Veteran to classic -- three pot thoughts
One of the pleasant things about running Motor Sport is the communication one receives from readers and clubs, which even if space does not permit comments and quotes, keeps us in touch with that side of the motoring world. Thus it was that I came upon an item of considerable interest in the June Newsletter of the Pre-War Austin Seven Club, whose Membership Secretary, for those owners of pre-war A7s who have not yet joined, is John Tantum, 90 Dovedale Avenue, Long Eaton, Nottingham, NGI0 3HU.
The item I am referring to was a reproduction, from The Motor Cycle of 1949, of a study by a writer called “Ubique” of the future of in-line three-cylinder engines in the motorcycle context. This had been prompted by thoughts of the record-breaking achievements of an MG with just that unusual number of cylinders. This is an excuse, as if any excuse were needed, to digress into the realms of how very effective were the record-breaking onslaughts of MG cars, both before and after World War Two. Record-breaking can be more exacting than racing, inasmuch as to succeed you have to improve on a performance which is the best-yet in a given category and the longer the distance or duration, the greater the chances of failure. Whereas in a race the retirement of other cars and a modicum of luck can play a greater part.
The MG Car Company of Abingdon-on-Thames really did do some quite outstanding things in the record-breaking field, which put it in a highly commendable position, a credit to MG engineering and to British prestige. For instance, when fierce rivalry broke out between Austin and MG as to who would be the first to reach prestigious 750cc targets such as 100 mph for one hour, MG took the advantage. In February 1931 Capt George Eyston OBE, MC, was timed at Montlhéry Track near Paris at 103.13 mph in the Powerplus supercharged racing MG Ex 120 and later in 1931, with the same MG, he set the 750cc class hour-record to 101.1 mph, being badly burned after the car caught fire at the conclusion of the run.
Driving the new Ex 127 record-breaker, the “Magic Midget”, Ernest Eldridge, deputising for Eyston who was still in hospital, did five kilometres at 110.28 mph, which Eyston, recovered, and clad in asbestos overalls and a gas-mask, raised to 114.77 mph before the end of 1931. The saga continued, to such great effect that by the end of 1932 MG held every record up to 24-hours in the 750cc Class H, divided between a blown J2 and Ex 127 and drivers Eyston, little Bert Denly and the versatile journalist/racing man Tommy Wisdom. The kilo and mile had been covered by Ex 127 at over 120 mph, so the MG was the first 750cc four-wheeled car to have first achieved 100, 110 and 120 mph.
After the celebrated MG Ex 127 had been acquired by the German enthusiast Bobbie Kohlrausch and rebodied and somewhat modified mechanically, he took it to Gyon in Hungary in 1935 and set four Class-H records at up to 130.51 mph and the following year at Frankfurt broke three more, at up to 140.6 mph.
So MG added two more 750cc firsts to their very convincing repertoire — 130 and 140 mph. Incidentally, as previously, Kohlrausch painted the Union Jack on Ex 127, but in Germany the Nazis forced him to remove it.
In fairness to the Austin Motor Company of Longbridge, Birmingham, it must be said that Lord Austin’s long insistence on side-valve engines even for racing, and then the death in 1938 in a Brooklands calamity of Murray-Jamieson who had eventually designed the twin-cam racing A7s, reduced competition in the Class-H category, in which the fast Ridley Special had crashed, after doing 105.92 mph in 1931, injuring Lord Ridley.
MG continued their record-breaking activities after the war, in an extremely ingenious manner, a further tribute to their engineering abilities. For example, Major Goldie Gardner, DSO, MC, acquired the slim single-seater Zoller-blown K3 Magnette with which Ron Horton had raced successfully at Brooklands and used the revised Powerplus-blown car to raise Class-G (up-to-1100cc) records held by Maserati, the faster of these two records set up on the Frankfurt autobahn being 142.63 mph, raised with re-instated Zoller blower to over 148 mph. Gardner continued his more successful record-bids, with the ex-Eyston MG Ex 135, using a Centric supercharger and fully-streamlined Reid Railton-designed body, clocking 203.9 mph at Dessau in May 1939, a significant achievement.
Technically this speed on 202 bhp was meritorious, and a credit also to Goldie Gardner, who had leg injuries received from a flying accident and motor racing to contend with. Nor was it the end of this record attempt, because the mechanics bored-out the engine’s cylinders (after they had been officially measured following the 1100cc round runs) with the power unit still in Ex 135, to 1106cc, to put it in the Class-F (up-to-1500cc) category. Then, with WW2 on the near-horizon, Gardner broke three 1-1/2-litre records, the fastest the fs kilo at 204.2 mph. So with only 1100cc, MG had a car more than half as fast as John Cobb’s 26,900cc Railton Special which in 1939 held the LSR, and which had come within 153.6 mph of the speed of Eyston’s 73,000cc Thunderbolt. The intention had been to push 750cc records up to even higher speeds, using a six-cylinder engine, but Hitler and his Nazis stopped play. .. .
After the war the record-breaking was resumed, again with consummate success. Space precludes describing how Gardner having temperately severed connection with the MG Company, but retaining the services of mechanics Enever and Jackson on a diplomatic basis, set more records in various classes, leaving the quickest 1-1/2-litre record at 189.5 mph by August 1952, using a blown push-rod MG TD engine in his Gardner-MG. Very complete coverage of this is contained in Maintaining The Breed by Lt Col John Thornley, OBE, (MRP, 1950) reprinted in 1951, 1956, 1971 and 1990, quite one of the best one-make motor racing books ever. So to try to obtain a copy if you wish to know in great detail what was done to enable the Gardner-MG to take 500cc records from Count Lurani’s Guzzi-powered Nibbio at 118 mph, using a six-cylinder engine with two cylinders blanked off, or set 2-litre records at up to 177 mph with a non-supercharged, four-cylinder experimental twin-cam Jaguar engine which gave 146 bhp at 1100 rpm, in the car, etc.
