1923 Aston Martin Cloverleaf

Engine 1487cc sidevalve four-cylinder, sidedraught Zenith carburettor Power c38bhp Transmission Four-speed nonsynchromesh manual, rear-wheel drive Suspension Beam axles, semi-elliptic leaf springs, friction dampers Brakes Mechanical drums, actuated by footbrake at front, handbrake rear Weight c750kg Top speed c77mph

Yuki is also here today, with his family, to experience his new acquisition on Aston Hill. He thought it too good an opportunity to miss, and it’s thanks to his generosity that Octane is about to experience it too.

BEFORE THAT HAPPENS, there’s Simon Diffey’s potent-looking Bugatti to examine. It’s a more minimal machine than the Aston, with road visible where you would expect to see floor, gearlever outside the cockpit, two Bosch magnetos within it driven from the back of the engine. Two? The 1.5-litre, overhead-camshaft motor has two sparkplugs per cylinder, you see, off to the side of the combustion chamber because there’s no room anywhere else.

There are two sparkplugs per cylinder because each chamber contains four valves – yes, it’s an early 16-valve motor – which are moved by ‘banana’ tappets. These are curved, and run in curved guides, so that a single central camshaft can actuate two rows of vertical valves, one row each side on the camshaft’s axis. Complex stuff, and it must have been a nightmare to machine those guides.

Here, again, we find a water pump. Also like the Aston, the Bugatti has a single brass-bodied Zenith carburettor, but updraught rather than sidedraught. There’s a shortage of brakes, though; only the rear wheels are subject to the forces of retardation, applied either by handbrake to the brake drums or by pedal to the transmission brake.

All Simon knows of his Brescia’s history is that Herefordshire Bugatti specalist Wolf Zeuner assembled it in the 1970s from bits acquired from historian, dealer and racing driver Colin Crabbe. Ivan Dutton, guru of all things to do with Bugatti maintenance in the

UK, has looked after it for the past ten years or so and, give or take the variable presence of a reliable tickover, it’s in fighting form today.

The Brescia is almost a ‘toy’ Bugatti, with its small engine and a weight of just 450kg. Simon tells me that it has a Raymond Mays camshaft, which lifts power to 60bhp, so there’s the promise of quite a lot of pace for a car just short of its centenary. The standard, original Bugatti spec resulted in 40bhp, but it was still enough for three Bugatti Type 13s to fill the top four places at the 1921 Brescia Voiturette Grand Prix and give the car its name, retrospectively in Simon’s car’s case. This type number, and its Type 22 and 23 developments, continued until 1926, by which time over 2000 had been built. That’s quite a contrast with the 57 production cars built by Bamford and Martin.

This little blue bomb – its wheelbase measuring just two metres, the notion of explosion heightened by that barrel of a petrol tank across the tail – isn’t so much styled as lightly clad over its mechanical parts. The exposed bits look worryingly spidery, and its narrow, beaded-edge tyres will surely feel skittish on the slippery road that awaits. I’m intrigued by its quarter-elliptic rear springs, anchored behind the rear axle rather than in front as would be normal; doing it this way encourages the tail to rise under braking, which you don’t necessarily want, but is also said to improve traction.

I climb in over the side, and rest my left heel on the gearbox as instructed. Fuel pressure is achieved by pumping a large plunger outside the side panel but, once the engine is running (easily achieved thanks to the recent addition of a self-starter), a small engine-driven air compressor takes over. That monobloc engine sounds impossibly keen for something so ancient, and now we’re off down the hill.

There’s no synchromesh, obviously, but there’s also very little flywheel effect so with the right timing it’s surprisingly easy to get super-quick upshifts – as Simon does all the time when he’s racing the Bugatti. Downshifts are nearly as fast, just requiring the three quick pedal-dabs of a doubledeclutch while working the external gearlever. Slightly more taxing is the need to remember that first and third require the lever to be pulled back, not pushed forward.

That, plus the fear of a rear-wheel skid when braking, make me ultra-cautious at first but Simon is encouraging me to try harder. Once on the level I do just that and discover a joyous surge of power as the engine heads bombastically towards the 4000rpm beyond which it’s unwise to venture. And now we’re turning round, I’ve learnt that the little Bug steers with surprising accuracy, its brakes are fairly trustworthy and we’re haring up the hill on a rather enjoyable surge of torque. We even get into fourth gear at the summit as the