The Lotus 23 was designed by
Colin Chapman
Anthony Colin Bruce Chapman (19 May 1928 – 16 December 1982) was an English design engineer, inventor, and builder in the automotive industry, and founder of Lotus Cars.
In 1952 he founded the sports car company Lotus Cars. Chapman ...
as a small-displacement
sports racing car
Sports car racing is a form of motorsport road racing which utilises sports cars that have two seats and enclosed wheels. They may be purpose-built prototypes or grand tourers based on road-going models. Broadly speaking, sports car racing is o ...
. Nominally a two-seater, it was purpose-built for FIA Group 4 racing in 1962–1963. Unlike its predecessors
Lotus 15
The Lotus 15 is a front-engine sports racing car designed by Colin Chapman of Lotus, built from 1958 until 1960.
Series 1
The 15 is a two-seater, front-engine, rear wheel drive sports racer with an aluminium body over a space frame configuratio ...
and
17, the engine was mounted amidship behind the driver in the similar configuration developed on
Lotus 19
The Lotus 19 or Monte Carlo is a mid-engine sports-racing car designed by Colin Chapman of Lotus and built from 1960 until 1962.
Lotus 19
The 19 is a mid-engine, rear wheel drive sports racer with a fiberglass body over a space frame, original ...
.
The 23
To comply with FIA rules, it had a regulation trunk space to the right-rear of the driver, a windshield wiper, a horn, pairs of headlights and tail lights, rear center license plate light, a wire-operated emergency brake, and a mounting space for one spare tire under the front body. The 23 used a wider version of the
Lotus 22
The Lotus 22 was a racing car built by Lotus cars in 1962, and a total of 77 cars were built. It was developed from the 1962 Lotus 20, with the major differences that it had disc brakes all round, a top link and the 'rubber donut' to the rear su ...
space frame
In architecture and structural engineering, a space frame or space structure ( 3D truss) is a rigid, lightweight, truss-like structure constructed from interlocking struts in a geometric pattern. Space frames can be used to span large areas with ...
, clothed in a fibreglass body.
It was originally intended for engines of 750 cc to 1300 cc (45-80ci) with a Renault 4-speed transaxle, but had a 5-speed
Hewland Mk.III in production, which used the entire Volkswagen magnesium alloy transaxle case in upside-down configuration, housing bespoke straight-cut gears with dog-rings, and the Volkswagen differential gear set. Unlike the later Mk.IV/V, the Mk.III had the shifter rod at the end of the VW nose casing, so the shifting rod (pipe) from the centre shifter knob location extended to the tail end of the chassis. As this part was not completely covered by the bodywork, a following driver with good eyesight could tell when the 23 with Hewland Mk.III shifted gears.
The front suspension was a typical double wishbone arms with outboard coil/damper unit using the
Triumph
The Roman triumph (Latin triumphus) was a celebration for a victorious military commander in ancient Rome. For later imitations, in life or in art, see Trionfo. Numerous later uses of the term, up to the present, are derived directly or indirectl ...
upright made by
Alford & Alder,
Triumph Herald
The Triumph Herald is a small two-door car introduced by Standard-Triumph of Coventry in 1959 and made through to 1971. The body design was by the Italian stylist Giovanni Michelotti, and the car was offered in saloon, convertible, coupé, ...
rack and pinion steering, and outboard
Girling non-ventilated disc brake. The rear had the top link with lower reversed wishbone, top and bottom radius arms with the top arm at the height of the halfshaft, combined with the outboard disc brakes and coil/damper unit. Unlike the arrangement for
Lotus 20
Lotus 20 was a Formula Junior car built by Lotus for the 1961 season as a successor to the Lotus 18.
The chassis was a spaceframe, clothed in fibreglass bodywork. It had front double wishbone suspension, but the rear had a lower wishbone with ...
suspension, the halfshafts had Metalastic rubber 'doughnuts' on the inside, carrying no cornering (side) forces. The side forces are carried by the lower wishbone, together with the top 'I' arm link, which connects the tail end of the upper side tube in the frame with the extended top end of cast alloy upright.
