Caterham 7 Buying Guide
The United Kingdom has always been home to some of the best sports cars the world has ever seen. But one, in particular, has a long history bringing it to what it is today, the Caterham 7. Colin Chapman, Lotus founder engineer, and inventor, designed the Lotus MK1 in 1948. He built it from an Austin Seven while still a student at University College London.
He would then enter private races, and when he won, he designed and built the Lotus MK2. He then made the Lotus MK3 in 1951, which he would take on road races still on the Austin 7 chassis required to pass requirements. The MK3 had a more powerful engine and lighter chassis. Through its success, Chapman went on to design the Lotus MKVI, which was Lotus’ first production car.
The Lotus used a 1172cc engine in the MKVI, but the engine bay had mounting points for several engines. Thus, customers could purchase it without an engine and put in an engine of their choice, provided it fit the factory mounts. Only 110 units were built, and the Lotus Seven was unveiled in 1957 to replace the Lotus MKVI.
The name Lotus Seven came from the first car Chapman had built, the MK1 from the Austin Seven. Chapman designed the Lotus Seven based on the Lotus Eleven and used the same 1172cc engine from the MKVI. There were chances of failure when producing the Lotus Eleven due to a shortage of funds as Lotus directed most funds to prep the Lotus Eleven for Le mans.
Lotus Produced the Lotus Seven until 1973 and sold it through dealerships across the UK, one of which is Caterham, established by Graham Nearn in 1959. Graham noticed a decline in Lotus sales and decided to approach Chapman with an offer. Lotus had tried several measures to lower manufacturing costs but failed.
After Lotus sold manufacturing rights to Graham, Caterham Cars was founded as an automobile private limited company in 1973 and set out to make the Caterham 7 their first official production car. Graham loved the Lotus Seven but, as an engineer himself, had some ideas to improve it.
Graham turned the Caterham 7 into one of the most loved British sports cars. It was common on race tracks and town roads as it was safer to drive and more thrilling than the Lotus Seven. The Caterham 7 has been produced in different variants with various engine options, such as the Super Seven SV, built for taller drivers who like more interior space and a little comfort.
Since the Caterham 7’s design is easy to replicate, companies such as Australia-based Elfin and Fraser in New Zealand have made their versions of the Seven. Caterham has tried fighting infringement issues with some manufacturers, such as Birkin, who made the Birkin Seven but failed. However, this did not deter their progress, as they are still making the Caterham 7.
Models and Specifications
1957-1960 Lotus Seven (S1)
Lotus unveiled the first Lotus Seven in 1957, which was available for purchase later that year. Like the Lotus VI, Chapman sold the Lotus Seven as a complete car. This is because it couldn’t be sold as a disassembled car, which would attract British purchase taxes imposed on disassembled cars. Since the purchase tax laws stated that a vehicle couldn’t be sold with assembly instructions, Lotus sold the Seven S1 with disassembly instructions for customers to customize their Sevens.
At the time of production, Lotus was also building the Lotus Eleven, so they used the same 1.2-liter engine from the Lotus VI to cut manufacturing costs. Early production units also used the same chassis as the Lotus Eleven, which is an advantage since it’s light as the Eleven was built mainly for racing. As a result, the Lotus Seven S1 has a slightly shorter nose than its predecessors, which have a different chassis.
Today’s standards might deem the engine underpowered, but according to Britain’s Motor Magazine, the Lotus Seven S1 could do 0-60 in under 6.5 seconds. Who even knew they measured 0-60 times in the 1950s? The Seven’s top speed is around 90mph, but good luck getting to 70mph if you’re driving one today.
However, customers in the United States didn’t find the Lotus Seven as fun to drive and quick as customers in Britain. For this reason, they swapped out the Ford 1.2-liter engine and replaced it with a 948cc BMC engine. It had only three horsepower more than the Ford engine, which made 40 horsepower, but it was the only preferred engine by American customers.
1961-1967 Lotus Seven (S2)
In 1961 Lotus introduced the Seven Series 2 with a Cosworth-tuned 1.3-liter Ford engine and a new lighter chassis. This meant an increase in performance which most customers wanted. Two more Cosworth-tuned Ford engines were introduced in later production years, a 1.5-liter and 1.6-liter engine used in the Lotus Seven 1500 and Lotus Super Seven.
A new 4-speed manual transmission was introduced for all Seven S2s with Cosworth-tuned ford engines to handle the extra power. Lotus also increased the Fuel tank size, and since it was mounted at the back, the battery was moved to the front for a better weight ratio. The increased nose size also enabled the battery to fit at the front.
However, introducing a lighter chassis with fewer tubes to lower manufacturing costs wasn’t enough. The Lotus Seven S2 has a fiberglass front nose cone, replacing the more expensive aluminum one on the S1. Early Lotus S2 model years also had all-around drum brakes, which Lotus replaced with front disc brakes after increased sales.
