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Wheels

SB2237 has had a number of different sets of wheels during its lifetime, all 13″, as far as we have been able to learn.

In 1968 it had Elan wheels, suggesting that it may very well have been delivered with these. As can be seen from the picture, no hubcaps were fitted, and the tires were quite narrow.

Later, likely when used for racing, it was fitted with American Racing Libre wheels and wider tires – with the rear wheels being considerably wider than the front wheels. These were on the car when it was brought back to the UK, but they were unfortunately lost (as was the  steering wheel) previous to the restoration.

When restored in 1993, the car was fitted with a set of new Minilite style wheels.

Although the Minilites were nice period wheels, we have since sourced a set of Elan wheels and use these both with and without Lotus hubcaps.

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Roll bar

We are not sure whether our Seven had a roll bar when delivered. The one we have on the car was fitted when the car was restored in the 90es.

Besides the (debatable?) safety improvement of having one fitted, the roll bar is of course a topic for purists, as the look is more clean without and as most Lotus Sevens were not delivered with one.

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Rear wings

For a long time we had been contemplating switching to narrow rear wings from the somewhat wider wings that were on the car when we acquired it. Opinions differ as to whether the narrow rear wings are actually too narrow, even when using wheels and tires in line with original specifications.

A common ‘trick’ back in the 60es seems to be to simply cut away part of the rear wing edge, which can actually be seen on the 1968 picture of SB2237 with Elan wheels.

Having changed from wider Minilites to Elan wheels and also fitted narrower tires, the wider wings did look a bit odd.

So we decided to give the narrow wings a try. We sourced new wings from Redline and we are quite happy with the result.

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Standard 10 axle

The Standard 10 rear axle of the Lotus 7 Series 2 is probably the most controversial component of the car. Colin Chapman’s concept of a lightweight, live axle with a simple A-frame to provide longitudinal and lateral guidance gives a performance that is close to an independent suspension. The concept is brilliant, but its implementation is doubtful. Had the axle been suspended the way it was designed for, no doubt it would be capable of handling the most powerful Series 2 Sevens. However, Colin Chapman’s concept supports the axle in a manner it was never designed for, leading to frequent failures, even on the not so powerful cars. One problem is that the suspension introduces large torsional loads on the axle casing leading to cracks and oil spillage, and subsequently seizure of the differential. The addition of the Thesaurus plate helped that problem to some extent.

To make things worse, the concept introduced large local loads where the A-frame is attached to the lower part of the differential casing. This led to a crack in SB2237’s casing as far back as in 1968, according to a previous owner. The crack was braze welded and doesn’t seem to cause any problems.

We treasure our Standard 10 rear axle which has caused no trouble since we bought the car. We inherited a minor problem caused by bad shimming  of the half-axle making it difficult to fixate the left rear hub. This problem was solved by our Lotus mechanic.

With our engine and tire selection we do think that our Standard 10 rear axle will survive.

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Engine

We have learned from an early owner that SB2237 was originally delivered with a pre-crossflow engine with one Weber 40DCOE 2. During its life, the car has been equipped with a number of different engines, including Holbay and Cosworth racing trims.

Today, it is again equipped as when it was delivered, with a 1500 cc pre-crossflow engine and the single Weber mounted on the original Lotus alloy inlet manifold. The Lotus manifold was kindly provided by a previous owner.

The performance of the basic engine is moderate, 66 HP at 4600 rev/min. Therefore, the ports of our engine have been enlarged and the combustion chamber has been flowed moderately. Also, humps and edges in the inlet manifold have been smoothed out and the exhaust is 4-2-1. Most importantly, the engine is equipped with a GT cam.

With the 0.06″ overbore our data show a power output of some 80 HP at 5200 rpm. Not a high revving engine but an engine with good midrange torque.

With this setup up the car is lively and has no hesitation during acceleration.

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Steering wheel and instruments

The steering wheel was donated by Caterham Cars during restoration and we have been told it came off a Lotus in the Caterham historic collection. The wheel was custom built for Lotus by Moto-Lita probably in the 50es. We would be most interested in hearing from anyone who knows more about this steering wheel – including which car it came off.

When we bought the car the instruments were not original but would pass as period and the original lay-out of the dash had been kept. We have through the years changed the instruments to new (old) ones to original specification.

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Seats

With their leather trim and almost comfortable shape, the seats on SB2237 are far from original specification. Apart from their nice look and feel, as they were made by an upholsterer in Hong Kong they are a part of the car’s history.

As can be seen on the pictures, not only the seats, but also the dash, side panels and piping are black. Although this is somewhat unusual for an S2 it was how some of the late production S2s were delivered.