2013 Ford Shelby GT500 Trinity 5.8L V8 - Power Of Three
How Ford's Special Vehicle Team stuffed 100 extra non-gas-guzzling, emissions-legal, Warrantied horsepower into the 2013 Shelby GT500 engine
From the March, 2012 issue of 5.0 Mustang & Super Fords
By Tom Wilson
Photography by Courtesy of Ford Motor Company
The world's most powerful...
The world's most powerful production V-8, coming to a Ford showroom near you this summer. With its world leading power and incredibly wide powerband, the 5.8-liter V-8 promises to propel the '13 Mustang Shelby GT500 into a new level of Ford performance.
If you doubt there's a horsepower race going on, this article ought to clear it up. For all the green hubbub about soybean seat cushions and cars that plug into walls, the age-old truth that high-performance machinery is always in style has never had so much boost behind it.
And, quite literally, never has a Ford production gasoline engine had as much boost as the new 5.8-liter V-8 in the 2013 Mustang Shelby GT500.This new development of the modular engine family is the most powerful production V-8 in the world. That's quite a claim for a mass producer such as Ford, but the perfect accomplishment for its in-house performance arm, the Special Vehicle Team.
While the engineering boss in the corner office at SVT, Jamal Hameedi, notes his team's goal wasn't setting a world horsepower record, they knew they had to go big when upgrading the GT500 Mustang. Not only were the other guys in town working hard on their ZL1, Ford's own Boss 302 was edging toward GT500 performance. So the Shelby GT500, although impressively upgraded for 2011 with an aluminum block and 550 hp, was scheduled for a complete makeover as a 2013 model to go on sale in mid-2012.
This re-engineering of the GT500 is all-encompassing, covering handling, braking, performance, and aerodynamics. In fact, we sense the upcoming GT500 will still be a Mustang, but one galloping so far ahead of the traditional ponycar herd that it'll run more with thoroughbred exotics than everyday quarter horses. It's aiming to be the ultimate Mustang, and we'll eat its 10-rib blower belt without butter if it isn't.
Subtle machining is the only...
Subtle machining is the only difference between the Condor 5.4 and Trinity 5.8 cylinder blocks, which are whittled from the same casting. One change impossible to see is the 5.8's deck height is 255.71 mm versus the 5.4's 256.00 mm. That minor 0.29mm difference accommodates the 5.8's thicker headgasket. Another invisible change is in the water jacket cores. The 5.8's cores were lightly massaged in spots to increase coolant flow while maintaining wall thickness. But major locations of interest to hot rodders, such as bellhousing bolt patterns, head retention, water and oil pump locations, and so on, are identical to 5.4 practice.
The joys of driving the new GT500 are still months away for us, however, and Ford is still teasing us enthusiasts with details. But as part of the tease, SVT graciously agreed to give us the cook's tour through the Shelby's new 5.8-liter V-8; the story you are reading is the result. It's a story impossible to write without SVT's cooperation, and we know you'll add your thanks to ours in being granted all-access to SVT's engine building team.
For the record, the code name Trinity covers the entire 2013 GT500 car, so the new 5.8 engine is formally known as the Trinity Engine or 5.8-liter V-8. That's a little different from Coyote, which designates just the 5.0 TiVCT V-8 in the Mustang GT, or RoadRunner for the Boss 302 engine. Finally, for reference, the previous generation 5.4 GT500 engine is codenamed Condor.
While this story concentrates strictly on the new 5.8 engine, it's important to remember the engine is part of an expansive, whole-car upgrade. SVT's goal was to transform the 2013 GT500 into a no-excuse super-Mustang, something far more complex than stuffing the largest displacement possible under the Mustang hood and heading to the dragstrip. Not only must the new GT500 be world-class fast in a straight line, it also must stand clearly atop an increasingly sophisticated Mustang lineup that includes the already potent Mustang GT and the fabulously well-rounded Boss 302. And haloing a Boss 302 in every category is going to take a lot more than a smaller blower pulley.
As Jamal Hameedi explains, "...this project didn't start out trying to outdo anyone or anything. It was really about keeping the separation in the Mustang line-up. Just like Porsche has the 911 and a GT3, which is track-focused--not the crazy power but a good, agile balanced car, an all-around good track car--and then you've got like a GT-2 which is... the fastest in the lineup on a track, in a straight line, top speed and everything. ...It's the same thing with a [Corvette] Z06 and a ZR1. ...but we did such a good job with the Boss that it was pretty close to the Shelby GT500, and so what we wanted to do was... keep that separation from the Mustang GT to the Boss to the Shelby GT500."
Unsaid but obvious, keeping the GT500 relevant includes not only topping the Mustang line, but also the Camaro offerings. With Chevy finally announcing the long-anticipated ZL1 at only 580 hp, the SVT team no doubt confirmed to themselves that they had made the right choice in going for all they could under the hood.
Brutally strong and amazingly...
Brutally strong and amazingly durable, this is what 650 showroom stock horsepower is made of. This early SVT publicity photo shows a few prototype parts such as the no-logo supercharger. It also displays the clutch, giving us the chance to note the 5.8 has moved from the 5.4's 250mm to a 260mm disc with upgraded materials for high-rpm use. Clamping force is also increased in the pressure plate to hang on to the additional torque.
Isn't this a spider of an...
Isn't this a spider of an oil filter adapter? Here we see the system configured with the oil-to-water “brick” heat exchanger and pressed-in hose nipples as used with standard cooling. With Track Cooling the oil thermostat replaces the “brick,” the hose nipples are deleted, and the spider is machined to accept SAE O-ring-type, threaded, stainless steel hose connectors. SVT says they don’t use AN fittings because they tend to loosen from vibration. The black hex seen under the “brick” is covering the pressure bypass loop (a spring-loaded pressure relief valve) used with Track Cooling. The same oil filter is used on all 5.4 and 5.8 engines.
Standard oil-to-water cooling...
Standard oil-to-water cooling uses the cooling system's thermostat to regulate both oil and water temperatures, but when oil-to-air Track Cooling is fitted, that thermostat is no longer available to the oil. Therefore an oil thermostat replaces the oil-water heat exchanger; it uses the same expanding wax pellet principle as the familiar engine coolant thermostat. This is a prototype of the oil thermostat--it's a billet piece for testing, but will be an aluminum casting in production. The thermostat is mandatory because water dilution (a normal byproduct of combustion) of the oil accumulates at low oil temperatures, plus the oil needs to be 180 degrees or higher for all its chemical additives to work properly.
When SVT sat down to set specific goals, they arrived at engine targets of 650 hp, 600 lb-ft of torque, a nominal redline of 6,250 rpm backed with an ability to momentarily over-rev to 7,000 rpm, and not invoke the Gas Guzzler tax penalty. While we aren't privy to Trinity's financial constraints, the 5.8 is a low-volume engine, so costs had to be tightly controlled. Exotic solutions would have to be paid for by relatively few customers, and we're sure Ford management is dedicated to keeping the GT500's sticker price competitive.
What SVT did to arrive at the 5.8 is start with the 5.4 GT500 engine and adjust it as necessary to support an initial goal of 640 hp. As the program developed, it was soon clear 650 hp would be just as easy to hit given the changes being made, so the target was officially bumped to 650 hp.
