Seven made by Lotus between 1957 - 1973
by John Watson
The Mark V
Chronologically the next Lotus to have been produced should have been the Mk V. However although this designation was planned to be a 750 Formula car capable of 100mph, in fact it was never built.
The Mark VI
With the help of Colin Chapman's friend, Patrick Stephens, who was to become a renowned specialist publisher of motoring titles, Lotus Engineering Co had a well compiled advertisement in Motorsport as well as decent headed notepaper for the first time. The advert, offering “A complete service for the Special Builder”, pulled in just enough money for Colin Chapman to commence with building the first Mark VI which he had designed at the end of 1951. Whilst all the previous marks had used chassis components based on the Austin Seven, the new car was to have an all Lotus designed space frame chassis. As before the front suspension was by swing axle from the Ford Ten, split in half, but this time utilising coil spring damper units in lieu of the leaf springs used previously. The rear axle was again from the Ford Ten but with the torque tube shortened to suite the wheel-base of a two-seater sports car. Again, as at the front, coil spring damper units were used on the rear. The cable operated brakes and worm & nut steering box were modified Ford 10. Whilst larger than previous models to accommodate two people side by side in the car, rather than half in and half out of it, the cockpit was still without much in the way of creature comforts. A daily driver during the week and a racecar without the need of a trailer at week-ends, it was definitely to be the forerunner of our beloved Seven which is still being produced more than half a century later.
Engines
Right from the outset, it was planned that the new car was to be designed to accept a variety of engines. The unit chosen for the prototype was the overhead valve unit from the newly introduced Ford Consul with a capacity of 1508cc which, being ‘fresh’ on the market, proved difficult to source. Colin had no success via the usual trade outlets and a letter to Ford’s Chairman did no better, so in the end the engine was built up of bought in parts from a variety of Ford dealers in the London area! 1508cc was not a good capacity for competition as it was just too large for the under 1500cc class. In order to lose 9cc, the solution was to eccentrically grind the big end journals and fit oversize bearings, effectively shortening the stroke. The 4-speed gearbox used was from an Austin with aluminium adaptor pieces between it, the engine and the torque tube. Other engine/gearbox combinations that Lotus recommended were:- the overhead valve MG TC XPAG unit of 1250cc with matching 4-speed gearbox, the side valve Ford 10 E93A unit of 1172cc and matching 3-speed gearbox with Buckler close-ratio gear set, and much later in production, some owners fitted the aluminium cased single overhead camshaft Coventry Climax FWA units of 1098 along with uprated Lotus Mk IX running gear.
Debut & Disaster for the Prototype
The prototype, XML6, made its competition debut at the MG Car Club’s meeting at Silverstone on 5th July 1952 where it caused quite a stir finishing 2nd in two races. However shortly after, on the morning of 1st August 1952, whilst being driven on the road by Nigel Allen, it was hit in the side by a bread van and completely written off. Luckily it was covered by insurance or Lotus Engineering might have been a commercial write-off as well. As always it was sometime before the insurance money arrived, but fortunately the adverts in Motor Sport were still pulling in orders.
A limited company is formed
By the end of 1952 Michael Allen and Colin were not getting on and Michael left to continue with dentistry. Now on his own, Colin borrowed £25 from Hazel and spent it on forming Lotus Engineering Company Ltd. specialising in automobile and component manufacture and racing and competition car design and development. The directors were Colin, his father, Stanley and Hazel as director and company secretary, the company was described as “Manufacturers of the Lotus chassis frame and based at 7, Tottenham Lane, Hornsey, London, N8. Telephone MOUntview 8353.
Selling a Kit - not a Car
Marketing literature of the day titled; “LOTUS – faster than you think !” states; “The Lotus System enables any enthusiast to build himself a replica of a Mk VI Lotus Sports Car with the minimum of difficulty and expense.” It goes on to boast an aluminium clad semi-monocoque design of chassis frame with all attachment points fitted weighing in at just 63 lbs. What Lotus were offering was not a car but a kit of special components to build one. These parts included: Chassis Frame c/w skinning @ £110:0:0, Conversion to Independent Front Suspension @ £16:10:0, Modifications to Brake Linkage @ £2:1:6, Shortening of Torque Tube & Prop Shaft @ £6:0:0, Panhard Rod & Coil Spring/Damper Units @ £23:5:0, Steering Column and Brake Assemblies @ £17:1:6, Fuel Tank @ £10:0:0, Radiator @ £13:0:0, Upholstery Kit @ £22:0:0, Windscreen @ £11:10:0 and Hood & Frame @ £13:15:0, etc. To complete the car the customer would have to source the engine, gearbox, axles and wheels direct from his local motor agent. Details like the choice of instruments and their layout would be entirely up to the builder.
Production
Lotus Mk VI chassis frames were available from 1952 to 1955 and in all around 80 were made. The Progress Chassis Company made the mild steel tubular frames whilst Williams and Pritchard formed and fitted the aluminium skinning. Both companies were local to Lotus and went on to produce many other models including both the famous Eleven Le Mans and the Series One Seven.
Racing Success
In 1953, the first full season, the first four Mk VI cars to start racing gained 47 awards in competitive events including 19 first places. Colin Chapman’s own linered down Ford sidevalve powered car remained unbeaten in it’s class in that year and alone took 20 awards. In 1954, Peter Gammon driving a modified MG XPAG powered car achieved the following results: 17 Firsts, 5 Seconds, 6 Thirds, 1 Fourth and 1 Sixth place - An impressive record for a kit car in those days.
All photographs by courtesy of Ferret Fotographics 01453-543243
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