Lotus Seven Buying Guide

One of the most focused driver’s cars ever, the Seven is hugely desirable – but despite its simplicity, there’s plenty to consider when buying

Lotus Seven Buying Guide

How much to pay

• Project £4000-11,000 • Good £8250-19,000 • Concours £16,500-39,000

Overview

Practicality ★★
Running costs ★★★★
Spares ★★★
DIY friendly ★★★★
Investment ★★★★
Desirability ★★★★

If imitation is the sincerest form of flattery, Colin Chapman would be pretty chuffed to see how many copies of his Seven are now available. Aside from the Cobra, this oversized rollerskate must be the most copied car ever, and that’s for a good reason – it puts the fun back into motoring.

Ever since the first Seven was shown in 1957, it’s been possible to have some serious fun behind the wheel for relatively little money – and the prospect of going on a track day then drive home without having to swap cars is as appealing as ever. However, while few models are as simple as the Seven, high prices, a degree of fragility and poor availability of some parts mean you have to buy very carefully.

Your AutoClassics Lotus Seven inspection checklist

Engine

Engines wear out eventually, especially as they tend to get used hard, but to counter this the Seven’s low kerbweight helps increase powerplant longevity. Some units are highly tuned, though, so you need to make sure that whatever is fitted hasn’t been overstressed.

Lotus used Ford, BMC and Coventry-Climax powerplants, as well as its own. Over the years many of these cars have been fitted with newer engines, although as Seven values have risen, many examples have been returned to – or close to – original spec.

The Coventry-Climax unit is the nicest of the early motors, but these suffer from internal corrosion and cracked cylinder heads. The 1340 Cosworth in the S2 is also sought after, but it’s equally rare and temperamental thanks to its three-bearing crank. This leaves the 1500 (in both Cosworth and non-Cosworth forms) as the most likely powerplants you’ll track down, other than a Twin-Cam.

This latter engine is the best of all the units fitted to the Lotus cars, but if neglected it’ll soon be down on power. The motor is intolerant of low-maintenance regimes, and once things have started to deteriorate it doesn’t take too much for an overhaul to be required. Rebuilding one of these engines is very expensive, and if the cylinder head needs replacing you’re looking at big money for a new casting.

Gearbox

Seven gearboxes tend not to give problems, whether they’re of the three-speed Ford or four-speed BMC types. Once a rebuild is due it’ll be obvious, and while some parts are now scarce, most transmissions can be overhauled if your pockets are deep enough.

Lotus used Nash Metropolitan axles until 1960, when the Standard Companion unit took over. Neither is very strong, so many have been swapped for Marina or Escort items. These are much more durable and easier to rebuild.

Suspension and brakes

All Sevens have rack-and-pinion steering, except for the very first few, which had a worm-and-nut system. In 1958 a Morris Minor rack was adopted, but the following year this was superseded by a Triumph Herald unit and later one from a Spitfire MkIV.

There are 22 bushes in the suspension, and they all wear out at different rates. Replacing them is cheap and easy, as is swapping out the one that locates the A-frame for the rear suspension. This perishes because of oil saturation from gearbox and engine leaks, and can be treated as a consumable. Replacement takes no more than a couple of hours and transforms the handling.

Apart from Series 1 cars, which used 15-inch wire or pressed-steel wheels, Sevens were fitted with 13-inch pressed-steel rims from either the Triumph Herald or Ford Cortina. If wires are fitted, the splines and spokes will need to be checked, but otherwise there shouldn’t be any problems.

Because the Seven is so light, its brakes have a relatively easy time. From new, cars with de Dion rear suspension usually had four-wheel disc brakes, while all live-axle cars had rear drums. Upgrading to ventilated discs is easy enough, but it’s not necessary unless the car is going to be hammered regularly.

Bodywork

It’s the chassis that needs the most careful inspection when buying a Seven. Replacement sections and even complete chassis are available, but it’s rarely a DIY job.

Rust will normally only be a problem if the car has been shunted and poorly repaired, unless you’re looking at a Seven S4. These featured a bodyshell that was bonded to the chassis, and not only is the car much more prone to rust, but it’s also harder to inspect the chassis and much more tricky to properly repair any corrosion.

