Читать книгу Ford Coyote Engines - Jim Smart - Страница 7
ОглавлениеThe 5.0L Ti-VCT Coyote block is a durable machined casting right out of the box. It can easily withstand outrageous amounts of power courting the 600- to 800-hp mark. The 5.0L Ti-VCT 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 was increased to 3.629 inches (92.2 mm) along with an increased stroke of 3.649 inches (92.8 mm), which was still a “square” engine design with identical bore and stroke. Where the Ti-VCT 5.0L block differs is in an entirely new design with heavier webbing and other internal improvements intended to support greater power output from modest displacement.
When the Coyote was introduced for 2011, Ford said, “This aluminum block was developed for optimized windage and oil drainback under lateral conditions and high-RPM use, such as a track-day outing,” meaning this was an engine designed specifically for performance. Ford added, “Increased main bearing bulkhead widths and nodular iron cross-bolted main bearing caps with upsized bolts were also employed to accommodate the significant performance increase.”
The Ti-VCT engine employs a rugged aluminum block with paper-thin iron cylinder liners. Because the Coyote’s iron cylinder liners are quite thin, this block must be sleeved with thicker cylinder liners for all-out racing in the 800- 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 stay put, ensuring block integrity. You can build one of these thick-cylinder bore blocks for the street if you’re an avid weekend racer. Thick cylinder liners are a good life insurance policy for a block already able to take extreme punishment. Cylinders can be bored as high as 3.700 inches to achieve 5.2L.
The basic 5.0L Ti-VCT block is the most rugged Modular-based casting to date, but it has nothing in common with the 4.6L Modular except bore spacing and deck height. This block can withstand 800 to 1,000 hp, although it is suggested that you opt for the Pro Mod or Holbrook block with thicker cylinder liners if you plan on pushing power beyond 800 hp.
Holbrook Racing Engines offers its own thick-cylinder-liner Coyote block as well. Holbrook can take your block or an existing block from stock and set you up with an improved thick cylinder block, which can also be bored to 3.700 inches.
Rugged block architecture is what holds this engine together. Main bearing webs are thicker and heavier, allowing for performance extremes from enthusiasts and Ford product planners. This means the basic Coyote block can stand up to naturally aspirated performance demands, supercharging, nitrous, direct injection, and more. It can be said with confidence that this block will withstand more than 1,500 hp when sleeved with the thicker ductile iron cylinder liners mentioned earlier.
Performance enthusiasts like the Coyote block with its extensive network of ribs and beefcake support, which means strength and durability. These left-side (driver) block casting ribs and gussets provide unprecedented strength across block decks and pan rails. Cross-bolted main caps with interference fit provide the security of Fort Knox. One weakness has been among 4- and 8-cylinder bores, which have experienced cooling problems and blown cylinder walls. Improved coolant flow at the back of the block and heads can solve this problem.
The right side (passenger) yields the same story of crossed, vertical, and horizontal ribs providing extraordinary strength. What this means for you is a bulletproof block for street and weekend strip activity.
It used to be that rear main seals were integral with the five-main-bearing cap; not anymore. The rear main seal is fitted into a bolt-on cast-aluminum aft block cover, which is separate from the five-main-bearing cap, which makes rear main seal replacement easier and ensures a more leak-proof seal.
Skirted blocks, an old-school design approach that went away with the 90-degree Fairlane V-8 (221/260/289/302/351W) and 385-series big-blocks (429/460) designed in the 1960s, is back because it provides the greatest strength around a high-revving bottom end. The 5.0L Ti-VCT is a “square” engine (identical bore and stroke) that likes to rev. This engine makes its greatest power at high RPM. The downside to this design is limited potential for growth. You can’t make this engine any larger than 5.0L unless you go with thicker cylinder liners. And with that, the most you can go is 5.2L.
With this new block come 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 robbing power. The result is a more positive ring seal, which helps efficiency and power. Gone is the Modular’s coolant tube down the middle of the valley. Instead, coolant is routed through the front of the block, leaving plenty of room for exotic induction systems and superchargers.
In the spirit of classic Ford 406 and 427 FE-Series big-blocks, the Coyote has cross-bolted main caps. The Modular 4.6L/5.4L engines had jackscrews (Romeo) or dowel pins (Windsor) to shim up main caps. The Ti-VCT Coyote does the Modular engine one better with perfect-fit main caps machined exactly to the proper size so that jackscrews and dowels are unnecessary.
