V-8-Swapped 2003 Mini Cooper S Sleeper Found on HOT ROD Power Tour

Duane Smith is a hot-rodder to the core with some bona fides you wouldn’t believe. So why does he drive a 2003 Mini Hardtop Cooper S? Believe it or not, underneath that mostly-stock Mini Cooper S hood (those are functional heat extractors) is a 355ci small-block Chevy V-8. It’s rear-wheel drive, too; Duane loves the handling of E36 BMWs, so he thought, “Why not?” and harvested the front and rear suspension parts from a junkyard E36, then proceeded to hand-fabricate and fit all the components to the Mini in his home workshop.

But how does one decide to cram a longitudinally-mounted small-block Chevy V-8 into the space that used to hold a transverse 1.6-liter supercharged inline-four? For Duane, it started with a Chevy Sprint Turbo. Actually, it started with a 1986 Toyota Supra Turbo. Maybe it was the E36 BMW with an LS-swap that really gave Duane the idea to build his Mini Hardtop Power Tour cruiser. No, he was getting tired of doing frame-off restorations and wanted to get back to his engine-swapping roots. Wait, wait … actually, it was the amount of power Duane’s twin-turbo 1955 Bel Air was putting down to the ground that really (sorta) forced Mr. Smith to double the cylinder count and more than triple the displacement of his ’03 Cooper S.

A dive into Duane’s gearhead history might clear up some of this thought process. Growing up in the Milwaukee, Wisconsin, area, Duane always had a strong interest in cars. His uncle—who conveniently lived next door—was an avid car nut and a professional photographer and would take Duane and his cousin all over the region to various tracks and shows. Events at Road America and Great Lakes Dragaway, Chicago Auto Show, hanging out with the local service station regulars—all had an influence on Duane’s taste for cars and performance.

Duane attended a technical high school, taking all the shop and auto classes he could, and started out his working life in the service bay of a gas station. That eventually led to a job at his local Chevrolet dealership, where he was put through the GM Automotive Service Training program. Ever-curious about the process of building and maintaining cars, and always trying to build something cool for himself—like a 350-swapped MGB he was told would be impossible to construct, or shoving numerous small-blocks into Chevy Vegas and Monzas—Duane was always in the other shops at the service center, picking up paint and body skills, learning how to fabricate parts and fixtures, and teaching himself how to weld.

It was around 1965 when Duane met his friend Joe Gazzana, who got him into drag racing. He started in street cars, but the success of Joe’s Ford Mustang Cammer that they raced in BB/Gas that got the pair into alcohol Funny Cars. At the time, NHRA didn’t allow alcohol Funny Cars to run, but the UDRA did. After two national championships running alcohol-fueled cars, NHRA started to change their minds, but Duane was done with drag racing and wanted to get into road racing.

Before we get into Duane’s impressive road racing career, we need to expand more on his working life. Still working at the Chevy dealership, but racing as much as possible with Joe, Duane’s schedules were becoming too hard to balance. Then Joe had a great idea—buy an airplane and become private pilots together. We’re cutting huge chunks out of that story for the sake of brevity (which is not this editor’s strong suit by any means), but the important point is that Duane did become a private pilot, flying first for a wealthy Texas oil magnate, then for big corporations like Bucyrus-Erie and Johnson Controls.

The freedom of schedule and monetary compensation Duane earned as a private pilot afforded him the opportunity to get involved with road racing, and he dove head-first into the deep end. Early in his road racing career, Duane was flying 85 percent of the time and racing 15, but by the time he decided to hang up his firesuit, those proportions were totally reversed.

Duane’s road racing operation wasn’t a simple weekend-warrior deal, either. After cutting his teeth in series like Formula V and Formula Atlantic, Duane’s racing operation, Hill Racing, was a full-on professional outfit, with brand-new semis to haul the two-car team all over the country, a 10,000-square-foot workshop where he was constantly making and fixing parts for his Sports 2000 and Trans Am cars, and multi-year sponsorship deals from the likes of Coca-Cola, Jack Link’s Snack Foods, and Automated Systems Incorporated (a high-end computer parts manufacturer).

By then it was 1991-ish, and years of burning the candle at both ends was starting to catch up with Duane. He was tired of the pro-racing grind, despite having won the SCCA Central Division Championship, the National Championship, and Professional Championship series—in one year. Duane was missing the simplicity of flying full-time and racing for fun on the weekends.

Duane Smith is the third owner of this factory-lightweight 1963 Ford Galaxie, and just finished the frame-off restoration. He inherited the Galaxie from the cousin he grew up doing car things with, who purchased it from the original owner 30 years before it came to Duane.

It was also around this time he decided to take on his first frame-off-style restoration with a 1968 Camaro Z28. And not just any Camaro Z28; a Z28 that was originally purchased from the Chevy dealership where Duane used to work, and that he, personally, had set-up and made ready for sale when it was delivered to the dealership. This wasn’t Duane’s first attempt at painting a car, though—that was on a Buick Skylark, also at the Chevy dealership in the 1960s, that was so well-done the paint shop manager swore Duane couldn’t have done it himself.