Compared to the now familiar Coyote 5.0, which was essentially a clean-sheet-of-paper design that owed next to nothing to the previous 4.6 Three-Valve starting point, it's tempting to say the 5.8 is a stretched 5.4 with the boost turned up. In fact, when described in overview, the 5.8 is indistinguishable from the 5.4 starting point. Like the 5.4, the 5.8 is an all-aluminum V-8 with double overhead camshafts, four valves per cylinder, a belt-driven supercharger, and air-to-water charge cooling. Like the 5.4, the 5.8 does not use variable cam timing, much less twin independent cam timing, nor does it use direct fuel injection. Indeed, the 5.8 does use the same fundamental architecture of the 5.4, meaning basics such as the bore spacing, nominal deck height, pan rail width, cylinder head design, and so on, are identical.
However, scratch just below the surface of the basic architecture and an amazing number of details differ. It's those details that make up this story, and they are there to support four major changes: greater displacement, significantly higher boost, piston oil squirters, and higher rpm.
So the 5.8 is it's own engine. Few components interchange between a 5.8 and a 5.4. However, even if they physically bolt on, the power of the 5.8 is in a different league than the 5.4. As a quick measure of that, the Condor 5.4 runs 9 pounds of supercharger boost; the Trinity 5.8 runs 15 pounds.
An overview of the bottom...
An overview of the bottom of the 5.8 block shows no changes at first glance. The main bearing caps and their six-bolt retention is carryover from the 5.4, as are the three shared PCV breathing and oil drainback passages visible on the inside of the block skirt. Also common are the three round bay-to-bay breathing holes in the bulkheads as modeled by the rear main bulkhead in this view, along with the oil pan rails, bolt patterns, and such. Get close and there are differences, however. SVT notes the 5.8 main bearing caps have an extra chamfer on them to ease assembly, but they remain interchangeable with the 5.4 version.
It's impossible to see a lip...
It's impossible to see a lip or edge between the parent aluminum and the 5.8's cylinder lining. The bore itself, however, looks and feels like iron--because it is. SVT says the Plasma Transfer Wire Arc process, which is finished with diamond hones and deck plates, helps make a dimensionally accurate cylinder. This facilitates the 5.8's tight piston clearance, which helps promote a tight piston ring seal. SVT also notes the 5.8's 93.5mm bore is the largest possible in this block.
Spotting the oil squirter...
Spotting the oil squirter hole in the main bearing bulkhead can take practice. The oil squirter itself is installed in a drilled passage underneath the main bearing insert. With the insert in place as it is here, the oil squirter is not visible, as it's buried in the bulkhead at approximately 8 o'clock to the bearing. The small groove in the bearing insert that feeds oil to the squirter is visible. Looking closely at the edge of the bulkhead, just before it reaches the cylinder bore and a little lower than the breather hole is a small slit. That slit is an angled passage from which the piston squirter shoots.
There's little mystery on how SVT ended up at 5.8 liters. From an engineering side, it's always easiest and least expensive to increase power via increased displacement, so the first move of an engineer with a directive to add 20 percent more power to an already highly stressed engine is make the engine bigger. The larger engine is less stressed at a given power level, and when talking about the most powerful production V-8 in the world, a little less stress is a good thing.
That said, marketing has to have played a large part in the 5.8's displacement. There's plenty of glory surrounding the 351ci displacement in Mustang history, a displacement that translated into 5.8 liters when Detroit went metric. Taking the historic theme a step further, the 5.8 is the perfect upscale displacement from the 5.0 in the Mustang GT, so you know management didn't waste any time landing on 5.8 liters of displacement for the GT500 engine.
How to achieve the extra 400cc displacement over the 5.4 must not have taken long, either. The 5.4 V-8 is already physically constrained in stroke, both inside the crankcase and outside, as a physical package that must fit a Mustang engine compartment. In the crankcase, the careful juggling act of stroke, piston height, rod length, and crankshaft counterweight clearance is already pretty well played out in the 5.4. Lengthening the stroke would quickly crash the pistons and crankshaft counterweights, leaving the other stroke-increasing option of raising the deck height. But raising the deck height on a V engine means making the engine both taller and wider, an impossibility given the Mustang's engine-bay dimensions.
If a longer stroke was out, then a bore increase was not without issues, either. As detailed in our Coyote and RoadRunner articles, Ford's multimillion-dollar investment in V-8 machining centers is not flexible when it comes to changing bore centers, and the modular engine family is thus fixed at 100mm bore centers. So, the SVT engineers couldn't stretch the 5.4's cylinders farther apart. Nor could they move over to the bigger architecture of the 6.2 V-8 as found in the SVT Raptor. That engine is too large for the Mustang engine compartment, plus it would be prohibitively expensive to design a better breathing Four-Valve cylinder head for it, as well.
That left increasing the 5.4's bore, an option open thanks to the recent maturation of spray-bore technology. This is a technique Ford has invested in for years and quietly debuted in the 2011 Shelby's aluminum block.
Best visual clue to identifying...
Best visual clue to identifying the 5.8 block is the drilled water passage at the 6 o'clock position below each cylinder. This passage flows water to the cylinder head where it is directed between the exhaust valves seats. Also note the slightly larger round holes between the cylinders. These are found on both 5.4 and 5.8 blocks, but in the 5.8 block the passages are drilled, as detailed in the next photo.
A spray bore is special because it eliminates the iron cylinder liners. This technology saves weight since the mass of iron lost is significant and it comes off where every Mustang could stand to lose a few pounds, right over the front axle. But, most importantly in the 5.8, eliminating the liner's thickness allowed the absolute maximum bore the aluminum block architecture would allow.
The trick is, pistons and piston rings can't live without the durable, non-galling iron cylinder surface. Bare aluminum is far too soft to coexist with the piston and rings, and so some other, harder material must be added to the raw aluminum bore. Many have worked on this problem for decades, including Reynolds Aluminum 40 years ago in big-block Chevy Can Am engines. Porsche is another notable experimenter. These earlier methods involved both adding material into the as-cast aluminum, along with wet sprays such as Nikasil, which are applied after casting.
Ford's approach, first used in the 2011 GT500 block, differs in that it is a post-casting, dry application of molten iron, resulting in a thin, durable, lightweight, oil-holding metal lattice joined to the aluminum bore's surface. The process is called Plasma Transfer Wire Arc, and was developed jointly by Ford and Flame-Spray Industries in Long Island, New York. Besides the GT500 blocks, it's used in gas turbines and Caterpillar remanufacturers its diesel cylinders with it, so it's tough stuff. Ford says the iron liners removed from the 2011 GT500 block weighed 7 or 8.5 pounds (depending on who you ask), and the PTWA coating is only 150 microns (0.006-inch) thick, so little weight is replaced.
This is what SVT means when...
This is what SVT means when it says the 5.8 block is "cross-drilled." Looking closely just below the edge of the between-cylinder water hole is a drilled passage. It leads to that cylinder's matching water hole. It's this small passage that provides the needed inter-cylinder deck cooling required by the 5.8.
For the GT500 block, the application begins in Germany, where casting specialist Honsel gravity-pours the GT500 block as a sand-casting with chill plates. Honsel then machines a spiral groove into the cylinder to act as a ledge for the sprayed iron to grip onto. Next, what is essentially a rotating arc welder is inserted into the cylinder. It uses a wire feed, an electric arc, and compressed air to blast a stream of 35,000-degree iron plasma onto the cylinder walls. The molten iron droplets are tiny, just 20 to 30 microns (0.0008 to 0.0011 inch) in diameter, and they dry in 10-6
seconds. The wire-fed plasma jet is maneuvered to form the lattice pattern; later the cylinder is diamond-honed for final crosshatching.
