Looking Round the Speed Shops

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Downton Engineering

When we called on Daniel Richmond to see what the Downton Engineering Works are offering in the way of “hotting-up” equipment we found him trying to start a 1920 Rolls-Royce “Silver Ghost,” reminder that he used to be a Rolls-Royce and Bentley specialist. For the past year, however, he has concentrated on tuning equipment, mainly for B.M.C.-engined cars, to such effect that he claims to have supplied to date 400 A35 and 300 Sprite kits, many of them being exported.

By way of demonstrating his wares he persuaded us to take two brief runs, the first in his A35 van, the second in a red Austin A40. The van has a combined Downton three-branch exhaust system and special inlet manifold to accommodate a single 1¼ -in. S.U. carburetter at 45 deg., a special head with enlarged valves giving a compression-ratio of 9.4 to 1, stronger valve springs, and a Gaston anti-roll bar. It can do about 80 m.p.h. and handles safely. The A40 had completely normal suspension but the engine had been endowed with Downton twin-carburetter (1¼-in. S.U.s) manifolding with triple exhaust offtakes and a head giving an 8.9 to 1 compression-ratio. An easy 70 m.p.h. showed up with no apparent decrease in flexibility and 100-octane petrol isn’t necessary.

Downton can supply these combined manifolds, with proper length induction pipes, for single or twin carburetters, stage 1 or 2 cylinder heads, and special Servais silencers for A-series B.M.C. engines “over the counter” and similar parts for B-series engines to order. A typical single-carburetter conversion complete with special head, fitted, costs £37 10s., the manifolds being priced at £15, Stage 1 heads at £12 10s. and Stage 2 heads at £20, while twin H2 carburetters, with linkage and piping, to replace H1s, cost £16.

If more advanced methods are sought Downton offer their own high-lift camshafts for the A-series B.M.C., Triumph TR, M.G.-A and M.G. Twin-Cam engines. A Sprite camshaft costs £13 10s., or £9 16s. on an exchange basis. Solid-skirt, flat-topped racing pistons and lightened rockers are also available for Sprite enthusiasts.

Downton modified A35s and Sprites have been building up a fine reputation in racing, so much so that at a recent Goodwood Members’ Meeting some ten out of 14 of these cars were Downton tuned. Well-known Sprite drivers using Daniel Richmond’s parts include Gaston and Mackenzie, while Noble’s Austin A40 is similarly equipped. A Downton-converted Sprite has lapped Snetterton at 70¼ m.p.h., the Gosport quarter-mile has been covered in 18.34 sec., and a Stage 2 A35 has lapped Goodwood at 69.79 m.p.h. An Austin A35 with special head and twin H2 carburetters can be expected to do 0 to 60 m,p.h. in 16.6 sec. and the s.s. quarter-mile in 20½ sec., the conversion totalling £56 5s. fitted. The aforesaid Gaston anti-roll bar for A35, A40 and Minor costs £8 10s. (fitting £1 extra).

An example of advanced tuning of the Sprite includes Stage 2 mods., with 10.3 to 1 compression-ratio, lightened flywheel, high-lift camshaft, modified valve gear and attention to engine balancing, such an engine costing £130 on an exchange basis. From this 0-60 in under 13 sec., the s.s. quarter-mile in about 19.3 secs., and some 94 m.p.h., is claimed.

A Renault Dauphine conversion consisting of special manifolding, a cylinder head giving a compression-ratio of 8.2 to 1, an S.U. H2 carburetter, etc., is available, totalling £47. Such treatment increases speed by some 8½ m.p.h. and the 0-60 time is halved.

At the time of our visit, apart from a Cadillac-Allard, an M.G.-A and another Sprite, work was in progress on Gaston’s Austin-Healey Sprite. This now weighs 12 cwt., we were told, and has clocked a Prescott time of 50.67 sec. Twin 1½ S.U.s, a double-figure compression-ratio, and the Downton manifolding figure in the specification. The car is fastest in hard-top form. The suspension, excellent at standard weight, is proving rather troublesome with the car in lightened trim and Koni rear dampers were being experimented with.

We reminded Richmond that earlier this season his cars sometimes developed trouble which led to retirement in club races. He explained that the A35 oil pump proved less efficient than the A30 pump and some engines were wrecked until this was appreciated. He is certainly getting very good results now and although this “hotting-up” business is highly competitive, as rivals bring out new cylinder heads, etc., we shall be very surprised if Downton lags behind. — W.B.

