Tech: New Developments In Coyote Camshaft Technology With Comp Cams

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Although original equipment manufacturers are not typically in the business of producing performance parts, many of the decisions they make during the research and development process of designing an engine can come into play once the aftermarket begins to further enhance said engine design’s capabilities.

This is the case when it comes to a new array of camshaft designs from none other than Comp Cams in production for the world-beating 5.0-liter Ford Coyote V8 engine. From its initial release in the 2011 Mustang, where it pumped out 412 horsepower, to today’s offerings in the 2016 Mustang, the Coyote engine has been improved by Ford to currently produce 435 horsepower.

Some of the improvements in the engine’s performance are a direct result of the Boss 302 cylinder head design, but others have come about through extensive testing and dyno development time on the camshaft profiles. In this article, Comp’s Billy Godbold will discuss some of the advancements made at the OE level and explain how they have improved the aftermarket’s ability to produce a better component – and in the process, build more power under the curve and provide a user-friendly camshaft design. Read on for the details…

Our Coyote Cobra Jet engine as installed in our Factory Five Cobra.

Our Coyote Cobra Jet engine as installed in our Factory Five Cobra Challenge car.

What’s Happening On The OE Side

According to Godbold, the advancements that have been made in the area of overhead-camshaft engine design are the primary driver behind the new thought processes and areas of development for Comp’s Coyote camshaft lineup.

“We’ve been on the same parallel path with Ford. When we got our hands on the first Modular engines all those years ago, we realized that the valvetrain was huge dimensionally,” says Godbold.

L-R: 2V Modular, 3V Modular, Coyote camshaft followers. As the physical size of the folower has been reduced, strength has gone up, Sojem of this strength improvement can also be attributed to more robust materials. In addition, with the reduction in size comes a reduction in weight, and valve events can be more aggressive as a result.

Left to right: 2V Modular, 3V Modular, Coyote camshaft followers. As the physical size of the follower has been reduced, strength has improved. Some of this strength increase can also be attributed to more robust materials. In addition, with the reduction in size comes a reduction in weight, and valve events can be more aggressive as a result.

“That valvetrain was done that way for a reason – they needed the strength. One way you can make a cam last longer is to use more expensive materials; the other way is to decrease the loads. Going to larger physical lobes made for lower loads, making for a fairly inexpensive camshaft that lasted a long time and could be used in everything from taxicabs to police cars. Those engines lasted a very long time.”

This system lets us use higher acceleration rates than we even thought were possible. – Billy Godbold, Comp Cams

In addition to the large camshaft lobe dimensions, the rest of the valvetrain also required an attendant increase in dimensions to maintain the strength and durability goals of the engine platform. The two- and four-valve modular engines — the predecessors to the 5.0-liter Coyote — used these robust, inexpensive parts. Larger roller followers and larger hydraulic lash posts are two areas where the material dimensions were large, inexpensive, and, as it turns out, hindrances to performance.

“They finally came to the conclusion that these parts were heavy, and started to look at ways to make the valvetrain lighter and more compact, which they did with the Coyote. With the Coyote, the lobe is still large when compared to an old pushrod lobe, but it’s smaller when compared to the older modular engines,” says Godbold.

Ford took the valve motion that was used in the modular engines and refined it for the first-generation Coyote engine, opening up a world of unexpected efficiency and performance.

“Because of the SEMA Technology Exchange, we get to look at what Ford’s done in terms of development. We’ve been making our modular camshafts better and better over the last 25 years, but little did we know that this new valvetrain setup would let us go even faster,” Godbold says.

Ramping Up

Valvetrain stability has always been the Holy Grail of camshaft development. For example, with a pushrod engine, the stiffer the pushrod and rocker arm, the more aggressive the camshaft ramp rates can be without losing the valve’s motion and hurting performance, or worse, destroying parts. Although an overhead-cam valvetrain design doesn’t have a pushrod in the mix, cylinder head strength, camshaft stiffness, and especially roller-follower stiffness and strength play a huge part in camshaft design.

The compact dimensions and reduced weight of the Coyote's valvetrain system mean that accelerated camshaft events are possible.

The compact dimensions and reduced weight of the Coyote’s valvetrain system mean that accelerated camshaft events are possible.

Ford set out to redesign the valvetrain system atop the Coyote, and it’s through these enhancements that the engineers discovered that there was more potential in the Coyote’s valvetrain than previously thought possible.