The Z28 got the ball rolling on Duane’s restoration hobby, which led him to the aforementioned twin-turbo 1955 Bel Air, also the recipient of a frame-off resto, but initially intended to be a dual-quad/tunnel ram induction set-up. It seems to us that Duane’s mantra is, Why not? That sounds like fun, because when by happenstance he came across an old Banks Power twin-turbo kit, he knew it had to go on the Bel Air.

The ’55 Bel Air led to a Bloomington-winning 1962 Corvette restomod with a then-new Chevy 350 Ram Jet crate engine, then a concours-style 1967 Corvette restoration that, on its first outing, took Best Corvette and Best in Show at a local meet. Those led to his 1962 Impala SS409 Bel Air Convertible creation. Keep those hands still, keyboard warriors—we know the Impala and Bel Air are two separate trim levels in the 1962 full-size Chevy lineup. Duane’s ’62 Chevy Convertible is a real 409ci, 409-hp Impala SS, but he prefers the more subtle styling of the Bel Air trim (and loves to rile up the fans), so he de-rated the Impala himself.

While Duane was doing all these meticulous restorations in his personal workshop, he was also building fun cars, like the LT1-swapped six-speed 1986 Supra and Chevy Sprint Turbo we mentioned earlier. Duane loved the handling of his independent rear suspension Supra, and how easy it was to manage the rear-wheel-drive chassis components with its removable subframe. The LT1-swapped Supra then inspired Duane to do something with the more tired of his two Sprint Turbos.

Did we forget to mention Duane owned two of these rare gems? He’s currently driving the nicer of the two (which is stock) as his daily; gas is over five dollars a gallon around his Rogers, Arkansas, home as of this writing, so why not enjoy the peppy 1.0-liter three-cylinder turbo that can pull a Fox-body Mustang GT through the 1/8th-mile, and it’s miserly, 30-plus mpg thirst? Back to building cars—inspired by the Supra, Duane started scouring the junkyards looking for an independent-suspension rear-wheel drive subframe.

Duane always keeps his eyes wide open at the junkyard, stating one never knows what kind of gold they might find (does he know Steve Magnante?), and—after spotting a BMW E36 on its side—he decided he had a plan for dropping a small-block Chevy and rear-wheel drive into his Sprint. But then he changed his mind. The BMW’s rear subframe was going to work perfectly for his needs, but Duane also thought the E36’s front suspension would benefit the handling of his V-8-swap Sprint idea. However, after thinking it over for an evening, he decided if he was going to do that much work swapping a V-8 into a subcompact and graft in most of the chassis of an E36 Bimmer, why not just 350-swap the BMW instead?

Yet another car Duane built before we get to the promised Mini this article is really about— Duane found a solid E36, drove it stock as his daily for a few years, then the Why not? mantra took over again. After seeing kits online for LS swaps into the E36 chassis, he embarked on building his own V-8-powered 3-Series. A wrecked 2012 Camaro SS donated its LS3 and TR-6060, and, with only 40 miles of testing on the newly minted BMW 362i (it has an actual badge), Duane and his wife, Nancy, set out for HOT ROD Power Tour, where the V-8-powered BMW 3 Series was a fan-favorite.

After all these swaps, restorations, and more, Duane needed to get back to his roots—a “simple” engine swap in a fun car. He’s always liked the new Mini platform, but wasn’t initially looking for Hardtop. His search began with looking for a Mini Clubman (longer wheelbase and barn-door hatch access instead of lift-gate) and was going to drop an LS4 out of the front-wheel-drive Malibu SS in the cargo area, but the gods of custom cardom shone the light on the 2003 Mini Hardtop Cooper S you see pictured here.

At this time, Duane had already pulled the twin-turbo 350 out of his Tri-Five, stating he was a little too greedy with the boost knob and that you can never really trust pump gas. Nancy had also asked that they start using the Bel Air for more long cruises, which necessitated air conditioning. It may have been a hoot to fry tires above 4,500 rpm in any gear, courtesy of the Banks Power twin-turbo kit feeding the built Dart Little M 350 putting 767 hp to the wheels, but the LS7 Duane swapped into his Bel Air made running a well-functioning HVAC system much easier.

He can’t leave anything alone, though, so the LS7 wears a Holley front accessory drive, ARP hardware, Holley Terminator X Max EFI, and Hooker Supercomp headers going to a Holley X pipe, and it has JE pistons and Oliver rods reciprocating inside its cylinders. But what was he going to do with a spare small-block Chevy? Do you have to ask at this point? Obviously it went into the Mini.

Seven-hundred-plus horsepower in a 2,800-pound short-wheelbase car sounds like fun, but Duane was thinking more fun cruiser than barn-storming Mini-monster for this build. He bored the Dart block 0.030-over (hence the 355 ci displacement) and did a naturally-aspirated rebuild with a higher-compression rotating assembly and street-friendly camshaft, then started cutting metal out of the Mini.

Duane already knew the plan was to use E36 front and rear subframes and suspension parts, but step one was to make way for the 355ci V-8 and a Muncie four-speed manual transmission. He started by removing as little of the firewall and transmission tunnel as possible, just enough to clear the short-block, then continued removing the firewall and trans tunnel as he added heads, valve covers, and induction parts.