Speedex of Luton

It is now 22 years since the Austin Seven went out of production and one would think that the popularity of the Austin-based Special would be on the wane. Several years ago various “experts” gave the Austin Special a very short life because of the worsening spares situation and the availability of more potent modern machinery, but today the 750 special seems to be as popular as ever it was.

One man who has pinned his faith on the Austin Seven is J. G. W. “Jem” Marsh, the proprietor of the Speedex company of Luton. Since he formed this firm only just over a year ago he obviously had to be sure that there would he a market for his special building components. To find out how the firm had progressed in its first year we journeyed to Luton to see Mr. Marsh.

Jem Marsh has been building specials for a number of years mainly as a hobby, but occasionally he built one for a friend and they seemed to be fairly successful, but a spell in the Navy stopped all special building for a while and after leaving the sea he took a series of “safe” jobs as there seemed to be little money in making “one off” specials. At last his opportunity came when a special building firm needed a manager; he was the only one of the many applicants who knew anything about specials. After learning about the business side of specials he decided to take the plunge and go into business on his own.

With very little capital he took over a disused hat factory and practically single-handed began to build up a thriving business. He was fortunate in being able to obtain castings and the first job was to design an aluminium cylinder head. This has deep fins for cooling and rigidity and a combustion chamber shape suitable for the use of oversize inlet valves. The compression ratio is 7.2 to 1, which seems rather low by modern standards, but if too much metal is removed the pistons can strike the cylinder head at high revs. A cast alloy water manifold is used in conjunction with this head and is reversible for use with both the standard radiator and the modern cross-flow type, using a header tank. Other castings in the Speedex range include a deep alloy finned sump which holds a further half-gallon of oil. This is useful for racing where the oil would get distinctly hot in the standard sump. A cast alloy four-branch exhaust manifold and single and twin-carburetter manifolds are also used for maximum performance.

The Austin wire wheels are not very pretty even when modified and Mr. Marsh hit upon the idea of having some cast-alloy ones made. They have five ribs and besides being much stronger than the 15-in, wire wheels are 2 lb. lighter. They are off-set  ¾ in. so that they do not prevent cooling air reaching the brake drums. Jem Marsh is now a regular competitor in 750 Formula events with one of his own cars and his i.f.s. system has been developed in the light of this experience. Simplicity is the keynote, with a tranverse leaf spring at the top and lower wishbones pivoted in the centre meeting up with fabricated axle ends which take the Austin Seven stub axles. The unit bolts on to the standard Austin Seven nosepiece without modification. Telescopic shock absorbers can be fitted at both front and rear and special mounting brackets are available to enable them to be fitted with the minimum of trouble.

All the usual engine mods. are available from Speedex from lightened flywheels to modified camshafts, in fact everything for getting the most out of an Austin Seven engine. The piece de resistance of the Speedex range is the aluminium body. Mr. Marsh had noticed that the average special builder spent most of his money on the engine and chassis, so that when it came to putting a body on the car it meant either buying a difficult to mount and expensive glass-fibre body or bodging up an aluminium one in his backyard. He therefore designed the sleek and low Speedex body, costing only £49. This body has a tubular steel frame with seven lugs for attaching to the chassis, steering column support, dashboard and prop-shaft tunnel, adjustable mudgard stays, radiator mounting brackets, and even throttle linkage lugs which enable the standard Austin Seven throttle bar to be used. This may not seem remarkable but the enthusiast who has made his own bodywork will know the amount of time these small items seem to swallow up. When bolted to the standard Austin Seven chassis, Mr. Marsh reckons that the “A” shaped chassis needs no boxing-in and to prove it he runs his 750 Formula car without any stiffening whatsoever.

At the time of our visit two cars were available for inspection, one being the silver 750 Formula car and the other a less potent road car. Both cars being equipped for road use, we were allowed to sample the Formula car. Mr. Marsh is 6 ft. 3 in. tall so there was a little difficulty in fitting into the car. The gearbox is a four-speed type with helical gears modified to give closer ratios. These are first, 3.25 to 1; second, 2 to 1; third, 1.25 to 1; top 1 to 1. The engine started and warmed up, we gripped the handsome wooden steering wheel, put the gear lever into first, let the clutch in and promptly stalled the engine. Having been assured that everyone does it at first, we tried again, this time with plenty of throttle. The car leapt away with a positive banshee shriek from the gearbox which persisted in all the gears. With the noise from the engine as well this car isn’t exactly aimed at putting Rolls-Royce out of business. Nevertheless the performance is really startling and our short trip was quite enlightening. The car gives a choppy ride but is not unduly uncomfortable and the steering is nicely direct while the power is quite remarkable for an Austin Seven. Coming out of a roundabout on a damp road one has to be careful with the throttle as the rear can be slid out easily in the lower gears. Mr. Marsh told us he reckoned the car was on a par with the TR3! Seeing the way he left rubber on the road when he accelerated away we can quite believe it — we thought we had the handbrake on in our Sprite when we tried to follow him. Incidentally Mr. Marsh uses a VW Microbus for deliveries and taking his racer to meetings. The rear torsion bars are set up for a fairly heavy load so that when he drove us to his body-building shop it displayed some peculiarities on cornering — the rear wheels being reluctant to stay on the ground.