“The 2015 induction system uses a cast version of the Boss 302 cylinder head, with a higher-lift spring and quicker camshaft ramp rates, which is just a little bit better than previous designs,” says Godbold. “Higher lift and acceleration are built into the 2015 camshafts. So, instead of taking our 2011-14 cams and just adding lift, we also increased acceleration to work with the valvetrain system’s improved spring technology.”

The Design Process

With an overhead camshaft valvetrain design, the roller follower’s ratio is never static, which complicates the camshaft design technique — especially when compared to a traditional cam-in-block engine platform.

“With a pushrod engine, we can can design the tappet motion and trust that the rocker arm is going to be about the same,” says Godbold. “But on overhead camshaft engines, you have to design from the valve motion and run it back through the valvetrain to come up with the camshaft. You don’t design the cam, you design the valve motion and come up with the camshaft from that motion.”

As the mad scientist behind the development of Comp's camshaft grinds, Godbold describes himself as a 'redneck with a physics degree'.

As the mad scientist behind the development of Comp’s camshaft grinds, Godbold describes himself as a ‘redneck with a physics degree.’

Locking In The Middle

[caption id="attachment_688266" align="aligncenter" width="640"] The lockout kit (shown above) is not required for 2015 Coyote engines due to the mid-lock camshaft phaser.[/caption]

A new item used in the 2015 engines is the mid-lock camshaft phaser design. The 2011-’14 engines use a camshaft phaser that permits full exhaust advance and full intake retard, but in order to provide an engine that would pass this test, the phaser design was revised for 2015 to incorporate the mid-lock design for the intake camshaft.

Godbold says this has to do with European emissions testing, where they use something called a ‘bag test.’ This is where they take a plastic bag, similar to a leaf bag, and place it over the exhaust pipes at startup to see what types of pollutants the engine emits at startup. In the previous-generation phaser, combustion is not very clean for the first few seconds – the engine had to build oil pressure and move the camshaft up from the full-retard position to the position where it gets good cylinder pressure and clean emissions. During normal operation, the phaser still permits the full 50-degree range of adjustment; this mid-lock situation only occurs at startup.

There’s a reason that camshaft design has long been thought of as a black art; many enthusiasts simply don’t have the mathematical skill to figure out the tiny details that can make or break an engine’s performance. It’s figuring out these small details that are Godbold’s domain.

“As you’re designing valve motion, you also need to determine how much acceleration the valvetrain can handle. Too fast, and it creates deflection and throws the valve out of control – trying to free parts from the valve cover,” he says. “This system lets us use higher acceleration rates than we even thought were possible. This gain is from the stiffness of the compact rocker,” he explains.

An interesting portion of the conversation revolved around the advances made in camshaft technology in regards to time. As time passes, and more development resources are brought to bear on the projects in question, the products become more advanced.

This thought process is similar to the advancement seen in computer memory – Moore’s Law – which is the observation that the number of transistors in a dense integrated circuit doubles approximately every two years. Camshaft performance doesn’t necessarily double, but the more resources expended upon their development, the better they perform.

Godbold explains that when the LS engine originally hit the market, the first camshaft designs were nothing more than warmed-over small-block Chevy profiles. Testing, customer feedback, and computer simulations advanced the development of the design, and the same process is at work here with the Coyote engine.

Material development has surely helped, but these advanced simulation processes – and on-track testing by many of Comp’s customers – has also hastened the improvement of the products, along with the knowledge gained from the SEMA Technology Exchange.

“The surest way to make something better is to compete with it,” says Godbold.

Exploiting The Knowledge With New Products

The valve spring upgrade from the factory in the 2015-16 Coyote engine has allowed Comp Cams to develop camshaft profiles that are specific to these model years, increasing performance capability without any other changes.

“We have a new series of camshafts called the CY-r Series. These use the upgraded lobe profiles that have higher lift, and quicker ramp rates. They are drop-in camshafts for these engines – they don’t require new springs. But we also know that there are plenty of guys that have a 2011-14 who would really like to have the hot rod cams made for the newer engine. Now we also have the CY-r for the 2011-14, but they require springs in those older engines,” says Godbold.

Project FFR Cobra Jet On The Dyno

The profiles on all CY-r camshafts (2011-14, 2015+) are the same, but the spring needs an upgrade in the earlier engines to handle the increased camshaft lift and ramp.

A complete, modified cam phaser for the 2011-'14 engines.

A complete, modified cam phaser for the 2011-’14 engines.