The tie-rod end, front top and bottom wishbone outside joints were
ball joint
In an automobile, ball joints are spherical bearings that connect the control arms to the steering knuckles, and are used on virtually every automobile made. They bionically resemble the ball-and-socket joints found in most tetrapod animals. ...
s, and the rear lower wishbone inside joints were
Rose joint. The rest of the suspension joints were rubber joint, with joint-mounting pipes welded onto the ends of suspension arms. While most of the suspension arms were in common with Lotus 22, the angle of the rear radius arms on the plan view was different from the narrower-frame Lotus 22, so they were not interchangeable with the 22.
On the frame structure, the lower side pipes and the width-wise lower pipe behind the cockpit were rectangle tubes, with most of the other frame pipes being round steel tubes in various diameter. The upper left round pipe was used as the water feed pipe (the use of anti-freeze chemicals was prohibited by most of the race organisers at the time for the danger of making the
tarmac Tarmac may refer to:
Engineered surfaces
* Tarmacadam, a mainly historical tar-based material for macadamising road surfaces, patented in 1902
* Asphalt concrete, a macadamising material using asphalt instead of tar which has largely superseded ta ...
slippery) for the radiator up front, and the lower right side pipe and a half of the width-wise lower rear cockpit pipe were used as the return path. Likewise, the upper right side pipe was the oil feed to the oil cooler, and the lower left tube was the return. This frame was mostly made by Arch Motors, carrying 'AM' serial number.
This water/oil-bearing frame configuration was shared with
Lotus 22
The Lotus 22 was a racing car built by Lotus cars in 1962, and a total of 77 cars were built. It was developed from the 1962 Lotus 20, with the major differences that it had disc brakes all round, a top link and the 'rubber donut' to the rear su ...
and other later Lotus formula cars, but the combination of a wider and thus larger radiator, wider and bulkier steel frame acting as a cooling device, and the small displacement engines resulted in more than ample cooling capacity. Atypical of the contemporary racing cars, Lotus 23 models sometimes experienced an over-cooling problem when the thermostat was not installed in the coolant circuit in sprint races, and displayed a very stable water/oil temperature in endurance racing.
The 23B
The 23B in 1963 had the original center gear shifter relocated to the right side of the driver, and the radiator and oil cooler were combined into a single unit, with the lower 1/5 or so acting as the oil cooler. The frame received additional structural tubes to take the torque of
Lotus TwinCam
The Lotus-Ford Twin Cam is an inline-four petrol engine developed by Lotus for the 1962 Lotus Elan. A few early examples displaced 1.5 litres, but the majority were 1.55-litre (1557ml) engines. It used a Ford 116E iron cylinder block and a new ...
-based 1.6 litre
Cosworth Mk.XII and
Mk.XIII, mated to "high torque spec" 5-speed
Hewland Mk.V transaxle. Smaller displacement engines were mated to 5-speed
Hewland Mk.IV. Both the Mk.IV and Mk.V transaxles had
GKN
GKN Ltd is a British multinational automotive and aerospace components business headquartered in Redditch, England. It is a long-running business known for many decades as Guest, Keen and Nettlefolds. It can trace its origins back to 1759 an ...
(
Ford Zephyr
The Ford Zephyr is an executive car manufactured by Ford of Britain from 1950 until 1972. The Zephyr and its luxury variants, the Ford Zodiac and Ford Executive, were the largest passenger cars in the British Ford range from 1950 until their r ...
) differential gears and a forward-facing selector rod on the right side in a bespoke (Hewland made) tail casing.
The intake funnels on the Weber carburetors on 23B (and the 23C) were housed in a "cold air box" which received fresh air from two oval holes cut out on the top side of the rear body behind the driver.
The 23C
The 23B proved to be very successful in being a "giant killer" often beating cars in larger classes, but the limited road adhesion due to the narrow tyre width became apparent as the shortcoming in running with the larger cars. The 23C was developed using much wider Formula Two tyres mounted on wider 6-stud, six-spoke magnesium wheels front and rear. The body received wing-extensions to cover the wider tyres, with the characteristic 23/23B rear wings (covering the top half of the wheels on the outside) cut-out to expose the entire tyre/wheel in the side view.
