1963 Lotus 23B

The Colin Chapman designed Lotus 23B sports racing car was introduced in 1962 and would achieve such a high level of competition success that the French ACO banned it from appearing at Le Mans, knowing that no other car in its class would have the capability to keep pace. The small-capacity racer was successful in national and International sports-racing car competition not only in the British home market but also virtually throughout the countries of Europe, the USA, Canada, South Africa, Australia and New Zealand. It became one of the Lotus marque's biggest-selling pure-bred racing cars and was the last small-capacity pure-bred sports-racing car to be designed from the ground up by Colin Chapman and his team.

The 1100cc Lotus 23 sports-racing car was a rear-engined derivative of the 1960/61 big-engined Lotus Type 19 and the rear-engined single-seater Lotus 20/21/22 designs of 1961-62. It was introduced in 1962 at the London Racing Car Show and although it was intended essentially as a 1,100cc class contender, up-to-1,000cc engines were another option. Alternative engines were soon fitted, as small as a 745cc Coventry Climax unit in one chassis intended to run at Le Mans but was denied entry. French scrutineers rejected the 997cc Lotus 23 and the 745cc version due to the front wheels having four-stud fixings and the rears used a six-stud setup. Rules stipulated that the statutory spare wheel should fit both front and rear. In response, Chapman had the rear fixing modified to accept four studs only and so match the fronts. Scrutineers ruled out that ploy on the basis that if six studs were required in the original design, the Lotus would be plainly unsafe on only four. Thus, Chapman was forced to withdraw the two 23s, vowing that his Lotus team would never race at Le Mans again. Until his death in 1982, Lotus did not race again at Le Mans, and even then, the factory did not return again until 1997.

Early in the 1962 season, Lotus developed its own twin-cam headed version of the Ford engine, which emerged as a 1,498cc unit. A works Type 23 fitted with one of these engines was driven by Jim Cark in the ADAC 1,000Kms World Championship round at the Nürburgring. His small sports racer outpaced the entire field, including the works Ferrari team and Lightweight E-Type Jaguars. He opened up a 27-second lead over the Porsche piloted by Dan Gurney. Clark would surely have won had he not been overcome by fumes from a broken exhaust pipe, losing control of the car and crashing mildly.

The Lotus 23 was most commonly fitted with engine capacities of 1100cc while the Lotus 23B received Lotus-Ford twin-cam power of 1600cc (1,558cc) displacement. To cope with the increase in power, many components including the frame were strengthened. Thus, the Lotus 23 and 23B were suitable for racing categories at everything from the modest club to the most major International level raced throughout the UK, Europe, the Americas, Southern Africa, and Australia - from the 1-liter, 1,100cc, and 1,600cc racing categories.

By the time production ceased in 1964, a total of 130 to 131 were produced in standard 23, 23B and 23C form.

Specifications
Since these sports racers competed in a variety of races on numerous types of tracks, the specifications vary. Early cars were powered by a 1097cc Cosworth-Ford engine allied to a Renault four-speed gearbox. Typical configurations included an independent suspension with coil springs and anti-roll bars, four-wheel disc brakes, and a five-speed Hewland Mark IV transaxle. The multi-tubular spaceframe chassis used the main longitudinal members to act as oil/water conduits between the nose-located radiators and mid-mounted engine The wheelbase measured 90-inches. The Lotus-Ford 1558cc 'Twin Cam' dual overhead camshaft four-cylinder engine fitted with dual twin-choke Weber DCOE carburetors produced approximately 190 horsepower.

The Lotus 23 was aerodynamically sound and its lightweight bodywork housed a sparse cockpit featuring the semi-recumbent driving position then growing in popularity.

by Daniel Vaughan | Jan 2022