THE OUTER CIRCUIT “200s”
SEPTEMBER 20th was fixed as the day for the fourth J.C.C. 200-Mile Race at Brooklands, and this time, apart from the 1,100-c.c.. and li-litre categories, a 750-c.c. class was introduced. When entries closed at single fees 47 had come in, comprising HuntleyWalker’s Darracq team, five Bugattis, four Horstmans, two Alvis,. four Aston-Martins, two Warwicks, two Thomas-Specials, two A.C.s, a Riley, a Ceirano and two unspecified entries in the largest class ; Bovier’s Salmson team, H. F. S. Morgan’s two Morgans, Ware’s Morgan, a Newton, a Frazer-Nash, and Ringwood’s unspecified car in the ” 1,100 ” category ; and RO fewer than nine Austin Sevens against a lone French Vagova in the new 750-c.c.
Newsome’s Warwicks turned out to be the 1923 cars, which failed to run in that race, but with Jarivier 60 X 130-mm. engines having o.h. valves of 1i-in. diameter operated via dutralumin pushrods from opposed camshafts in the crankcase, the timing gears being chevrons in a casing at the front of the engine. The crankshaft ran in two plain bearings and the camshafts also in plain bearings, while the mushroom tappets were adjustable at the base of the push-rods. Aluminium pistons with two compression and one scraper ring gave a compression ratio of 7/, to 1, and the piston clown was in the form of a truncated cone staggered in relation to the gudgeon pin. A forward extension of the near-side timing pinion drove the water pump, and a eross-shaft drove a Scintilla magneto which fired plugs in the off side of the head, the plugs on the near side being fired by another Scintilla magneto alongside the crankcase. The oil pump was driven from the end of the off-side camshaft and forced oil from a 1-gallon sump to the bearings, while a 2-gallon tank in the dash enabled the supply to be replenished by hand-pump to a union in the main filler above the timing cover. A steel flywheel was used and the engine was a standard job, With two Solex carburetters, a special high-lift camshaft and stronger valve springs ; it gave over 50 b.h.p. at 4,000 r.p.m., and ‘did its early tests on a two-thirds petrol, one-third benzole mixture, on a gear ratio of about 3.5 to 1 and 30-in. x 34-in. s.s. covers. A 4-speed gearbox was in unit with the engine, and for the 1924 race new bodies with extended detachable scuttles, and fully streamlined underparts from which only the sump protruded, were built.
Naturally, following their spectacular treatment of the race in 1921 and 1922 (they were absent in 192:1) the Darraeqs aroused the greatest interest. They were tested at high speed over French roads by J. Scales, of the T.-1). racing department. Segrave, Guinness and Dario Resta were nominated as drivers. The cars were entirely new, based on the 1923 Talbots, but with Sunbeam-type Roots blowers and lower e.g. The 4-cylinder 67 x 105.6-mm. engines had steel cylinders, two inclined o.h. valves per cylinder, operated by twin o.h. camshafts driven from the rear by a train of straight-tooth spur gears, and were 3-point mounted.
