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Home » The Atlantic chassis components – Update #3

The Atlantic chassis components – Update #3

Tom Andrews sourced as many original Bugatti parts internationally as possible for the Atlantic coupe chassis and running gear. The remaining components required were hand-crafted here in New Zealand.


The Unique Fasteners

Ettore Bugatti was an engineer, a designer, an inventor and a perfectionist. Over his lifetime, he filed approximately 1000 patents under his name.

One of his well-known quotes, “Nothing is too beautiful, nothing is too expensive” portrayed Ettore’s approach to life. If he didn’t like the aesthetics or quality of something, he simply designed and manufactured it himself. This desire for perfection was evident in his personal life and the motoring industry in which he was so entrenched.

One such range of components that Ettore Bugatti designed and produced was the fasteners used throughout his vehicles. Instead of the industry standard metric diameter at that time of 6, 8,10 and 12mm, Ettore designed a range of nuts and bolts in 1923 with diameters of 5, 7, 9 and 11mm, which were unique to the Bugatti vehicles.

The square-head bolts were manufactured at the Bugatti factory with a collar, and the nuts had an integral washer attached during production, meaning they were less likely to loosen under vibration.

The unique Bugatti fasteners.

As our restoration team began setting up the chassis components, Greg researched the Bugatti fasteners available today and discovered a French company called Bugatelier. Situated in Oberhausbergen, France, Bugatelier specialises in new Bugatti parts “which fully meet the original specifications of the Molsheim factory.”

Greg has found Bugatelier to be an incredibly reliable and helpful company to deal with and an asset to both Bugatti projects.

NB. We should add that the photos published in this post during the early stages of setting up the Atlantic chassis show standard nuts and bolts securing the various components. These were used for test fitting, etc. as components were fitted and removed several times. At the final stage of construction, the period-correct, unique Bugatti fasteners were used throughout the build.


The Components

Tom Andrews sourced as many original Bugatti parts as possible for the Bugatti Type 57S chassis. Some of the original components are detailed below:

  • An original Bugatti steering box was sourced in Switzerland and was reconditioned at the Classics Museum workshop.
  • The Type 57S chassis originally had a split front axle. It became apparent very quickly that we would not find a split axle, but Tom did source an original Type 57 axle in Switzerland which has been used in this build.
  • Original Bugatti spring hangers were sourced from Europe.
  • A Bugatti gearbox was obtained from Erik Koux. The gearbox retains the original Bugatti internals, however a new housing had to be cast due to damage. The casting type we produced was unique to the Type 57S chassis due to its different clutch operation which enabled the driver to sit lower.
  • Tom sourced an original Type 57 differential from an earlier Bugatti model in Switzerland. To make the diff authentic to the Atlantic coupe, a new larger finned housing was cast, as well as a new crown wheel and pinion. The diff, however, still retains its original EB-stamped axle, axle tubes and other internal components.

The restoration team at Classics Museum was in a unique position as they began the Bugatti Atlantic coupe build. Sitting in the workshop and at their disposal was the original Bugatti Type 57 Ventoux which Tom purchased in France. Having the Ventoux at their fingertips meant the team could reference and replicate the majority of the remaining Bugatti components required for the Type 57S chassis.

During the initial set-up, the team temporarily placed the original Bugatti diff from the Ventoux into the Type 57S chassis.

The leaf springs were manufactured locally using reference photos and the Ventoux springs as examples.

The rear leaf springs and spring hangers mounted on the Bugatti Atlantic chassis.
The rear leaf springs and spring hangers are shown mounted on the Type 57S chassis.

To keep the leaf springs authentic, the team milled down spring steel as per the original Bugatti Ventoux examples, taking special note of the variable thickness of each spring.

Greg manufactured the torque arm to suit the Type 57S chassis of the Atlantic. The cross members were temporarily bolted into place and were hot riveted at a later time.

The torque arm and the cross members temporarily bolted in place on the Atlantic T57S chassis.
The torque arm and the cross members were temporarily bolted in place.
An example of the hot riveting carried out on the Type 57S chassis.
An example of the hot riveting eventually carried out on the Type 57S chassis.

The original steering box sourced from Switzerland was mounted to the chassis and the steering wheel alignment was checked.

The original Bugatti steering box mounted to the chassis with the steering wheel in place.
The original Bugatti steering box is shown mounted to the chassis.

The block of the Ventoux engine was temporarily used as part of the initial chassis set-up to position the engine mounts and cross member.

The Ventoux engine block temporarily in place to assist with the set up.
The Ventoux engine block was temporarily used during the initial chassis set-up.