For the enthusiast who has plenty of money to spare all at once Mr. Marsh offers complete kits of parts. For £200 one can obtain a pretty potent car which with careful assembly would stand a chance of winning some pots in 750 Formula racing, and this is still surely the cheapest form of motor racing in the world today. — M.L.T.

Cambridge Engineering

Cambridge Engineering is probably one of the oldest-established tuning establishments for the “special” builder, having been started by Bill Williams in 1934, and is especially devoted to tuning the Austin Seven. Mr. Williams has recently retired and has written a successful book on building Austin Seven Specials. The business has been acquired by Mr. Thomas but the practical work is carried out by Mr. Brown, who has been with the firm for over twelve years and has a very comprehensive knowledge of the Austin Seven.

It can be fairly said that Cambridge Engineering caters for the man with very little money who wants to get a sporty car on the road for next to nothing. The little workshop and stores nevertheless stocks a considerable amount of equipment, and the man with money who wants to go fast could obviously build himself a very potent car by visiting Cambridge Engineering. The latest introduction is an independent front suspension unit for the Austin Seven, which Mr. Brown claims ia very effective. It is based on the principle of unequal-length wishbones, with the lower wishbone in this case being a transverse-leaf-spring. The upper wishbone is mounted in a housing which also takes the mounting for the Newton dampers. The whole suspension, excluding the dampers, is priced at £13 17s. 6d., and Newton dampers are available at £2  2s. each. For simplicity it can be bolted to the chassis using the four existing bolt holes. For the man who cannot afford the i.f.s. Cambridge offer to lower the standard suspension by 4½ in. by lowering the axle beam and resetting the front and rear springs and supplying the necessary links and bolts to lower the radius-rods. This can be done for £9 5s. provided the axle beam, road springs and track-rod are offered in exchange.

Cambridge offer one of the cheapest bodies on the market. It is rather reminiscent of the J2 M.G. and does not pretend to be aerodynamic, but it is well built of aluminium on an ash frame with a flared scuttle and separate wings. There are no doors but the body sides are cut away for easy access. This body weighs only 43 lb. and for the short-chassis model up to 1931 costs £27, and for the long-chassis post-1931 models is £30. All the necessary chassis extension angle irons are provided to bolt the body to the standard chassis. A 10-gallon wedge-shaped petrol tank is available for mounting behind the body at £9 10s.

A large variety of speed equipment is offered from the high-compression cylinder head at £7 10s. to the four-branch exhaust and inlet manifold combined and fitted with twin S.U. carburetters at £22 10s. 

With these various mods. the car will be capable of pretty high speeds and it will be necessary to modify the brakes to stop the car properly, which the standard brakes certainly will not do. Cambridge offer a relatively simple but effective alternative by using enclosed Bowden cables to the front brakes and long levers to the rear.

These are the basic mods. offered by Cambridge and when the standard chassis is converted to this specification a lively little car should result at a very modest outlay. — M.L.T.

Speedwell

When John Sprinzel began racing an A.35 just over two years ago he little realised what it would lead to. Up to that time no one had seriously thought of racing the smallest member of the B.M.C. range and it was usually dismissed by the enthusiast as only fit for the District Nurse and such like. When he saw the interest that his car had created he realised that there was a potential market for tuning-kits and promptly set up as Speedwell Performance Conversions, the name Speedwell being taken from the local telephone exchange.

Right from the start the conversions were a success and the Speedwell “flash” became almost standard-wear on rally and racing cars. Although Speedwell directors Len Adams, George Hulbert, Lutz Arnstein, John Sprinzel and G.P. driver Graham Hill are reluctant to discuss figures it is pretty certain that around 1,000 cars are fitted with Speedwell “bolt-on goodies” in one form or another.

