It isn't widely known on other hand it isn't exactly a secret, that the Mini Cooper used for personal transport by Alec Issigonis (creator of the BMC Minis and their akimbo engined kin) incorporates a Downton performance conversion. This is a fact more meaningful than a royal appointment that Daniel & Bunty Richmond, partners in marriage and Downton Engineering Works Ltd, could be forgiven for ramming down your throat. But they don't. I had it from another source, asked if it was true, and they diffidently admitted it was.
If you measure success by volume of trade, Downton’s place on the performance-equipment ladder is two or three rungs from the top. But a yardstick calibrated in degrees of satisfaction vis-a-vis the greatest number of genuinely knowledgeable customers gives this family firm a summit rating. One reason is that the Richmonds, like Jack Spratt and his wife, exactly complement each other. Daniel lives his life in a state of almost total engrossment in engine development in general and breathing problems in particular, but I've known gorillas who were abler businessmen. Bunty, who says she knows nothing about engines but can out point an averagely enthusiastic motor-male on the subject, has a self-taught grasp , of commercial mumbo and thus is able to quarantine Daniel completely from such banes and bores as invoices, PAYE and all that jazz.
I have yet to drive, or even to hear of, a Downton-converted car that fell down on the claims made for it. And if in your innocence you imagine that all so called performance equipment makes cars go faster, or accelerate better, or both, I must sorrowfully disabuse you. Take the case, for instance, of a certain item of bolt-on tackle (necessarily anonymous, so we'll call it Brand X) that literally ten of thousands of happy purchaser are convinced is lending them wings. Downton bought a sample and bench-tested it. It made a difference of 2 bhp. Up? Oh, no-down.
Although not plighted exclusively to BMC products, Downton’s efforts are nine-tenths concentrated on the makes in the group. It is the basic philosophy of the specialist, of course, that it's better to know a lot about a few things than a little about many. In Downton's case the policy has proved rewarding. In particular, BMC‘s A series engine (ie, the small Morris, Austin, Austin Healey, Riley and Wolseley in capacities ranging from the cooking Minis to the Morris and M.G. eleven hundreds’ 1098) is the apple of Richmond's sighting-eye. It’s probably true to say nobody outside of BMC and very few people on the inside know more than he does about wringing nonstandard power and torque from the Corporation's ubiquitous A. Power and torque, on second thoughts, is putting the cart before horse. Make that torque and power. Except in racing applications is the primary object of nearly all Downton quests, researches and empirical gropings. Torque is what people want nowadays to get to 70 quickly,’ says Richmond. 'What happens beyond 80 isn’t so important.
Drive almost any Downton treated road car and you'll see he practices what he preaches. I sampled several during a recent visit to the firm's little works in Wiltshire and although they were all faster than the standard versions by substantial margins, what impressed me most was their acceleration from moderate engine speeds and their tractability at the bottom of the rpm range. For example an over bored Mini Cooper (up from 997 to 1098 cc) throttled back from a snatchless 12 mph then took full throttle at a gulp without a change-down. Similarly a twin-carburettor Morris 1100, its capacity raised from 1098 to 1162cc, almost exactly reproduced he Cooper’s non-snatch crawl and clean pick-up therefrom. In the 20-50mph range in top, indeed anywhere above their speed in cruising-gear, the cars response to the throttle as nothing short of startling. It’s a stock apologia for performance conversions that, in exchange for gains on the roundabouts, you must be reconciled to losses on the swings. In other words speed, and extra performance of any colour, involves an un-duckable penalty in terms of marred flexibility and increased roughness. Daniel Richmond doesn’t accept that. Except for racing, he'll disown any conversion that doesn't positively and demonstrably make a car easier, as well as more fun, to drive.
‘The day of the cheap bolt-on are gone’, he says. 'Or anyway its going’. This sort of deal, with the customer hoping to get something for practically nothing, led to too many disappointments. Not that Downton itself was ever classifiable as a purveyor of cheap bolt-on goodies. It's true the firm always has done and still does a brisk trade in, for example, free flow exhaust systems standing, so to speak, in its own grounds. But they, as befits the high standard of their design and workmanship, aren't particularly cheap. And neither are the results from using them negligible. (Incidentally, Downton has a pat answer for any doubting Thomas who demands proof that the invisible interior of a manifold has the kind of finish that will speed the parting gas. He's handed a hacksaw and invited to vivisect it. If It's smooth, he pays. If it's rough-which it won't be-he's had his fun for nothing.)
