Building and running a Lotus Super Seven
The story of how three staff members built a Lotus Super Seven, together with road impressions after the car had covered 5,000 miles.
Motor Sport’s Proprietor is reasonably indulgent when members of his editorial staff try to convince him that their present car is worn out and that a new mount is of the utmost urgency, but even he was a little shaken when a new recruit to the staff demanded a Lotus Super Seven. The young man was Ted Wilkinson (Yes, the same E. L. W. who doesn’t know that a Ford 8 cylinder head won’t fit a 100E engine!) and as he had joined the staff primarily to report trials and hill-climbs he felt he ought to have a suitably spartan machine, to which idea the other members of the staff agreed, having had to lend him their cars for trips to all corners of the country. The Proprietor finally capitulated when told that the building of a kit car would provide good copy for the magazine as well as giving one or two staffmen some competition experience in hill-climbs and the like. So an order was placed with Lotus for a Super Seven and within a month the Lotus van arrived at the Assistant Editor’s house with all the bits and pieces on board. The Assistant Editor’s house was chosen for the task as his was the only one with enough spare garage space to accommodate the car as well as his own Sprite. Staff photographer Laurie Morton was press ganged into helping mainly because he had the best set of tools and also because he was required to take photographs throughout the construction stage.
Lotus claim that the car can be assembled with normal hand tools in 22 hours but we spent about 20 of the 22 sorting out all the various parts. (See Photo 1.) Actually, unless you happen to get the car on Saturday and want to race it on Sunday it is wiser to take plenty of time and in fact due to our heavy commitments at week ends it was over two months before the car was running on the road. The Lotus arrives in a pretty fully assembled state with the bodywork riveted to the space frame chassis and all instruments, wiring and the petrol tank in position and construction is merely a matter of adding the front and rear suspension, brakes, steering, engine and gearbox, radiator, lights, front wings and a number of smaller components. The Purchase Tax regulations do not allow instructions to be given with a kit car as this constitutes professional help and there are one or two items on the Lotus which can be fitted incorrectly as the Lotus Service Department will testify having seen many a Seven arrive with nose pointing up in the air, the owner having put the front suspension wishbones on the wrong side of the car. However, having placed the chassis/body unit on a couple of trestles and laid the various components in their approximate positions we were fairly confident of not having too many pieces left over when the car was completed.
The first job was the front suspension which consists of a lower wishbone with a single top arm and an anti-roll bar. (See Photo 2). Our ideas that this would go together like a piece of Meccano were soon dispelled and a fair amount of work removing paint and swarf was required before the rubber bushes of the wishbone would slip over the chassis lugs. It is necessary to fit the wishbone on the correct side of the chassis and this can be determined by fitting it with the mounting point of the coil spring/damper unit projecting below the centre line of the wishbone. The upper link was then fitted along with the coil spring/damper unit as they have a common upper mounting point. The modified Triumph Herald king post and Girling front brake assemblies were fitted next, care being taken not to tighten nuts more than finger tight until the car was on its wheels.
We fitted the anti-roll bar next but this is incorrect and should not be done until the car is on its wheels, or at least should not be tightened up until then. It is located at each end by two Metalastic half bushes working in the upper link arms and on the chassis by alloy blocks bolted to the uprights of the front box section. The anti-roll bar was finished in black paint and it was necessary to clean off this paint and lap the bar in with grinding paste. When the roll bar was working smoothly the paste was wiped away, the blocks tightened up and the grease nipples fitted. Another prevalent fault is to fit the anti-roll bar on upside down; the correct way is to have the cranked ends of the bar parallel with the ground when the car is at normal ride level. This is the main reason why the bar should not be finally fitted until the car is on its wheels.
The steering came next, this being a modified Triumph Herald rack and pinion unit which is located on the chassis by two light alloy mounting blocks. Here we met our first snag as Lotus had drilled the holes in the fabricated steel platform on the chassis too near one side so that a nut could not be fitted to the bolt. However, this was resolved by filing a larger flat on one side of the bolt head and passing the bolt upwards through the casting rather than downwards. (See Photo 3.) The coupling of the tie rods was then done, a note being made of the fact that the 1/8 in. toe-in had to be set when the car was on its wheels.
The rather fragile looking steering column was then slipped through the facia mounted bush and down to the rack assembly to which it is connected by a splined universal joint. Great care was taken to push the column well onto the splines and also to push the u.j. well down onto the spline of the rack as there is very little clearance between the u.j. and a chassis tube. The u.j. pinch bolts were then tightened.
