Lotus engine series: –
Lady Godiva –The Naked Truth: Coventry Climax Revealed
“It’s such a neat simple engine and set the template for engine designs years later”
The engine series are neither technical treatise or Haynes Manuals on the engineering minutiae of the engines or how they can be overhauled etc. Important as it is, it’s better covered elsewhere [see references below] and is readily available in published form or on the net.
Rather our study concentrates on how and why Chapman and his colleagues’ selected engines and their contribution to Lotus success and sales.
In his choice of major mechanical components Chapman added both performance to a sophisticated chassis and extraordinary added value.
Lotus were not a major engine manufacturer until quite late on. Despite this they used and adopted a range of mainstream engines to extraordinary effect.
Chapman and Lotus practice provides inspiration for all Industrial Designers /Specialists in their search for urgency and added value.
Our study focuses heavily on the fitment of these engines along with a visual representation. We debate the appeal to owners / racers and the beneficial publicity accredited to the manufacturers.
We believe that subscribers will be well able from this base line to research specific topics according to their needs.
The contribution of Coventry Climax engines to Colin Chapman and Lotus is extremely significant .It’s probable that Chapman and his brand would not have achieved the competition success, sales and reputation they did, without Coventry Climax. Indeed their contribution to British motor sport was such that it in part galvanized the nation’s preeminence in motorsport in the period c 1955-1965.The legacy and catalyst effect continued far beyond this.
This article briefly:-
- Examines the engineering background of Coventry Climax and evaluates why they could produce successful racing engines
- Examines the Design priorities and objectives set by Coventry Climax
- Studies and provides illustrations of Coventry Climax applications in Lotus
- Debates the significance of successful independent component within a wider Industrial Design process
This article has a resonance with a wide audience including design engineers, historians [various branches not least the British specialist car industry], artists and Industrial/Product design professionals.
Subscribers might like to see related A&R pieces:-
- Individual dedicated articles on Lotus types using Coventry Climax engines [ see listing below] special reference Lotus Seven S1
- Lotus Power Plants
- Austin, MG engines
- Ford engine and derivatives
- Cosworth-Ford derivatives and DFV
- Bob Freeman-automotive art
Brands, Badges, Trademarks
The Coventry Climax font/script and Lady Godiva image in bass relief were proudly promoted on the cam covers of most engines, products and advertising material of Coventry Climax.
Lady Godiva is enshrined in Coventry folk law extending back to the middle ages when it’s claimed she rode naked through the city streets in an attempt to persuade her husband to reduce tax on the poor.
The Godiva image is memorable and is indelible with the brand.
Not only was the Coventry Climax engine very well engineered it was attractively presented .Form and function were harmonized.
When Chapman selected the Coventry Climax engine for the Elite it was inspired as there was a homogeneity and holistic relationship between the chassis and engine. They were totally complementary and brought an added value to the Elite.
Figure 2.Magazine advertisement, A&R collection
Coventry Climax brief history
We understand the company was started by H.P.Lee in 1903.Circa 1917 it was known as Coventry Climax.They were primarily an independent engine manufacturer [see list of customers below].
Other engines they made included:-
- Military including those for gun turrets
- Diesel engines
- Power generators
- Units for small power plants –typically portable
From the wiki and net:-
“Coventry Climax ET 199 (1949 model)
In the late 1940s, the company shifted away from automobile engines and into other markets, including marine diesels, fire pumps, and forklift trucks. In 1946, the ET199 was announced, which the company claimed was the first British-produced forklift truck. The ET199 was designed to carry a 4,000 lb. (1,800 kg) load with a 24-inch (610 mm) load centre, and with a 9 ft. (2.7 m) lift height.
In 1950, Harry Mundy (previously of Alvis, ERA, Morris and BRM) and Walter Hassan (previously employed by Bentley, ERA and Jaguar) joined Coventry Climax, and a new lightweight all-aluminium overhead camshaft engine was developed in response to the government’s ambitious requisition outline asking for a portable fire pump that is capable of pumping double the amount of water specified in the previous outline, with half the weight.