I have no intention of poaching on John Thornley’s preserves in these fascinating matters. I must enlarge, however, on the later Class-I and J records established by Gardner, using an in-line three-cylinder engine because — I trust you have been patient? — this is, as it were, where we came in because in 1949, to attack the new 500cc records which Nibbio had lifted to 129 mph, Sid Enever of MG’s devised a three-cylinder 493.8cc power unit with its crank-throws at 120 deg. It was this MG engine which had made the then-Editor of The Motor Cycle request that article by “Ubique” about the possible future of such engines for motorcycle use. The Gardner-MG, with MG monograms again on its flanks, was taken to Jabbeke in 1949 and set three new Class-I records, the kilo at 154.91 mph, doing nearly 160 mph in one direction.
The following year, with No 6 piston removed to get the Gardner-MG into Class-J (up to 350cc), Major Goldie Gardner broke three records in that class, doing the two-way mile at 121.048 mph, the 330cc engine running at 8200rpm. Major Gardner, in spite of his previously referred to disabilities and a further injury at Utah, continued to smash records up to the age of 63, when ill-health called a halt.
As for MG Ex 135, it was the first car with a 350cc engine to exceed 120 mph, with 500cc to exceed 120 mph, with 750cc to pass 150 mph, with 1100cc to exceed 120, 150, and 200 mph, as a 1-1/2-litre to better 200 mph, and with the Jaguar 2-litre power unit, to do over 150 mph — some record! It should make all MG enthusiasts very proud to recall this.
All its variations, apart from use of the Jaguar engine, were basically K3, the three cylinder engine, for instance, having its crankshaft extended as a plain shaft through what would have been throws, 1,2, and 3, using the two front main bearings, to drive the Shorrocks supercharger. In the end MG achieved nearly 255 mph from 1506cc using a twin-cam engine based on the production car of this type.
Coming to three-cylinder engines in ordinary cars, around the turn of the century some manufacturers listed such models, including Swift, Panhard-Levassor, Clyde, Duryea, Minerva, Brooke, Belsize, Argyll, Maudslay and Durkopp. It was commonplace for steam cars, and Henry Royce’s 1905 15hp Royce had that number of cylinders, although he made only six, against 19 twins at this time.
The reasons why three-cylinder engines were used is difficult to evaluate, but presumably compactness and the ability to use multiples of existing cylinder blocks when graduating to a six-cylinder car may have had some influence. But when discussing that experimental in-line three aforesaid, “Ubique” recalled the problem of rocking couples caused by the power impulses being applied to crank throws at different planes. He was cautious about the prospects for such engines in the post-war period and made only passing reference to two photographs of a small inline-three-cylinder car engine that accompanied his article. This was almost certainly an experimental engine built around 1939 by Austin, perhaps with the idea of competing with the 570 cc Fiat Topolino, although the specialist A7 books make no mention of it and only one Austin historian seems to have done so. Why Austin went for a “three-pot” is a conundrum, unless to save under-bonnet space. It was of about 6hp, with a 120 deg crankshaft.
The flat-twin-cylinder, or horizontally-opposed, engine is almost perfectly balanced and in the early 1920s was used by Jowett, Rover, ABC, Wolseley, Unit No 1, Kiddy, Coventry-Victor-engined Amazon, Matchless, etc. The perhaps easier-to-cool narrow-angle Vee-twin was for cyclecars, adopted from the two-wheeler world, where it had to be squeezed into motor-cycle frames, although GN (and Buckingham) had developed their own 90 deg vee-twin with heavier flywheel. Then the Austin 7 arrived in 1922 and encouraged the four-cylinder theme for little cars among British motorists, such cars already popular in Europe. In spite of arguments that, in those days of owner-maintenance, four valves took less time to grind-in than eight, and that twins were less delicate to strip and administer to than fours, the multi-cylinder small car soon ousted most of the flat or vee twins, the Jowett excepted.
The three-cylinder in-line power-unit was difficult to carburate and it suffered from primary and secondary couples, causing vibration, which may be why Austin did not proceed with their “Six-Three” engine (hp/ number of pots). The Autocar had apparently tested it and found it “brisk and smooth,” although I am not sure whether its identity was revealed. It was the 900cc four-cylinder Austin 8 which replaced the A7, and after the war Fiat replaced the four-cylinder Topolino with the air-cooled vertical-twin 500. Citroën had preferred a flat-twin, but we have recently seen this go out of production, while Fiat’s more difficult to balance vertical-twin lives on!
In the motorcycle world Scott had a big three-cylinder engine and in 1945 I was able to try the 1108cc version of this “three-potter” in a Morgan 4/4, which I drove to Harrogate to Rivers-Fletcher’s Cockfosters Rally and back. But no more was heard of this 78 x 78mm in-line-three, which gave 40 bhp at 4000 rpm. DKW had their two-stroke 3/6 engines, of various sizes, developed from a 1940 prototype, which Saab copied in 1955, at first as the 748cc Model 93 which was in the 1960s up-rated up to the triple carburettor 850cc 60 bhp Monte Carlo version.
Otherwise, the “triple-pot” theme seems to be a lost cause, apart from its revival for their smaller cars by Japanese manufacturers like Daihatsu and Suzuki. (I was impressed with the 796cc Suzuki Alto FX which I tested in 1984). Now Ford and GM are experimenting with the two-stroke, three-cylinder OCP engines. Never mind! It has been an excuse to remind ourselves of some very impressive MG record-breaking. — WB