Ford is certainly invested in spray-bore technology, holding 25 patents in this area, and it's paying off. Nissan licenses the technology from Ford for its GT-R V-6 bores, and empirically, we've heard of no issues with '11-'12 GT500 blocks. The SVT engineers say the iron has a strong purchase on the aluminum, so liners may be a thing of the past with Ford performance engines. One consideration is that the thin iron coating can't be overbored, and we're not sure a GT500 block could be sleeved should things go awry after a night of heavy passion by an aftermarket tuner. SVT says the bores can be re-sprayed, but obviously this is not a field fix, so it sounds like a new block is required should damage occur.
In any case, the new 5.8 uses the identical aluminum block casting as the 5.4 with a few extra machining steps. And thanks mainly to spray-bore technology, SVT was able to increase the bore from 90.2 to 93.5 mm and thereby reach 5.8 liters with the stock 5.4 stroke.
The oil squirter valves are...
The oil squirter valves are linked to the piston bottom so we're showing them together. The oil squirters are not simple nozzles, but spring-loaded valves designed to open at 50 psi. And while it's admittedly small, the not-miniscule hole in the squirter is a good clue that the squirter shoots a steady stream of oil, not a mist or spray like a fuel injector. Besides providing the necessary oil volume, the garden hose-like stream allows a more accurate, longer-range aim.
Both the 5.4 and 5.8 crankshafts...
Both the 5.4 and 5.8 crankshafts begin life as identical forgings in Ford's Windsor, Ontario, Canada plant, which is certainly appropriate for the 5.8. There are no center counterweights on either crank, and all major dimensions, such as journal dimensions, oiling, and flywheel retention, are identical. Because the GT500 is available only with a manual transmission, all are fitted with a pilot bearing. The only differences are balance and harmonic-dampener retention.
Besides its beefier construction,...
Besides its beefier construction, the 5.8 piston bowl volume was filled in from the 5.4's 13.2 cc to 10.3 cc. That, along with the bore increase, raised the compression ratio from 8.4 to 9.0:1 in order to improve off-boost fuel economy. Also visible are the moly anti-friction coating on the skirt and the new 5.8 ring pack. Looking to offset every gram possible from the increased piston weight, along with reducing friction, supporting the 7,000-rpm over-rev, and mating with the cylinder wall finish, Brendan Vido went from cast-iron to reduced-tension chromed steel on the compression rings and carried over the oil control rings. The steel rings are lighter, moving the total ring package weight from 26.4 to 23.3 grams. And that moly patch earns its keep considering the 5.8's piston-to-cylinder wall clearance is a scant 45 microns or 0.0017 inch.
Because the thermal activity in the 5.8 at full chat is probably adequate to give the devil sweats, attention to the cooling and oil systems was required. Specifically, SVT needed to verify coolant flow completely around the cylinders just below the block deck, as well as between the exhaust valve seats in the cylinder heads. In the block's bottom end the pistons are subjected to diesel-level heat and pressure and so they needed oil cooling jets.
For the cooling system upgrades, SVT turned to computational fluid dynamics modeling. Perhaps the greatest need was to get coolant flow between the exhaust valve seats, a journey that begins in the block as the coolant flow is from the water pump through the block, up through the heads, and out to the radiator. Existing 5.4 coolant flow directed water up through the block's deck and nicely around the exhaust valves, but not between them. That's where the CFD came in especially useful, letting the SVT engineers establish the additional paths required to route coolant between the exhaust seats at the correct flow velocities and volumes. These additional coolant paths in the heads needed to be fed by new passages in the block's deck.
Furthermore, flowing water around the top of the cylinders meant another new set of passages was required between the cylinders. Luckily, the CFD showed the solution to both new cooling paths turned out to be small passages drilled in the block and heads. Because simple drilling operations gave the needed extra coolant flow, there was no need to make a casting change in either the block or heads, which is one reason why both the head and block castings are carryover 5.4 parts.
In the bottom end of the block, the big 5.8 attraction are the piston squirters. These are actually tiny spring-loaded valves positioned in newly drilled passages in the main bearing bulkheads. Access to the squirters is found under the main bearing inserts, and their shooting path is through another carefully placed diagonal hole drilled into the side of the main bearing bulkhead. Considerations on how to aim the squirters include both aiming at the desired portion of the piston--that would be the underside of the dome and the pin boss, and not the skirts or especially the connecting rod's beam--and the length of time the oil stream is on target. The engineers say they're hosing down the piston about 60 percent of its stroke, an on-target average that took considerable effort, they report.
The oil squirter valves are tensioned to open at 50 psi. This is necessary to assure adequate oil flow at the critical main bearing-to-crank journal clearance. It also keeps the squirters from filling the crankcase volume like a bunch of drunk frat boys playing with fire hoses. Only under higher loads and crankshaft speeds do the oil squirters provide maximum flow, and that's exactly when the piston needs the extra cooling. Otherwise, having the squirters continuously flow at full volume would only cause excessive windage, which drags on the crankshaft costing horsepower and fuel economy.
What the oil squirters do for piston temperatures is "awesome," say the engineers. That's a good thing, as the 5.8 piston is subjected to incredible heat and pressure. To put numbers to it, the cylinder pressure in the Condor 5.4 is already an impressive 1,650 psi, while the 5.8 endures a crushing 2,000 psi or so at maximum load. That literally flattens the dome on a 5.4 piston--not from detonation, but simply from combustion pressure.
As you might recall from physics class, such piston-collapsing pressure is due to tremendous heat. And it's never far from the engine designer's mind that the piston dome is not only subjected to searing heat, but it also has one of the longest heat rejection paths in the engine. So besides needing a new, larger-diameter piston, the 5.8 designers needed a much stronger piston.
SVT says the cylinder of tungsten...
SVT says the cylinder of tungsten weight stuffed into almost every 5.8 crankshaft's first counterweight, as seen here, will stay in place without welding it in place. One reason the team is sure is that force-monitoring equipment in the factory keeps tabs on the tungsten's press-in process. The other 5.8 crankshaft feature is deeper threads in the crank snout for improved harmonic damper retention. The extra grip is needed to offset the 5.8's
The 5.8 connecting rod, cap,...
The 5.8 connecting rod, cap, bolts, and bearings are identical to the 5.4 assembly with the exception of the narrowed small end. SVT says the angle-ground small end of the 5.8 rod poses no meaningful loss of strength--which would be tested at the top of the overlap stroke when piston inertia keeps it moving upward while the crankshaft is pulling downward. The significantly increased loads are in compression through the beam of the rod during the firing stroke say the engineers. Those loads are
Getting the 5.8 piston to...
Getting the 5.8 piston to survive 2,000-psi cylinder pressures meant adding a lot of mass to the center of the piston crown, plus bringing the piston pin bosses inward for increased support. The pin bosses are even angled inward in a slight pyramid shape to better support the piston dome. Considerable finite element analysis was expended to develop this shape, which helps conserve weight. Even so, piston weight grew from 342 grams in the 5.4 to 403 grams in the 5.8.
Assembling the piston, pin,...
