Racing Car Development - The K3 MG Magnette
WHEN THE MG Car Co. was at the height of its racing activities in the nineteen-thirties they offered the 1,087 c.c. supercharged K3 Magnette as a ready-to-race model, in sports car trim with mudguards and lamps or stripped in pure racing trim. Many of them were turned into pure single-seater racing cars and one of them was constructed as such from scratch. This was number 23 in the production series and it was specially built in the Abingdon racing department for Capt. George Eyston, and consequently had the works number EX135 given to it.
Eyston’s idea was to have a dual-purpose car that could be used for road-racing events as well as track events, using suitable body styles for each activity. In the normal K3 Magnette the engine and propshaft were mounted on the cenre-line of the chassis, with the driver sitting alongside the propshaft. This placed the seat on top of the chassis side-rail, so it was not a particularly low, but it did mean that regulation two-seater bodies could be fitted for sports car events, or offset single-water shells for racing events. In EX135 the engine was mounted at an angle of 6-degrees to the centre-line so that the propshaft ran diagonally towards the left rear corner of the chassis. A special rear axle was made with the differential/crownwheel and pinion housing off set to the left, and the left-hand chassis side rail was made with a bulge in it to accommodate the housing. This layout allowed the driving seat to be mounted between the propshaft and the right-hand chassis rail, giving the possibility of building a much lower car. A special semi-circular radiator core was made and a very simple aluminium bodyshell was made for road-racing, which followed the lines of this radiator. For record-breaking and track events a very sleek bodyshell was made, with a minimal opening in the front for radiator air, only the driver’s head protuding form the cockpit surround, and a long pointed tail with head-fairing behind the cockpit. This special body was painted with longitudinal stripes of cream and brown, the MG racing colours, and the car was nicknamed “Humbug”. When EX135 was being built at Abingdon in the spring of 1934 MOTOR SPORT went to see it and called it the “Magic Magna”, following on the popular name given to Eyston’s previous record-breaking car which was the 750 c.c. “Magic Midget”. The Magna was a production 6 cylinder sports MG, and the Magnette was a more exciting competition version of it. By the time EX135 was completed It was being called the “Magic Magnette”.
During 1934 Capt. Eyston raced EX135 in the International Trophy at Brooklands, where it retired with clutch trouble, in the Mannin Beg race in the Isle of Man, where it finished 3rd, and in the British Empire Trophy Race at Brooklands, on an artificially contrived road-course, which it won. At the end of the season the road-racing body was removed and the sleek track-racing body was fitted. In this form it ran in the 500-mile race on the banked Outer-circuit and was in the lead at one point, averaging 116 m.p.h. Then a ball-race seized in the rear axle and the car spun off the track. This was followed by a bout of record-breaking at Montlhery in which Eyston took records in the 1,100 c.c. Class tor the flying-start mile and kilometre, the 200 kilometres and for 1 hour.
In 1935 the car passed to Donald Letts, still in its record-breaking form as regards bodywork, and he raced it at Brooklands with the Bellevue Garage of Wandsworth, South London, doing the preparation. Meanwhile, in another part of the K3 MG world which was subsequently to affect the fate of EX135, Major A. T. G. Gardner had acquired K3 MG number 7 from R. T. Horton, This was a narrow single-seater which Horton had developed into a very fast track-racing car, with the assistance of R. R. Jackson and his Brooklands tuning shop.
In October 1937 Major Gardner took the ex-Horton car to a “Speed Week” held on the Frankfurt-Darrnstadt autobahn, and he set Class G records at 148 m.p.h. which was a pretty impressive speed from 1,100 c.c. in those days. German engineers who were there with Auto Union suggested he should fit an all-enveloping bodywork, enclosing all the wheels. The following winter Gardner got the support of the MG Car Company to build a pure record-car, for K3007 was really no more than a highly-developed track-racing car. With the blessing of Lord Nuffield and Cecil Kimber, a serious project was started by the MG experimental department, with Reid A. Railton assisting on the aerodynamics of the bodywork, and Robin Jackson continuing the development work on the engine. The first step was to acquire K3023, or EX135 as they still knew it, from Bellevue Garages, in order to utilise the special offset transmission line and low seating position. As the car was only going to run in a straight line the driving position was laid back at a shallow angle to reduce overall height, a rectangular steering wheel being used, with high gearing so that it only had to turn a few degrees in each direction. The Jackson-developed engine was taken out of the ex-Horton car and put into EX135 and Railton designed a superb bodyshell which enclosed all the wheels. It had a ducted radiator system and each wheel was enclosed in its own box, with great attention paid to air-flow over, under and through the car. Railton was one of those natural geniuses with a flair for getting it right first time, and without recourse to a wind-tunnel he made all his calculations. The result was that the first record-run by the rejuvenated EX135 saw a speed of 186.58 m.p.h. for the flying mile, with no aerodynamic problems.
In 1939 the German Automobile Club organised a “Speed Week” on a specially built stretch of autobahn without a central reservation, at Dessau, south-west of Berlin. Major Gardner was there with EX135 (which combined K3007 and K3023) and pushed the Class G records up to 203.5 m.p.h. On the spot the MG technicians bored out the cylinder block by 20 thou, fitted oversize pistons, and ran the car again in the 1,500 c.c. class though the capacity was only a fraction over 1,100 c.c.. and set records at 204.2 m.p.h. The motor racing engineering world at large found the speeds almost unbelievable for such a small engine, but the records were official.
The car was retained by the MG Car Company and after the war it was rejuvenated once and used for all manner of short-distance records with various engines installed. It was finally pensioned off when a totally new car was built at Abingdon in 1954, following the same lines. It remained in the safe-keeping of MG and has now passed into the British Leyland Heritage, but to MG enthusiasts K3023, or EX135 as it is better known, in the heritage of the MG Car Company and Major Gardner; long before British Leyland was ever dreamed of.