This MGB GT's Jaguar V12 Engine Blew So The Owner Completely Redesigned The Car Without A Roof

Photo: Mark Sawatsky
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We thought Mark Sawatsky had the engine swap of the century when he fit a Jaguar V12 into an MGB GT. Only problem: it didn’t really work, and then that lovely V12 died. So he did what any sensible person would do: hacked the roof off, added a Buick turbo four-cylinder, designed a new tube frame and suspension, and honed the aerodynamics using a computer simulation popular with Formula One teams.

You know, as one does.

Sawatsky’s “Pink Panther” race car was built to run in the SCCA’s modified autocross classes, where things are a bit more open to crazy ideas like taking a Jaguar V12 that’s just sitting there and putting it into an MGB. When it ran, it was spectacular. Those noises from a big British motor were coming out of this little British car.

But the V12 was never quite happy in that car and ultimately failed, according to Sawatsky.

“The V12 and the trans adapter I used on it did not work well together and the trans input shaft was pushing on the crank of the engine,” Sawatsky told Jalopnik via email. “The engine thrust bearings were damaged and fell out, which dropped oil pressure and damaged all the rod bearings.”

Worst of all, it was heavy, which is a cardinal sin in a motorsport that values agility through quick transitions. The V12-swapped car weighed around 2,500 lbs in a class known for featherweight vehicles.

If you haven’t autocrossed before—first off, you should, because it’s a blast to hoon around a car as fast as possible on the cheap and you routinely see insane builds like this—this obsession with lightness all goes back to inertia. Objects in motion want to stay in motion in the direction they’re already headed. The more there is of that object (in this case, your car), the harder it is to make that object to change direction. When your chosen form of racing loves slaloms, weight is the ultimate enemy.

Sawatsky first tried to swap the blown-up V12 for a Ford 5.0 V8 engine donated to the project by a fan, to which he added aluminum heads, a roller cam and ported intake, but it was still too heavy. That car rang in at 2,250 lbs and the suspension geometry wasn’t good.

So, Sawatsky wanted to do things right this time, and completely rethink his MGB GT, using the same computational design tools that many engineers use to build cars from the ground-up.

Sadly for fans of the MGB GT’s funky ur-clownshoe shape, this meant that the roof had to go. Keeping weight low in the car is another trick to help it handle quick turns better. This opened a can of worms as then the cage simply wasn’t stiff enough to compensate for the lack of roof overhead.

It’s a common complaint I have with the convertibles-über-alles set: remove roof, lose rigidity. Then your well-meaning attempts to turn may just flop parts of the car around before you finally change direction—again, bad for autocross.

So, he taught himself how to use computer-aided design (CAD) programs to completely redesign the chassis and suspension. The new chassis made of DOM steel tubing weighed only 310 lbs. Per the figures in his CAD program, it would take 12,500 lbs of force to twist the chassis one degree, so it was stiff. A fiberglass body kit was acquired that widened Sawatsky’s un-GT’d MGB by six inches and covered up the new chassis.

Redesigning the frame and suspension from scratch also allowed Sawatsky to use the lightest brakes and uprights possible, which in turn let him switch from 15-inch wheels to lighter 13-inch ones. It incorporated a pushrod suspension design (a design frequently used on formula cars) that used Ohlins motorcycle shocks.

Up next was figuring out which engine would work. General Motors’ 2.0-liter turbocharged Ecotec fits in a 24-inch cube of a space and weighs just 375 lbs, so Mark bought a complete 2013 Buick Regal Turbo from an insurance auction, plucked the engine and sold the rest to a wrecker.

The redesign and rebuild process took a few years, but the final car weighed just 1900 lbs with Mark sitting in it, with a near-perfect weight balance that put 53 percent of the car’s weight on the rear wheels. With only a mild tune to run VP race fuel, the engine made 350 horsepower and 375 lb-ft of torque, which is delightfully absurd in a car that light.

It was ready by the 2016 season, where Mark says it did over 200 runs in autocross, a bunch of drag strip passes and even some road racing “without even a nut coming loose.”

But it still wasn’t exactly to his liking. The rear tires locked up under braking too easily, and the inside rear tire liked to lift up whenever he was turning and accelerating. The car only finished mid-pack at the 2016 SCCA Solo Nationals, so Sawatsky took the winter to reconfigure some things.