PREPARATIONS FOR THE 1924 RACE
A Bosch magneto was driven by a crossshaft and fired one K.L.G. plug per cylinder. The crankshaft ran in five roller bearings and drove the supercharger from the front, and the H-section connectingrods had roller big-ends, Nyhile there was a pressure and a scavenge oil puny in conjunction with dry-sump lubrication,. the former feeding to the front of the crankshaft and to the valve gears from a reservoir amidships. The carburetter was a racing Solex. The engines ran at 5,000 to 5,500 r.p.m. and gave some 108 b.h.p., maintaining this output for 60 minutes. The front axle was of tubular type, in three sections, and the front. springs passed through it, a la Bugatti, Lionel Martin entered a-standard, longchassis s.v. Aston-Martin with the 8-valve, twin-o.h.e. engine of 65 x 112 mm. designed by the Hon. John Benson and recently referred to and illustrated in cIflrTh–) During the early nineteen-twenties small cars were doing outstanding things in B.A.R.C. short handicaps and in the field of record-breaking, but perhaps they achieved their greatest allure in the J.C.C. 200-Mile Races, run over the Outer Circuit in 1921-1924. Previous articles in this interesting series appeared in the February, March, April, May, July and August issues, when the races of 1921, 1922 and 1923
were dealt with. MOTOR SPORT. The axle ratio was slightly raised and experiments pointed to a Memini carburetter and B.T.H. magneto being uscd, with Disco’ fuel and K.1..(;. plugs. It tide wheels carried 710 x 90-mm. Rapsons, and -a Bensondesigned streamlined body was planned. Lionel Martin also had ” Bunny ” in again, now wit h o.h.v. engine and streamlined undersIlie Id. (Its radiator was only recently give(i to Inman-Hunter when the last owner broke the car up.) B. S. Marshall hoped for a reliable rather than fast drive in his fairly standard road-racing Brescia Bugatti, with which he won the G.P. of Boulogne. It bad a niedium-length chassis and long propeller shaft and used Perrot f.w.b. T. C. Edwards entered Horstman I, which had a s.v. British Anzani engine supercharged With an Alfa-Romeo blower fed by a Memini carburetter. Signor Memini was said to have bench-tested the engine and to have got over 80 b.h.p. at 4,200 r.p.m. in the early stages. The engine was a standard s.v. Anzani, with the exception of a built-up roller-bearing crankshaft, and a lap speed of 106 m.p.h. was expected. Three other Horstmans
were merely tuned-up sports models, but tl w fourth car was also likely to be blown. Coe was to handle Edwards’s car.
Alvis, Ltd., after their 1923 victory, were, naturally, putting in special cars. Capt. Miller was to have the 1923 winner and Harvey and Halford new cars., These latter weighed 11 cwt. (pretty incredible when you reflect that the . Editor’s 1924 ” duck’s back ” weighs 17 cwt.) and had a wheelbase of 7 ft. 6 in. and a track of 4 ft. 1 in. The generouslydrilled frames tapered outwards at the front and swept up over the rear axle, where the side members united. ,A front tubular cross-monber was strengthened by diagonal stays to stiffen up the front of the chassis in case f.w.b. were used, while two bowed members braced the chassis in the centre and were united to form a support for the spherical housing at the back of the gearbox. The gearbox and clutch housing were in unit with the engine, the whole mounted on a patented 3-point suspension, which incorporated engine bearers on special rubber buffers, and the spherical gearbox mounting aforementioned. The engine followed previous ” 12/50 ” practice, but had enlarged inlet and exhaust ports, carefully polished, and a large Solex carburetter, while the emnpression ratio was put up to 6.6 to I. Dry sump lubrication was used and the connecting-rods, of one per cent. nickel steel, were machined lighter than standard. Two oil pumps were used, scavenge and pressure,. driven from the camshaft, and the tank was on the side of the chassis. Only the camshaft was splash lubricated. B.T.H. polar inductor magnetos were retained, and the aluminium 3-ring pistons had their gudgetm pins clamped in the connecting-rods (unlike later big-port sports engines, which used pads). The engine gave 50 to 60 b.h.p, at over 4,000 r.p.m., and power was well maintained for 300 to 4(X) r.p.m. below peak speed. The clutch was an inverted cone and the rear axle had a ratio of 3.5 to 1. This axle was solid, with exposed shaft and single brake, as on the 1923 car. Drive was via a torque-tube-enclosed shaft and rear suspension was by i-elliptic springs, the master leaf of which passed through a patent clip having two small helical springs at right angles to, and below, the main leaves. A second brake was incorporated at the hack of the gearbox, consisting of two contracting shoes operated by hand-lever via quick-action threads. 710-mm. Rapson tyres were used and the ears were very stable, needing only slackset shock-absorbers and being able to rush round Brooklands at full chat at the very inner edge of the Track. Driver and mechanic sat very low, one on each side of the propeller shaft, and the bodies had short tails, while three exhaust pipes Oft the Off-side merged into the big Brooklands expansion boxes. The radiators and dumb-irons were most un-Alvislike in appearance. Joyce had a new A.C. which was outwardly similar to the car which finished 3rd in 1923 after much tyre trouble-and this time it really was ready. The 4-cylinder 69 x 100-mm. engine had four tulip o.h.. valves per cylinder, operated