With the advent of the A.40 and the Sprite, Speedwell turned their attention to modifying them, which was not difficult as regards the engine but different treatments have been evolved for suspension and bodywork modifications. Now that the A.35 is virtually unobtainable, attention for saloon car motorists is naturally focused on the A.40, at least until the new “baby” models are released. Speedwell have attempted to get away from the “hot-rod” impression which the word “conversion” has created in this country and their modifications turn the A.40 into a faster but more comfortable car.

For the full A.40 conversion Speedwell supply the “Supersport” engine having modified cylinder-head, valve-gear, pistons, balanced crankshaft, special exhaust system, lightened flywheel, stronger clutch, twin-S.U. carburetters, together with an anti-roll bar for the front suspension and a safety belt for the driver. The car can be obtained in this form from Speedwell for £765 but they hope that you will prefer to have their special equipment specification which includes the fitting of water temperature and oil pressure gauges on either side of the steering-column, fully-fitted carpets to match upholstery, radiator blind, an interior light, spot and fog-lamps, metal door trim shields, rear ashtrays, windscreen-washers, heater, special brake-linings and a sound insulated engine compartment. If the car is purchased from Speedwell the price of £840 includes number plates, delivery charges, tax for a quarter and a full tank of petrol. Alternatively the car can be had in Stage II form for £810. Speedwell also recommend that customers purchase a higher axle ratio as this lowers engine revs. and adds to the luxury effect given by the interior treatment. Also included in the £840 is a two-tone paint job — the bottom half of the body is sprayed in the same colour as the roof. The advantage of buying the car and extras from Speedwell is that a lot of trouble is saved as the enthusiast will probably buy many of the extras anyway and purchase tax is saved by buying in bulk, which is duly passed on to the customer. This de-luxe treatment can he applied to all models in the B.M.C. range and extras can be fitted according to customers’ specification.

The Sprite is receiving the “full treatment” from Speedwell and a Gran Turismo version will soon be available. This will include a handsome aluminium bonnet with faired-in headlamps which hinges at the front, a wrap round windscreen and a hardtop. With these additions the Sprite should be able to compete with the Fiat-Abarth-Zagato in looks if not in speed. Experiments which are going on at present with Amal carburetters promise to provide a lot more power for the Sprite. A full racing-engine intended for Formula Junior is being experimented with, having the Elva particularly in mind and something like 70 b.h.p. is hoped for, using the Amal carburetters. A 65 b.h.p. version is fitted to one of the A.35’s used for circuit racing and some good times have been realised in practice. This engine is of course not suitable for road work and will only be sold for racing.

Apart from full conversions which is the main source of business for Speedwell they can and do sell all sorts of items for tuning B.M.C. cars. One particular item which sells by the thousand is the front mounted anti-roll bar which is available for practically the whole of the B.M.C. range. This is priced at £7 for all models. For the Morris Minor 1000, Riley 1.5 and Wolseley 1500 a Gran Turismo suspension-kit is available which includes telescopic rear shock absorbers and is priced from £16 10s. to £18 10s.

The “B” Series 1500 c.c. engine is not forgotten and a conversion is available for the Wolseley 1500, Austin A.55, Nash Metropolitan and 1958 Morris Oxford at £80 plus £10 for fitting. The kit for M.G.-A, Magnette, and 1.5 Riley which already have twin-carburetters is priced at £50.

At the time of our visit the small Speedwell works in Finchley Road was bursting at the seams with cars being prepared for customers while there were several demonstration and experimental cars being worked on. The Speedwell directors are keen and successful racing and rally drivers and the preparation of their cars takes a lot of space and time but the results are undoubtedly worth the trouble. John Sprinzel drives in the official B.M.C. team and is currently planning for the Liege-Rome-Liege as well as several British rallies. Len Adams takes part in circuit racing as much as possible while Graham Hill drives when his Grand Prix commitments allow. The Speedwell team won the Six-Hour Relay race last season and are out to repeat that win in this year’s event using two A.35’s and an A.40.

Being car dealers as well as tuners Speedwell have to take part-exchanges and at the time of our visit were amusing themselves with a pre-war Rolls-Royce which a customer wanted to exchange. There was some talk of putting a label bearing the legend “Yet another Speedwell conversion” in the rear window but in the end wiser counsel prevailed. Although they are sorry to see the passing of the A.35, Speedwell are making plans to “ameliorate” its successors and from what we have seen they will be just as successful — M.L.T.