At least it’s easy to see most of the chassis of any Seven other than an S4. Badly repaired accident damage is the most likely problem, especially from a frontal impact. Look for bent tubes or badly let-in replacement sections. To get the best view you’ll need to remove the bonnet and nosecone, and when you test drive the car make sure it’s not pulling to one side.

Because the Seven’s bodywork is made of aluminium and glassfibre, rust isn’t an issue, although dented alloy panels are. Unpainted panels can also become pitted if they haven’t been kept clean, and glassfibre can become cracked and crazed. At least the latter is cheap and easy to replace, although S4s are harder to fix because the rear wings, dash and scuttle are integrated.

Replacing flared wheelarches with the cycle type (which are more popular nowadays) will leave a line of holes along the front wings. Swapping the other way is possible and fairly easy, as the holes will be covered up.

The only other likely bodywork issue is with the aluminium fuel tank, which sits behind the two occupants. The tank can rub at its mounting points, so the rubber wears thin and starts leaking; replacement means the removal of the roll bar, if one is fitted.

Interior

There’s so little interior trim that even the tattiest cabin is going to be cheap and easy to put right, unless you’re keen to retain the car’s originality. The chances are the vehicle will have been updated anyway, with changes to the steering wheel and perhaps the instruments.

Interior panels are just trimmed cards, and as long as the seats, carpets and weather protection are intact, there isn’t much to have a look at inside. The outside is much the same – brightwork is minimal and it’s easy enough to replace.

So little equipment is fitted that the wiring loom is about as simple as it’s possible to get. Consequently, checking that everything works takes no time at all, and neither does inspecting the whole loom for damage or evidence of past bodgery.

The biggest problem is with earthing, so anything that isn’t working is normally easily fixed. But don’t underestimate the task of finding original parts – simple things such as the headlights can be devilishly tricky to source.

History

  • 1957: Lotus Seven is launched with a Ford 100E engine, 15-inch wheels, Austin Metropolitan axle and drum brakes. This is later known as the 7F.
  • 1958: Super Seven arrives with a Coventry-Climax FWA 1100cc engine – this is subsequently known as the 7C.
  • 1959: An A-series engine heralds the launch of the Lotus 7A.
  • 1960: Seven America appears with an Austin-Healey Sprite engine, flared wings, glassfibre nose and tubular bumpers.
  • 1961: A Ford 105E engine replaces the 100E and A-series units.
  • 1962: Super Seven 1500 goes on sale, with a Ford Cortina powerplant. The fuel-tank capacity increases from 5.5 to 8 gallons.
  • 1963: Flared wings replace cycle wings.
  • 1967: Series 2 ½ is launched, with a Ford 1600 Crossflow engine.
  • 1968: Series 3 arrives with 1300 or 1600 Crossflow engines, front disc brakes and negative-earth electrics.
  • 1970: Series 4 is introduced with a new glassfibre bodyshell and spaceframe chassis.
  • 1972: Lotus Seven production ceases.

AutoClassics says…

Find a good Lotus Seven at the right price, and there’s no reason not to purchase it. It’ll be a cast-iron investment but it’ll also be an absolute blast to drive. The tragedy is that many buyers see their Sevens in this order; an investment first and a great car second.

If you’re on a budget it might be worth seeking out a Series 4, but these cars aren’t as light as their predecessors, they’re less pretty and they’re far less sought after. As a result, selling one on can be tricky, unless it’s priced to sell.

Of the earlier Sevens, it’s the Coventry-Climax, Lotus Twin-Cam and Cosworth-engined variants that are the most sought after. As a result these are the best investment, but the lowlier versions are more affordable and just as much fun to drive, if not generally quite as quick.

Specifications

Lotus Seven S1 100E
  Power 40bhp
  Top speed 78mph
  0-60mph 19sec
  Economy 40mpg

Lotus Seven S1 948 A-series
  Power 37bhp
  Top speed 85mph
  0-60mph 14.5sec
  Economy 40mpg

Lotus Seven S1 Coventry-Climax
  Power 75bhp
  Top speed 104mph
  0-60mph 9.2sec
  Economy 37mpg

Lotus Seven S2 105E
  Power 39bhp
  Top speed 83mph
  0-60mph 14.8sec
  Economy 36mpg

Lotus Seven S2 1500 Cosworth
  Power 95bhp
  Top speed 104mph
  0-60mph 7.7sec
  Economy 34mpg

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Picture courtesy of MagicCarPics