• by an o.h. camshaft driven by exposed silent chain. Each crankshaft throw was separately balanced, and the clutch and flywheel were liberally drilled. The valves worked in special sphericallyseated guides and the compression ratio was approximately 6.75 to 1. Cooling was thermo-syphon, assisted by a pump, and ignition by dual vertical distributors on the off side, of Delco Remy manufacture. Forced lubrication to all bearings of any importance was used, with an auxiliary filter in the line from pump to camshaft, and supplementary feed by hand pump. The radiator was flexibly mounted and the stay rod was connected to a flexible tongue on the header tank, it being possible to push the radiator back slightly by hand-pressure. The drive went via a floating single-plate clutch to a universal joint having a self-aligning Skefko ball race, and by open shaft to a torque tube anchored at its forward end to a tubular cross-member which also carried the pads for the i-elliptic rear springs. The rear axle was the now famous A.C. racing type, solid, with exposed shafts and brake drums up against the bevel box. Steering was as in 1923, likewise the unique front axle assembly, but with better fairing in. The gearbox was, naturally, in the back axle. The channel-steel frame was very narrow for a 2-seater car and was liberally drilled and upswept at the rear, and an ash skeleton carried the aluminium tail. Hartford shock-absorbers were used all round, those at the front engaging the axle G.N. fashion via fibre-lined forks, and those at the rear being supplemented by two groups of six strands of aeroplane elastic. The radiator was very narrow indeed and partially cowled, and the 18gallon fuel tank was in the tail, suspended at two points on the off side and one on the near side. Two Claudel Hobson carburetters on the near side had air intakes protruding from the bonnet to give a slight ram effect. This A.C. weighed slightly under 10 cwt. and pulled a top gear of 3.36 to 1. The passenger thrust his right arm through a hole behind Joyce’s seat and hung on to a grip in approved schoolboy thriller fashion.
Meeson’s A.C. had an Anzani engine and was expected to be blown. Thomas’s entries were the barrel-shaped Marlborough-Thomas cars that appeared in 1923. Of the other *litre entries, Mrs. Agnew finally nominated the 1922 Eric Campbell, now with s.v. Aston-Martin engine, for Morgan to drive. , Gillow had a well-streamlined s.v. Riley which was afterwards raced in short handicaps for many years, and O’Day entered Montant, 131ackstock, and Gallop in short-chassis, barrel-bodied Brescia Bugattis, similar to Cushman’s 1923 car. Newton was to drive the Ceirano, Katon a Marseal, and Densham and Cushman short-chassis Brescia Bugattis. Peacock’s Frazer-Nash was a 4-cylinder job. As practice progressed it was seen that the Darracqs were very fast and consistent and beautifully prepared. Resta’s sad death let Duller into the team. The cars lapped at about 106 m.p.h., Duller using larger wheels than those tried at first, after which experiment Lee Guinness and Segrave had their rear axles stripped
and the gear ratio raised. O’Day’s Bugattis were more advanced than Cushman’s car, the engine of which was stripped on the Tuesday before the race. Joyce’s A.C. did some 103 m.p.h. and Coe’s Horstman was said to be giving, finally, some 87 b.h.p. and to lap at 100. Alvis, Aston-Martin, Warwick and ThomasSpecial all kept their maximum abilities dark, but Duller won a short handicap with his Thomas-Special at the August B.A.R.C. Meeting, at 85f m.p.h. Lionel Martin experienced very miserable luck when the special Aston-Martin crashed into its towing car and was wrecked ; as is now history, H. S. Eaton sportingly took over the entry with a quite standard touring s.v. 3-seater. Eyston’s AstonMartin, too, crashed badly at Boulogne and could not be repaired in time to run, and the Ceirano was withdrawn.
Amongst the 1,100-c.c. cars, the Salmsons were naturally the favourites, and were very largely unchanged from 1922 form, with the well-known twin o.h.c. engines as before. They were said to weigh around 71 cwt., had tubular front axles, bound springs, f.w.b., and undershields enclosing all but the sump. Aeroplane elastic was used instead of shockabsorbers. Hawkes, Zborowski and 0. Wilson Jones were to handle them.