Attention then moved to the rear end and the axle (taken from the Standard Companion and fitted with Herald 1200 gears) was placed in position after having slipped the Hardy Spicer propeller shaft into the tunnel. Two “U” bolts secure a platform to each end of the axle easing into which the lower end of the coil spring/damper unit is bolted. (See Photo 4.) Having secured the damper units to the axle they were then secured at their upper ends just behind the seats making sure that the rubber bushes were fitted in the correct sequence with one rubber and two steel caps below the chassis bracket and one rubber and one steel cap above the bracket. The “A” bracket was then fitted, a great deal of reamering being required before the bolts would go home. Lastly the radius arms were fitted, the upper mounting point being on a lug on the chassis within the rear mudguard and the lower mounting is on the same bolt which locates the coil spring/damper unit to the axle. Care should be taken to fit the radius arms the right way up. The arm should curve down from the spring/damper unit. The brakes are already fitted to the axle when delivered so we were now able to fit the wheels and lower the car off its trestles.
The next step was to fit the 1,340 c.c. Ford Classic engine which had been breathed on by Cosworth to the tune of 85 b.h.p. It was supplied with the modified cylinder head already fitted but the twin Weber carburetters and manifolds had to be fitted later. A hoist is a necessity as some manoeuvring is required to persuade the engine and gearbox into the chassis. (See Photo 5, page 163.) Before lowering the engine we removed the remote control gear lever, distributor cap and petrol pump sediment bowl and covered vulnerable parts like hydraulic pipes, with rags or split rubber hose. After fitting the tubular steel engine bearers to their rubber mountings on the chassis (See Photo 6, page 163) the engine was lowered, making sure the tail shaft entered the tunnel first and that the single point gearbox mounting went home. The splined propeller shaft was slipped into place and the four-point mountings on each side of the engine were then tightened up and the hoist removed. The remote control, which is a modified Triumph Herald component was then replaced together with a new paper gasket at which point it was discovered that the gear lever was too long, almost fouling the lower edge of the facia. However, Lotus cut and re-threaded the lever at the 500-mile service.
When connecting up the various accessories connected with the engine such as oil pressure pipe, clutch piping, temperature gauge we discovered that we had made a ghastly error in not fitting the right angle speedometer drive take-off to the offside of the gearbox and there was insufficient clearance between the gearbox and the tunnel to fit it while in position. Bilking at the thought of removing the engine we cut a hole in the tunnel, fitted the speedometer drive and riveted a piece of aluminium over the hole.
The radiator, which is held by two top-hat rubbers, one bolt and the water hoses, was fitted next, the hoses being rather difficult to fit. In fact it is best to fit the radiator before the steering rack as some complicated juggling is required to get it into position when the rack is in place. Fitting of the Weber carburettors and exhaust manifolds came next and a considerable amount of time was taken in sawing and filing the various flanges to obtain a good fit. The manifolds are secured to the head by Allen screws and due to the angled inlet pipes are very difficult to tighten, requiring a specially made Allen key. (See Photo 7, page 164.) When the Webers are bolted to the inlet manifolds they have rubber “O” rings inserted in between and adjusting the tension on the double spring washers so that the carburetter intake pipes have a total vertical movement of about 3/8 in. will ensure correct carburation, as loose carburetters will allow air leaks and too tight ones will cause frothing. The throttle linkages came next and caused a fair amount of trouble as there are a large number of threaded rods, ball joints and so on, but careful study of a Formula Junior Lotus in the paddock at Silverstone showed us how it all went together. The fuel lines and throttle cable were then connected up but we did not fit the choke cable as we had an idea that there would be no starting problems with those two big Webers and later events proved us right.
By now there was only a very small pile of pieces left over on the bench and the car was very near completion. The front wing stays were fitted and the flared glass fibre wings attached, care being taken to incorporate the piping between wing and body. The sidelamps were then attached to the wings and the wiring connected. The windscreen fitted easily and the wiper motor was bolted into position under the bulkhead, care being taken to fit the spacer tubes over the wipers rack. If this is not done the cables will flex themselves and not move the wiper blades at all. The pedals were then fitted, this operation requiring some ingenuity and a reclining posture under the bulkhead. (See Photo 8, page 164.) This was followed by the handbrake and its linkage after which the hydraulic piping was connected, the master cylinders filled and the brake and clutch systems bled. The coil was then fitted to the driver’s footbox using the steel backing plate provided, the silencer bolted to the outside of the passengers side of the car and the flexible piping attached to the exhaust manifold down pipe by a jubilee clip and the two-blade fan bolted to the water pump pulley with the two aluminium spacer blocks in between so that the blades did not touch a chassis cross tube. By now all that remained was the hood, this being supplied complete except for the Lift-the-Dot fasteners which were fitted with the fabric laid over the hood sticks so that a good fit was obtained.