Lotus 23 proved a competitive, durable, and popular race car. These cars are still a mainstay of vintage racing in Europe and the United States today.
Including the 23B and 23C, about 130 examples were made in period, but the popularity of the model led to many additional cars assembled from replacement and reproduction parts. The current estimate on the total number ranges between 200 and 400 excluding
Xanthos
Xanthos ( Lycian: 𐊀𐊕𐊑𐊏𐊀 ''Arñna'', el, Ξάνθος, Latin: ''Xanthus'', Turkish: ''Ksantos'') was an ancient major city near present-day Kınık, Antalya Province, Turkey. The remains of Xanthos lie on a hill on the left ba ...
and
Noble
A noble is a member of the nobility.
Noble may also refer to:
Places Antarctica
* Noble Glacier, King George Island
* Noble Nunatak, Marie Byrd Land
* Noble Peak, Wiencke Island
* Noble Rocks, Graham Land
Australia
* Noble Island, Great B ...
.
Debut at the Nürburgring
The debut of the 23 was at the
''Nordschleife'' in May 1962. The tiny Lotus 23 with the newly developed
Cosworth Mk.X 1.5 litre based on the
Lotus TwinCam
The Lotus-Ford Twin Cam is an inline-four petrol engine developed by Lotus for the 1962 Lotus Elan. A few early examples displaced 1.5 litres, but the majority were 1.55-litre (1557ml) engines. It used a Ford 116E iron cylinder block and a new ...
engine shot away from the field of
Porsche
Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche (; see #Pronunciation, below), is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans, headquartered in Stuttgart, Baden-Württemberg, Germany ...
s,
Aston Martin
Aston Martin Lagonda Global Holdings PLC is an English manufacturer of luxury sports cars and grand tourers. Its predecessor was founded in 1913 by Lionel Martin and Robert Bamford. Steered from 1947 by David Brown, it became associated with ...
s and
Ferrari
Ferrari S.p.A. (; ) is an Italian luxury sports car manufacturer based in Maranello, Italy. Founded by Enzo Ferrari (1898–1988) in 1939 from the Alfa Romeo racing division as ''Auto Avio Costruzioni'', the company built its first car in ...
s with
Jim Clark
James Clark Jr. OBE (4 March 1936 – 7 April 1968) was a British Formula One racing driver from Scotland, who won two World Championships, in 1963 and 1965. A versatile driver, he competed in sports cars, touring cars and in the Indianapol ...
at the wheel in the rain. Even though some cars had four times the power of the Lotus, Clark was 27 seconds ahead of
Dan Gurney
Daniel Sexton Gurney (April 13, 1931 – January 14, 2018) was an American racing driver, race car constructor, and team owner who reached racing's highest levels starting in 1958. Gurney won races in the Formula One, Indy Car, NASCAR, Can-Am, ...
's Porsche after the first lap in the wet. Extending his lead on each lap until the track dried, Clark was overcome by exhaust fumes from a damaged exhaust manifold on lap 12 and crashed out.
Banned from Le Mans
With the sensational Nürburgring debut well publicised in the press, two 23s were entered at
Le Mans
Le Mans (, ) is a city in northwestern France on the Sarthe River where it meets the Huisne. Traditionally the capital of the province of Maine, it is now the capital of the Sarthe department and the seat of the Roman Catholic diocese of Le Man ...
in June 1962. One with a aluminium-block
DOHC
An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion c ...
Coventry Climax FWMC with drivers
Les Leston
Alfred Lazarus Fingleston (16 December 1920 – 13 May 2012), better known as Les Leston, or in full Leslie Leston, was a British racing driver, born in Bulwell, Nottinghamshire.
Early life
In his early life Leston was a successful drummer for ...
/
Tony Shelly
Anthony Lionel Shelly (2 February 1937 – 4 October 1998) was a racing driver from New Zealand. He competed in Formula One in , participating in 3 World Championship Grands Prix, and several non-Championship races. He scored no World Champi ...