Lowering the manufacturing costs enabled Lotus to make profits without reducing the car’s market price to make more sales. A cheaper Seven S2 was made available with the 1.2-liter engine from the Seven S1 mated to a 3-speed manual transmission to keep customers happy.
1968-1969 Lotus Seven (S3)
For the third generation, Lotus replaced the De Dion rear suspension with a broader Ford Triumph-sourced rear axle; thus, the Seven S3 is wider than the S2. The new suspension was heavier, but it had to be changed as the old one was prone to breaking, especially on track-driven Sevens.
The spare tire had to be removed to balance the weight. But, on the upside, you can get a Seven S3 with a retractable roof and detachable doors, unavailable in the S1 and S2.
Lotus had developed a relationship with ford; thus, the production costs of the Seven S3 were lower than its predecessors. Ford provided the rear suspension and a 1.6-liter Crossflow engine, making 85 horsepower. The engine, combined with the lightweight chassis, made the Lotus Seven S3 one of the quickest cars in the UK at the production time.
But some customers expected more from the Lotus Seven and were willing to pay more. For that reason, Lotus slapped the 1.5-liter Twin Cam engine from the Lotus Elan into a Lotus Seven S4. Only 13 units were fitted with this engine and were sold as the Lotus Seven Twin Cam SS. The 1.5-liter engine made 125 horsepower, and given that the Seven S4 was light and nimble, it was quicker than the Elan and did 0-60 in just over 6 seconds.
1970-1973 Lotus Seven (S4)
By 1970, Lotus had moved away from using aluminum and steel body panels due to the improvement of fiberglass construction technology when making the Lotus Elan, among other production vehicles. Thus, when they unveiled the Lotus Seven S4, it had a fiberglass unibody with curved lines. Therefore, it was lighter than its predecessors. The front grill is also boxier due to Lotus’ attempts to make the Seven more appealing to the 1970s era.
Lotus still used several ford components, including the 4-speed manual transmission and the rear axle. They also still used the Ford 1.3-liter engine. But customers preferred the 1.5-liter and 1.7-liter engines as they made more power.
To reduce weight, Lotus sold the Seven S4 with steel alloy wheels, which were lightweight and looked better than the steel wheels used in previous generations. They are also easier to maintain as they don’t need much polishing, which comes in handy for owners who love showing off at car shows.
Customers could get the Lotus S4 with comfort options such as a radio, windscreen washers, seat belts, and AC which only had a heating option as it drew hot air from the engine. It was also the first time the Lotus Seven was sold with framed doors and a roll cage to hold the roof. The roll cage wasn’t effective in terms of safety, but at least it had the doors, windows, and a soft top for long-distance trips, which were slowly becoming a culture in the 1970s.
In 1972 Chapman decided that Lotus would no longer make “kit cars” and should instead focus on high-end sports cars for a more exclusive audience. Lotus then made the Espirit concept and unveiled it at the 1972 Geneva Motor show. Production of the Lotus Seven S4 ended in 1973, and Lotus sold copyrights to two companies, Caterham based in Britain and Steel Brothers in New Zealand.
The Steel Brothers attempted to make the Lotus Seven for the American Market, but their business partner, who was to import the cars to the United States, ran out of funds. They only managed to make approximately 51 units, all of which carried the Lotus badge. On the other hand, Caterham was successful in the early stages of manufacturing the Seven even after the S3 and S4 shells provided to them by Lotus got depleted.
1973-Present Caterham 7
The first changes Caterham undertook on the Seven included eliminating the front wings and re-introducing the De Dion rear suspension. Graham believed that downforce was better than lift which Chapman believed in, thus removing the front wings and replacing them with bicycle-like mudguards. He also knew that the De Dion rear suspension handled better than the Ford rear axle and was prone to premature wear and tear; thus, it was revised before being used on the Caterham 7.
Production of the Seven kicked off by first using Lotus Seven S3 and S4 shells, and Caterham still retained the “Seven” name, which they still use to date. Engines used in the early years of production include 1.3-liter and 1.6-liter Ford Crossflow engines and the 1.5-liter Lotus Twin Cam engine used in Series three.
Unlike Lotus, Caterham didn’t produce the Seven in any specific generational order. Still, some models, such as the Sprint, Supersprint, GT series, BDR, Superlight, and Roadsport, were produced more frequently than others.
The Sprint, Supersprint, and GT series have the 1.3-liter and 1.6-liter Ford Crossflow engines, but the 1700 Supersprint has a 1.7-liter Caterham-tuned Crossflow engine built from the 1.6-liter engine. Most early production Caterham 7 were identified according to their engines. For example, the Seven 1600 Sprint, 1600 GT, and 1300 GT.