These piston-cooling oil jets provide good heat transfer to the oil, which carries excessive heat away, especially in boosted applications. Some confusion surrounds them because the 2011–2013 Coyote blocks had them and then Ford dropped them. In the course of 2015–2016 production, piston-cooling jets returned. Expect to see some blocks with this provision and some without.
Here’s a Coyote block without the piston-cooling jet provision. Unless you’re opting for supercharging, turbocharging, or nitrous, you probably don’t need them. Forged and coated pistons probably don’t need them either. The logic is better to have and not need them than need them and not have them.
The Coyote’s bottom end from another angle demonstrates how rugged this engine is. Whether you are towing, hauling, or racing, the Coyote is up to the task. Properly torqued to Ford’s critical specifications, this is a virtually bulletproof bottom end that can take anywhere from 600 to 1,000 hp. With thick-wall cylinder liners and a studded ARP fastener bottom end, your Coyote will stay together beyond 1,000 hp.
A close-up look illustrates the Coyote’s paper-thin iron cylinder walls. Believe it or not, these cylinder sleeves can withstand 600 to 800 hp. Although some have gone to 1,000 hp without consequence, it is strongly suggested that you opt for thicker cylinder sleeves if you’re going beyond 800 hp. Note the abundance of cooling passages between block and heads. In addition, 11-mm head bolts reach deep into the bottom of this block, which prevents deck distortion. Some engine builders have concluded that you don’t need torque plates for honing with this block. It is still suggested, however, that you use a torque plate for cylinder honing.
The Coyote block is easily identified by its deeply webbed valley, which is designed to clear almost any induction system. It has two knock sensor bungs, one for each bank. Also note the crankcase ventilation “chimneys” (arrows) known as “bay-to-bay” breathing. These chimneys also provide excellent oil scavenging.
Here’s another look at the “bay-to-bay” ventilation chimneys, which improve crankcase breathing and oil drainback at high RPM. This ensures oil reaches all the right places at high RPM, when an engine is most vulnerable.
Block Modifications and Improvements
Although Ford has come up with a virtually bulletproof engine block capable of withstanding outrageous amounts of power, it does have its weak spots. Coyote blocks suffer from cylinder wall failures due to excessive heat issues, primarily in high-boost situations. Modular Motorsports offers a Head Cooling Mod Kit (455478), an easy bolt-on that improves coolant flow where it is needed most at the back of the engine.
If you’re planning more than 800 hp you should opt for a sleeved block from Modular Motorsports or Holbrook Racing, which are purpose-built blocks for racers. These blocks are machined for the thicker cylinder liners, and they can be bored to a displacement as high as 5.2L. Thanks to the way these sleeves are configured in the block, they’re virtually indestructible, which means they can withstand 1,000 to 2,000 hp. This is a remarkable statement for a lightweight aluminum block. Ford has never produced a stronger block; you can build your Coyote with confidence knowing it will stay together.
Holbrook Racing Engines re-sleeves Coyote blocks with thicker cylinder liners for those of you seeking in excess of 800 to 1,000 hp. Holbrook can take your stock Coyote block and re-sleeve or can take a block from its inventory.
Traditional engine building technique applies to the Coyote block. As with any other production casting, you can expect to find flaws that can lead to engine failure. Deburr the block and remove any casting flash in your block preparation. Remove stress risers than can lead to cracking and failure. Thoroughly examine oil and cooling passages and chase them to remove debris that can do engine damage. Oil galley passages should be massaged to eliminate turbulence. All bolt holes should be chased for more accurate torque readings during assembly.
Here’s a closer look at the Holbrook thick-sleeve Coyote block. In the background is a stock bored block. Closer is the Holbrook sleeved block. Because Chris Holbrook is himself a long-time avid drag racer, he understands what works with the Coyote and what doesn’t. The Holbrook block isn’t purchased from a supplier. It is bored, sleeved and finish-honed in the Holbrook shop where everything is closely monitored and inspected.
This close-up of the Holbrook block demonstrates what you’re getting for your money. Cylinder bores are bored and step cut to the point at which there’s no chance of cylinder movement. Cylinder bores in the Holbrook block are siamesed for security.
The Ford Performance M-6010-M50R Coyote race block enables you to take peak horsepower well into four-digit territory for just under $3,000. What makes this block stronger isn’t so much the bottom end, which is the same as the stock block, according to Jesse Kershaw, drag racing parts and competition manager at Ford Performance. It is the block deck and thicker material around the thin-wall cylinder liners that give this race block extraordinary strength. Cast-in cylinder supports on the intake side help hold things together. (Photo Courtesy Ford Performance Parts)
This 2011–2014 oil filter mount with filter and dyno cell connections is different from the 2015–2016 version because it does not have the oil drainback provision.