This was designated the FW, for “Feather Weight”. The engine was displayed at the Motor Show in London and attracted attention from the motor racing fraternity for its very high “Horsepower per Pound of weight“. With strong persuasions at the Show including those by Cyril Kieft (who had Stirling Moss as a F3 driver) and a young Colin Chapman, Lee concluded that success in competition could lead to more customers for the company and so the team designed the FWA, a Feather Weight engine for ‘A’utomobiles.
Kieft 1100 at 1954 24 Hours of Le Mans
The first Coventry Climax racing engine appeared at the 1954 24 Hours of Le Mans in the front of one of two Kieft 1100 sports racers, but both cars (one with a MG engine) failed to finish the race for problems unrelated to engine. The FWA became popular in sports car racing and was followed by Mark II and then by the FWB which had a capacity of nearly 1.5-litres. The new Formula Two regulations suited the 1.5-litre engine and it quickly became the engine to have in F2 racing. The following year, the first Climax engines began to appear in Formula One in the back of Cooper chassis.
Initially, these were FWBs but the FPF engine followed. Stirling Moss scored the company’s first Formula One victory in Argentina in 1958, using a 2-litre version of the engine. In general terms, however, the engines were not powerful enough to compete with the 2.5-litre machinery and it was not until the 2.5-litre version of the FPF arrived in 1959 that Jack Brabham was able to win the World Championship in a Cooper-Climax. At the same time, the company produced the FWE engine for Lotus Elite and this enjoyed considerable success in sports car racing, with a series of class wins at the Le Mans event in the early 1960s.
In 1961, there was a new 1.5-litre formula and the FPF engine was given a new lease of life, although the company began work on a V8 engine, designated the FWMV, and this began winning races in 1962 with Jim Clark. There would be a total of 22 Grand Prix victories before 1966 with crossplane, flatplane, 2 valve and 4 valve versions of FWMV. When the new 3-litre formula was introduced, Coventry Climax decided not to build engines for the new formula, withdrew from racing after the disastrous FWMW project, with the exception of the new 2-Litre version of FWMV.
Also in the early 1960s, Coventry Climax was approached by Rootes to mass-produce FWMA for use in a compact family car project called Apex with all aluminium alloy over head cam engine combined with full-syncromesh aluminium transaxle. This combination was considered very radical at the time, especially the syncromesh on all forward gears had been declared ‘impossible’ by Alec Issigonis of the BMC Mini fame. The adoption to mass-production was successful, and the project came out to the market as 875cc Hillman Imp totaling over 400,000 units made by 1976 including the later 998cc version.”
Standard Engine Data
Mass production engines of the era are compared in data below:-
The editor’s belief that much of the success of the Climax engines was rooted in the experience the engineers; gained through practical experience and feedback; the functions/customers; and the product served.
The fire pumps and military equipment was used in the defense of the nation linked to the protection of the emergency services, civilians and property. Integrity was required in use and Coventry Climax delivered. Performance in these circumstances required a deep appreciation of the internal stresses and strains applied to the engine.It required a full understanding of metallurgy supported by precautionary design construction techniques.
Reading Hammill the editors became aware of the extensive testing that Coventry
Climax undertook; one instance suggests 1800 hours nonstop.
When the company tendered for a Government contract for high performance pump engine they brought together the experience outlined. Furthermore this was reinforced by some of the best engineers of the era [see below].
The size of the contract [volumes], the additional potential in other areas leading to financial security etc. encouraged the combination of brains and product planning. The totality of events suggested a fresh start, clean page concept be pursued.
This resulted in the extremely functional fire pump design of the early 1950 that exceeded specification particularly with regard to light weight [almost half of the specified ceiling]
Coventry Climax Engineering Personnel
Perhaps what made Coventry Climax so exceptional was the concentrations of engineering skill that collacesed in the company during the 1950’s.
Leonard Lee must be considered a very inspired owner in that he permitted the development of the racing engines and went to some length to make them affordable; possibly using a degree of cross subsidy. Although the glamour of the FI achievement reflected on selling the more utility products.
It can be understood that the decision to leave FI was justified [Hammill developes the case]
The engineering design would not have resulted in success without the skill base of the artisan/craftsmen employed.Hammill lists these by name; here we abbreviate to the occupational categories.