A local engineer used the original Ventoux spindles as samples to manufacture a set for the Atlantic coupe.

A set of hand-crafted spindles.
The hand-crafted spindles.

Alan Sharp is an engineer in Hamilton and a very close friend of the Classics Museum restoration team. Using the Ventoux stub axles as a reference, Alan machined a new set from a solid block of steel.

The locally machined stub axles.
The set of stub axles machined by Alan Sharp.

Alan also reproduced a new set of aluminium brake drums for the Atlantic build. Once again, these were machined from a solid block of aluminium that initially weighed 44 kg. By the time the machining was completed, the brake drums weighed only 4 kg!

The aluminium brake drums then had a heat treated cast iron insert pressed into place to form a suitable surface for the brake shoes to run against.

The front brake backing plates which locate all the brake components were cast using the original Ventoux plates as patterns.

The following images of the brake drums showcase Alan’s beautiful workmanship.

A view of the backing plate (left) and the outside of the brake drum.
A view of the backing plate (left) and the inside of the brake drum.
The backing plate and aluminium brake drum.

Bugatti originally cast the brake shoes at its factory in Molsheim. To precisely replicate these, we 3-D scanned the Ventoux brake shoes and decided to have them machined out of a solid block of aluminium using a 5-axis mill.

The Bugatti Atlantic brake shoes fitted on the backing plate.

The aluminium brake shoes are shown positioned in place.

The team used the original Ventoux hand brake lever as a reference to manufacture one for the Atlantic coupe. This was achieved by copying the basic profile out of plate and then machining to the correct dimensions.

The hand-crafted hand brake lever.
The hand-crafted hand brake lever.

The Classics team used a specialist company here in New Zealand to manufacture and certify a new set of steering arms to be used on the Atlantic build.

The manufactured and certified steering arms.
The locally manufactured and certified steering arms.

The engine support cross member was manufactured and welded in-house at the Classics restoration workshop using photographs as a reference.

A view of the engine support cross member that was manufactured in-house.
The engine support cross member.

The hand brake shaft, drive shaft and pedal assembly are further examples of the components that had to be manufactured by the team. Historic drawings and photographs of the original Bugatti ‘S’ chassis were used as a reference to verify accuracy and functionality.

The hand brake shaft, drive shaft and pedal assembly.
The hand brake shaft, drive shaft and pedal assembly.

The following photo captured the Type 57S chassis with many of the components fitted.

The Type 57S chassis with various components fitted.
The Type 57S chassis.

A Rare Sight

It is not often that the Type 57 and Type 57S chassis are seen side by side as a comparison.

Although we haven’t touched on the Ventoux restoration yet, we wanted to share the following images of the two chassis to highlight the differences between them.

The side view shows the painted Type 57 chassis in the foreground. This chassis was introduced in 1934 with a 3.3 metre wheelbase. The lowered Type 57S shown in the background was introduced two years later, in 1936, with a reduced wheelbase of 2.98 metres. The special feature of the hole cut in the chassis rail is visible on the Type 57S where the rear axle passes through.

The front view of both chassis (Type 57S on the left). The contrast between the two chassis is clearly noticeable from front to back.

Lastly, a bird’s eye view of the two Bugatti chassis, again showing the variations to the Type 57S chassis.

As the wheels and tyres were fitted, the team got a first glimpse of the rolling Type 57S chassis.

The next area of focus for the Type 57S Atlantic coupe project was the motor, but a worldwide search for an original Bugatti engine was proving difficult.

However, to our surprise, the most amazing discovery was about to be uncovered and was already on our doorstep……


Sources / References:

Bugatti – The Designer By Barry Eaglesfield

https://newsroom.bugatti.com/press-releases/the-genius-of-ettore-bugatti

https://shop.bugatelier.eu/en/home/

https://www.bugattirevue.com/revue55/type57s.htm

Comments

  1. Amazing ! Such incredible detailing , research, and commitment, to originality. Truly amazing !! Very Impressive. Thank you for sharing the update. Regards to Tom , Greg, and Alan Sharp . John Lee

  2. Wow !!!!!! Such a fantastic restoration so far nothing left to chance and beautifully engineered. So lovely to see the amazing progress done with such attention to the minutist detail. A wonderful job done here at The Classics Museum in Hamilton. Im looking forward to seeing the next phase of this precious restoration project.Its going to look amazing when completed. Excellent work and hats off to all involved. Cheers Si.

  3. Thanks for sharing this important build – the attention to detail is to be commended, the quality of workmanship is excellent.

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