Cosworth developed specific engines for the Caterham 7, which Ford provided. These were used in the Caterham 71600 BDR, 1700 BDR, and HPC (High Performance Club) 1700, which were track-focused cars. The HPC 1700 was the first Seven to have an LSD; thus, it was more expensive than any other Seven and required a special performance driving test for any interested customer.
The Caterham 7 Superlight was designed for drivers who preferred spending most of their time at the track and thus stripped of all unnecessary weight. Depending on the year of manufacture, you get the Superlight with a Rover K-series, Cosworth/Caterham Ford Duratec, or a Ford Sigma engine. On the other hand, the Roadsport is designed for comfort but has similar engine options to the Superlight.
Caterham has also used motorcycle engines such as the Honda Blackbird, Suzuki Hayabusa, and Honda Fireblade engines used in units made in the early 2000s. However, they are some of the rarest Caterham 7 produced, as production didn’t reach 30 units for each model.
Currently, Caterham offers nine variants of the Caterham 7. Base models, the Caterham Seven 170 and Seven 600 have a 660cc turbocharged Suzuki Kei engine, while the rest have Ford Duratec and Sigma engines tuned to different power levels. The Caterham Seven 620 is the most powerful, with a 2.0-liter turbocharged Ford Duratec engine that makes approximately 310 horsepower.
Which Seven Should You Buy?
The Lotus Seven is an iconic car that many would love to have in their garage, and thanks to it, we got the Caterham 7, a blistering quick sports car capable of shaming supercars and high-end sports cars. You can get one for a fraction of what most sports cars and supercars are worth. It’s desirable to have both, but if you only have the opportunity of buying one, which one should you go for?
If performance is a non-issue for you, get the Lotus Seven but don’t let its age fool you that it’s an old grandpa’s roadster with a loud exhaust and Polished aluminum panels and wheels just for the looks. The Lotus Seven is no slouch, but it’s not quicker than the Caterham 7, which is more refined. Buying one guarantees fun weekend drives on back roads, and with some engine restoration and tuning, a Lotus Seven is just as quick as it was when new.
The only significant downsides with the Lotus Seven are that there’s no engine cooling and an inefficient braking system. This is a characteristic of most sports cars from the 1950s and 1960s, but you’ll need better brakes and engine cooling measures when doing long drives or track weekends. Also, enthusiastic drivers might not enjoy the 3-speed manual transmission, but some units have a 4-speed manual transmission which is more engaging.
When Caterham obtained the rights to manufacture the Seven, they set out to make it better than Lotus. Of course, there’s no difference between the early model years Caterham 7 and the Lotus Seven Since Caterham used Lotus Seven shells and the same engines that Lotus used on the Seven. But later model years are quicker, handle better, and at least have some load space.
Constant years of production have enabled Caterham to make one of the best sports cars in the motoring world, with one model year being better than the previous. There’s a wide range to choose from depending on your favorite engine option, among other preferences.
Due to rarity, the Lotus Seven is more highly-priced than some Caterham 7 Models, including brand new ones. For example, a 1961 Lotus Super Seven with 4-speed manual transmission costs just as much as a brand-new Caterham 7 170 with the 660cc turbocharged Suzuki Kei engine, which outperforms the Lotus. Both are solid sports cars, but you get a little more grunt with the Caterham 7.
Some might say that new cars are boring, but the Caterham 7 is the opposite. It carries DNA from the original Lotus Seven and is everything the Lotus isn’t. If performance is a priority, get the more modern Caterham 7. The Lotus is enticing to own and only appeals to collectors and classic car enthusiasts. You’ll never find one being thrown around as much as a Caterham 7.
Due to production strains, Lotus had to discontinue the Lotus Seven in 1973. It was in Colin Chapman’s interest to focus on better sports cars such as the Lotus Eleven and Formula one Lotus cars and engines.
As per the Lotus Seven Register, Lotus built 1959 Lotus Seve units between September 1957 and August 1973.
No, the Lotus Seven was built by Lotus from 1957 to 1973, and Caterham took over production from September 1973, and the Seven is still under production by Caterham.
There’s no notable difference between the Lotus Seven and the early production Caterham Sevens. However, the Caterham Seven has Bicycle mudguards, and the tail lights are flush with the rear bumper, unlike the Lotus Seven, which has front wings, and the taillights protrude from the rear bumper.
The only way to buy a Caterham Seven in the United States is by buying an imported and assembled car. United States laws prohibit the importation of kit cars such as the Caterham Seven if fully assembled.
In 1973 Caterham, owned by Graham Nearn, bought manufacturing rights from Lotus’ owner Colin Chapman, who originally designed the Lotus Seven.