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						V12 Cobra A12
One-of-a-Kind Cobra

860 cubic-inch V12 Cobra roadster

Story and Photos by Steve Temple

Jeff Caron is hardly one to shy away from big horsepower numbers. After all, he owns four Hemi-powered muscle cars, including a drag-strip-only ’65 Plymouth Belvedere lightweight A990 that track officials forbid him to run without adding a chute.

So when it came time to build a Cobra, the venom he chose is so potent, it required four extra cylinders — 12, count ’em — 12 in all. They add up to 860 cubes, or 14 liters of displacement, and deliver 1,150 horses, with an equal amount of torque. This V12, all-aluminum monster had so much power, Jeff detuned it to 1,000 hp so the tires wouldn’t disintegrate on his way to the grocery store. (At only 1,600 rpm, the torque is already cresting 800 lb-ft.) His particular engine was built and dyno’d by Hasselgren Engineering in Berkeley, California.

Originally designed for marine applications by the aptly named (but now defunct) Torque Engineering, only 12 of these mammoth mills were ever built since they cost $125,000 each. However, Jeff claims that his engine is the only one in existence that runs.

Getting that to happen in a Cobra was quite the task, requiring five-plus years of meticulous fabrication work by the talented technicians at Kirkham Motorsports. This firm has never been one to shy away from extreme projects, aptly qualifying them for Jeff’s ambitious build.

But the devil’s in the details, as they say, and these included relocating the firewall rearward several inches and making room in the body for six-tube headers on each side. In addition, the stainless steel 4-inch frame rails required some modification in order to accept the Brobdingnagian block.

Bolted on top are custom-machined billet throttle bodies with 65-pound injectors located under the butterfly valves. Feeding them is “one big-ass Weldon billet fuel pump,” Jeff declares. It delivers 300 gallons per hour, in order to keep pace with the car’s voracious consumption rate. This thirsty snake gets only 3.5 mpg (and that’s just at cruise). No wonder it has a 40-gallon tank. The fuel lines are more than a half-inch in diameter, thicker than your thumb, and the pump draws so much juice it requires 8-gauge wiring.

To squeeze the engine into the Cobra’s constricted bay, the coaming at the base of the windshield extends over the pair of the throttle bodies located right in front of the firewall. The ECM actuating them is a Pectel SQ6 with custom Mil-Spec wiring from Zentec, designed for off-road racing. Fortunately, the car lives in Arizona where collector cars are exempt from smog regs. “This thing would never pass emissions testing,” Jeff admits.

To further accommodate the extra length of the engine, the TREMEC TKO 600 five-speed was shortened and fitted with a Tilton dual-disc clutch and a 9.5-inch drive shaft. The large hump in the cockpit covers a pair of reverse-rotation Tilton Super Starters typically used in NASCAR vehicles.

Once it’s up and running with a ferocious rumble (check out those hand-fabricated sidepipes with six header tubes per side), you’d think excess heat might be a problem. And you’d be right, as “It gets real toasty real quick,” Jeff says. So he has an individual Stewart electric water pump for each bank of cylinders, along with the largest four-core radiator that Kirkham Motorsports offers, which gulps down 26 quarts of coolant.

The 3.54-ratio Dana 44 rear end also required some slight modification to handle the V12’s twist. Its CV joints and half-shafts were upgraded to a much harder maraging steel (a material employed on rocket and missile skins). It’s such an improvement, Kirkham Motorsports ended up using it on all its Cobras.

Even so, Jeff’s Cobra is not a racer, but a “go out and play” car. And when he does, the reactions are priceless — women scream, guys grin. After all the time, expenses, and technical challenges, would he do it again? “No!” But he is real happy that he now owns a one-of-a-kind Cobra.

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