The arrow indicates the additional block oil return passage along with a revised oil filter adaptor (not pictured) for 2015–2016. This change was adopted to improve fuel economy. The block and oil filter adaptor must match.
This Modular Motorsports’ Head Cooling Mod Kit was developed to solve cooling problems at the rear of Coyote engines. It installs where the rear cylinder head freeze plugs are located, which allows improved coolant flow. The weakness is excessive heat around the number-4 and -8 cylinders, primarily in boosted applications.
A nice option is to stud your Coyote block’s main caps for improved durability. ARP and/or Ford Performance can help with main stud packages engineered to hold things together under extreme conditions. These engines are already rugged and use factory torque-to-yield fasteners. Studding the block makes them virtually indestructible.
The 5.2L Voodoo block looks like the Coyote block at first glance. It is, in fact, a different block with larger 3.700-inch (94-mm) sleeveless cylinder bores. When you think of sleeveless cylinders in an aluminum block, it sparks memories of Chevrolet’s sleeveless Vega 4-cylinder engine, which suffered from grave durability issues. Such is not the case with Ford’s state-of-the-art DOHC V-8. Cylinder walls are finished using the Plasma Transferred Wire Arc (PTWA) coating process developed in a cooperative effort between Ford and Flame-Spray Industries. The result is a super tough, lightweight, low-friction surface also used on the 5.4L DOHC engine in the Shelby GT500. This process sheds 8.5 pounds from the 5.2L Voodoo block.
PTWA is nothing new in the aerospace and heavy-equipment industries. However, it is surely new for Ford Motor Company. PTWA uses compressed air along with high-intensity electricity to create an extremely hot, 35,000-degree F plasma jet that coats the aluminum cylinder wall. This, of course, is an oversimplification of the PTWA process. Suffice it to say, PTWA gets the weight out and durability up by spraying on the sleeve as a coating instead of inserting an iron sleeve. Where this process gets challenging for Ford is the amount of time spent per cylinder. PTWA is a very time-consuming process and is therefore costly. The PTWA process takes more time than just inserting an iron sleeve. This is something Ford and Spray-Flame are working on at press time.
Here’s the PTWA cylinder-liner process being applied to the 5.2L block during manufacture. Ford has brought this technology in-house, which reduces production time and expense, to result in a lighter-weight block. (Photo Courtesy Ford Performance Parts)
This is the 5.2L Shelby GT350 block during manufacture. What makes the 5.2L block innovative is Ford’s patented Plasma Transferred Wire Arc (PTWA) cylinder-liner technology. This process eliminates typical heavy iron cylinder liners with a deposition process. This is the 5.2L block in manufacture prior to the PTWA cylinder-liner process. (Photo Courtesy Ford Performance Parts)
Ford recommends a 500-mile break-in period with the new 5.2L engine to achieve good ring and bearing seating. Break-in with the PTWA cylinder bores is the same as with traditional ductile iron bores. Periodic hard acceleration in third or fourth gear at speed helps seat the rings. Keep revs conservative (under 6,000 rpm) when you’re wearing in the rings. Change the break-in oil at 1,000 to 1,500 miles. Then, opt for a good synthetic 5W50 engine oil. Keep in mind the 5.2L Voodoo engine calls for 5W50. However, the 5.0L Coyote uses 5W20.
This is the 5.2L GT350 block now available from Ford Performance Racing Parts. It is the same production block used in the Shelby GT350 and GT350R. You can get it now for your 5.2L big-bore Coyote build project. (Photo Courtesy Ford Performance Parts)
If you’re impressed with the 5.0L Coyote block, the 5.2L Voodoo block is even more impressive, with thicker main webs within an even stronger casting. Ford Performance Parts will have a 5.2L Coyote block available by the time this book comes off the press, which means the sky is the limit for your S197, S-550, or F-150 engine project. It means greater displacement, thanks to a larger bore size. In fact, the new 5.2L Coyote block from Ford Performance makes it possible to get more displacement from the 5.0L’s stroke without the thicker sleeves, which cost, on average, $1,000 if you’re doing a 5.0L block. This is a nice alternative to a bored thick-sleeve 5.0L block because you get more displacement without having to sleeve.
