Because it has a dual-sheave...
Because it has a dual-sheave damper and the oil pump is 6mm longer, the Coyote crankshaft wears a slightly longer nose than a 4.6. This is why a Coyote crank will not work in a 4.6 block.
Key challenges during the surrogate phase were the intake and exhaust manifolding layout and runner length; camshaft selection; and lubrication. From an enthusiast's perspective, this is where the Coyote got its howl. Fundamental architecture changes were possible, or as Jeff put it, "During this phase, particularly testing this engine on the dyno, we had good opportunity to influence the design."
In fact, Jeff and Adam were simultaneously running their phases of the Coyote program-one in hardware and the other in software-yet constantly comparing results and cross-verifying and improving their work as they went. Not much later Adam and Jeff would work with those laying out the Coyote's architecture, while continuing to develop and validate the Coyote's fundamental power-making ability.
In short, Coyote development more exploded in several directions instead of a connected straight-line series of dots. It was a tumultuous, tiring effort, but it worked. In just 16 months the first Coyotes hit the dynos in January 2009. "The first engine out of the box in the development cell ran for 800 hours, and that's Performance Run, and so it was a very good success," says Gary.
Laying open the leading edge...
Laying open the leading edge of the crankshaft journal oiling holes was hand-detailing race shop work on the pushrod 5.0 engines-now it's factory stock. It's just of many detail improvements to the oil passages on the Coyote oiling system to support 7,000 rpm.
"And our first engine went to map, and for us, we were just very proud of that-it was good enough for map right out the door. We thought it was impossible when we first started off." Going to map means the engine was good enough to have its core combustion personality set in stone. Once mapped, the fundamental engine would be frozen and the long validation and calibration work would begin.
Besides meeting the performance goals the Coyote had to pass all of Ford's standard durability tests. These dyno sessions are incredibly brutal, always far exceeding what any rational customer would do to his engine, and occasionally surpassing what is physically possible in a car.
We observed some of this internal combustion water-boarding, and for anyone with a foot-pound of mechanical sympathy it isn't pretty. Engines run fatigue cycles equivalent to 62 Daytona 500 races. Others replicate customer drive cycles for 1,000 running hours to include 1,000 cold starts, plus hitting its peak torque and power for sustained periods. That test alone runs 100 hours a week for two and a half months.
The Coyote mounts its crank...
The Coyote mounts its crank trigger between the crankshaft and flywheel because the rear of the crank is less distorted by torsional stresses than the front. The greatly increased accuracy is needed to meet increasingly tighter on-board diagnostic requirements-misfires are now measured at all engine speeds and loads. Also, the crank trigger slings a lot of oil at 7,000 rpm, so it's best to get it out of the front cover anyway. All Coyote cranks use an eight-bolt flywheel attachment.
We witnessed another torture session where the engine was run at WOT for several minutes, the headers glowing just a hint of red, then the engine shut off and after several seconds of sitting, -20 degree ice water was forced through the cooling system. Frost formed on the test rig as the engine was about frozen to death, then the ice water stopped, the engine started and after a handful of seconds idling was taken back to max rpm, max load for another heat cycle up to 225 degrees. Each complete cycle takes about 10 minutes, and the engine must survive days of these non-stop thermal shocks.
Most incredibly, "It can't be on its last legs at the end of the test," says Mike. "It can't be that it hasn't seized yet, we need to see crosshatching on the cylinders, no full-face ring wear, leak down needs to be below, oh, eight percent; it has to be very, very functional and could go do it again, quite frankly."
Be assured, this is one team, and engine, that has gone the extra mile to produce a no-excuses Mustang V-8.

The coyote damper is a traditional...

The coyote damper is a traditional two-piece, single-elastomer design. Most telling are the dual sheaves on an engine with nothing more than a water pump, alternator, and air conditioning compressor. Currently the inner sheave is used for the AC and the outer sheave for everything else. But it's obvious to us that the inner sheave is for a belt-driven supercharger at some future date. There is no provision for power steering as Ford has switched to electric power-assisted steering.

Like current Mustang GT rods,...

Like current Mustang GT rods, Coyote connecting rods are forged from powdered metal. Optimized for reduced weight and redesigned for uniform bearing loads around the big end, the Coyote rod eliminates the 4.6 rod's balance pad. These rods are plenty strong for stock rpm and power but will not survive forced induction.

Looking racy except for the...

Looking racy except for the production ring package, the Coyote's slim, hypereutectic pistons were designed to present as little contact with the cylinder walls as possible. Yielding 11:1 compression, the design is nearly identical to its 3.7-liter V-6 starting point, including the gray band of hard anodizing around the top ring groove. This withstands ring land pound-out and possible piston breakage. The dark patch is a friction-reducing moly coating.

Extensive hollowing, lightening,...

Extensive hollowing, lightening, and cross-hatching are obvious here. Pin oiling is via the oil ring groove. The 22mm pin diameter is the same as the 4.6, but the pin length is increased for greater rod/piston assembly strength. Mahle supplies the pistons from its Tennessee plant.

Total rod and piston weight...

Total rod and piston weight is approximately "1 kilo" says Ford. Conserving this weight was especially importantly in the Coyote because less reciprocating weight meant less counterweight diameter on the crankshaft, a crucial packaging concern in the crammed Coyote crankcase. The ring package is 1.2 mm x 1.2mm x 2.5mm and weighs just 24 grams. The top ring is moly-coated and sits 1mm lower on the piston than in the 4.6 for increased durability. Because of the 4.6 rod center-to-center length in a 2.8mm (0.110-inch) longer stroke, the piston height packaging is a little tighter.

As with this display engine,...

As with this display engine, the Coyote development engines we've seen to date wear flexplates for automatic transmissions. The manual applications get a dual-mass flywheel to dampen a driveline rattle and use a higher-torque rated version of the 280mm clutch from the Three-Valve 4.6.