Assembling the piston, pin, and connecting rod shows the taper ground into the small end of the 5.8 connecting rod. Interestingly, the piston pin is a pure carryover 5.4 part. Because of the stronger, more supportive piston, plus a slight reduction in pin-to-connecting rod clearance, pin bending is reduced and no increased pin strength is needed. Pin retention is via the usual circlip retainer.
The new piston is supplied by Mahle. While a conventional design, it does feature thick bulkheads to better support the piston dome. The angled geometry of these bulkheads is such that the small end of the connecting rod would no longer fit, so the small end of the rod was ground off at an angle, with the top of the small end narrower than the bottom of the piston-pin bore in the rod.
"Of course, if you change one thing you change another, and narrowing the small end of the rod closed the edge distance from the piston pin oiling hole in the top of the rod so much that Brendan Vido's computer modeling showed the rod became weak. Luckily the oil squirters put so much oil onto the bottom of the piston that there's no need for the oil hole in the 5.8, so the hole was deleted and rod strength preserved. Otherwise, the 5.8 connecting rod is unchanged from its 5.4 starting point.
Likewise, the main and rod bearings are unchanged. The 5.4 was the last Ford engine using a high-quality, tri-metal bearing insert, and it runs just fine in the 5.8. The tri-metal bearings are more expensive, but "really forgiving of any debris, contamination, high load, all that kind of stuff." This is a good example of the premium nature of the 5.8--even the new Coyote and its hot-rodded RoadRunner offshoot use the standard aluminum-backed modular bearing.
From the front, there's no...
From the front, there's no differentiating a 5.4 from a 5.8 oil pump because both pumps are identical except for their back plates. All internal gears, their swept volume, the front casting, internal passages, and so on are identical, even though the 5.8 has a definite need for more oil flow than the 5.4.
Because the larger, stronger 5.8 pistons are heavier than the 5.4 variety, the crankshaft balance falls out of tolerance on most 5.8 engines. This is handled by inserting a heavy tungsten weight into the front counterweight on 99 out of every 100 5.8 crankshafts, according to SVT.
Such balance concerns take on more, ahem, weight, when considering the mandate for a 7,000-rpm over-rev capability. The Achilles' heel of the modular engine family is its small cylinder-bore capability. We've beat this topic to death in our Coyote and RoadRunner stories, but as a quick refresher, the modular's 100mm bore spacing limit puts an emphasis on long piston strokes, and that in turn means high piston speeds. The 5.4/5.8 modular stroke is 13mm (0.510-inch) longer than the 5.0 Coyote/RoadRunner, for example, which is why the GT500 redline has traditionally been 6,250 rpm. Even the vaunted '00 Cobra R 5.4--a raging, naturally aspirated beast if there ever was one--saw fit to quit at 6,250 rpm, and all because that's an F1 or NASCAR-like piston speed with the 5.4/5.8 stroke.
So here comes management with a need for an occasional 7,000 rpm over-rev capability. That's 24.7 meters per second, or 4,861 feet per minute for us old guys, and let's just say that's way, way out there for a production engine. The result is a need to keep everything as light as possible in the piston and ring packaging. It also underscores SVT's labeling the 7,000 rpm as a trick up your Nomex sleeve and not a daily habit (anyone who can rev a 2013 Shelby to 7,000 rpm on a daily basis is living large on any account...). We asked Jeff Albers if the Copperhead PCM counts time over 6,250 rpm or anything like that, and he said no. "You can go there as often as you want," but if coolant temperatures exceed 251, the computer will progressively limit throttle opening and rpm.
The idea of the over-rev is track-oriented. “We maintained a continuous rev limit of 6,250 rpm,” Albers explained, “which is the same as the 5.4, but we allow a temporary over-rev up to 7,000 rpm to facilitate things like quarter-mile runs where you want to stretch the motor a little bit more, or say on a race track, a road course, where you might want to hang onto a gear through a corner and not shift, that sort of thing. So, we give time at the higher rpm, enough for any reasonable use of the car and the engine, but limit the amount of time up there just to limit exposure to those high rpm.”
With the 5.8 pan no deeper...
With the 5.8 pan no deeper than the 5.4 oil pan, the 5.4 oil pump pickup was reused, saving money. The 5.8 pan employs a simple stamped-metal baffle for anti-slosh protection in the sump, and the new pan has no trouble handling road racing acrobatics says SVT. Any increase in engine rigidity or sound suppression provided by the casting is unintentional say the engineers; the only reason for the cast construction was to achieve the necessary shape. SVT also clarified the 5.8's increased oil capacity does not increase its oil-change interval. The 5W-50 synthetic should be changed every 5,000 miles under severe duty or track conditions.
Testing showed the 5.4's oil...
Testing showed the 5.4's oil pump back plate deforms under heavy load, costing a reduction in oil flow. The simple cure was to replace the stamped rear cover with this billet-steel plate, and voila, no more deformation. Both flow and pressure are increased sufficiently to keep up with the increased demand of the piston oil squirters. The 5.8 oil pump bypass valve is set for 90 psi.
SVT added a combination oil...
SVT added a combination oil pan gasket/windage tray in 2011 and is carrying it over to the 5.8. Rob Waara, who handled 5.8 oiling, is pleased with the tray, saying it keeps windage below 5 percent even at high rpm. The tray is molded from glass-filled nylon into the complex shape seen here.
Relatively little work was required to turn the 5.4 cylinder head into the 5.8 head. In fact, from a power standpoint, the ports handled the increased airflow delivered by the increased boost and more aggressive camming, so no porting work was required. What was left for the SVT engineers was making the exhaust valves live through the resulting higher temperatures. This took development of the valves, valve seats, and cooling system.
We’ve already touched on the coolant passage improvements and that after extensive computer analysis the only mechanical changes were drilled passages to promote coolant flow between the exhaust valve seats. This sounds simple, but the engineers were set on evening coolant flow as much as possible throughout the cylinder head, and that entailed many computer simulations.
In the end, they were pleased with the 5.8’s top-end cooling as they got water flowing evenly between the exhaust valve seats, plus the coolant flow balance between the engine’s two banks is an even 49 percent on the right and 51 percent on the left (this is affected by water pump direction of rotation, which might also partially explain why cylinder No. 3 is always the hottest). Furthermore, this was accomplished with the first physical modifications as the development work was done completely in the computer. This saved tremendous time and money.
Getting the exhaust valve to live was done with improved materials and a little extra mass. Incredibly, the extra mass found on the combustion chamber side of the valve head is there simply to withstand the hellacious cylinder pressure. The original concave profile of the 5.4 valve deformed at 5.8 temperatures and pressures, so the head of the valve was made slightly thicker.
The harder valve material is Nimonic, trade name for a super steel alloy, along with a Stellite ring inlaid into the valve’s seating face. The Stellite is fitted to a groove machined into the valve face, and welded and machined in place. In the cylinder head, the exhaust valve seats were upgraded from W236 to W100 Stellite. That’s truly hard stuff normally found in “dry-gas” applications such as propane-burning engines. In the 5.8, the W100 is there strictly for its increased surface hardness as lubricity was not an issue.