, and another with one litre Iron block
pushrod
A valvetrain or valve train is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) ...
Cosworth Mk.III with drivers
Jim Clark
James Clark Jr. OBE (4 March 1936 – 7 April 1968) was a British Formula One racing driver from Scotland, who won two World Championships, in 1963 and 1965. A versatile driver, he competed in sports cars, touring cars and in the Indianapol ...
/
Trevor Taylor.
The 23s failed to pass the scrutineering on several technical grounds, including an insufficient windscreen height, fuel tank capacity being too large, turning circle too large, ground clearance too small, and the spare tyre requirement not met.
[Setright, p.1230-1, says Chapman refused to have the 23 carry two different spare wheels, and after producing the four-bolt rear hubs, ]scrutineer
A scrutineer (also called a poll-watcher or a challenger in the United States) is a person who observes any process which requires rigorous oversight. Scrutineers have the tasks of preventing the occurrence of corruption and of detecting genuine ...
s proclaimed the cars dangerous. Fitted with a makeshift tall wind screen, all but the spare tyre issue was rectified almost immediately.
The original 23 and the later 23B had 4 stud front and 6 stud rear
wobbly-web wheel
The wobbly-web wheel is a form of metal disc wheel where the disc is 'wobbled' into spokes. This provides a stiffer, lightweight wheel.
Wobbly-web wheels are best known through their iconic use on Lotus racing cars of the late 1950s and 1960s.
...
s, and carried the narrower and lighter front wheel with its tyre mounted as the spare. (23C had wider 6 stud front and rear wheels.)
The French scrutineers argued the requirement to carry a spare tyre is for the purpose of changing a flat, which is not satisfied by the 23 in the case of a flat occurring on one of the rear tyres. So the Lotus factory had a 4 stud rear hubs drafted and machined over-night, and had a person carry them and flown to Le Mans the next day. After being presented with the 23s with 4 stud rears installed, the scrutineers rejected again on the grounds that the 6 stud configuration must have been a reflection of strength requirement in the original design, so the 4 stud configuration was deemed unsafe. This is a rare of Les Leston Lotus 23 with tall windscreen and 4 stud rear hub.
The scrutineers and the
ACO did not change this position even after
Mike Costin
Michael Charles Costin (born 10 July 1929, in Hendon) was, together with Keith Duckworth, the co-founder of Cosworth Engineering, a producer of Ford-funded and sponsored engines. Drivers including Graham Hill, Jackie Stewart, Jochen Rindt, Emerso ...
, the Lotus engineer on site, offered to go over structural analysis calculations showing the difference falls within the safety margin built in the design to accommodate more powerful
Cosworth Mk.IV and
Cosworth Mk.VII engines.
One of the two Lotus 23s with 4 stud rears, with Cosworth Mk.III engine, was sold off ''sans'' engine on the spot to the 1 litre class winning driver of the event, with a lease on the engine and support contract attached, on a strict condition imposed by Chapman to keep the 4 stud configuration for longer than one racing season. The French driver/buyer,
:fr:Bernard Consten, not only obliged but won
Clermont-Ferrand 6 Hours and
1000 km of Montlhery that year with this 23 without breaking the studs, the hub, or the wheel.
Team Lotus
Team Lotus was the motorsport sister company of English sports car manufacturer Lotus Cars. The team ran cars in many motorsport categories including Formula One, Formula Two, Formula Ford, Formula Junior, IndyCar, and sports car racing. More ...
remained on the scene for the entire 1962 event supporting and winning the 1.3 litre GT class and the Index of Performance prize by a
Lotus Elite
The Lotus Elite name has been used for two production vehicles and one concept vehicle developed and manufactured by British automobile manufacturer Lotus Cars. The first generation Elite Type 14 was produced from 1957 until 1963 and the second ...
driven by
David Hobbs and
Frank Gardner. ACO officials then made the situation worse in admitting a mistake, offering a financial compensation for the 23 entries after the race. With pro-Lotus motoring journalist
Gérard Crombac
Gérard "Jabby" Crombac (7 March 1929, Zurich – 18 November 2005, Paris) was a Swiss auto-racing journalist and author.
