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Opel Manta GT-J 3.0 transformed from rust bucket to dream machine

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September 12, 2019
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A self-taught car restorer from Watlington in Norfolk has transformed a limited edition rust bucket Opel Manta Coupe GT-J into a highly polished head-turning dream machine that keeps picking up awards for its ground-up renovation. 

Clive Moss bought the 1981 Manta because he owned an Opel almost new back in 1983. It was a ’79 Berlinetta 2.0 SR in white with blue cloth trim. “It drove like a dream with a nice exhaust note, and it looked good too. When I got to a certain time in my life I decided I wanted another one.”

Opel Manta 1

Opel Manta was ravaged by rust

When he acquired the GT-J it was pretty rotten. Creeping rust had ravaged the chassis legs, floor, jacking points and wings so he had to replace them all with new steel parts.

The 2.0 litre engine was also kaput so he whipped it out and squeezed in a bigger 3.0 litre power unit, with a little tinkering. 

He had to alter the cross member supports, anti-roll-bar and fabricate new radiator brackets to fit one in the nose of the car.

At shows the Opel Manta gets plenty of attention not least because of the triple Weber 40 carbs which look and sound awesome, especially gunning along the straight. 

But the bigger engine unit presented its own problems, especially when it came to keeping it cool. 

Clive explained: “The cooling system was a worry but amazingly it works well. I use an expansion system with twin fans and have added a cooler to the carbs via a small electric fan. She runs better now than when I first had the car because it was fitted with triple 45 Solex carbs which were much too large and ran over rich.”

Opel Manta

Opel Manta’s retro look was important

Once the new carbs were fitted and the car was running like a dream, he started thinking about the cosmetic appearance and the colour, which caused many sleepless nights. 

“I wanted a retro look that retained a little bit of contemporary street cool. I settled on the bright yellow. The car had factory fitted black satin bumpers and black chrome and interior which contrasted nicely with the yellow. I kept the interior black too and had the seats recovered but this time with matching yellow piping.”

Now the inside was looking good and the outside was looking good, but Clive still felt something was missing. 

He had always liked the  Porsche look with the decal low down the doors and that inspired him to borrow the idea and get decals made in black with Manta GT-J 3.0 on them. 

He improved the look further by swapping out the single headlamps for twins and then acquired a new boot lid with solid spoiler to rid the car of the rubber option factory fitted as standard. 

The exterior look was finished off with smart looking retro 14in alloys while the suspension is pretty much standard with stiffer springs all round to handle the extra weight.

Opel Manta

Engineering background ‘useful during restoration’

Rear brakes are also standard but Clive removed the reducer as it was no longer needed. The reducer was fitted on the original Opel Manta because the back brakes had a tendency to lock-up as it was so light on the back end.

The front brakes were adapted from Audi discs drilled out to fit the original hubs and the Opel Monza calipers fitted almost straight on. The master cylinder is slightly larger than the Omega 2.0 and fits the original servo with just a little adjustment.

The Opel Manta has now been renovated from the ground up but the restoration wasn’t all plain sailing.

Clive admits: “Modifying a car from its factory spec with no firm plans is always going to present some problems. 

“There was a very steep learning curve, especially with the triple carbs. I initially fitted old 1970s rebuilt Solex 45s which caused so many running problems. It didn’t matter what plugs I fitted, it fouled up the plugs every 100 miles or so. Changing to brand new Weber 40s changed all that and it now runs a lot better and for a lot longer.”

Having an engineering background came in useful during the restoration project. “I made the manifolds using three sections of original parts from the Solex and original parts from the old Monza manifold.”

Opel Manta

Opel Manta now boasts Senator 3.0 12v engine

“The first 3.0 engine I fitted was from a Monza but it was a bad unit. I then found a Senator 3.0 12v unit which was superb. I just had to change the distributor and the flywheel. 

“I used a Manta water pump which fits the Monza 4 speed Getrag 264 gearbox perfectly. Some slight alterations were needed to the gearbox remote linkage as otherwise it was too close to the handbrake but now it’s as good as gold.”

Certainly car enthusiasts at shows seem to agree with that view as the Opel Manta has turned heads and picked up a number of trophies throughout East Anglia. 

The latest honour was the Adrian Flux award for Best in Show award at the Magpie Craft & Country Fair at Wallington Hall, South Runcton, Kings Lynn, on Sunday, August 18.

Clive said: “I always wanted a retro-looking car that sounded nice so I reckon I’ve done my job. Having said that, there is more I would like to do with the car. 

“When I show her I try to have the bonnet up because that engine looks and sounds so good. Car enthusiasts look on in amazement. “


Opel Manta is crammed with 80’s memorabilia

“To complete the picture, when it’s on show I have 1981 memorabilia inside including the ‘brick’ telephone we had then, a newspaper from Charles and Diana’s wedding plus a magazine from a James Bond film which was out at the time. There is also a camera manufactured in 1981 and one or two interesting toys from the era.”

He added: “Yes, I’ve won a few shows perhaps on the restoration work that’s gone into it, or perhaps on the car’s appearance. 

“Admittedly, it’s not for everyone but I enjoy seeing people’s faces and appreciate the compliments I get and if it helps inspire other would-be restorers, so much the better.” 

You may think that now Clive’s turned his knackered old rust bucket into a prize winner he would take it a little bit easier. Not on your life… he’s just started a new restoration project to breath new life and good looks into a standard 1977 Lancia Beta Coupe which he imported from Australia.

Luckily, the Lancia is rust-free. Watch this space for progress reports on the latest restoration project.

bonnet open

Adrian Flux has insurance for every eventuality

If you are planning a restoration it won’t have to be on the monumental scale of  Clive’s Open Manta or Lancia project for you to want to ensure your investment is well protected. 

Adrian Flux offers extremely good rates for grey import, modified and classic car insurance and for cars while they are laid-up while being worked on. And for all those DIY mechanics out there, they even have a policy for your spare parts too.

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