Pickett carried out some extremely interesting experiments with a supercharged G.N. engine. The well-known 900 o.h.v. V-twin was blown with a German centrifugal blower which delivered air to the carburetter. On test a comfortable 45 b.h.p. was obtained but, unfortunately, a piston broke at the gudgeon-pin bosses while the engine was running at full throttle and the cylinder head was irreparably damaged. Pickett therefore substituted his normal V-twin Frazer-Nash-G.N., which was almost identical to his 1923 car, but with modified bevel gearing and said to be ” hotter ” than previous 200-Mile G.N.s. Of the Morgans, Ware had a J.A.P.-engined car and Beart and Norris handled the ” works ” ears, which were similar in appearance to standard ” Aeros.” These cars went very high round the banking, lapping at some 90 m.p.h., and were expected to be faster than before. The Newton, with twin o.h.c. engine, had fourwheel brakes and a well-streamlined body. In the 750-c.c. class Capt. Waite’s Austin Seven was very similar to the 1923 racing jobs, but with a completely fairedin ” Brooklands “-type. body, the steering column being lengthened to give a lower seating position and a celluloid screen filling the space between the wheel and the scuttle, giving good instrument visibility. On the left of the mechanic was an extra oil tank and a doublebarrelled hand-pump, each barrel of which held one-sixth of a pint of oil, forward movement of a lever discharging one barrel into the crankcase while recharging the other. The fuel tank held 91 gallons, and so a non-stop run was expected. The body was fabric-covered, and unladen the car weighed 6 cwt., or 10 cwt. ready to race. A Zenith carburetter and B.L.I.C. magneto were used, and the tyres were 700 x 75-mm. Palmers. The valves were somewhat larger than standard, and had duplex springs. Singlering aluminium pistons gave a compression ratio of 6.8 to 1, the radiator was standard, and forced-feed lubrication was employed. With a 4.5 to 1 top gear, 5,000 r. p. n . equalled over 80 m.p.h. Capt. Waite purposely used light tyres to obviate wheel wobble. Gordon England’s Austin Seven had a chassis standard save for minor modifications. Special Hart ford shock-absorbers were used, those at the front set transversely, those at the back beneath the springs, on special, drilled brackets. Axles, driving shafts and gear ratios were 100 per cent. stan dard. The body, including bonnet and fairings, was only 50 lb. It was built of very thin 3-ply on an ash framework, with staggered seating. Its width was 23 in. and height 36 in. from the ground. The underpart was faired with fabric and was completely flat, and both axles were streamlined by fairings. An aluminium heel-plate was used in lieu of floor boards. The seats were of beaten aluminium, and below the level of the propeller shaft, which had an aluminium tunnel over it. A wedge on the chassis raked the steering column, which also inclined to the near side, and the handbrake had no ratchet and was on the left of the gear-lever, which was practically horizontal, to clear the fuel tank. The latter held 81 gallons and was 3-point mounted under the scuttle dash. (Consumption in 1923 was 6f gallons for the 200 miles. ) A 1-gallon oil tank over the engine, supported from the front of the fuel tank, fed to the sump on the bird-feed principle, to maintain the level, but only as a precautionary measure. The feed pipe entered the normal filler cap and a rubber sleeve enabled it to be withdrawn. Tubular connecting-rods were used and the aluminium pistons were very light and had two narrow top rings. The head had three-sixty-fourths of an inch machined off and the valves were of special steel, actuated by a high-lift camshaft. Thin oil was used in the back axle, steering box and gearbox, careful assembly being relied upon to obviate leakage. The standard pressure lubrication system was employed for the engine, which had two 30 H.K. Zenith carburetters and DelcoRemy coil ignition. The shell-less radiator was inclined rearwards inside a fairing and had tubular support running vertically to the header tank. Palmer 26 in. x 3-in. tyres were used and no spare wheel was fitted. It was hoped to maintain 4,750 r.p.m., equal to a lap speed of 85 m.p.h, and England considered that the engine had reached the peak of its development in unblown form ; he proposed to experiment with supercharging for the 1925 race. The fuel tank rear