RR Cloud Conversions (continued)

Researching the construction of the original Mulliner cars reveals a mixture of very good and not so good workmanship and design. 
Tipping the seats forward for access to the rear is a minor challenge. Hydraulics and electrics will offer a solution.  
The long-lived 6.75-litre RR engine is reliable and quite powerful, so there’s no reason to change it. An overhaul will yield another 100,000 miles of smooth torque. 
The same applies to the SU carburettors. Overhauled with modern component compounds to cope with current poor-quality fuels, they are good to go for many years.
Ancient electrics can be the source of failures to proceed, although Rolls-Royces obviously never break down. Replacement and optional updates/upgrades is the smart move. 
The second or production prototype is Iain Ayre’s personal Bentley S1, although Open Clouds are usually based on Cloud III. Structurally they’re all identical, it’s just a matter of flavour. 
Again a matter of personal flavour – the 1957 Bentley’s 4.9-litre straight six is silky, torquey, economical and sculpturally beautiful. Literally and pleasingly, different strokes.  
Very entertaining experience with the massive performance of a Bentley Turbo R has encouraged Ayrspeed to offer the fitting of a Turbo R drivetrain to Open Clouds to create the Storm Cloud.  

The heavy new steelwork secreted within the body at sill/rocker panel level weighs about the same as the deleted steel roof, but that weight has descended by four feet, lowering the car’s centre of gravity but leaving the overall weight the same. The silky ride of the Cloud is preserved and slightly improved, but the dynamic improvements to structural stiffness and the lowered centre of gravity offer a substantial improvement to the car’s handling, should you require that either for emergencies or for entertainment. 

It’s unrealistic to expect sixty-year-old electrics to be completely reliable, so the wiring is replaced with modern wire, relays and fusing. Quality is still old-school, the wires are thick and the changes are invisible. 

Mulliner’s approach was essentially superficial coachbuilding to a budget, while Ayrspeed’s approach is a change of design direction towards holistic internal structural overkill, based on long evaluation and design experience with fearsomely fast boutique high-performance sports and track cars. 

The origins of the Open Cloud body structure design go back to the early 1990s and the Ayrspeed Six XK120 replicas, which replaced the crude Jaguar ladder chassis with a blend of spaceframe and perimeter frame structures in medium and heavy steel tubing.  

The Silver Cloud chassis remains unaltered, other than being slightly stiffened by its connection to the new Open Cloud conversion body substructures. 

It may seem arrogant to ‘improve’ a Rolls-Royce coachbuilt by Mulliner Park Ward, but just because high-end cars are very expensive does not mean they are always entirely well executed. Take a look under a Ferrari 512TR for a real shocker.  


The useful and comfy door armrests are missing in some conversion replicas, or they are in the wrong place, or the seat back doesn’t tip forwards enough for easy entry to the back seats: Ayrspeed’s sideways but effective solution is to use an electric/hydraulic motor to tip the entire seat structure upwards and forwards. This also allows the rear of the seat to be height-adjustable and suspended on rubber pads, a little extra luxury touch.    


The wiring in Silver Clouds is now at least 55 years old. Ayrspeed renews it with a high quality custom loom in substantial wire gauges, built to our spec in consultation with our classic loom suppliers. It retains Lucas colours but sidesteps Lucas earthing issues. Most failures-to-proceed are electrical in nature. 

Modern materials and methods are used where they don’t impinge on the styling of the car.  For example, new sound-deadening mat is incredibly effective, and while the period fascias of original AM frequency radios are worth preserving, the internals are not. Discreet new sound systems rule. 

Soft top

The electrically/hydraulically operated soft top frame is a modified version of a roof system made by a major American manufacturer, ensuring a long-term worldwide supply of the frame, hydraulic and electric components used. These cars will need to retain their value as a long-term investment, and for that they must remain practical and easily repairable.  

Our internal redesign of the boot and tonneau panel area of the body allows the roof to be retracted fully inside the car, allowing the pleasing curve of the waist swage line to shine, uninterrupted by the previous clumsy dumping of the roof on top of the tonneau panel. Possibly Mulliner were starved of budget, or prohibited from using external hinges. (Nobody who has seen our new external hinges has so far noticed that they’re not supposed be there.) 

This redesign has allowed a longer and more pleasing rear window panel, set at a sexier angle and with a slightly lower roof crown. This involves no loss of headroom, as we use a new heavier roof material that provides the required silence and serenity without the need for an inner headliner. 

The rear passenger windows are also slightly larger, offering safer rear quarter vision and making the rear seat passengers feel less claustrophobic. 

This also makes the roof look slightly sleeker, lower and less like a van, although the improvements are subtle and would only be noticeable when an Open Cloud was parked next to a Mulliner car.


The Silver Cloud III’s V8 is a well-developed engine that remained in use from 1965 until 1997. The GM 400 transmission is also strong and reliable. Once the electrical system is sorted, there is no reason why an Ayrspeed Open Cloud should be any less reliable than a new vehicle. Possibly even more reliable: it has many fewer parts and complexities than a modern.   

Depending on your use of the car, a large range of updates and upgrades can be either fitted during its build, or retro-fitted to existing Open Clouds, with anything from the options list.  


One of the pleasing aspects of this whole project is that we replace most of the rear half of the external bodywork with new quarter panels, as well as fabricating new inner and outer rocker structures and new door panels. With this level of major reconstruction, most of the usual Cloud body rust is cut out. This means we can rescue otherwise fine Silver Clouds with body corrosion that has gone beyond economic restoration – and return them to their former glory and more. We can also convert your own Cloud or Bentley.

Storm Clouds

The Silver Cloud has an adequate performance, with realistically 250bhp and 300+lbs.ft of torque pushing 4600lbs of car. With the same basic 6.75-litre RR V8, the Bentley Turbo R makes 300+bhp and something over 420lbs.ft of torque pushing a 5000lb car.  The performance of a good Bentley Turbo R is remarkable. The Silver Cloud’s 0-60mph time is reasonable at 13.5 seconds, but the 7-second battleship rush of the Bentley is genuinely rapid. It’s also exhilarating: you are pushed backwards very hard into an excellent armchair. 

An Ayrspeed-converted Silver Cloud would weigh in at roughly 4500lbs, so using a managed, injected and turbocharged version of the same engine, it would be substantially but secretly faster than a Bentley Turbo R. 

The 1990s computers controlling the turbo engine’s ignition and injection are now of the same period as Atari and Commodore PCs: it would be optimistic to expect reliability. Ayrspeed uses new processors with our own performance mapping. 

It would also be possible to invisibly replace the steel front fenders, doors and rear quarter panels in carbon fibre. In which case the Cloud becomes a secret hooligan: we would recommend upgrades to the brakes and suspension.  


Any paint colour, roof colour, trim colour and material choice is available. A re-veneer in African Mahogany looks glorious when matched with quiet interior colours.

Landaulette roof: either the front section or the rear section can be convertible, or optionally both, with a central bar and division. The four-door format can be retained. 

The Surrey top option is a detachable hard front roof section that stows in the trunk. 

Four-door convertible. This does not look as good as a two-door, but if you need four doors it’s an option.   

Modern electric power steering.

Fuel injection and custom mapping.

Eco clean burn gas/propane switchable fuel option. (also reduces fuel bill 50%)

Multi-calliper vented disc brakes.


The Storm Cloud: a complete powertrain transplant from a Bentley Turbo R.

La Moderne – 7-series BMW V12 Silver Seraph drivetrain.

Concert system. Block-rocking beats, but visually discreet.

Cocktail system – mini fridge/ice maker, spirits rack in trunk.