To support the extra airflow coming off the 5.8’s larger supercharger, SVT employed the age-old expedient of reaching for an already developed and proven camshaft, or in this case, all four cams from the 5.4-liter Ford GT engine. These are more aggressive grinds than the 5.4 GT500 sticks, as seen by the gain of 1.1 mm of intake and 1.4 mm of exhaust valve lift, and the engineers say they really helped. No other valvetrain modifications were necessary, so the intake valves, all valvesprings, retainers, roller-finger rockers, lash adjusters, timing sprockets, timing chains, tensioners, and pulse wheels are carryover 5.4 parts. The front timing cover is carryover as well, as are the valve covers and even the ignition system. Well, to help combat gap growth, the 5.4 platinum-tip spark plug has been replaced by an iridium-tipped plug.
Because the piston oil squirters...
Because the piston oil squirters decrease the oil reserve in the oil pan, the 5.8 requires two more quarts of oil capacity. The resulting 8.5-quart 5.8 oil pan is cast aluminum because a sheetmetal stamping can not achieve the complex shape required. In fact, the casting supplier had to work hard to achieve consistent filling of the intricate mold even when using horizontal instead of vertical mold separations. The new pan is no deeper than the 5.4 pan in order to maintain ground clearance, hence the need to fill every nook and cranny in a horizontal direction.
Anyone familiar with the 5.4...
Anyone familiar with the 5.4 GT500 cylinder head will certainly recognize the 5.8 variety. Like the block, the 5.8 head uses the existing 5.4 casting with a few machining differences. Additionally, although the head gasket is thicker, the block deck height has been machined to match, so the 5.8 cylinder head sits in exactly the same point in space in the engine compartment as the 5.4. With no changes in the ports, that's good news for header manufacturers who can use the same exhaust on 5.4 or 5.8 GT500s.
Shutterbug Dale Amy points...
Shutterbug Dale Amy points to the one visible feature on the 5.8 cylinder head--the drilled coolant passage directing water to between the exhaust valve seats. There is no corresponding exit to this new water entrance; once the coolant has flown between the valve seats, it rejoins the general water flow in the larger cooling jacket above the combustion chamber. It's details such as these that give the SVT engine the durability to run at maximum torque for 100 hours during durability testing with no appreciable wear to the engine.
Cooler Heads Prevail
It's impossible to see the...
It's impossible to see the new exhaust valve seats in the 5.8 cylinder head, and while SVT says its adjusted some of the existing cooling system holes to tweak the coolant flow end-to-end in the cylinder head, we couldn't visually identify those changes either. Remaining steadfast to the 5.4 architecture paid off in the valvetrain as with the cams, crankshaft, and everything in between in the same place. The timing chains, associated drive parts, and even the front cover remain 5.4 carryover parts in the 5.8.
Buyers of 2013 GT500 Shelbys will have their choice of two oil cooling systems. An oil-to-water system is standard on every GT500, while an optional Track Cooling Package reconfigures the oil cooling to oil-to-air. Both systems have their advantages, and one is not really better than the other, they just meet different needs.
For regular street driving the standard oil-to-water system is the smart choice. For starters, it's included in the price of the car so it costs less. And by transferring the oil heat to the water in the engine's regular cooling system you are assured rapid oil warm-up in the morning (a good thing, especially in cold climes) plus stable oil temperatures. Total engine cooling, both water and oil, is more than sufficient to meet any street driving need and some track driving as well. Certainly the typical daily driver Shelby enthusiast who indulges in the odd autocross or test-and-tune night at the dragstrip will be well served by the standard oil cooling.
If the oil-to-water system has a downside it's that all engine cooling--both water and oil--goes through the radiator. This limits ultimate cooling capacity which can be reached in protracted track sessions. Therefore, track-day fans, and perhaps the handful of Southwest desert drivers who habitually hard-charge through the saguaros are the intended market for the air-to-oil Track Cooling package. The big advantage to the air-to-oil option is greater total cooling capacity. The radiator becomes "larger" because it no longer has to shed oil heat, just engine coolant heat. Meanwhile, the oil gets its own cooler, so the total heat exchanger area to the atmosphere is increased. In fact, SVT notes that with Track Cooling the 5.8 has about 20 percent more cooling capacity than the 5.4. Of course, the option costs more, but it's a must for the open-track crowd.
SVT saved considerable work...
SVT saved considerable work by not machining the combustion chambers to match the new larger bore diameter. The result is a lip of material not covered by the head gasket, but it hasn't amounted to anything in testing. But it sure illustrates how a 93.5mm bore on 100mm bore spacing leaves but 6.5mm between cylinders. This narrow area is especially tough on the head gasket and block; engineers found cross-drilling the block to water-cool this area was mandatory to block and head-gasket longevity.
How SVT offers the two oil cooling systems is rather clever. Bolted to the left side of the block is a convoluted aluminum casting full of passages and mounting the oil filter. With standard cooling, this snake-like casting also mounts an oil-to-water heat exchanger, which looks rather like an aluminum brick. The casting also offers hose nipples for piping the coolant between the radiator and the oil-to-water brick. For Track Cooling the oil-to-water brick is replaced by a thermostatic housing. Furthermore, the hose nipples are exchanged for threaded plumbing fittings to connect with an air-to-oil heat exchanger mounted in the front of the car, behind the grille. In this way, the casting's passages are converted from water to oil galleys, and SVT doesn't have to build another adaptor. In all, it's a creative use of resources.
So what about a car with standard cooling that gets open-tracked. Will it overheat and hurt itself? No, says SVT. Copperhead will start closing the throttle and limiting engine speed when the coolant hits 251. If the driver persists, or there is a mechanical issue such as a punctured radiator, the PCM can deactivate cylinders into a limp-home mode.
For the concours crowd 20 years hence, we'll note the 5.8 dipstick has a couple of extra marks in it for "overfill" use by the assembly plant. Jeff Albers explains, "We fill the engine with oil at the [Romeo] engine plant and don't top it off at the vehicle assembly plant [Flat Rock]. At the vehicle assembly plant [if Track Cooling is ordered], we add the cooler lines, so when you fill that with oil, the level drops. So, the two engine codes have two different fill levels. We support that so Romeo Engine Plant can do a quick visual inspection on the dock of the oil fill level... we added some other indicators that don't mean anything to the customer, it's just for internal check. That's why those extra marks are on there."
For the record, it takes about one extra quart to fill the lines and the cooler. The oil is full synthetic 5W-50, which can survive up to 300 degrees. Typical oil temperatures are 200 with the oil-to-water cooling, with 230 being the useful high end for that system. Extended track driving will raise oil temps closer to 300, which is why open-track fans need the Track Cooling package.
There wasn't a pair of 5.8...
There wasn't a pair of 5.8 valves available for photography during our SVT visit, so this pair of 5.4 valves is standing in for them. In the case of the intake valve on the left, it doesn't matter as the 5.4 valve is carried over without changes to the 5.8. The exhaust valve at right is at least a visual twin to the 5.8 valve from this angle, but the 5.8 exhaust valve is made from stronger, more heat-resistant metal, including a super-hard inlay of Stellite around the seating face. The 5.8 exhaust valve head does not have a bowl like the intake as that area has been filled in for strength.
Increased cylinder pressures...
Increased cylinder pressures in the 5.8 required new, harder head bolts to maintain the clamping load on the cylinder head gasket. They reduce head lift an extra 6 to 7 microns. Still, the 5.8 head lifts more than the 5.4, so an upgraded MLS head gasket from Federal Mogul was required. The 5.4 gasket uses three active and one inert layer; the 5.8 gasket adds an extra active layer, the better to remain in simultaneous contact with block and head when high combustion loads are doing their best to separate them. The engineers say the extra gasket layer really helped.
