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BMC cars take 21 International Class records at Bonneville Salt Flats, powered by supercharged MG and Austin-Healey Sprite engines

In 1957, a vehicle known as B.M.C. Development Project EX179, fitted with what was later to become the 950cc Austin-Healey Sprite engine, made two long-distance runs on a ten-mile circular course at Bonneville Salt Flats, Utah.

One run was of 12 hours duration, which was completed at an average speed of 118.13mph, and the other of six hours, averaging 132.13mph. In the process, seven International Class G records (750-1100cc) were taken.

During 1959, preparations were made at Abingdon for another record-breaking expedition to Utah and a development of EX179, known as EX219, was built, again to be powered by a supercharged Sprite engine. The renewed efforts of the Development Department at Abingdon were outstandingly successful, for in September 1959 no less than 15 International Class G records were smashed by the new car, including lifting the 12 hours standing-start record to the amazing figure of 138.75mph. In addition, a further 12 American National records were broken – at this very home of American high-speed motoring!

The chassis of the car is substantially orthodox, having independent coil spring front suspension, lead springs and solid rear axle behind, and rack-and-pinion steering. Two power units were taken for the attempts, both in most respects quite standard BMC ‘A’ Series engines and gearboxes, to each of which had been added a Shorrock low-pressure belt-driven supercharger kit. This gives a manifold pressure of 6-7lb. per sq. in. and the engine for the long-distance records developed 78bhp at 5,500rpm or 86bhp at 6,000rpm. For the shorter distances, up to the one-hour record, a ‘sprint’ engine was used, running at a higher compression ratio and developing 98bhp at 6,500rpm.

Then, after delays due to wet weather, Phil Hill took out the famous EX181 – the MG streamliner with the supercharged Twin Cam engine, with which Stirling Moss recorded over 245mph for the flying mile in 1957. It set up remarkable new records in the 1500cc class that time, but in 1959 it was bored out to I506cc and established even more startling figures for International Class E (1501-2000cc), one new record being more than 70mph faster than the previously held figure.

The Records

EX219 (Sprite engine)

International Class G (750-1100cc)

50Km              (142.01mph) 145.56mph
50 Miles         (140.87mph) 145.48mph
100Km           (141.14mph) 145.08mph
100 Miles       (140.21mph) 146.17mph
200Km           (140.19mph) 146.64mph
1 hour            (137.26mph) 146.95mph

500km            (132.39mph) 138.85mph
1000Km         (131.84mph) 138.39mph
2000km          (120.81mph) 138.86mph
200Miles        (131.89mph) 138.15mph
500 Miles       (131.38mph) 137.72mph
1000 Miles     (120.62mph) 138.55mph
3 hours          (132.62mph) 139.38mph
6 hours          (132.13mph) 139.09mph
12 hours        (118.13mph) 138.75

American National Class G

25 miles: 127.88mph;
50 km: 129.86mph;
50 miles: 132.94mph;
75 miles: 135.17mph;
100km: 134.09mph;
100 miles: 136.53mph;
200km: 137.15 mph;
1 hour: 137.38mph;
250km: 137.68mph;
300km: 138.12mph;
400km: 138.48 mph;
250 miles: 138.49mph.

EX181 (MG engine)
International Class E (1501cc to 2000cc)

1km                 (185.41mph) 254.91mph
1 Mile             (180.50mph) 254.33mph
5km                 (170.52mph) 232.97mph
5 Miles           (140.17mph) 238.36mph
10km              (140.07mph) 234.49mph
10 Miles         (138.34mph) 191.03mph