If you were an avid reader of Hot4s & Performance Cars or ZOOM magazines back in the day, then there’s a good chance that COPDAT is a recognisable little Datsun to you. Known for its unique Subaru EJ flat-four engine swap, COPDAT graced the cover of both of those magazines when it was in the hands of former owner Terry Boyle.
First published in the January 2026 issue of Street Machine

“People still think it’s his car, and in fairness, he and I have stayed in touch and have a great relationship,” says current owner Emma Mullins. “Although we’ve kept the basic idea of what he’s built, there isn’t a nut or bolt on this car that hasn’t been changed.”

Not long after Emma came into ownership of the Datto, a few spots of rust on the rear quarters prompted what would turn into a full-blown rebuild. “I was recommended to go to a repair shop in Toowoomba [in South-East Queensland], but what we thought was a few rust spots turned into a heap more rust and lots of bog,” says Emma. “I wasn’t comfortable with all the filler, so we replaced almost all the car – new bonnet, sills, driver’s door, rear beaver tail, rear quarters, driver’s-side floorpan – there wasn’t much of the old car used by the time we were done.”



While two years’ worth of bodywork was underway, Emma was also having a fresh 2.5-litre Subaru EJ25 built for the 1600 by Deshele Performance.
“It had the 2.0-litre in it from when it was first built, but I wanted the torquier 2.5-litre engine for street driving,” says Emma. “We kept it Subaru powered to keep the original spirit of the car, but modernised with a new engine and better parts.”

The EJ25 uses an STi nitrided crank, Deshele I-beam conrods and forged pistons. The heads are beefed up with 14mm head studs, with Deshele Stage 2 278 camshafts. For boost, a GCG-spec Garrett G35-900 shoves upwards of 30psi down the flat-four’s gullet, making the package good for 585rwhp with a splash of ethanol and control from a Haltech Elite 1500.
“I’ve noticed Subarus have a bit of a ‘stink’ about them in the car scene, a bit of a nose turn-up here and there,” says Emma. “But the most common thing I hear when I pop the bonnet is ‘that’s different!’, and no one seems to be as offended by the Subaru engine anymore.”

Getting the EJ25 to fit was a tight enough squeeze, but then the decision was made to upgrade the gearbox to a Toyota R154 five-speed cog-swapper. “That required a custom bellhousing from Bill Hincher in the US, and the transmission tunnel had to be cut to move the engine 10mm forward to get the tailshaft angles right,” says Emma. “Fitting an EJ in a 1600 is hard work, let alone with a turbo! People ask if it’s AWD, being a Subaru engine, but that wouldn’t be as much fun.”
Once all the extensive bodywork and paint was sorted, the car came down from Toowoomba and back into Emma’s hands at home in Moruya on the southern coast of New South Wales.

A technology teacher by day, Emma wasn’t afraid of getting stuck in to get the car ready for its grand debut at Street Machine Summernats 37. “We missed Summernats 36 the year before, which was a bit heartbreaking for me,” she says. “I entrusted others to do the majority of the work, because the standard I want is beyond anything I could achieve with my skillset,” she says. “But I have been hands-on where I can, and it’s been a steep learning curve, one that I am really enjoying.”




The final major step before getting the Datsun to Summernats was the interior, with the car getting decked out in fresh tan leather by Ben O’Brien from Southside Stitching in Nowra.
“Benny made the interior everything I had dreamed of,” says Emma. “Originally, I was going all black with a teal stitch, but Benny said it would have no impact. I’d been seeing a lot of tartan stitch in my feed, so we decided to try that with the tan leather. It was a mission to get it done in such a short time frame, but I am eternally grateful for Benny’s work. It may be a bit sex-spec, but I love it!”

The mad thrash went down to the wire before scrutineering day, but the push to Australia’s biggest car festival paid off for Emma and her Datto when it took out the Top Retro-Tech award in the Street judging. “Summernats has always been a bucket-list one for me, so to win there and win with a Datsun was the most surreal feeling,” she says. “We had an issue with the timing belt skipping when we unloaded it off the trailer, so in the mayhem of diagnosing that, I got the text to say I’d made the Top 50 in Street.




“To make it through to the Top 10 and then win the Retro-Tech award, it was incredible,” she continues. “The judges also gave me a few ideas for what we could change for next time, and we’ve already done some of those. Jason Pollock has smoothed and painted the engine bay and fixed up a lot of imperfections, and SDR Motorsport has tidied up the intercooler piping for the new Plazmaman intercooler, so it’s ready to come back for the next Summernats, and I’m super excited.”



EMMA MULLINS
1970 DATSUN 1600
| Paint: | Mirage Lake |
| ENGINE | |
| Brand: | Subaru EJ25 flat-four |
| Induction: | Process West manifold |
| ECU: | Haltech Elite 1500 |
| Turbo: | GCG G35-900 |
| Heads: | Standard, 14mm head studs |
| Camshafts: | Deshele Stage 2 278 |
| Conrods: | Deshele I-beam |
| Pistons: | Forged 2168 |
| Crank: | STi nitrided |
| Oil pump: | High-volume |
| Fuel system: | Injector Dynamics ID1700-XDS injectors |
| Cooling: | South Coast Radiators radiator |
| Exhaust: | 3in stainless |
| Ignition: | Subaru grey coils |
| TRANSMISSION | |
| Gearbox: | Toyota R154 five-speed manual |
| Clutch: | Direct Clutch Services twin-plate |
| Diff: | Datsun IRS |
| SUSPENSION & BRAKES | |
| Front: | MCA coil-overs |
| Rear: | Standard IRS, lowered |
| Brakes: | TBS discs (f & r) |
| Master cylinder: | Skyline |
| WHEELS & TYRES | |
| Rims: | Simmons FR18 (f & r) |
| Rubber: | Nitto 205/40R18 (f & r) |
THANKS
Terry Boyle; the guys at Powertune; Jason Pollock at Kustom Paint; Matt at SDR Motorsport; Benny at Southside Stitching.

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