Martin Dolan
May 18, 2016

“When they open the hood, they won’t know what they’re looking at.”

Talk about your understatement.

Tony Arme, master builder at Brown’s Classic Autos in Scottsdale, Ariz., is referring to the 427-cubic-inch aluminum street version of Roush Yates Engines’ fabled NASCAR motor that will propel “Concealed,” a 1965 2+2 Mustang that Arme will debut at the SEMA show in late October.

Roush Yates offers its RY45-series powerplants for hill-climbers, dirt-track and off-road racers, but Concealed will be the first time it’s been shoehorned into a car you can drive to the grocery store or anywhere else your heart desires.

Gregg Grisham of Brown's Custom Autos works on the interior of Concealed

“There’s a lot of little details on the car that I’ve never seen before,” said Arme, “but there isn’t going to be anyone else who has that engine. That’s really what makes this car its own.”

Arme expects the RY45 to produce about 850 horsepower and 500 pound-feet of torque. Roush Yates built a special high-lift, long-duration camshaft to allow the small-block V8 to produce power across a wide band of rpm, instead of the 8,000 to 10,000 rpm power range in the Roush Yates FR9s that Ford vehicles have used in Sprint Cup, Nationwide, and Camping World Truck series since 2009. The normally 358ci motor was stroked to 427 cubes, an iconic displacement for Ford lovers. It will idle at 1,000 rpm and run like a bat out of hell on pump gas.

Roush Yates is as stoked about Concealed as Arme is. “As far as a street application, this will be the first one. That’s why we’re so excited about it,” said Jeff Clark, vice president of sales for the Mooresville, N.C., engine builder, whose initiatives for 2016 include putting their products onto the streets.

“It’ll actually have more power than a NASCAR engine, but it’ll be at a streetable and drivable rpm range.”

An artist's rendering of Concealed, which will be painted a custom Sherwin-Williams titanium silver with satin clear coat.

The RY45, Clark said, is “the AMG of performance engines,” adding that it “has incredible power at low and midrange, which makes it really good for the street.” The engine, which uses Holley’s HP fuel injection system and ECU, is being dyno-tested back in North Carolina, and should be in Scottsdale in the next few weeks.

“If we wanted to put this at full-on with the calibration,” Clark said, “it should be every bit of 700 foot-pounds of torque and 900 horsepower with a capability of 8,500 rpm. Now for that car and that weight, we’re probably going to set it a little conservative, especially in break-in mode. We’ll probably bring it out there with 600 foot-pounds and 800 horsepower and back the maximum rpm limit down to about 8,000.”

Concealed also will feature RideTech coil-over suspension; the biggest Wilwood brakes that will fit on a ’65 Mustang; a Tremec T56 Magnum six-speed; a 9-inch Ford rear end with 3:73 gears; custom wheels by B-Forged; and custom titanium-silver paint from Sherwin-Williams. Arme and his crew—Jonathan Williams, John Harper, Gregg Grisham and Charlie Sullens—are building the Mustang for a Mesa, Ariz., man who’d rather stay out of the limelight (at least until he gets behind the wheel). But he’s not one of those car guys who’s content to just take his ride to a car show, set up a lawn chair and gab about it, Arme said. He wants to drive it. A lot.

The owner came to Brown’s Classic Autos, which does resto-mods, frame-off restorations and full-blown custom rides, as well as maintenance on rare and high-end vehicles, in January 2015. He was looking for a fastback ’65 Mustang but was particular about what he wanted in the finished product: It had to be powered by a big, honkin’ Ford and it had to retain the shock towers in the engine bay.

Arme said it was an unusual request because it’s simpler and more typical to buy a Mustang II front-end kit from TCI or Heidts.“He (the owner) doesn’t want to take away from the fact that it’s a Mustang,” Arme said. “He thinks when you pop the hood on a (first-gen) Mustang, you expect to see shock towers.”

Roush Yates sent a mock-up of the RY45 engine to Brown's Classic Autos; it's shown mated to the Tremec T56 six-speed.

But with so many powerful Ford mills available now, such as the 5.2-liter Voodoo in the Shelby Mustang GT350R, why go with the RY45, which costs more than $50,000? The original plan, Arme said, was to install a 535-horsepower 351 Windsor stroked to 427 ci, but the owner “wasn’t sure it would be enough.” They discussed supercharging the engine, which would nudge the ponies close to 700. The owner asked whether more modifications could be done later if even that wasn’t sufficient power.