Duane surprises crowds on two fronts every where he takes his V-8-powered Mini: 1) The rumble of the small-block Chevy that is totally unexpected in the stock-appearing subcompact, and 2) The rear tires that get turned into smoke when Duane decides to exhibit some speed for the onlookers. Photo by Wes Allison

He didn’t stick with the Muncie four-speed, however; the Mini build was always intended to be a HOT ROD Power Tour cruiser for the six-time Long Hauler, so Duane decided a five-speed transmission was necessary and went with a Tremec T5 instead. Once the engine and transmission were in place, grafting the E36 rear subframe in was easy; the control arms were already perfectly wide enough so that Duane didn’t have to modify the BMW rear suspension too much (just a few structural reinforcements on the Mini side), and wheels with different back-spacing to fit under the stock bodywork.

The front suspension was where things got tricky. Tight packaging is the name of the game with new car design, and the Mini’s front crossmember and steering linkage—living high up in the engine compartment, behind the front axle—needed to be relocated ahead of the front axle and dropped lower. Duane started the process by cutting the E36 front crossmember in half, widening it to accommodate the Mini’s frame rails and shock tower location, then chopped everything off the steering knuckles except the bearing cup and ball joint pivot-points.

With a backing plate-reinforced bearing support, where he was able to attach hand-made steering arms, Duane was off to the races. Chassis and suspension were dialed-in and square thanks to a laser array and chalk lines laid out on the floor of his workshop with exact measurements taken from BMW and Mini factory drawings. Then it was time to start fitting accessories, the cooling stack, and HVAC. Duane and Nancy want to enjoy the long drives of HOT ROD Power Tour and other cruises, not just survive them, so HVAC is a necessity.

The Mini’s HVAC unit straddles the firewall inside and outside of the cab, so Duane pulled all that out and put the Vintage Air MINI unit (pure coincidence on naming) fully inside the cab. Duane didn’t have to modify the stock Mini HVAC ducts to meet up with the Vintage Air manifold, but he did lose a paltry 2 inches out of the back of the glove box. On the hot side of the firewall, the SBC’s distributor lives where the stock Mini HVAC unit used to live—with just ¼-inch of clearance all the way around. Admittedly, maintenance on Duane’s SBC-swapped Mini isn’t the easiest task.

A short water pump fits between the engine and the aluminum radiator, and a GM power steering pump ties into the BMW rack and pinion perfectly. As for functionality, the only capability the Mini lost was anti-lock brakes—even the airbags still work. Duane’s biggest issue was getting the GM and Mini electronics to talk to each other, but he had dealt with similar issues during the 362i’s LS3 swap.

Inside, the pedal assembly had to be modified to accommodate the wider transmission tunnel and new throttle assembly, but all Duane had to do there was straighten and shorten the Mini’s stock pedal arms. For instrumentation, Duane kept the speedo and tach in their original locations, fitting Marshal gauges in the Mini binnacles. He also added a gauge pod to monitor vitals, as the new gauges meant no warning lights. The only other modifications inside are the fuel cell and battery enclosed in steel housings where the back seat used to be. The front seats are in their original location, and 6-foot-3-inch-tall Duane tells us he fits perfectly.

Apart from the ride being a little stiff, Duane and Nancy couldn’t be happier with the way the Mini handles and drives. Duane thought it would have a tendency to oversteer with the weight of the small-block Chevy riding on the front axle, but the weight distribution is more even than stock because the weight of the powertrain was spread more evenly along the full length of the car with the front-engine-rear-drive conversion.

What does it sound like? A big, burly V-8, of course! But would you know a V-8 is hiding under the hood at all without hearing it? No way! Duane had to source and modify two left-side small-block Chevy shorty headers to fit between the tires, then get a little fancy fitting mufflers, but the dual exhaust tips peek out from the center of the stock Mini Cooper S rear valance, just like they did with the original supercharged four-banger.

We’ve spoken with Duane a number of times—first at Lucas Oil Raceway and State Farm Center on Days 3 and 5 of HOT ROD Power Tour 2021, and then a couple of times over the phone—about what the public reaction to his SBC-swapped Mini has been, and he couldn’t be happier. “When I take it out in traffic and I pull up to a stop light, and you start seeing heads swiveling all over, ‘Where is that sound coming from, where is that sound coming from?!’ and all of sudden they realize it’s the Mini and then they start smiling and the phones come out and people are taking pictures and all that kind of stuff, it’s hilarious,” Duane recounted on our most recent call.

We couldn’t agree more. We literally pulled a Scooby-Doo double-take when we were walking the show lot at Lucas Oil Raceway on Day 3 of HOT ROD Power Tour 2021 and spotted the signature orange of the small-block Chevy V-8 hiding under the blue body work. We hope Duane and Nancy Smith, on their seventh and sixth respective years long-hauling, enjoy HOT ROD Power Tour 2022. If you’re there, look for the blue Mini smoking tires and embarrassing muscle cars, and talk to Duane, because we couldn’t do the stories he’s shared with us justice in these few short words.

Photos Courtesy of Owner: Duane Smith