Matching the new entry into...
Matching the new entry into the blower case is a new SVT-designed blower inlet. At left is the 5.4 blower inlet; the more D-shaped inlet at right is the 5.8's. The new inlet is 33-percent larger and much less restrictive to airflow in this critical, naturally aspirated section of the inlet air path.
When asked if the 5.8 would be used in any other car, Jamal Hameedi replied, "It will only be a GT500 engine. That's pretty cool for a buyer of this car because, you know, you go out and spend a lot of money on an AMG or... another domestic car company and you buy a performance car and that engine is in a lot of different products. And when you go out and buy a Shelby, there's only one place, and that gets back to the SVT exclusivity pillar that we offer. And it's a special engine. The most power V-8 in the world, right?"
As for how many 5.8's SVT might bring into the world, as usual with SVT, that depends on how many of us show up at the dealership. "One less than the demand" was the classic SVT answer to the "how many" question, and it's just as operational today. In real terms, the GT500 sells a bit above 5,000 cars per year; we'd expect the over-achieving 2013 model to sell a few more as the Shelby extends its appeal. It will make one heck of a Ford Racing Performance Parts crate engine, too.
There's no doubt the new 5.8 modular is the most powerful V-8 in current volume production, but depending on how you want to parse the phrase "volume production," it might not hold the record.
In our personal experience, the 427ci V-8 in the Saleen S7 was rated at 750 hp and it was a production engine, albeit truly limited production. The Saleen V-8 was emission-certified in the U.S. and Europe, was warrantied, and Saleen produced and sold roughly 30 such Twin Turbos before the S7 lost its crash certification due to lack of a passive restraint (airbag). Saleen VP of Engineering Billy Tally developed the S7 engine from Ford Clevor architecture and it made its 750 hp in a walk; boost was but 4.5 pounds. We witnessed an engine dyno verification of a track-only (not emission-legal) special-order S7 engine that had nothing more than the wastegates screwed down to 8 pounds of boost. It made 1,012 hp.
A surprising number of other high-powered contenders turn out to be V-10s or V-12s, such as the Viper V-10, which doesn't equal the 5.8's power in any event. Then there's Chevy's ZR1 Corvette V-8, boasting 6.2 liters of displacement and the same Eaton 2.3-liter supercharger as the Ford 5.8, but coming up a hair short at 638 hp. Mercedes Benz has turned out some hefty V-8s, but not equaling 650 hp. Shelby Super Cars SSC Ultimate Aero has used blown or turbo'd small-block Chevy derivatives variously rated in the high 1,100hp league, but we seriously doubt these are emission-legal engines.
Koenigsegg, a Swedish supercar builder, has produced a 904hp twin-turbo V-8 certified for European road use, but it's never been legalized in the more restrictive North American market. Like the Saleen S7, the Koenigsegg is produced in numbers Ford would consider appropriate for prototype testing.
The same can be said for the Danish-sourced Zenvo ST1, which uses a bespoke aluminum version of the Chevy LS block, a supercharger, and two turbos to post a 1,100-plus-horsepower rating. But with only 15 cars scheduled for production, significant secrecy around the entire project, and North American emissions doubtful, it's not our idea of a production V-8 either.
We're sure other boutique V-8s can challenge SVT's 5.8-liter on horsepower, but none come even laughably close to meeting Ford durability standards, pricing, warranty service in one of several thousand dealerships across the U.S., or production by the thousands. When it comes to the most powerful real-world production engine, SVT's 5.8 is the one to beat.
There's nothing trick in the...
There's nothing trick in the 5.8 throttle body; it's the same 2x60mm twin-bore throttle body used on the 5.4. SVT says the air-filter box, mass air, and inlet tube also proved up to feeding the 5.8, so they carry over as well.
In a big step forward, SVT...
In a big step forward, SVT has moved to the 2.3-liter Eaton TVS supercharger pullied for 15 pounds of boost. Obviously the blower's outer housing is an SVT-specific casting, but there's more to it than adding logos and laying out the rib pattern. SVT computer modeling showed the short-turn radius on the blower inlet critical to airflow, so this area was enlarged and carefully shaped. In this photo, the blower inlet is the large opening at the right end of the assembly. The intake manifold and associated charge cooler water plumbing below the blower are carryover 5.4 parts.
We asked SVT if it would machine...
We asked SVT if it would machine smooth and bright the "SVT" and "5.8" so prominently cast into the supercharger housing and they said they'd leave that to owners as they were, "more function than bling." The extensive ribbing is some for looks, some for strength and some for reduced noise. Asked if the ribbing really made that much difference in noise transmission and Jeff Albers said, "Get that wrong and you'll hear it in the driver's seat." So we guess it matters.
|Bore Spacing:||100mm (3.937-in.)||100mm (3.937-in.)||100mm (3.937-in.)||100mm (3.937-in.)|
|Bore:||90.2 mm (3.544-in)||92.2mm (3.623-in.)||90.2mm (3.544-in)||93.5 mm (3.674-in)|
|Stroke:||90.0mm (3.537-in.)||92.8mm (3.653-in.)||105.8mm (4.165-in.)||105.8mm (4.165-in.)|
|Deck Height:||227mm (8.937-in.)||227mm (8.937-in.)||256mm (10.079-in)||255.71mm (10.049-in)|
|Con Rod Length, C to C:||150.7mm (5.933-in.)||150.7mm (5.933-in.)||169.1m (6.658-in.)||169.1m (6.658-in.)|
Several details are visible...
Several details are visible at the rear of the supercharger and intake assembly. The tube running bottom to top is an oil scavenge pipe. It uses intake vacuum to suck up oil mist and blow-by that find their way to the low spot of the induction tract below the charge cooler. The black canister just below the blower inlet is the bypass vacuum motor; the flat device with the bright tube running into it is the EGR valve.
We never make a trip to Ford Motor Company without being overwhelmed by the scale of the company and the number of bright, hard-working people employed there. It's a feeling impossible to describe or address by listing everyone involved even in just one engine project. Even at SVT, where the total personnel count is just under 50 employees--and almost entirely engineers we might add--it's impossible to know everybody who contributed to the 5.8 engine. That's because the Special Vehicle Team is part of Ford Motor Compay and fully integrated with the greater company's awesome resources. So while we're able to highlight a mere handful of key 5.8 players in this story, there are many others throughout Ford who lent critical expertise. Two of those, both Ph.D.s based in Ford's "mainstream" engineering campus, were cited by the troops at SVT as important to the 5.8--Jagadish Sorab, Bottom End Technical Specialist specializing in short-blocks and rotating components, and Kevin Tallio, Top End Technical Specialist, who handles cylinder heads, gaskets, and valvetrains.
Primary to raising the power of the new 5.8 was increasing supercharger output, and SVT didn’t waste any time moving from 9 pounds in the 5.4 to 15 pounds in the 5.8. The mid-teen boost figure is no surprise for an all-out factory effort; numerous aftermarket builds have shown 15 pounds of boost is near or at the realistic limit for readily available 91-octane premium gasoline and the Four-Valve modular architecture.
SVT's options on how to produce 15 pounds of boost were certainly technically numerous, but practically speaking, the proven, cost-effective, and OEM-certified family of Eaton superchargers was the only logical option. And while SVT could have continued with the Eaton-built M122 Roots blower on the Condor 5.4-liter engine, the 2.3-liter Twin Vortices Series also sourced from Eaton is more efficient at these elevated boost levels.
