Getting back to the grid
Digital scanning and manufacturing techniques restore iconic Nasamax race car
The historic former team Nasamax car, renowned as the first alternatively fuelled competitor at Le Mans, has made a welcome return to endurance racing thanks to the reverse engineering capabilities of KW Heritage, the restoration and optimisation arm of KW Special Projects.
Originally fuelled by bio-ethanol, the distinctive race car is probably best known for its record-breaking speed down the Mulsanne Straight at Le Mans, achieving a top speed of almost 200mph. For more than a decade though, the Nasamax race car has been garaged, unable to compete due to strict FIA regulations.
This all changed in 2017, when the Masters Historic Racing series reviewed its entry criteria to allow a broader range of cars to compete. While the vehicle’s original 5-litre V10 Judd Series 1 engine was no longer viable, a newer 5.5 litre V10- Judd Series 2 engine did meet the new regulations. KW Heritage was the ideal partner to complete the engine replacement, thanks to its longstanding connection with the car from its days as a Reynard 01Q LMP model. Indeed, KW Motorsport founder, Kieron Salter, was previously chief designer and head of the special projects team at Reynard Motorsport.
Exploiting digital manufacturing techniques
While engine replacement is not typically a daunting challenge, highly technical chassis modifications to accommodate the new powertrain presented significant engineering challenges. The engine transplant involved a torque assessment to ensure transmission and driveline compatibility; the manufacture and fitment of new engine mounts; an airbox adapter and modifications to the exhaust system. Detailed changes were also required for the cooling, oil, water and fuel systems, as well as the Clutch / Starter Ring Gear.
While modifications to the carbon-fibre chassis could have been completed through traditional engineering and tooling, this would have added time and cost to the one-off project, potentially making it unviable. KW Heritage’s access to archived CAD data meant it could exploit digital manufacturing techniques to accelerate the project, while remaining on budget.
Edward Smith, head of heritage engineering at KW Heritage, explained: “Our longstanding association with Reynard Motorsport and previous involvement with the car provided valuable access to CAD data. This enabled us to quickly position the Judd engine model in Solidworks, with missing information being captured through 3D scanning techniques.
“The next step was to design the new engine installation kit, utilising advanced manufacturing techniques to develop mould tooling and loose tool inserts for the development of a replacement carbon-fibre front engine mount beam. The central core of the new beam was a pair of encapsulated 3D-printed ABS inserts that controlled shape and located the two aluminium inserts required to house the new engine studs. At the outboard ends, a pair of loose ABS tools were used to create the external flanges of the new beam. These conform to the similar outboard shapes of the original structure.”
Such a method enabled KW Heritage to engineer a component that was largely self-jigging, eliminating the need for a costly, single-use positioning jig. The new component was bonded in place using specialist structural adhesive, with the new beam bonded to both flanges and fully across the back of the chassis to provide greater structural integrity.
Bridging the gap between old and new
A further challenge facing KW Heritage was a 60mm height difference between the new and original airbox mounting trays. This was exacerbated by the fact the new unit used a different hole pattern for attachment to the engine. To overcome this, a carbon-fibre adapter ring was manufactured to bridge the gap and provide the correct hole positions, ensuring the original airbox, with its restrictors and filter, could be retained.
The entire project saw KW Heritage combine the use of CAD data with additive manufacturing and digital scanning to reverse engineer an effective solution. The company also worked closely with the customer to project manage the job, taking care of procurement and inspection to deliver a complete solution.
Smith added: “It was not possible to transport the car to our workshop, so we did everything on site with the customer.
“Once correctly dressed and kitted out, we removed the old beam, prepared new and old surfaces, and bonded the replacement beam in place. We installed the new engine with the new shear plate and studs and the original A-frames.”
KW Heritage’s unique ability to couple scanned vehicle data with digital manufacturing techniques enabled it to quickly and efficiently overcome the perennial spare parts challenge that is often an issue with classic vehicle such as the Nasamax race car.
Robbie and Dean Stirling from Team Nasamax, commented: “We were very pleased with the design and fitting work KWSP did for our engine installation. They were very helpful and clear in communication throughout each process of completing the task.”
Photos credit KWSP