Tuesday, Nov 20 04:11pm
AUTHOR: Simon Chapman

Feature: 1984 Mazdaspeed March 84G restoration nearing completion

The long awaited rebuild of the Mortimer Motorsport-owned 1984 Mazdaspeed March 84G is nearing completion.


The team hope it will be on its wheels and rolling in December with the car running and on-track by the first quarter of next year.


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It’s been a long and complicated road for the Mortimer Motorsport crew, who are now nearing the finish line.




The car has a brief racing history but is significant for being the only twin turbocharged rotary-powered race car Mazda produced.




Designed by legendary engineer Adrian Newey, it was driven by Yoshimi Katayama and Takashi Yorino in the 1984 Fuji 1000 and completed 153 of the prescribed 226 laps. It retired due to a turbocharger failure, and that spelled the end of Mazda’s turbo foray in Group C racing.




It was effectively left to rot after it’s one and only race. Fortunately, the car was never stripped for parts as a lot of its componentry was bespoke for the time being the only twin turbocharged 13B.


Engine old


It was a double-edged sword for the Mortimer Motorsport team, however. Here they had a car that was complete in every sense of the word but was crumbling right in front of them having sat still for over 30 years.




“Basically, the car was neglected but it was absolutely complete in every respect,” Mortimer said.


“Nothing has been raided off it. It was all there. That made it a lot easier to pull a part and decipher what was and wasn’t required and what needed to be replaced and rebuilt.


“That list was enormous.”


More rotting


The team brought the car home in 2015, and it made a surprise first appearance at the New Zealand Festival of Motor Racing in February that year in proper ‘barn find’ guise. The team have been working on it ever since.


Getting the car to New Zealand was a mission on its own – but that’s a story for another day.


Bare tub


The March tub wasn’t in great shape when it arrived. A lot of the magnesium parts had corroded away, which meant plenty of the componentry had to be remanufactured.


Tub from top


It was decided the original 13B engine couldn’t be restored and refitted. That was for several reasons including the historical significance of the engine and Mazda’s desires for it never to be seen – again, another story for another day.


Tub side


What it meant was a replica twin turbo 13B engine and gearbox was fitted.


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While it might seem minor, details like discontinued period correct aircraft rivets and aircraft glue was sourced and fitted. The team got lucky there too with a nearby friend having a stash of the rivets.




The rebuild is close to being done. Now what’s left to do is fit the remanufactured suspensions componentry. Much of that was made of magnesium, and a lot of that rotted too. They spared no expense on the new parts though, which have been crack tested and x-rayed.




Aesthetically the car has new fiberglass panels that will be stickered in the original Fuji 1000 livery. The team still have the original panels and plans are being hatched to build a replica model fitted with the worn panels.  




It’s been a team effort on all fronts with Garry Roper working on the tub almost daily. Grant Munroe from Rotasport helped with the engine, while Steve Murch rebuilt the original turbos. Scott and Bill Buckley of BSL and Dan Slater helped with the fabrication.


Thousands of photos have been taken by Roper to document the rebuild (pictured at start).




The team have been extra careful to keep the car as true and original as possible. The dashboard is original, down to the handwriting (pictured above).




“I just go and look at it every day and get excited about it,” Mortimer said.


“It’s been a restoration which is most probably better than other people would have done.




“There’s been no stopping to say we’re not going to do this or replace that. If it was suspect, then we replaced it.


“It’s been a complicated job as well, something that I would not have contemplated when we first looked at it.


“When you get into it, it’s been a long process and we needed someone very professional to do it and Garry [Roper] has done it from start to finish.”




Roper (pictured above) said it’s been the most comprehensive rebuild he’s ever undertaken. The nature of the corrosion meant that in many ways it was worse than a crashed car as they discovered more and more parts of the car that were falling apart as the build progressed.




It was made especially hard as they had to be delicate with the car and hope that parts didn’t fall apart while they use them as reference points throughout the chassis.


Back 3/4


The car is a shadow of itself compared to when they first got it. However, it’s as close to original as feasibly possible.




There are hopes the car will be ready in time for Mad Mike’s Summer Bash where the team would like to debut the car.




Whiddett is bringing out two very high-profile rotary-powered cars too. The legendary 1988 Mazda 767B and 1979 Mooncraft MC S.




Mortimer said he’s excited to see the 767B but is also keen to show their car to the Japanese crew coming down. Likewise, for Roper he’s looking forward to seeing it cut some laps.