Finally the engine, gearbox, rear axle, radiator and petrol tank were filled with the appropriate fluids, the wooden steering wheel slipped on its splines and bolted down and with some trepidation the ignition was switched on and the bulkhead-mounted starter button pressed. After a few seconds delay while the carburetters filled with fuel the engine burst into noisy life and idled happily, while the proud builders looked on affectionately.
History
Since the Editorial Lotus Super Seven passed its 500-mile factory check the car has done nearly 6,000 miles at the time of going to press. Whilst still in the final stages of running in it was apparent that such a light vehicle would cause problems in wet conditions. The lesson was not fully learnt until an argument with a London Transport ‘bus occurred on a narrow railway bridge on a soaking wet August Bank Holiday. A mangled off-side front suspension and torn sump brought home the lesson that locked brakes on a wet road changes the Lotus from a car to a toboggan. With the damage made good the teething troubles commenced and it took several visits to the Lotus Service Department at Panshanger, and finally the fitting of a new rack and pinion before the car began to steer and brake efficiently again.
The electric horn, which is mounted on the nearside engine bearer, suffered from acute vibration which culminated in a replacement being fitted and, at our suggestion, the re-mounting of the unit on a firmer chassis point. At 2,342 miles the water-pump casting split as a result of the pump bearings seizing and a new water-pump was supplied free of charge. Just before 3,000 miles were up the mechanical cooling fan broke at speed and came through the fibreglass nose cowling, severing the upper radiator hose in the process. As this occurred on the Motorway section of the A1 at about 10.00 a.m. on a Sunday, few of the Ford agents in the area would help out, being content to sell petrol and oils, yet still calling themselves Ford agents and having the sign “Garage” or “Service Station” over their portals. However The Bawtry Motor Co., some twenty miles from where the breakdown occurred showed enterprise in opening their stores on a Sunday morning and willingly sold a Ford 109E fan blade for 2s. 9d. The damaged fibreglass was repaired by the Lotus Service Department effectively but far from invisibly. Three other water-pumps were fitted at intervals of less than 200 miles and it was not until the mechanical fan, which required a heavy spacer to clear a chassis cross-tube, was replaced by an electric fan thus relieving the undue weight on the water-pump bearings that the trouble was finally remedied.
The electric fan, mounted in front of the radiator appeared to suffer from the airflow to such an extent that within six days of being fitted by Lotus the blade had fallen off. This was re-fitted by Lotus but came off again within two days and is now in the process of being returned to the factory for examination.
As soon as full performance was usable it was noticed that the bolts locating the differential housing were working loose, allowing the oil to escape on one occasion when the car was driven for nearly 50 miles with no oil in the axle save for a slight plating of Molyslip which could well have contributed to the fact that no damage had been done. An attempt by the Lotus Service Department to rectify this fault did not prove successful and the remedy has been to drill the bolt heads and wire them. It is understood that Lotus have now developed a special taper bolt which is supplied on all new models which will keep the differential housing in place.
Apart from the above the car has been trouble free with the exception that one baffle plate is now loose in the exhaust system but does not appear to have altered the silencing qualities in any way except for a slight rattle audible when throttling back. The Lucas spotlamps have been removed, having proved inadequate for fast night driving and we are at present experimenting with a pair of matching Butler spot and foglamps; the foglamp proving a distinct advantage while the spotlamp is not quite up to the standard of the Lucas spotlamp. The original rubber mats wore out within 2,000 miles and were replaced with a pair of fitted rubber-link mats made by Typrod of Brighton. These are competitively priced, unaffected by oil and are guaranteed for ten years.
A 5s. can of bitumastic paint sufficed to completely underseal the body, in particular the pop-rivet seams where water came in very rapidly, and to protect the engine bulkhead which had been attacked by battery acid. On such a low-slung, high performance car a windscreen washer is essential and a Tudor Accessories washer, using a flat water container has been fitted. A further modification which will be carried out in the near future is the making of a gull-winged detachable hard-top incorporating a wrap-round rear window and lockable doors. The throttle cable is being altered to use a copper tube packed with grease as an outer cable to overcome a tendency of the existing cable to slip out of its retaining bucket. The awkward fuel filler cap is being modified by means of a curved piece of radiator hose, jubilee clips and another filler neck to take the cap outside the body.
