Lotus Seven Series 4

Lotus 7 meets Beach Buggy

The Lotus 7 Series 4 is sufficiently unlike other Sevens as to deserve an article all its own.

The Lotus Seven is probably the second most fun thing you can buy.  It was never as much fun as that for Lotus.  They lost money on every one they sold, which was fairly typical for Lotus.  The most expensive piece of any Lotus / Caterham Seven Series 3 is the chassis frame, a complex collection of steel tubes welded together by hand.


Caterham 7 Spaceframe

If Lotus were going to make money from the Seven they needed something less expensive to make.  A little more comfort and better weather-proofing wouldn’t be a bad idea.  Something that looked, well, more 1970’s as opposed to 1950’s wouldn’t go amiss either.

lotus-sevenS4The 1970’s was the era of peace and love in California, and the beach buggy. So, although the Lotus type 60, a.k.a. Lotus Seven S4, was unmistakably a 7, it borrowed some echoes of a beach buggy in both its styling and construction.  The S4 was longer and wider than its illustrious predecessors, was built on a much simpler spaceframe with spot-welded flat steel sides to the cockpit, and had a glassfibre body that was bolted to the chassis for extra strength.

The body / cockpit was a single piece glassfibre bathtub, which was self coloured and came complete except for the bolted-on front wings and single piece, front tilting bonnet.  Even the scuttle and facia were part of the cockpit moulding.


Mechanically the 7 S4 was similar to earlier sevens, using mainly mass produced Ford parts, from the Escort rear axle to 1,300cc and 1,600 cc Ford crossflow engines.  Snag with the 1,300 cc engine was that it didn’t fit the chassis.  This problem was solved in typical Lotus fashion by cutting out an offending chassis tube.  Luckily not many 1,300 cc engined S4’s were made.

Amazingly, the Seven S4 even made a profit for Lotus on each unit sold.  (However, the development was way over budget, and who knows if the project was ever profitable over all.)

The Ford engines were also available with Holbay tuning modifications, and at the top of the range was the Lotus-Holbay Twin Cam.  These more powerful engines are not a brilliant idea in an original specification S4.  The  little car just cannot put that much power on the road.  Flooring the throttle at the peak of the rev. range will give you savage axle tramping.

The rear suspension in a S4 is a pair of fore and aft Watts links, mounted on big rubber bushes, with a  transverse arm for lateral location.  At the front are double pressed steel wishbones, (borrowed from the Lotus Europa), fitted without an anti-roll bar.  Coil spring / dampers are fitted at all four corners.

Handling and road holding in an S4 is, skittish.  But the same can be said for other sevens.  What is slightly less acceptable is that a Series 4 will lift its inside rear wheel off the ground under hard cornering.  I have had a massive spin in an S4, in the wet, at fairly low speed, so I can say that slow-in and fast-out of corners is possibly the driving style to adopt.

lotus-S4-interiorInside an S4 is a fairly nice place to sit, there is plenty of room for taller drivers, and you can fit adjustable seats.  The S4 doesn’t seem to be as draughty as other sevens with the top up, nor does it leak much in the rain.  However, like almost all open cars, the Lotus 7 S4 rattles, groans, and bangs unless the road is billiard-table smooth.  Unlike some open cars, there is absolutely no scuttle shake.

Only around 600 Series 4’s were built, and if you can find one, it will be expensive.  Like all Seven’s the asking price will depend on specification and condition, but you can expect to pay anything from £10,000 upwards.  Which begs the question, why choose a Lotus 7 Series 4?  Well, they are rare, which carries a little cachet.  They are fairly practical, but not a great deal more so than any other Seven.  The performance is very similar to any Lotus Seven that has the same mechanical specification as the S4 in question ~ meaning that it will accelerate with primeval savagery up to around 80 mph, when the box-kite aerodynamics take over.  Anything over 100 mph is fairly unlikely.

An S4 will not be as fast as a cycle-winged Caterham 7 with a similar engine.  Nor will it put down its power as well, or cope with the twisty bits as well as a De-Dion Caterham.

SNLPFMAlternatives to the S4 include another Lotus / Caterham 7, or any other Lotus, or Morgan, MGB, Triumph TR6, TVR, and among newer cars the Mazda MX-5 and Toyota MR2.  Personally, if I wanted a rare fibreglass sports car I might look for a Clan Crusader or even a Ginetta G15.

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