Hammill lists these at length and identifies those in the various activities including:-
- Draughtsman [various levels/specialisms]
- Engine fitters[ditto]
- Cylinder heads
- Engine testing
- Tool room machinist
Of course he pays special attention to:-
- Walter Hassan -[Chief Engineer &Technical Director]
- Harry Munday-Chief Designer
- Leonard Lee-Managing Director of Coventry Climax
Quoted in “The Coventry Climax Racing Engine 1961-65” [see Unique Books]
“modern GP circuits vary considerably , some placing a premium upon acceleration ,others upon maximum speed ,however , if the use of engine performance is studied relative to the various circuits ,it is evident that the time during which the car operates at maximum rpm and power is extremely small compared with the time spent accelerating in order to reach its maximum only to commence braking for the next bend .the most successful engine is therefore the one which combines a good maximum power with exceptional torque spread over at least 2,500 rpm or better still 3,500 rpm .under these conditions the driver will have far less fatiquing time ,because gear changing will become less exacting and he will have more time to deal with the actual driving of the car , that is steering , braking and the like …………..
It has been our policy to produce engines possessing good torque characteristics in the middle speed range .to achieve this it is impossible if valves and ports of unlimited size are used in order to achieve the highest maximum power regardless of other requirements……………..
The design was deliberately simple and aimed at trouble free manufacture in extremely small quantities .a total of 20 engines was envisaged, and therefore “tooling up” was out of the question”
The Coventry Climax engine was designed and built deliberately to be:-
- High power to weight ratio
Design Follow –up: Maintenance
“because of the level of sophistication of the FMMV engines, the maintenance schedule was all new .no engine parts were made available to owners, as was the case with all previous racing engines .instead these engines could only be maintained by Coventry Climax at Widdrington Road, and they had to be maintained as the company prescribed .Coventry Climax ran a very strict inspection schedule on all of its FWMV Grand Prix engines as part of the deal…………
Each racing engine had to be returned to the factory after it had completed the pre –race practice sessions [that’s about four hours running ] ………in most instances ,very little was replaced ,it was more a question of constantly checking to see if anything had happened ………or if anything was slowly going wrong .the FWMV were all designed and built to be inspected regularly to guarantee absolute reliability as far as possible .there was nothing really “light” about the construction of these engines , and some parts were known to be slightly over built”
Lotus Applications: extracted from “Lotus Book”
Figure 4.Editors sketch of the Coventry Climax cam cover
Figure 5.A&R component used as basis for drawing [see chapter dealing with prominent trademark]
The Coventry Climax FWP &related engine costs
The editors have seen figures that suggest the smallest capacity Coventry Climax engines retailed for £250 in 1955 [Lotus racing Engines price list].In addition alluding to Lotus Seven authors have quoted £356 for engine [ note versus £499 basic kit]
John Cooper informs us that the Coventry Climax engine, all aluminium, 4 cylinder chain driven ohc of 1020cc with magneto ignition produced 35 bhp at 3.500 rpm and weighed 365 lbs.
He gives the dimensions as:-
Overall length with starter 47in.