The pleasure of driving such a potent piece of machinery on the open roads, the envy of one’s friends with their buzzing Minis and Sprites completely outweighs the earlier trials and tribulations of Lotus owning although they, in turn, laugh at the 17-20 m.p.g. fuel consumption of the Lotus! The only regret is that the 1,340 c.c. Super Seven was superseded by the later model incorporating the 1,500 c.c. 5-bearing crank engine with all synchromesh close-ratio gearbox and such extras as sidescreens, better view p.v.c. hood, revolution counter, disc brakes, sealed beam headlamps all for the same price just after the Editorial Super Seven was put on the road!
Driving impressions
Some people liken driving a Lotus to a visit to the dentist—it’s awful while it’s happening but wonderful when it stops—but these people are seldom Lotus owners and if one is a Lotus owner then one is prepared to make many sacrifices such as pre-war Bugatti owners must have done. To refresh his memory as to what Lotus driving was like the Assistant Editor set out one morning when the cold spell was at its height for a long run in the car which he had helped to build.
Getting into the car provides some exercise especially with the hood and sidescreens in position and until the drill is learned the driver usually manages to tramp his muddy boots all over the seat cushions or get his leg stuck through the steering wheel. Once in position he is held securely between the body side and tunnel and his legs disappear into an ever-narrowing tunnel where one size-10 shoe seems to cover all the pedals at once. We found it best to drive in plimsolls or shoes with no welts. Even in the bitter cold weather we have been experiencing recently the engine started first time from cold without a choke and ran with a delightful burble, the temperature rising to around 80°C, at which point it remained whatever the road speed. Tuned by Cosworth to give 85 b.h.p. at 6,000 r.p.m the engine is by no means silent, especially as the exposed exhaust system runs within a few inches of the passenger’s ear. The gearbox is the standard Ford Classic version which at the time we built the car had no synchromesh on first gear but even so is delightful to use, except for a slight tendency to snick reverse when changing from first to second. This is presumably a fault of the particular remote control fitted.
With only 8 1/2 cwt. the acceleration of the Lotus is pretty sensational although as there is no rev. counter on our car (it being a £17 10s. extra) we treated the engine with respect. With standard gear ratios (close ratio gearbox £40 extra) there is a fairly wide gap between second and third but such is the acceleration in second that this would only become an embarrassment on a race track as the speedometer needle can be taken to 60 m.p.h. in second with no sign of stress. Third is good for an indicated 85 m.p.h. and on more than one occasion the needle went past the 100 m.p.h. mark in top. Practically nothing can live with the Lotus on the road especially if there are any bends in sight but even in a straight line it will stay with an E-type Jaguar up to 80 m.p.h. Almost as exhilarating is the punch the engine gives when vivid acceleration is required for overtaking long strings of traffic, while the car will run along at 30 m.p.h. in top gear with no fuss at all.
The ride is uncompromisingly hard and roads which we had previously thought to be particularly smooth suddenly became full of bumps and potholes although the car was only deflected from its intended course by serious bumps. A number of rattles were with us almost permanently and there seems little hope of curing these with the present stiff suspension. Despite the generous use of bitumastic paint all over the underside there are numerous draughts which manage to creep in around the driver’s feet, while a stiff blast of cold air freezes his right elbow. Some heat comes back from the engine and the optionally extra heater (£12 16s. 7d.) is not really necessary.
Cornering of the Lotus on smooth roads is quite exceptional and with 2 3/4 turns from lock to lock the merest flick of the wrist gets the car round quite acute bends. Bumps do tend to displace the rear end but the car can be driven hard round acute bumpy bends without fear of completely losing adhesion, the limiting factor being the amount of jolting the occupants can endure.
The windscreen surround and sidescreen leading edge cause a considerable blind spot which renders the negotiation of roundabouts and hairpin bends hazardous and the car is so low that signposts are difficult to read with the sidescreens in place.
The brakes work very well and haul the car down from its habitual 90 m.p.h. cruising speed with no fuss at all, although a little grab was experienced when the drums were cold.
The normal driver of the car has made several modifications to make the car more habitable (which are detailed elsewhere) and is contemplating more. Certainly anyone intending to use a Lotus Seven as everyday transport would need to make several modifications and be able to put up with petty annoyances such as the lack of a fuel gauge, little luggage space, the need to lift the hood to fill the fuel tank, and to remove the bonnet panel to check oil and water. Judging by our experiences he should also be able to cope with a number of teething troubles as they occur as the car is guaranteed for only 90 days. All in all the Lotus owner will need to be a hardy soul as the majority of creature comforts present in much cheaper saloons are absent while the casual attitude of Lotus to such serious troubles as the inability of the rear axle to withstand the power of the engine will not endear the car to impecunious owners. Fortunately for Colin Chapman there appear to be plenty of people about who are willing to endure these hardships.
M. L. T./E. L. W.