AROC Magazine Article - Part 3

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Spacenut
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AROC Magazine Article - Part 3

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Third installment of the AROC article (warning: high levels of engineering content)

Rebuilding the Dream - continued

The height and reach adjustable steering column was sourced from a Rover SD1, which also included the legendary “Quartic” rectangular steering wheel and indicator and wiper stalks shared with the Lamborghini Countach, among others. To make the enormous steering wheel fit the confines of the Nova cockpit, I bought a new quartic wheel and cut it down to reduce the height and width, before welding it back together. The wheel was recovered in leather by Royle Steering Wheels. Of course these days rectangular steering wheels are commonplace on any kind of performance car, but I think this 1970s original compliments my rectilinear dashboard perfectly, something that one of those hideous F1-inspired butterfly steering wheels could never do.

The twin carburettors are operated by a hydraulic throttle pedal, a precursor to modern “fly-by-wire” systems. A business trip to the US introduced me to this novel drag racing technology, which is popular in Top Fuel cars where the chassis frame flexes so violently under acceleration that a conventional cable throttle will not work. A tiny slave cylinder is connected to the throttle pedal and compresses the hydraulic fluid through a Nylon hose which then operates the throttle bar via a master cylinder and fluid reservoir in the engine bay. Although it results in a relatively short pedal travel, the throttle is very smooth in operation.

The Alfasud pedal box was grafted onto the chassis and adapted for twin AP Racing master cylinders operated by a modified brake pedal fitted with an adjustable brake bias bar. This allows me to change the amount of braking effort between the front and rear wheels, which is important due to the radically different weight distribution of the Nova compared with the original donor chassis. Clutch actuation is through the standard Alfasud master cylinder.

The fuel tank is fitted under the bonnet, where it shares the space with the Alfasud radiator, front suspension and steering. The height of the rack can be adjusted using shims under the securing clamps which permit adjustment of bump-steer. The fuel tank is filled via an aero-style fuel filler cap located on the nearside front wing. A moulded fibreglass swirl pot is bonded to the underside of the wing panel and transfers the fuel into the tank. The front face of the tank is angled to direct the hot airflow from the radiator towards the bonnet vents, which were reversed for this purpose.

Even though the chassis was designed to fit the bodyshell, it still required considerable modification. The engine intrudes into the cockpit space behind the seats, so the entire rear panel had to be cut out, and new panels fabricated. Similarly the front bulkhead and spare wheel well had to go too. These were replaced with fabricated aluminium panels around the front and an aluminium honeycomb composite panel for the removable bulkhead. More composites were used around the engine bay, this time Nomex honeycomb and carbon fibre sheet material liberated from the scrap bins at work. A more powerful hydraulic pump from a commercial vehicle tail-lift was sourced for the canopy system and now resides in a space on the left of the engine bay, while the battery now lives in a compartment on the right of the engine.

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Under the louvre panel, Summer 2020. Alfasud 1.2 Ti gearbox, recently fitted Alfa 33 expansion tank. Rear view camera looks through the louvre panel when closed.

As well as the reversed bonnet “nostrils”, the large air intake in the nose, originally only for show, was opened up in the centre to feed the radiator and cabin air intakes were located on either side. A full-width grille fabricated from aluminium mesh covers the intake, and provides location for the number plate characters, in the same manner as the contemporary Lotus and Lamborghini Miura.

The rear panel of the car had been so badly hacked about to fit the non-standard VW 411 engine that it had to be scrapped, and was replaced with a rare unmolested example.

Headlight efficiency has always been an issue on the Nova. The lights are low down and located in deep tunnels and are not helped by scattering from the acutely angled Perspex lamp covers. To try and fix this I used a pair of Hella projector beam lamps for the dipped beams, set into rectangular chrome bezels (because nothing says 1970s more than rectangular headlights!) recovered from my smashed Cibie driving lamps. The bezel also houses the indicators, which I made using a matrix of automotive LEDs married up to a lens made from a pair of Land Rover reversing lights. All of the filament bulbs are accessed from behind the headlight tunnels via a removable inspection hatch (an idea I nicked from the McLaren F1), allowing the headlight covers to be sealed against the weather. Because the headlights are not hermetically sealed they are still subject to condensation and misting. I fitted a pair of laptop cooling fans into moulded ducts underneath the headlamp tunnels to provide demisting of the headlamp covers.

The single windscreen wiper fitted to the Nova was sourced from a DAF truck, and is powered by a self-contained Lucas motor and gearbox. Originally centrally mounted, the pantograph geometry swept only a small part of the huge windscreen, making driving in the rain all but impossible. I took inspiration from the Lamborghini Countach and relocated the wiper motor to the driver’s side of the canopy, revising the pantograph geometry so that the wiper sweeps up to the driver’s side A-pillar and parks on the passenger side. A secondary wiper from a Mini was welded to the main wiper arm. This clears the base of the screen on the driver’s side. A windscreen washer hose feeds a 3-way nozzle at the end of the wiper arm, and the electrical connections to the wiper motor are now made through an Alfasud Series 3 tailgate connector when the canopy is closed.

The enormous 1970s glass sunroof had been smashed in an attempt to steal the car. Attempts to locate a replacement sunroof glass were unsuccessful, and the thick aluminium frame and rubber seal looked ugly anyway, so in the end Neville filled in the sunroof aperture and I restoring the internal contours with low density polyurethane foam, re-trimming the canopy headlining in its original 1970s “Moonstone” fabric (so-called because it looks like lots of overlapping lunar craters, the perfect space-age theme!).

A 1980 1.5 Ti engine replaced the original single-carb unit, which had a cracked cylinder block, but not before it had donated all of its ancillaries and an inlet valve to this unused service replacement engine. The only change required was the relocation of the coolant expansion tank.

I designed the chassis for 15” wheels and tyres, rather than the 14” items originally specified. To get the car rolling I bought a set of Weller Racing steel wheels, 15 x 7” front and rear, with a 4 x 108mm PCD and 15mm offset. These wheels were popular in historic Formula Ford racing but are sadly no longer available in this size. If you squint a bit at the ring of cooling holes you could almost imagine you were looking at Alfa Campagnolos. The front wheels are shod with 185/65 R15 tyres, the rears with 205/60 R15. The completed Nova tips the scales at a relatively svelte 830 kg, so fat tyres just aren’t necessary. The mass is distributed between the front and rear axles in the ratio of 46% front and 54% rear, a better weight distribution than any of the cars that inspired it, and a complete vindication of the decision to fit a boxer engine and gearbox in-line.

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Brands Hatch GP 1974? No, Brooklands, January 2020. The Grey Machine looking suitably brooding under darkening skies...

To be continued...

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