“Lotus, Coventry Climax and Ford Cosworth Engines” includes some data that suggests the following prices applied:-
Base car engine £1,000
4 cylinder 2.5 L £2,250
1962 V8 FWMV, 1.5L £3,000
Figure 6.Editors sketch profile of the 4 cylinder Coventry Climax engine
Figure 7.Editors sketch of Coventry Climax engine used as display piece; below further sketch of Coventry Climax engine installed in Lotus Mk.VI
Coventry Climax FI Engines
From the net:-
The F1 engines were as follows (bore and stroke figures are unified in inches on Metric designs for comparison):
- “1954 FPE 2492cc V-8 2.95 x 2.78125″ 264 bhp (197 kW)@7900rpm Godiva
- 1956 FPF 1475cc 4 cyl 3.20 x 2.80″ 141 bhp (105 kW)@7300rpm for F2, ran in GP races
- 1957 FPF 1964cc 4 cyl 3.40 x 3.30″ 175 bhp (130 kW)@6500rpm
- 1958 FPF 2207cc 4 cyl 3.50 x 3.50″ power figures unknown
- 1958 FPF 2467cc 4 cyl 3.70 x 3.50″ 220 bhp (160 kW)@6500rpm
- 1960 FPF 2497cc 4 cyl 3.70 x 3.54″ 239 bhp (178 kW)@6750rpm
- 1961 FPF 2751cc 4 cyl 3.78 x 3.74″ Indianapolis and Formula Libre
- 1961 FPF Mk.II 1499.8cc 4 cyl 3.23 x 2.80″ 151 bhp (113 kW)@7500rpm
- 1961 FWMV Mk.I 1496cc V-8 2.48 x 2.36″ 181 bhp (135 kW)@8500rpm Crossplane crank
- 1962 FWMV Mk.II 1496cc V-8 2.48 x 2.36″ 186 bhp (139 kW)@8500rpm 1.35″ Intake, Crossplane
- 1963 FWMV Mk.III 1496cc V-8 2.675 x 2.03″ 195 bhp (145 kW)@9500rpm Fuel injection, Flatplane
- 1964 FWMV Mk.4 1499cc V-8 2.85 x 1.79″ 200 bhp (150 kW)@9750rpm 1.37″ Exhaust, Flatplane
- 1964 FWMV Mk.5 1499cc V-8 2.85 x 1.79″ 203 bhp (151 kW)@9750rpm 1.4″ Intake, Lotus
- 1965 FWMV Mk.6 1499cc V-8 2.85 x 1.79″ 212 bhp (158 kW)@10300rpm 4 valve/cyl, Lotus
- 1965 FWMV Mk.7 1499cc V-8 2.85 x 1.79″ 213 bhp (159 kW)@10500rpm 4 valve/cyl, 1.107″ Intake, Brabham
- 1966 FWMV Mk.8 1976cc V-8 2.85 x 2.36″ 244 bhp (182 kW)@8900rpm 2 valve/cyl, Lotus, Bonnier
- 1964 FWMW 1495cc F-16 2.13 x 1.60″ 209 bhp (156 kW)@12000rpm 2 valve/cyl”
There is an excellent cut away drawing of the later V8 Coventry Climax engine in “Grand Prix Motor Racing “ by Cimarosti who provides this caption to the drawing by Vic Berris:
“The V8 Coventry Climax was the most successful 1.5 litre Grand Prix motor. Cylinder dimensions were 62.9 x 57.4 mm -1496 cc] and power rose from 190 bhp to 213 bhp in the 32 valve version”
Figure 8.Editors sketch of FPF
Figure 9.Edotors etc. working drawing of FPF engine
Figure 10.Editors drawing of Coventry Climax engine in Lotus 16 note SU carburetters
Coventry Climax FPF –Lotus
Lotus used Coventry Climax engines extensively in their road, sports racing and FI cars.
The FPF was significant.
Figure 11.Editors rough sketch cross section
|Coventry Climax||FPF 1.5 -litre F2||FPF 2.5-litre Mk.”|
|Stroke/bore ratio||0.88 to1||0.96 to 1|
|Compression ratio||10 to 1||11.9 to 1|
|Piston area||207.22 cm2||277.7 cm2|
|Valves per cylinder||2||2|
|Carburetion||2 t/c Weber 40 DCO||2 t/c Weber58 DCO3|
|Max.bhp/rpm||143 @ 7250||243 @ 6750|
|Max.Torque lb/ft.||108.5 @ 6500||212 @ 5300|
|Bhp per litre||96.9||97.4|
|Fuel||100 oct. petrol||130 oct.AvGas|
Formula 1 cars of the 1.5 litre formula era 1961-1966
Statistics from Cimarosti
Figure 13.Editors sketch with basic cross section FWMV V8 engine
Some notable Coventry Climax-powered cars:
- 1911 GWK, 2 cyl. Coventry Simplex
- 1913 Bamford & Martin, 4 cyl. Coventry Simplex, The first Aston Martin
- 1922 Lea Francis C-Type, 1074cc OC
- 1929 AJS Nine, 1018cc OC
- 1930 Crossley 10, 1122cc OC
- 1933 Vale Special, 1098cc OC, 1476cc JM
- 1935 Triumph Gloria, 1087/1232cc OC, 1476/1991cc JM
- 1935 Crossley Regis, 1122cc OC, 1476 cc and 1640cc JM
