A smile spread across Bill Hardy's face as he talked about buying one of the most coveted of all vintage cars. The year was 1943. There was a wartime ban on non-essential private motoring in Britain, so the supercharged Bentley had been languishing in an orchard. It had been listed at £1720 - an enormous price for a car - when new in 1930. Mr Hardy bought it for £140.

Bentleys built before Rolls-Royce acquired the company in 1931 epitomise the Bulldog Drummond school of British engineering. They attracted Ettore Bugatti's famous remark, "The world's fastest trucks," and won the prestigious Le Mans 24-hour race in 1924,1927,1928, 1929 and 1930.

The prospect of getting behind the wheel of Mr. Hardy's car kept me awake at night. The mind's eye sees these barrel-chested heavyweights cruising along the almost deserted roads of pre-war England, crewed by characters straight from PG Wodehouse. It pictures them being raced by such swashbuckling 'Bentley Boys' as Woolf 'Babe' Barnato, the diamond millionaire, and fearless Sir Henry Birkin, whose friends and fans called him Tim.

But cars have changed almost beyond recognition since the 'blower' was regarded with the awe now reserved for the likes of the Jaguar XJ220 and McLaren Fl. I was concerned about factors that a modern motorist takes for granted, notably brakes and gears. I recalled what a friend with a sense of humour said about his vintage Bentley, "Three things happen when you push the brake pedal. First, the nose weaves from left to right a few times. Second, you smell a faint whiff of brake lining. Third, you may detect a slight reduction in speed."

Getting behind the wheel was an achievement in itself, because there is nothing so wimpish as a driver's door. You either slide in the passenger's side, or risk a technique similar to that adopted when mounting a horse. Points are lost for getting the gear lever up your trouser leg. We're talking about the right leg, because the lever is on the 'wrong' side of the cockpit.

The wheel looks big enough to have come from a Great Western Railway steam locomotive, and the leverage it provides is welcome when almost two tons is moving at very low speeds. Getting a vintage Bentley in and out of tight parking slots is a practical lesson in the upper torso's musculature. Enough dials and switches to delight Heath Robinson are scattered across the dashboard, but there is no sign of an ignition key. Sparking life into the four-cylinder, 4.4-litre engine depends on flicking two magneto switches, retarding the ignition and adjusting the mixture control before pressing the starter button. An exhaust pipe big enough to be mistaken for part of the Channel Tunnel plays basso profundo music.

The blower Bentley's image conceals the fact that Walter Owen Bentley opposed the idea of increasing power by supercharging the engine that produced 130bhp when tuned for Le Mans. Tim Birkin's enthusiasm for such a major modification was endorsed by Woolf Barnato, who was Bentley Motors' chairman as well as one of the team's star drivers. The huge Amherst Villiers supercharger boosted power to 175bhp at 3500rpm.

Birkin's car failed to go the distance at Le Mans in 1930, but hoisted the lap record to 89.69mph during a Boy's Own Paper duel with Rudolf Caracciola's supercharged Mercedes. Birkin later lapped Brooklands at 137.96mph in a single-seater blower that is still raced.

The swashbuckling baronet's team accounted for five of the cars. Fifty were bought by wealthy enthusiasts.

Brave men have wept and contemplated suicide while failing to master a vintage Bentley's gearbox. Getting it right involves the almost forgotten art of double de-clutching. Slot the lever into first, engage the clutch - no problem - and the Bentley moves off like any other car. The view down the long, louvred, leather-strapped bonnet is inspirational, even at a walking pace, but it is important to remember that the accelerator is where you expect the brake to be. Another prayer wings its way to heaven as I floor the clutch, move the gear lever into neutral, release the clutch, then floor it again and ease into second. Miracle of miracles! I can hear Birkin applauding in Valhalla.

Confidence grew as the Bentley accelerated and the steering lightened. Second to third? Perfect! But my attempt to change from third to top produced noises like the Anvil Chorus, leaving me with what the cognoscenti call a box full of neutrals. All you can do, apart from swear and apologise, is stop the car and start all over again.

But I was soon confident enough to hum Land Of Hope And Glory and The British Grenadiers as the Bentley thundered along roads so quiet we could have been time-warped back to 1930. The difference between vintage and modern brakes had to be taken into account, of course, and there is no way that a 64-year-old veteran's handling or ride will match up to what is taken for granted in even a run-of-the-mill 1994 runabout. To expect that is to label yourself a fool.

Modern cars insulate you from the outside world, but a vintage Bentley feels and sounds and even smells fast with its bellowing engine, howling gears and hot oil. And it can keep pace with today's traffic. The supercharger provides strong mid-range acceleration and The Autocar reported a top speed of 97.82mph when its issue of September 19th 1930 featured a report subtitled 'The Appeal of Immense Power, Linked with Great Docility'. The test car, GH 6951, was destined to be bought by Bill Hardy.

The vintage Bentley's peerless character is complemented by a tremendous appetite for hard work. I know an owner who took his blower to America for an 8000-mile tour that included races on both sides of the continent. Above all, these magnificent old motors are tangible and indomitable links with the days when Britannia ruled the waves and waived the rules.

Sotheby's sold Bill Hardy's beloved behemoth for £386,500 a few weeks after I drove it. That works out at about £2 profit per mile covered since 1943. But the fun factor is impossible to quantify. And fun is what these cars are all about.