Biography
In 1954 Crombac bought the Lotus Mark VI previously owned by Lotus founder Colin Chapman and began racing with th ...
(who reported the entire fiasco in a French publication, suggesting the
Ferrari
Ferrari S.p.A. (; ) is an Italian luxury sports car manufacturer based in Maranello, Italy. Founded by Enzo Ferrari (1898–1988) in 1939 from the Alfa Romeo racing division as ''Auto Avio Costruzioni'', the company built its first car in ...
246SP and 268SP had the same ground clearance issue, but were allowed to race unrectified after the Ferrari team threatened to withdraw the entire team) present as the interpreter in the meeting, Chapman suggested a figure which was too large for the officials to swallow. Upon being rejected, Chapman vowed "We will never race again at Le Mans!", a promise that Lotus kept until 1997, long after Chapman's death in 1982.
Chapman believed the fiasco was caused by the French contender for Index of Thermal Efficiency award,
René Bonnet
René Bonnet ( Vaumas, 27 December 1904 – 13 January 1983) was a French driver and automobile constructor.
Early life
The young René first learned about machines working with his father, a carpenter. By 1915, with most teachers conscripted, ...
. Gérard Crombac knew of a competitor to Bonnet,
Jean Rédélé
Jean Rédélé (17 May 1922, Dieppe, Seine-Maritime – 10 August 2007 Paris), was an automotive pioneer, pilot and founder of the French automotive brand Alpine.
With a HEC diploma, he was the youngest Renault dealer in France, with a dealershi ...
, who had a strong ambition to beat the then-dominant
Automobiles René Bonnet
Automobiles René Bonnet was a French automobile maker.
The firm was the continuation of Deutsch et Bonnet (DB) by René Bonnet when Charles Deutsch, the "D" in DB, founded his own firm CD. The business was based at Champigny-sur-Marne to the ...
in thermal efficiency at
Le Mans
Le Mans (, ) is a city in northwestern France on the Sarthe River where it meets the Huisne. Traditionally the capital of the province of Maine, it is now the capital of the Sarthe department and the seat of the Roman Catholic diocese of Le Man ...
, and gave the idea of helping
Alpine
Alpine may refer to any mountainous region. It may also refer to:
Places Europe
* Alps, a European mountain range
** Alpine states, which overlap with the European range
Australia
* Alpine, New South Wales, a Northern Village
* Alpine National Pa ...
instead of subsequent direct participation to Chapman. As a result, a 2-seater racing prototype was designed by a team of Lotus employees,
Len Terry
Leonard E. Terry (11 February 1924 – 25 August 2014) was an English racing car designer and engineer, known for his work with Team Lotus, Lotus, British Racing Motors, BRM and All American Racers, Eagle. He also designed chassis for many othe ...
,
Bob Dance and
Keith Duckworth
David Keith Duckworth (10 August 1933 – 18 December 2005) was an English mechanical engineer. He is most famous for designing the Cosworth DFV (Double Four Valve) engine, an engine that revolutionised the sport of Formula One.
Early life an ...
, based on Lotus 23.
This design was found to be non-compliant to the 1963 Le Mans regulations, so the frame structure was changed to a steel backbone design familiar to
Rédélé's team at Alpine, and became the
Alpine M63. M64 of 1964 had the original frame designed by Terry, and the French
Alpine M63 and M64 could fit British 6-stud
Wobbly Web wheels as a testament.
In
1964 Le Mans, Alpine won the Index of Thermal Efficiency with the M64 while setting a new distance record for the 1150cc Prototype class, with a M63B in the second place. Alpine went on to become the
Le Mans overall winner in 1978.
Restoration and replication of the Lotus 23
Beginning in the early 1980s a small group of enthusiasts began to make it possible to restore original Lotus 23 by remanufacturing parts. These parts are now easily available. It was at about this time that a Register was established for the Lotus 23. That Register is now part of the Historic Lotus Register of the UK. Some race organizers and the Historic Motor Sports Association began in 2007 to take steps to restrict race participation by replica cars.