Also, Godbold cautions that 2011-only owners will need to closely inspect the area between the roller and the boss where the hydraulic lash adjuster sits in the cylinder head for clearance once the camshafts are installed – it’s best to perform the camshaft upgrade with the cylinder heads removed from the engine on this model year, in case the boss area requires clearancing. This area was revised on the 2012-newer cylinder head casting and should not be an issue.

“On the ’11, I’d recommend changing the springs, then roll the cams around with the springs in it and check clearance with the wheel, and grind it and clean it out it you need to,” he explains.

The availability also exists for the CY-r lobes to be ground into custom camshafts, with specific lift and duration numbers; for racers looking for extra performance, it’s best to contact Comp directly to discuss your needs. For those with earlier Coyote engines that don’t want to expend the effort to install springs, Comp’s 2011-14 NSR (No Springs Required) camshafts remain in the catalog – there are six different shelf grinds for this configuration.

One of the 2011-14 CY-r camshafts with a phaser lockout plate.

One of the 2011-14 CY-r camshafts with a phaser lockout plate.

Stock 2015 Coyote camshafts measure .512-inch lift on both intake and exhaust valves, with 211 degrees of duration at .050-inch lift.

There are currently five CY-r Series camshafts from Comp available for the 2015-16 engine. Each grind is specifically tailored to different types of power increases – there are upgrades from stock (PN 243420) all the way through max-effort street-strip blower cams (PN 243480). The 2015-16 camshafts, unlike earlier years, do not require the use of camshaft phaser limiters. Two spring kits are available (PN 26113 and 26125) for those who are pushing the envelope and require more valve control due to high boost or RPM.

2015-up CY-r

The same CY-r grinds also exist for the 2011-14 engines, albeit with different part numbers. These do require the use of phaser limiters, also available from Comp (PN 4953).

2011-14 CY-r

A set of the new CY-r custom ground cams has been installed into one of our test engines – the Coyote Cobra Jet – and are expected to improve the engine’s performance, not only in the upper range of the RPM band, but also provide more power under the curve.

The engine also received an upgrade to a set of individual throttle bodies from the previous Cobra Jet intake manifold, with a plan to serve the engine well in its foray into the Factory Five Cobra Jet Challenge car our sister site, Turnology, is in the process of finishing up, which debuted in the Toyo booth at the 2015 SEMA Show in Las Vegas. Those camshafts are custom ground on the CY-r cores, and carry .516-inch lobe lift on the intake side with .514-inch lift on the exhaust side. Duration at .050-inch lift is 235 degrees for the intake camshafts and 237 degrees on the exhaust camshaft. Lobe separation is 127 degrees on both camshafts.

The Coyote Cobra Jet's new individual throttle body induction system. These will be put to the test with the new camshafts from Comp, with over 650 wheel horsepower expected.

The Coyote Cobra Jet’s new individual throttle body induction system. These will be put to the test with the new camshafts from Comp, with over 650 wheel horsepower expected.

For comparison, the old cams from this engine — which made 624.9 horsepower and 456.6 lb-ft of torque on the dyno — use specifications of .512-inch lift for the intake, with a duration of 240 at .050-inch. On the exhaust side, the camshafts area also .512-inch gross lift. Duration is 246 degrees at .050-inch lift, with 128 degrees of lobe separation on both intake and exhaust camshafts. The new camshafts add five degrees of overlap (18 degrees versus 13 degrees) which will provide more signal to the incoming intake charge and provide improvement to engine acceleration.

Note that while the new camshafts appear to be virtually the same — but with less duration at .050-inch — the ramp rates are quicker, leading to more usable power under the curve. As the engine will be used for road-course activity, the new design is a perfect match for the required characteristics, without the threat of power loss at high RPM. The individual throttle bodies from InnoV8 Race Engines recently installed on the engine are also expected to boost the high-RPM power level.

Video Of The ITBs In Action

In Conclusion

Perhaps the most important theme to take away from this article is that technology always marches on. Development processes never cease, even at the OE level, which continues to drive aftermarket improvements into the stratosphere. When companies collaborate on performance capabilities, the benefit to the end user – the enthusiast – is easily greater than the sum of the parts. If a hot Coyote engine is in the stable, perhaps it’s time to take a look at the potential power gains afforded by using the latest and greatest performance parts.

Article Sources

About the author

Jason Reiss

Jason draws on over 15 years of experience in the automotive publishing industry, and collaborates with many of the industry's movers and shakers to create compelling technical articles and high-quality race coverage.
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