Without over-simplification it isn't easy to capture the essence of Downton's craft-which of course is practiced with varying degrees of success by its many competitors -in a few, words. Fundamentally it consists of achieving optimum cylinder filling, then making the charge do the utmost work of which it's capable. Typically, then, if the cost factor isn't too stringent a road car engine conversion will involve carburettor duplication (assuming a single carb to be standard), replacement of the existing inlet and exhaust manifolds, much time-consuming work reshaping and polishing the combustion heads and ports, a, raise in compression ratio, and an increase in cylinder capacity by over boring. As examples Downton fattens the 997cc Mini Cooper’s cylinders from 62.24 to 65.5 mm, bringing the displacement to 1098 cc; the 1100 Morris and MG start at 64.57 and 1098 cc, go up to 65.5 mm and 1162 cc. The cuts leave room for a couple of rebores in afterlife, if needed.
Ports and fireplaces are jointly the source of the biggest single dividend in that kind of work. Any fool can impart a tasteful polish to the obvious areas and sculpt like mad with one hand while touching wood with the other; but unless you know to a decimal of,a millimeter where to attack and where to hold off the result will be worse than useless.
By that token Downton recently made the Interesting discovery that exhaust valve flow cannot be related to power output in the same way inlet flow can. The outfit nevertheless takes a lot of trouble to achieve optimum flow through the exhaust valve throat and port, since what that factor does indeed affect is valve life and temperature gradient in the head casting.
Downton Engineering doesn't call itself a speed shop, partly because the handy little American noun would, I suspect, be anathema to the so-English Richmonds but also because, as I have already hinted, speed per se is not primarily the shop's stock-in-trade. Just as extra power can be and often is an incidental byproduct of extra torque, a speed bonus almost inevitably comes as a free gift with a non-standard gob of acceleration.
Downton doesn't and never has advertised speed for sale, and indeed is always on guard against selling the commodity to boy racer types with more checker tape than brains. Daniel Richmond has evolved quite a technique of tact in talking such Johns out of buying his hotter conversions; in doubtful cases he just builds-in a governor.
Downton Engineering, acquired by the young Richmonds in 1947, was once simply a roadside garage. In fact the original premises, seven miles south of Salisbury on A338, still operate as such but the Richmonds' connection terminated two years ago. Engine conversions now occupy their whole time and energies, conversions carried out in compact,modern and well-equipped shops a short stroll north of the firm's birthplace.
In the first two years of the Austin and Morris Minis ' production run, Downton sold 3500 conversions of various calibers for the nimble 850s. Later the phenomenally successful Cooper Mini became Downton's staple outlet; it’s rare nowadays for owners of normal 850s to specify full-house treatment, but they still take simple and less expensive conversions by the dozen. There is a brisk and growing throughput of Morris 1100s which can be made to outperform their MG counterparts without much difficulty or expense. The smoothness with which Downton endows its engines is no accident, of course.
Conversions involving work on the head and ports also include, inter alia, meticulously accurate equalization of combustion chamber volumes within tolerances of a tenth of a cubic centimeter. In a predominantly agricultural region like South Wiltshire, craftsmen engineers of the level demanded for this sort of work don't exactly grow on trees, but Downton seems to find them somewhere. Although preparation of cars for competition occupies only a small fraction of Downton's time and energies, racing is the breath of life to the Richmonds. Daniel doesn't drive in circuit events because, he says, 'Bunty won't let me.' Both he and she are, however, expert hill climb drivers with successes galore to their credit. Daniel started out in climbs in the late forties, pedaling a brutally supercharged prewar Lagonda Rapier. Latterly his mounts for the slopes have been Minis of various types. But Richmond’s main fame in the racing context derives from the cars he's prepared for other people to drive. In the 1962 Targa Florio, you may remember, the Downton tweaked Austin Mini Cooper shared by Bernard Cahier and Prince Metternich set a sensational 50.04 mph average for the Sicilian killer's 447 miles, outlapping some of the Ferraris and placing second in the up-to-two litre prototipi class (what the contemporary reports didn't relate was that the car was minus second and third gears and showing zero oil pressure for more than half the race).
A Continental caper that put another feather in Richmond's cap last year was Dutchman Rob Slotemaker's win at Zandvoort in the Autosport World Cup meeting's touring-car race driving Daniel's Austin Cooper. Slotemaker's average, believe it or not, was better than that of Graham Warner's very special Lotus Elite in winning the World Cup itself a couple of years earlier. After the race the Richmonds and two friends went sightseeing in the Slotemaker car, pootling through dense traffic on the same set of plugs they used at Zandvoort without so much as a miss.
Like any other branch of automobile engineering, making inexpensive production engines perform like cost-no-object racebreds is part science, part art. And the Richmonds, it isn't surprising to discover, do indeed have an artistic ingredient in their personal makeup. Daniel 'would have liked to write books' and has furthermore contributed the occasional article (on fishi ng) to The Field. Bunty, when nobody is looking, ‘erupts into free verse’ but sees little prospect of ever becoming a best-seller like her uncle Willie - or as we know him, W Somerset Maugham. These literary frustrations notwithstanding, its something, isn't it, to be father and mother to the world's most exhilarating Minis?