Flipped on its back, the blower...
Flipped on its back, the blower and intake assembly show off even more ribbing at the bottom of the intake manifold. This is where the blower discharge air rams into the bottom of the casting and reverses direction, so it's something of a drumhead for intake noise.
By more efficient, we mean the 2.3-liter TVS blower requires less horsepower to drive, and at these higher boost levels it heats the charge air less. These are not inconsequential considerations, either, as SVT says it takes right at 100 hp to drive the 2.3 TVS at its maximum output. That's 100 hp the 5.8 engine must produce but is never seen by the rear tires. In other words, if the 5.8 is rated at 650 flywheel horsepower, its internal parts are producing at least 750 hp just when considering the supercharger drive requirements. That also means the engine is consuming 750 hp worth of gasoline, but that's all part of the fun.
Anecdotally, the SVT engineers guesstimate a more accurate power output of the core 5.8 engine is well over 800 hp.
Another yardstick is motor friction--how much torque it takes to rotate the 5.8 engine at high speed without the engine running. The 5.4 GT500 engine required 150 lb-ft to motor, the 5.8 consumes 225 lb-ft, and these figures do not include making boost--that's just the effort required to turn against compression, the valvesprings, oil pump, crankshaft seals, supercharger and other internal drag. The extra force required by the 5.8 is explained by incremental increases in many things such as the higher compression ratio, greater valve lift, and increased oil volume.
SVT could have switched to a screw supercharger in search of a little more efficiency than the TVS, but at great cost. The screw blowers are the last word in positive-displacement superchargers, but thanks to complicated, difficult-to-manufacture rotors, they are more expensive, something SVT would have had to pass along on the window sticker. We'll all get to see how this supercharger showdown plays out when the aftermarket inevitably fits the giant screws it has waiting on the 2013 GT500.
As the mechanical details of the 2.3-liter TVS supercharger are generally well known, we won't dwell on its construction other than to note it uses four-lobe rotors with 160 degrees of twist. By comparison, the M122 blower on the 5.4 uses a less efficient three-lobe, 60-degree-of-twist rotor pack. SVT worked with Eaton to fine-tune details of the 2.3 blower, especially at the inlet, but generally the big Eaton was fully developed when SVT selected it for the GT500.
As is normal with the Eaton superchargers, the SVT 2.3-liter blower uses a pressed on blower pulley, and at 69 mm (2.71 inches) in diameter it's already pretty small. In fact, the blower input shaft had to be machined slightly undersized from normal Eaton practice to fit the small pulley. SVT says typically Eaton would not fit anything smaller than a 72mm pulley to the 2.3, so it would seem SVT has the 2.3 wick turned up already. By comparison, the M122 on the 5.4 carries a 78mm (3.06-inch) blower pulley.
No matter how efficient the supercharger, higher boost means higher supercharger discharge temperatures. In addressing these elevated temperatures SVT not only wanted to add enough charge cooler to keep up with the increased boost, they wanted more additional cooling to ensure lap-after-lap consistency in the air-charge temperatures.
Their solution was a much larger radiator in their existing air-to-water charge cooling system. Described as "a touch wider, much taller, and definitely deeper" than the 5.4 heat exchanger, the new unit is said to be almost twice as large, and SVT literature says the 5.8's air-charge cooling capacity is more than double the 5.4's, so open-track fans should be pleased. SVT also says a new electric pump is used, and, as before, it's thermostatically controlled by the engine-management computer.
Separating the 2.3-liter TVS...
Separating the 2.3-liter TVS supercharger from the intake manifold allows inspection of its rarely seen belly. The triangle window is the discharge port with the two identical rotors inside. The round, brass throttle blade-like unit is the bypass valve.
Here the relationship between...
Here the relationship between the charge cooler and the three square ports of the bypass system behind it can be seen. The small black dot just to the left of the supercharger pulley is the fill hole for the blower's drive-gear lubricant. It's there mainly to provide a way to add lube at the factory as there is no need to change the lube in service, and SVT has found the lubrication level critical to supercharger temperatures. Best to leave it alone.
It looks identical to us,...
It looks identical to us, even after comparing them side-by-side, but the charge cooler in the 5.8 intake manifold is less restrictive to airflow than the 5.4 version, according to the engineers. Even they admit it takes a practiced eye to see the subtle differences in the fins.
Additionally, while it doesn't have much to do with cooling the air-charge temps, the intercooler under the supercharger has been upgraded to be less restrictive to the charge air passing over it.
Also apparently all-new but beyond the scope of this article is the fuel system. At the engine end, the injectors have moved up from 46.7 to 54.8-lb/hr units, but SVT says the entire fuel system feeding those injectors is new, including a plastic fuel tank, new pickups, pumps, and an all new Fuel Pump Driver Module, which they claim every Mustang tuner headed for big numbers will go out and buy. We don't doubt it, as SVT has sold more 5.4 FPDMs to tuners than they have to the assembly plant.
As we go to print, SVT has released no official horsepower or torque curves--no dyno sheets of any kind. Some of this is marketing, but it's also early yet as the official SAE rating tests are just now being run. But SVT shows every confidence of meeting the 650 hp and 600 lb-ft of torque targets, so the wait is going to be worth it.
Or, as Jamal Hameedi said, "It's like a diesel. We're not ready to publish the torque curve, but when you see it, you'll be amazed at just how broad the torque curve is, even more so than the 2012 engine. It absolutely is a stump-puller. And it revs to the moon as well.
"Take the best attribute of every kind of engine you may have ever experienced and throw it into one engine and it makes driveability fantastic. [The] performance is fantastic."
Horse Sense: Trinity was the code name for the United States' first nuclear test and was one of the best kept secrets in history. Ford chose the same code name for the 2013 Mustang Shelby GT500 project because it wanted the same level of secrecy--and probably the same over-achieving gain in power.
The complete exhaust system,...
The complete exhaust system, except for new high-flow cats, is carryover on the '13 GT500. Even after years of dynoing 800-plus-horsepower 5.4s with these cast-iron manifolds, we can't believe how much power they support, and they're sure to do a good job on the 5.8. Of course, they are big contributors to the 5.8's sobering 623-pound shipping weight. Heavy as that is--nearly 200 pounds more than a Coyote 5.0--it's but one pound more than the out-going 5.4.
The 5.8's 54.8-lb/hr fuel...
The 5.8's 54.8-lb/hr fuel injectors are just the tip of a completely revamped fuel system in the '13 GT500. The injectors are from Bosch and feature no less than 16 holes to positively hose down the intake port with fuel. They are a 12-ohm impedance, EV14 standard-length injector as commonly used on Fords. The fuel rail is carryover from the 5.4, but with a unique crossover to package with the 5.8.
SVT contracted heavily with...
SVT contracted heavily with Roush Industries on development of the 5.8 engine, including at least some of the dyno work seen here. Like everything else, computers have exponentially increased what's possible with test equipment, including replicating exact test-track conditions on engine dynos for faster, more scientific testing. SVT did a lot of that with the 5.8, along with the usual endless hours of validation tests and data gathering, such as what this engine is undergoing. This angle does a good job of showing off the 5.8's impressively wide 10-rib supercharger belt.
Exhaust temperature probes...
Exhaust temperature probes in each cylinder are just the beginning of the instrumentation on this
Typical of OEM testing, the...