“Do it now,” Arme advised him, “or don’t do it at all.”

Enter Roush Yates Engines, with a big assist from Sherwin-Williams Automotive Finishes. Roush Yates NASCAR teams have been using Sherwin-Williams’ paint systems since the early 2000s, Clark said, and the company is aggressively pursuing a bigger presence in high-end motorcycle and automotive shops like Brown’s. Bryan Nichols of Sherwin-Williams knew of Roush Yates’ street-car initiative and brought the two parties together.

“We’re really happy with the quality of the work these guys (at Brown’s) are bringing to this project,” Clark said. “It’s first-class, not just for the looks and the cosmetics but for their function. Their engine mounts, the drivelines, all the things they’re taking into account to make this thing run right. They’re really doing a good job, a smart job.”

With the engine question answered, the Brown’s team found a ’65 fastback that had been collecting cobwebs in the back of a Palm Springs, Calif., Ford dealership since 1971. A black-plate car, it had spent all of six years on the road. The dealership wasn’t eager to let it go, hoping to someday do a full restoration, but money ultimately talked.

The Mustang is a California black-plate car that had been off the road since 1971.

The first step, Arme says, was to make the car a car. At some point, the Mustang had been hit just above the passenger-side rear wheel, and the boys in the body shop had taken some shortcuts to fix it—a new quarter panel was simply welded over the damaged area. After the unibody was taken to a frame shop and straightened a smidgen, Arme’s crew removed the replacement panel and the damaged metal beneath it, using a section of a new quarter panel to make the repair seamless.

The crew also moved the gas-filler cap up to the top of the rear deck, modified the taillights, rear panel and drip rails, and flushed the louvers with the sloping lines of the C-pillars. The doors were redone to incorporate black anodized-aluminum exterior handles, and the bumpers were tucked closer to the sheet metal (they’re chrome now but will be painted to accent Concealed’s custom paint, which will be applied by Joe Perkins of American Tradition Auto Body in Mesa, Ariz.). The honeycomb grille was unique to the ’65 Mustang, so honeycomb inserts will accent the hood scoop and other features.

Wider wheel tubs from Detroit Speed were added to accept 10-inch tires in the back, and the transmission tunnel had to be widened to accept the much larger Tremec (the originally planned five-speed could not have handled that many horses). Because the owner is 6-foot-4, the shifter has been moved back six inches, which required cutting a new opening in the tunnel. The interior will use new materials over the original seats but otherwise will appear stock. Custom gauges by Classic Instruments will feature the Mustang’s color scheme and include the name Concealed.

In addition to the coil-overs from RideTech, the suspension was made “quite a bit beefier,” said Arme, 30, who came to Brown’s in 2013. “We did a bunch of frame braces and structural modifications to try to handle that horsepower,” he said. “It’ll handle a lot better than before.” Arme recommended a roll cage but the owner nixed the idea.

The original engine was a 289 Ford V-8.

The enormous size of the RY45 created conundrums in the engine bay. The shock towers were shaved, crossmembers were added for strength, and new motor mounts fabricated to lower the engine to accept the bigger six-speed. Designing headers that work efficiently in such tight quarters also was a challenge.

Arme suspects Concealed is the tip of the spear in trending builds, saying, “There’s going to be people that see this engine and say, ‘Oh, wow, I didn’t even know that was possible, I’ve got to have that.’ It can go in a Fairlane or a Cougar, assuming you keep it Ford. You might get a guy with a Camaro or something who’s like ‘I want the GM version of a NASCAR engine.’ All the (top-level) cars are starting to trend more to being race cars that are street-driven. This is the next step, really putting a race-car engine in it. A lot of people build race motors, but this is a true race engine.”

Clark looks forward to similar builds in the future and would gladly team with Brown’s again. “We have a lot of Cobra builders that are interested in this (RY45) engine. They’re investing $100,000 to $200,000 into a car, they’ll spend $50,000 for the engine,” he said.

“This is going to be your upper-tier of car builders, premium shops. I think this is why Brown’s wanted to do this; they wanted to put themselves on the map as a premium and not just a me-too. That’s what we saw in them.”

Photo Gallery

View Photo Gallery