Minis have a long history in Australia’s modified car culture. From their utter dominance at the ’66 Bathurst 500, through to rallying, circuit racing, speedway and more, these tiny British terrors introduced many Aussie revheads to the idea of bulk fun in a small package.

First published in the April 2026 issue of Street Machine

Newcastle’s Jason Roberts has taken that theme to the extreme with his ’76 Leyland Clubman, which he calls ‘Baby Monster’. A life-long Mini fan, Jason wanted this race-ready featherweight to give him maximum thrills in a small wheelbase.

“My first car 40-plus years ago was a Mini, so I’ve always had one on a list to do as a nice street car, but then it morphed,” he laughs. “I wanted to do something different with the engine in a Mini, but still stay true to the marque. People put Honda motors in these things all the time, and I’ve got a ’57 Buick [SM, Dec ’25] and an EH with LS engines, and an XM coupe with a Coyote. However, with the Mini, I wanted to keep the BMC A-series in there to retain its DNA.”

With that in mind, Jason tracked down a BMC 1275cc four-pot that had been given a Kent Auto Developments twin-cam conversion, so it’s still a BMC A-series at its heart. “Once I got to that point, I started thinking, ‘How crazy can we push this?’, so I decided to turn it into a track car.”

Jason’s goal was to push the Mini platform to its ultimate limit, and his plan for a simple build spiralled out of control as the packaging and engineering realities hit. “I wanted it to be low, so we moved all the suspension pick-up points so we could get the body low and maintain the suspension geometry,” he says. “This led to the inboard suspension operating with bell cranks, and it just kept getting crazier and crazier.”

The Baby Monster now uses a full tube-frame front end made by Warhorse Motorsports in Rutherford, north-west of Newcastle. “When the Mini got to us, it came with a fair few crates of parts,” says Warhorse Motorsports’ Brad Lowe. “Usually, we would sit down and catalogue the parts and then dry-assemble the car so we know what we’re missing, what we can use, and what needs to be modified. On this car, there was a fair bit we modified, and I feel this is the coolest circuit car we’ve done.”

Jason sorted a custom chrome-moly rollcage, while the Warhorse crew crafted a full alloy-sheet floor undertray to smooth out the under-car aero, along with a large front splitter and a bunch more fabrication. The adjustable JRI dampers use external reservoirs and Eibach springs, and operate on custom billet bell cranks from Newcastle’s Cobalt CNC, which also made other custom pieces on the car.

Even the hubs are a full-floating design made by UK Mini specialists Kent Auto Developments, and KAD hardware also features extensively in the drivetrain.

The BMC four-pot was next to come in for some work. “The engine had been ordered but never picked up, so it had been sitting on the shelf for 10 years when I bought it,” Jason says. “So, I sent it to Graham Russell at Russell Engineering to go through it, but he saw the KAD head and said he wasn’t touching that, so I sent it to Jake Bain at Bain Racing.”

While the Kent Auto Developments 16-valve twin-cam head is already a maximum-effort, race-spec piece, Jake heavily reworked it. The airflow guru reshaped the chambers, extended the runners, and generally pushed it to the edge of its potential.

Russell Engineering sorted the factory BMC 1275cc bottom end, pushing it to 1430cc (87ci) with a reground stock crank, Carrillo rods, and Omega 13.5:1 slugs suited to E85. Jason figures this should net around 200hp and rev to around 8500rpm, but he’s already planning a turbo build for when he’s shaken the Monster down and has the bugs ironed out of it.

“The engine lays forward 8° to get it to fit under the bonnet and to raise the pick-up point for driveshafts, because the body has been lowered down so much,” he says. ”Because we’ve kept it A-series, it also used a BMC four-speed gearbox, but it now has a KAD dog-engagement gearset, and a KAD LSD.”

For a classic car like a Mini, you might expect the electronics package to be simple, but the opposite is true on Baby Monster – it’s as high-tech as any tier-one race car.

“It’s got every bit of Bosch gear in it,” says Brad Lowe. “It has the Bosch Motorsport ABS, MS6.1 ECU, PDM and dash. It’s got tuneability in the ABS; it’s all top-tier stuff.”

Baby Monster broke cover at the Yokohama World Time Attack Challenge in Sydney last year, where it was featured as part of a static display, but it should soon be ready to rip as the build comes to a close.

“When the car was at World Time Attack last year, it was basically complete but wasn’t ready to start, as we were waiting for some engine parts to turn up, which have just landed in the last week or so,” says Brad. “I think we’ll probably see it out on track in the next few months. We initially talked with Jason about building it as a Sports Sedan, but that class has faded away lately, so it will probably run in Time Attack and at track days, for now.”

Jason’s Mini stands as the ultimate evolution of Sir Alec Issigonis’s masterful design, so you could say it’s been some 67 years in the making. It certainly provides a wild stablemate to Jason’s other V8 rides, and should be just as thrilling.

JASON ROBERTS
1976 LEYLAND MINI CLUBMAN

THANKS
Warhorse Motorsport; Russell Engineering; Cobalt CNC; Bain Racing; V-Sport; Force Racing Wheels; my friends and family for their support.

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