SEVENS

Last Updated 06/09/00

Types Of Seven

There are many derivatives of the original Lotus seven made by many different manufacturers. This article attempts to explain some of the differences and reasons for choosing one over the other.

Lotus
Caterham
Westfield
Rotus
Birkin
Dax Rush
Robin Hood S3
Striker
Tiger

I have written the Lotus and Caterham sections and plan to ask fellow seveners who represent the other marques to write their respective sections.

Lotus

A 1969 S3 and 1970 S4 both with twincam engines

History
The Lotus seven S1 was launched in 1957 with a 948cc engine and 4 speed gearbox from an Austin A35, later models had engines up to the 1498cc 116E from a Cortina. It evolved into the S2 which had A-frame rear suspension and then into the S3 in 1968. This was stiffer, had wider arches (as Caterhams) with a 1600 Ford crossflow engine and escort rear axle, this replaced the prehistoric (and fragile) standard 10 article. A twin cam version (the super seven) was also made available with 125 bhp. The S4 launched in 1970 was quite a departure to the earlier models. It had a simpler ladder, rather than spaceframe, chassis with stressed steel panels under a fibreglass body. This was the end of the seven as far as Lotus were concerned.

Pros and Cons
Obviously being an old car a Lotus seven is going to be comparatively underpowered, well worn and possibly in need of considerable work. However, it is the original article and a twincam is quicker that many modern variants. They are quite small in both width and leg room. The S4 styling is also not to everybody's liking (although I find it grows on you)

Prices
I recently saw an S3 and S4 in good condition at auction, both were estimated at Ł5000-8000. However, the S4 went for Ł2000.

Caterham

A Caterham Superlight or SL - 470 kg, 138 bhp Rover 1.6 K-series Supersport

A Caterham Superlight-R or SLR - 470 kg, 190 bhp Rover/Caterham 1.8 K-series VHPD (very high power derivative)

A Caterham Superlight-R500 or SLR500 - 460 kg, 230 bhp Rover/Caterham/Minster 1.8 K-series

History
Caterham used to be a Lotus dealer but upon hearing that Colin Chapman wanted to kill off the model in 1966 they redoubled their efforts at selling sevens and kept it alive until production stopped in 1971. In 1973 all the remaining part, jigs, moulds and manufacturing rights were passed to Caterham who made some S4s before reverting to a strengthened version of the more popular, lighter and agile S3.

As the years have gone on Caterham have produced many modifications:

1973 stiffened chassis
1600GT Sprint version of crossflow
1981 Morris Ital rear axle (as Escort Mk 2 axles ran out)
1984 1700SS Supersprint version of crossflow
.... engineered the chassis for Sierra 5 speed and the bespoke 6 speed gearbox with bellhousings to allow Rover K series and Vauxhall engines
1985 BDR 16V
1986 dedion rear end
1986 HPC later with Vauxhall 16V
1989 disc brakes all round
1989 2 position adjustable pedal box
1991 double wishbones at the front
1991 revised rear suspension
1991 more boot space
.... Rover K series and Supersport engines
1994 3 position adjustable pedal box
1994 stiffer still chassis with removable upper engine bay diagonals for easy access
1994 increased leg room

Pros and Cons
To many the only proper seven, although those of us on the list discourage this view, the L7oGB is perhaps the most puritanical of organisations. Caterham also produce the quickest seven ever made in the SLR500 (although the Westfield FW400 is also very rapid indeed).

The most popular models are based on standard or Supersports versions of the Rover K series producing 120-140 bhp in a car of 540 kg, this gives 0-60 of around 5.5-6 seconds. There are also a considerable range of factory upgrades and options available.

A Caterham is one of the smaller seven type cars and some may find its width a little restrictive, however, there is sufficient leg room for those of up to 6'6" (with 'short' legs or 6'2" with short legs) to get comfortable.

The build quality of a Caterham also reflects it comparatively high price, personally speaking I find the seats in particular more comfortable than any other road car I know. This build quality (although some cars from 96/97, such as mine, suffer from corrosion) and a lineage that can be traced directly to Lotus has resulted in a car with very little depreciation giving a strong reason to chose a Caterham.

Prices
Caterhams start at Ł11,000 for a component form, 1.6 8V Vauxhall powered car (100bhp) and range up to Ł30,000 for the fire breathing SLR500. The typical choice of a 1.8 K series costs Ł16,000 - Ł20,000 depending on whether it is a kit or ready built and the number of options chosen.