support was by a single bolt which enabled the tank flange to float on a bridge support to combat chassis whip, the tank being 3point suspended. A standard dished steering wheel was used, lightly cord bound; SamueLson’s late fee Austin entry was eventually withdrawn, proh:Lbly on account a the driver’s ill-hca lth, but Hall, Hendy, Dingle, Kings, Cutler, Braid, Selby-Bigge and Spencer Grey were due to drive these wonderful little cars, in varying degrees of “specialness.” The very greatest interest was aroused by Spencer Grey’s entry of a Vagova, built specially for the “200,” with a chassis very like that of the standard Vagova. This little French car had a supercharged 6-cylinder engine of 49.7 x 04 mm. (745.26 c.c.), giving 35-40 b.h.p. at 5,500 to 6,000 r.p.m. The cylinders were separate castings, bolted in pairs to an aluminiumalloy base chamber and surrounded by an aluminium-alloy one-piece water jacket. The crankshaft was built-up and ran in four ball bearings and the connectingrods were tubular, with roller-bearing big-ends. Aluminium-alloy pistons were used and a geared-up centrifugal blower sucked mixture from the carburetter. The blower was geared 5 to 1 and rotated at :30,000 r.p.m. at maximum engine speed. The valves were overhead and were positively operated by a fulcrum rocker-arm and double camshafts, a system eliminating valve springs and patented by Godet and Vareille. A separate 3-speed and reverse gearbox with central gate change was used, and the rear axle was differential-less. Front brakes of Hersot-type were used, with part of the operating gear on the axle, and there were no rear brakes. Two fuel tanks were built into the chassis just before the rear axle and partially under the seats. Suspension was ‘by A-elliptic springs at
the front, to which the forged steel front axle was attached about two-thirds along from the back shackle pin. At the rear double f-elliptics were used, set as a single i-elliptic, and .secured by a saddle surrounding the axle casing. The axle casing had a ball joint at each end, to allow oscillation between axle and springs. Again, the axle was about two-thirds back from the front shackle pin. The axle was a single steel casting and the propeller shaft ran in a casing acting as a torque tube, while a disc universal was used, supported by a small ball race in the centre. The engine was 3-point mounted, the clutch was a Ferodo-lined singleplate, and there was a transmission brake between engine and gearbox ; all brakes were operated simultaneously by pedal or lever. The Maron-Pot body was very fully streamlined, the rear axle being carefully enclosed and the radiator cap set beneath the bonnet. Rudge Wheels carried 710 x 90-mm. covers. The wheelbase was given as 8 ft. 9 in., and the track 3 ft. 4 in., in one reference, and 8 ft. 6 in. and 3 ft. 11 in. in another, early racing journalism not being entirely foolproof.
The patent rights for this remarkable little car were secured by Mann and Handover, but, alas, it never actually came to this country.
Nevertheless, with 50 entries at closing date, the 1924 ” 200 ” Was an assured success, even if some of the entries, such as the Marseal and Newton, did not run. Small cars were certainly mtich faster now, as witness the fact that a Hammq eventually won at 102.27 m.p.h., and the fastest lap was 106.55 m.p.h. The 1,1.00-e.c. ears were mostly also quicker and this evening up of speed decided the organisers to run all classes together instead of separately as before, in spite of the inclusion, for the first tune, Of a ” baby ” car category. This madethings easier for almost everyone, and new scoring arrangements added to the -amenities to be enjoyed at BrOoklands on September 20th twenty years ago. Yellow, red and green, respectively, identified the 1i74itre, 1,100-c.c. and 750-c.c. classes, and 43 ears were expected to start when the flag fell at 3 p.m.
The chase is on
In the top photograph Francois Cevert is hounded by the two John Player Lotus 72s during the early stages of the race while Regazzoni is in the lead. His team-mate…
One London Suburb reverberated to the sound of racing engines until 1972. Paul Fearnley takes a leisurely drive through a park that boasts a fast past Whit Monday, 1964. Top…
Historic racer: MGB Roadster
A new season should always bring hope, but for Ed Foster it yielded mostly frustration The view from the outside of Graham Hill Bend at Brands Hatch is a great…