This is when Mark’s rebuild got even more delightfully overkill. Some components were moved around for better weight distribution to fix the braking and wheelspin issues. He also had a shop change the gear ratios in his transmission to work better on SCCA Nationals-style autocross courses. Then Mark hired an aerodynamics engineer to model his freshly redesigned car in CAD and perform computational fluid dynamics (CFD) tests on it.

CFD often comes up in pro racing as a way to minimize expensive time needed to sort out a car in a wind tunnel. The engineer Sawatsky hired to work on his humble autocross car even went on to work with a Formula One team. (“Tinkered with the coolest MGB build on the internet” no doubt moved that resume up a few notches.)

The extra aero work gave Mark a laundry list of items to tweak.

“As a result of the CFD tests, I made changes to the splitter, front fenders, windshield, engine cover, diffuser and spoiler,” Sawatsky told Jalopnik. “The computer predicted a 1.2-second decrease in lap time on a 60-second autocross course.”

That 1.2 seconds is a lot when fractions of a second are what often separate Nationals-level autocrossers from each other in the standings.

Unfortunately, the 2017 season didn’t let him enjoy these tweaks for very long. Sawatsky’s transmission seized a bearing at the first event of the year, kicking off a battle with the transmission shop as to who was responsible for the failure. So, he was forced to buy a new transmission with the gear ratios he wanted in the meantime to avoid extra downtime.

The car’s next event was a 12-hour drive down from Mark’s home in Winnipeg, Manitoba, in Lincoln, Nebraska. The car cornered so much better now that the increased cornering loads caused the engine to lose oil pressure, which in turn destroyed the rod bearings in the new Ecotec.

A junkyard engine was acquired off eBay to make it to Spring Nationals back in Lincoln just a few weeks later, along with a road racing oil pan and Accusump to help keep oil pressure in hard turns. An adjustable clutch-style differential replaced the Torsen-style differential, which had also broken. All of this thrash-fixing paid off, as he finished third in his class at Spring Nationals.

But his woe wasn’t over. An overboost condition blew the new engine a few weeks after Spring Nationals, and although he was able to rebuild everything in time to make the main SCCA Solo Nationals in the fall, the car continued to have problems, as Sawatsky explained:

A fuel line fitting loosened off and stopped the car mid-run. A turbo hose popped off but was hidden and we made several runs with no boost and didn’t know why, and we were still lifting and spinning the inside rear tire when turning.

So, after blowing two engines, one transmission and a differential in one year, 2018 had to be better. It just had to!

First of all, Sawatsky finally found the source of his inner wheelspin over the winter. The Ohlin motorcycle shocks he’d used on the car didn’t allow enough suspension travel, causing the inside wheels to lift up in turns. So, he got rid of the pushrod suspension design entirely for a more conventional one using Penske shocks at all four corners to double the amount of suspension travel.

Making new suspension pieces with a CNC machine. These were later swapped for steel bits in the same design for legality’s sake.

The differential and gear ratios were tinkered with once more. A Torsen-style limited-slip differential went back on the car, and gear ratios swapped once more so that he would only need to use first and second gear on Nationals-level autocross courses.

Yet another expert was hired to analyze Sawatsky’s suspension, giving him the necessary specs to optimize the car for autocross domination.

“Some of the changes were easy, such as adjusting the anti-squat and anti-dive settings, other changes were more difficult like adding a rear sway bar and changing to a very different configuration of front sway bar,” Sawatsky told Jalopnik.

The car also got a fresh coat of hot pink paint—it is the Pink Panther, so it should be very pink—and more lightened pieces were added: a seat with holes drilled out for weight savings, and lighter custom parts out of Lexan and aluminum. So far, has had a more successful 2018.

“The car felt great [at Spring Nationals] and didn’t display any of the wheelspin or braking problems it had last year,” Sawatsky explained. “However, we used up our tires before the actual event and still finished mid-pack. When we got home, I put new tires on it and have set Fastest Time of Day at every event I have been to and am optimistic for Nationals.”

There’s an engine stumble he’s still trying to sort, but there’s really no backing away from a project like this at this point. I’m sure he’ll figure it out eventually.

You can keep up with the spectacular adventures of Mark’s extremely pink race car and dig deeper into the specifics of this build on Facebook here, an MG Experience build thread here, and on YouTube here.

We’re featuring the coolest project cars from across the internet on Build of the Week. What insane build have you been wrenching on lately? Drop me a line at stef dot schrader at jalopnik dot com with “Build of the Week” somewhere in the subject line if you’d like to be featured here. As always, massive bonus points if you’ve got any fascinating updates on something we’ve featured before.