There are several sources of replicas of Lotus 23 cars.
Xanthos 23
The Xanthos 23 (1999) is an exact reproduction of the 23B using the same frame design as the 1960s original. Powered by
Lotus-Ford Twin Cam
The Lotus-Ford Twin Cam is an inline-four petrol engine developed by Lotus for the 1962 Lotus Elan. A few early examples displaced 1.5 litres, but the majority were 1.55-litre (1557ml) engines. It used a Ford 116E iron cylinder block and a new ...
or its
Cosworth
Cosworth is a British automotive engineering company founded in London in 1958, specialising in high-performance internal combustion engines, powertrain, and electronics for automobile racing (motorsport) and mainstream automotive industrie ...
derivatives mostly mated to Hewland Mk.8 or Mk.9, it was built by Xanthos Sports Cars in Liverpool, a UK company owned by Lotus specialist Kelvin Jones. The company now seems to be Xanthos Cars North America, Inc.
Noble 23
Following the success of his
Ultima GTR
The Ultima GTR is a super car manufactured by Ultima Sports Ltd of Hinckley, Leicestershire, England, and described by commentators as a ''supercar''. The car was available both in kit form and as a "turnkey" (i.e. assembled by the factory) ve ...
project,
Lee Noble Lee Antony Noble is a British entrepreneur, car designer and engineer. He is the founder of the sports car companies Noble Automotive Ltd in 1999 and Fenix Automotive in 2009. He is also the designer of some low-volume sports cars, including the U ...
created a Lotus 23 replica in 1996 with a wider track than the original to allow for the use of wider tyres. With a lower level of adherence to the original design than the Xanthos, it proved successful in racing, with over 60 cars produced using either
Lotus TwinCam
The Lotus-Ford Twin Cam is an inline-four petrol engine developed by Lotus for the 1962 Lotus Elan. A few early examples displaced 1.5 litres, but the majority were 1.55-litre (1557ml) engines. It used a Ford 116E iron cylinder block and a new ...
or
Renault
Groupe Renault ( , , , also known as the Renault Group in English; legally Renault S.A.) is a French multinational automobile manufacturer established in 1899. The company produces a range of cars and vans, and in the past has manufactured ...
V6 engines. Noble's version continued in production, first by
Auriga Design
AURIGA (''Antenna Ultracriogenica Risonante per l'Indagine Gravitazionale Astronomica'') is an ultracryogenic resonant bar gravitational wave detector in Italy. It is at the Laboratori Nazionali di Legnaro of the Istituto Nazionale di Fisica Nuclea ...
using an
Alfa Romeo
Alfa Romeo Automobiles S.p.A. () is an Italian luxury car manufacturer and a subsidiary of Stellantis. The company was founded on 24 June 1910, in Milan, Italy. "Alfa" is an acronym of its founding name, "Anonima Lombarda Fabbrica Automobili." ...
engine and transaxle, and now as the C23 Lotus 23 replica by
Mamba Motorsport near Oxford, UK using
Ford
Ford commonly refers to:
* Ford Motor Company, an automobile manufacturer founded by Henry Ford
* Ford (crossing), a shallow crossing on a river
Ford may also refer to:
Ford Motor Company
* Henry Ford, founder of the Ford Motor Company
* Ford F ...
Duratec
Duratec is a brand name of the Ford Motor Company used for the company's range of gasoline-powered four-cylinder, five-cylinder and six-cylinder passenger car engines.
The original 1993 Duratec V6 engine was designed by Ford and Porsche. Ford ...
Engines.
LusoMotors LM23
The Portuguese LusoMotors kit-car company with João Matoso dynamics engineering support built a reinterpretation of the Lotus 23 (called LM23) which was shown at NEC 2009.
Tiger Racing ERA30
The UK Based Tiger Racing ERA 30 takes its design inspiration from the Lotus 23 although the car has been designed to be slightly larger with wider tyres and bigger brakes.
Notes
External links
Historic Lotus RegisterXanthosLusoMotors LM23 prototypeTiger Racing ERA30Mamba Motorsport
{{Lotus
23
Sports racing cars