race. For the street only you can get by with original Ford parts, the M-6004-A504 complete chain drive kit, which is available from Ford Performance Racing Parts or Summit Racing Equipment.
If you are opting for an aftermarket high-performance camshaft package, some kits call for the installation of cam phaser locks to keep timing consistent and eliminate the risk of valve to piston contact. Comp Cams has an adjustable cam phaser lock system that enables you to lock in cam timing. In addition, you can fine-tune the lock system for your individual requirements. MMR also manufactures an adjustable cam phaser lock kit for the Coyote.
Whenever you step up to a more aggressive camshaft, make sure that you confirm valvespring requirements from the manufacturer. If you’re in doubt, go to a stiffer valvespring for better results at high RPM. Few things are more discouraging than a hot cam and valve float at high RPM. Always follow the cam manufacturer’s instructions to the letter. If you get stumped, call the manufacturer’s tech line. The one thing you do not want is bent valves or more serious engine damage because you didn’t follow instructions.
The nice thing about the Coyote is the easy access to camshafts, valvetrain, and cam phasers. Remove the cam and timing covers and it is all right there for easy access. The key to success is getting the number-1 piston at true top dead center with all of the marked timing chain links at the marks before youstart swapping cams. When you are there, never change either the cam or chain position. If you are performing a cam swap, take note of camshaft position and install new cams at the exact same indexing. If you are not focused, this is an easy mistake to make.
Based on dyno testing at JGM Performance Engineering and a series of cam and induction system swaps, we’ve learned that you can make at least 100 more hp with a box-stock Coyote. The key is to choose a camshaft carefully based on the kind of driving you will do most of the time. Cam tech help lines can be very helpful, helping you to choose the right cam and spring combo. If you’re content with the factory’s Ti-VCT system, stay with it; and use phaser limiters when required. If you prefer to lock in valve timing, degree in the cams carefully along with a professional performance tune while you’re at it. In fact, a professional performance tune on a chassis dyno is something you must do any time you perform a cam and induction swap.
Written by Jim Smart and Posted with Permission of CarTechBooks