SB2237 is a Lotus Seven Series 2, vintage 1967, first registered in Dudley UK in the beginning of 1968. Today it lives in Copenhagen, Denmark. It has had various engines during its life but now is equipped with a pre-crossflow 1500 cc engine with one Weber 40DCOE 2 as when it was delivered. It has the original braced Standard 10 rear axle and the standard Ford 4-speed gearbox.
We bought the car in 2005 and have continuously amended and updated it in order for it to be close to original specification while respecting its history and – within this framework – a fast and enjoyable Seven. We have established most of the car’s history and in the process have been in contact with a number of very helpful people with knowledge of the car, including Lotus Cars, the Lotus Seven registrar, previous owners, and other Lotus enthusiasts.
This site is about how we have gone about this. We hope you find the site of interest, and we welcome any help, input and exchange of views.
Please also feel free to visit our list of what we have found to be useful Seven links or send us a mail at lotus-seven(at)paetsch.dk if you have any comments or questions.
We had been considering switching tires as our 145/80 tires looked somewhat small. The Seven Series 2 was delivered with 520 x 13 tires, with a width of 14 cm and a diameter of approximately 58 cm. Our 145/80’s were not too far off regarding width but had a diameter of only approximately 56 cm, even with their relatively high 80 profile. Our narrow wings leave very little space for larger tires but we decided to give a set of 155’s a go. We had been quite happy with our Uniroyal RainExpert tires but stumbled on a set of Retro Classics that have a very contemporary look. The diameter of the 155/80’s is approximately 58 cm and they fit nicely within the narrow wings.
Since 1996 the Copenhagen Historic Grand Prix has been held in early August in the centre of Copenhagen. We have been attending the event when possible since 2006.
It’s a great weekend of historic racing with lots of Loti (no Sevens, but Cortinas, Elans and 23s as well as the occasional Elite) and other beautiful classic cars in a great blend of skilled amateurs and famous professional race drivers.
The event sports lots of related activities for classic car enthusiasts, including the classic car park, where more cautious classic car owners (like ourselves) can meet. With quite a number of Lotus Sevens living in Denmark, usually the classic car park sees quite a few of them.
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.
Finally, we have fitted both 145/80 and 155/80 tires. Although the width of the 145’s is probably close to the width of the tires that were on the car when it was delivered back in the 1967, they did look a bit small, which is why we increased the tire size slightly. Wider tires than the 155’s might not fit inside the narrow rear wings – and the Standard 10 axle is probably better off with as little grip as possible.
We are not sure whether our Seven had an anti 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 anti 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.
We’ve been asked why we bought it and are at a loss for an answer, except that we had one many years ago and were missing it. “Car and Driver” already in 1964 perhaps stated it best:
“A Land Rover is at once a delightful runabout and a rolling torture chamber. It combines the best and worst features of a truck with the insouciance of an MG-TC. It is a car that every man feels compelled to buy at one time or another, but hardly anybody has a use for. It is best suited to off-the-road cross-country adventure. Conversely it is not specifically useful for shopping trips, or general family-household use, but that’s what people do with it. This is one of several instances where perfectly reasonable people have seemed to take leave of their senses on first meeting the Land Rover. It is less of a car than a state of mind.”
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.
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, also 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. However, if we should ever think of reinforcing the axle, we are much impressed by the Standard 10 axles that Chris Beebe builds. Due to the requirements of the racing rules in the US it has been mandatory to use the original axle. Chris Beebe’s approach to support the torsional loads and relieving the loads of the A-frame attachment is very appealing and, most importantly, has proved its worth in practice.
Some critics may question the originality of the reinforced axle, though.
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 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.