Typical of OEM testing, the porcupine mule was running on an expensive, precise electric dyno. Unlike more finicky water-brake dynos common in the aftermarket, these industrial-strength electric units can accurately absorb large amounts of power indefinitely. One clue to their endurance capability is the water-cooled engine exhaust in the foreground. Even so, the intense heat coming out of the 5.8 frequently
Peeking around the back of...
Peeking around the back of the porcupine test mule shows where a few spools of wire went, and also hint at what a young engineer called an
Developing power was a brief...
Developing power was a brief period in the 5.8's gestation--that's the easy part with a supercharger. Most dyno time was spent validating newly designed parts during endurance testing. After a typical 100-200 hours of testing, the dyno mules are disassembled for inspection by technicians such as Ken Kopas at the Roush dyno facility. Project engineers are obviously interested in eyeballing their test mules, but often experienced specialists from Ford's main engineering campus are brought in to investigate specific parts.
Trinity Engine Specs
First Model Year 2013
Engine Family Modular
Code Name Trinity Engine
Displacement 5,811cc (355ci)
Bore x Stroke 93.5x105.8mm (3.68x4.165-in)
Horsepower Est. 650 hp @ 6,500 rpm, 91 octane
Torque Est. 600 lb-ft @ 3,750 rpm, 91 octane
Note: Ford SVT has announced targets of 650 hp and 600 lb-ft of torque at unspecified rpm. The figures above are our estimates.
Shipping Weight 623 pounds, includes water pump
Block Low-pressure cast aluminum w/PTWA spray-bore iron linings
Bore Spacing 100mm (3.937-in)
Deck Height 255.71mm (10.067-in)
Deck Thickness 13mm (0.510-in)
Cylinder Head Retention 12mm bolts, four per cylinder, 10 bolts total per bank
Oil 5W-50 synthetic
Oil Pan Cast aluminum, 8.5 quarts
Windage Tray Integral w/oil pan gasket
Oil Pump Gerotor w/billet steel backing plate
Pistons Forged, short-skirt; moly friction-reducing coating; oil-jet cooled
Piston Weight 403 grams
Piston Pin Full-floating (5.4 co)
Piston Pin Retention Wire lock (5.4 co)
Piston Rings Lightweight, reduced tension steel, chrome top and second; iron oil control
Connecting Rod Forged steel, I-beam, no balance pad, angle ground small end
Connecting Rod Length 169.1mm (6.658-in) (5.4 co)
Rod/Stroke Ratio 1.60 (5.4 co)
Crankshaft Forged, air-cooled, medium carbon steel; tungsten mass balance; extended damper threads
Main Journal 67.5mm (2.652-in) diameter (5.4 co)
Rod Journal 53.0mm (2.082-in) diameter (5.4 co)
Flywheel Retention Eight-bolt (5.4 co)
Heads Aluminum, four-valve per cylinder, inter exhaust seat cooling
CAM Covers Cast aluminum (5.4 co)
Compression ratio 9.0:1
Valves 37x32mm (1.454x1.257-in), four per cylinder; intake (5.4 co), exhaust Nimonic w/Stellite face insert
Camshafts DOHC, four camshafts (carried over from Ford GT)
Camshaft Timing Fixed (5.4 co)
Duration 242 degrees intake, 247 degrees exhaust
Lift 11.18mm (0.439-in) intake, 11.48mm (0.451-in) exhaust
Valve Followers Roller finger follower (5.4 co)
Lash Adjusters Hydraulic (5.4 co)
Coolant Organic (red) (5.4 co)
Exhaust Manifold Cast-iron log-type (5.4 co)
Intake Manifold Cast aluminum adapter-plate-type w/integral charge cooler core mounting (5.4 co)
Throttle Body 2x60mm, twin-blade, electronic throttle (5.4 co)
Powertrain Control Module Copperhead
Mass Air Meter 105mm, digital (5.4 co)
Oxygen Sensors Wideband Universal Exhaust Gas, sensor pre-cat
Knock Sensors Two in block valley (5.4 co)
Ignition Timing Crank trigger, front of crankshaft
Firing Order 1-3-7-2-6-5-4-8
Cylinder Numbering Right bank: 1, 2, 3, 4; left bank 5, 6, 7, 8 (5.4 co)
Fuel System Electronic returnless fuel system
Fuel Injectors 54.8-lb/hr
Fuel Pressure 39-psi
Fuel Requirement 91-octane minimum, 93-octane recommended
Note: (5.4 co) = 5.4 carryover part
Our SVT visit corresponded...
Our SVT visit corresponded to the arrival of the first of thousands of 5.8-liter engine tags. Like the Shelby engines before it, the 5.8 will be hand assembled on the Romeo Niche Line. One recent change to the niche line is the elimination of two-man teams in favor of one tech, who sees the engine all the way through, and an assistant tech shared between two lead techs. Both technicians still sign each engine plaque, but the assistant gets to sign twice as many as the lead.
The lefthand side of the 5.8...
The lefthand side of the 5.8 is it's busier side. A two-belt engine, the alternator and water pump share a six-rib drive, while the supercharger and air conditioner--the two most important accesso- ries!--share a 10-rib belt. This engine uses standard cooling as denoted by the oil-to-water "brick" heat exchanger. Like all current Mustang engines, the 5.8 does not have a power steering pump thanks to electric power steering.
With more idlers than an unemployment...
With more idlers than an unemployment line, the 5.8's front engine dress is surprisingly busy and tightly wrapped. As expected, the torsional qualities of the harmonic balancer are unique to the 5.8, and the blower belt is a touch shorter due to the smaller diameter blower pulley, but the rest of the tensioners, idlers, and accessories are carryover 5.4 parts.
Like a diesel truck engine,...
Like a diesel truck engine, the 5.8 is surrounded on all sides by pipes and hoses trying desperately to contain the impressive heat and energy generated by this powerhouse. Viewing the bellhousing end shows header installers will still get to play with an EGR tube on the right side.
Jamal Hameedi, SVT Chief Nameplate...
Jamal Hameedi, SVT Chief Nameplate Engineer, oversees all SVT efforts, namely the Shelby GT500 and F-150 Raptor. Interestingly, Jamal's two decades at Ford includes eight years developing Ford-powered Trophy Truck powertrains, whose cylinder heads can be traced through the '00 Mustang Cobra R to the Ford GT, and ultimately the 5.8 GT500 engine.
Jeff Albers is the Trinity...
Jeff Albers is the Trinity Powertrain Program Manager and thus the boss of all heat-producing, torque-twisting equipment aboard the '13 Mustang Shelby GT500. He was also our lead guide through the 5.8 engine, a chore he gracefully endured when time was short.
Bryan Hoy is the SVT 5.8-liter...
Bryan Hoy is the SVT 5.8-liter Engine Systems Engineer, which makes him responsible for the overall 5.8 engine package, especially how it integrates with the chassis and its build in the Romeo Engine Plant.
Rob Waara is a Design and...
Rob Waara is a Design and Development Engineer detailed to the 5.8's lubrication system components, such as the oil pump, oil pan, and engine oil cooling system. He was a big help in our understanding of the 5.8's oil cooling options.
Brendan Vido is the 5.8-liter...
Brendan Vido is the 5.8-liter V-8 Design and Development Engineer responsible for all engine components from supercharger to crankshaft. He quickly became our go-to guy for our many questions about the 5.8's mechanical details.