"Whaddya wanna do today?"
"Oh, I don't know. Why don't we whip up an all-aluminum, short-deck, modular V-10, stick it in a Mustang, and call up those boneheads at the car magazines?"
"Sounds good. I was gettin' a little bored."
This is most assuredly not how the project began for the talented enthusiasts at Ford Motor Company's Powertrain Research & Advanced Engines division (they never even thought of us magazine boneheads), and they are never bored with this kind of hardware around. But it does make one wonder just how such a seemingly unlikely bit of vehicular R&D ever saw the light of day.
Had someone whispered to us even a few months ago that there was a New-Edge GT running around Detroit, wearing manufacturer's plates, and packing a DOHC 10-cylinder underhood, we would have laughingly dismissed the suggestion as fume-induced gearhead fantasy. Well, it turns out this thing has been unceremoniously prowling the streets of Motor City for more than a year now, proving once again that we should never be close-minded in this occasionally madcap business.
First, let's be clear that the 5.8 V-10 that is the centerpiece of this story has absolutely nothing in common with the cast-iron, tall-deck 6.8 10-banger found in Super Duty pickups and Excursions. Instead, this is an all-new engine that is most accurately visualized as a 4.6 Cobra short-block with two additional cylinders grafted on, and topped by similarly stretched Cobra R DOHC heads, resulting in an all-aluminum V-10 of sur-prisingly compact external dimensions and manageable weight. To be specific, it is some 60 pounds lighter than the 5.4 engine found in the '00 Cobra R. By adding the 25-percent displacement increase of two extra pots onto a 281, you get 351 ci. Therefore, it was only natural that the '99 GT it was strapped into should come to be known, in-house, as the Boss 351. Besides, the decals that emblazoned the '71 original of the same name were a cheap purchase, fitting nicely within the project's skinflint budget.
Indeed, the budget was so tiny, at least by Big Three standards, that it was described to us as a CCP-a credit card project-with most of the time spent in accomplishing it coming after regular business hours, or in the spare time of the can-do crew at Powertrain Research & Advanced Engines. You see, it was these guys who initiated the idea in the first place. They developed it on their own time as a project, researching possible means of providing a displacement increase to the short-deck 4.6 for applications where the taller deck (and subsequent increased width) of the 5.4 or 6.8 won't easily fit.
You won't find much argument around here that the little 281 could use a few more cubes. Because a major bore increase is not possible due to the modular's extremely tight cylinder spacing, it seemed a prac-tical experiment, they reasoned, to gain that extra displacement by cobbling together a V-10, especially since this same compact bore spacing would result in an increase of less than 4 inches (100 mm, to be exact) in overall engine length. And to help, uh, expedite matters, they decided to go ahead and build one and tell their corporate bosses about it afterward.
Unlikely as it sounds, these professional tinkerers got underway by cutting apart some existing 4.6 V-8 sand-casting cores and literally gluing them back together in V-10 form. They repeated this cutting-and-pasting process on Cobra R head cores, poured in some molten aluminum, and-voil-they had their basic castings. In comparison to having all-new tooling made up, this process was incredibly cost-effective. They calculated that 5.4 Cobra R cam specs should be fairly close, so they had new, longer billet bumpsticks made in that grind. And, since they had stuck with the stock 4.6 bore and stroke, they were able to use Terminator Cobra H-beam rods, connected to pistons of about 10:1 compression that they "had lying around from another project."