- 1936 Morgan 4-4, 1122cc OC
- 1954 Kieft-Climax 1100 LeMans, 1098cc FWA
- 1954 Kieft-Climax V8, 2492cc FPE, not raced
- 1955 Cooper T39 Climax ‘Bobtail’, 1098cc FWA
- 1955-64 Cooper Monaco Mk.I(T49),Mk.II(T57/59),Mk.III(T61/62/64), 1475/1964/2203/2467/2751cc FPF
- 1956/7 Lotus Eleven, 1098cc FWA, 1460cc FWB, 744cc FWC
- 1957 Cooper T43 Climax, 1964cc FPF, The first mid-engine car to win a Grand Prix
- 1957-58 Lotus 12 Climax, 1475/1964/2203cc FPF
- 1957-63 Lotus Elite, 1216cc FWE, 742cc FWMC (UDT Laystall, 1961 Le Mans)
- 1958 TVR Grantura, 1216cc FWE
- 1958-60 Lotus 16 Climax, 1475/1964/2467/2495cc FPF
- 1959 Lotus 17, 1098cc FWA, 1460cc FWB, 742cc FWMA
- 1959 Cooper T51, 2467cc FPF, World Champion
- 1959-65 Turner Sports, 1098cc FWA, 1216cc FWE
- 1960-61 Lotus 18, 2495cc FPF, 1475cc FPF
- 1960 Cooper T53, 2495cc FPF, World Champion
- 1960-63 Lotus 19, 2467/2495/2751cc FPF
- 1961 Cooper T54, 2751cc FPF, The first mid-engine Indy car
- 1962-64 Lotus 23, 742cc FWMC, 748cc FWMB
- 1962-65 Lotus 25, 1496/1497cc FWMV, World Champion
- 1963–76 Hillman Imp, 875 – 998cc derivative of the FWMA, adapted by Rootes
- 1964-65 Brabham BT11, 1497cc FWMV
- 1965 Lotus 33, 1497cc FWMV, World Champion
- 1965–75 Bond 875 and Bond Ranger, low compression version of Imp engine
- 1967-74 Ginetta G15, 875cc Imp and 998cc Rally Imp engines
- 1971-74 Clan Crusader, 875cc Imp engine
Our learning /educational opportunities are intended to be challenging thought provoking and requiring additional research and/or analysis.
These opportunities are particularly designed for a museum/education centre location where visitors would be able to enjoy access to all the structured resources available in conjunction with any concurrent exhibition.
In this instance we suggest the following might be appropriate:-
- Identify engines used by Lotus [suggest use of Lotus Book &A&R articles]
- Evaluate /benchmark Coventry Climax in Lotus achievement
- Compare and Contrast CC FI engine with Ford Cosworth DFV
- What has been Coventry Climax contribution to British motor sport industry
Exhibitions, Education and Economics
In the museum context the editors believe that commercial considerations are both necessary and complementary with its educational objectives.
For these reasons our suggested outline Business Plan includes provision for promoting products and services which share Chapman’s ideals of mechanical efficiency and sustainability. In addition we propose merchandising that explain and interprets the social and cultural context of Chapman’s designs in period. It’s suggested there will be catalogue for on line purchasing.
In this instance we consider the following appropriate:-
- Lotus: Sent to Coventry
- Concentration in Coventry
- Cubic Capacity and Coventry Climax
- The Coventry Connection
- Fire Engines
- Coventry Climax Climatic
Coventry Climax Legacy
“Coventry Climax ushered in the principle of proprietary engines, doing away with the idea, that cars and engines are naturally the products of the same manufacturer’s .they won 96 major FI races of which 40 were World Championships GP”
Of course this was not totally original as since the dawn of the automobile “specials” have been built often around a mix of components. None the less if we refer to the tabulation of GP marques the significance is that specialist marques were able to compete on favourable terms with the top echelons of the sport.
Coventry Climax possibly helped paved the way for the Ford-Cosworth DFV and enabled fledgling specialist manufacturers, entrepreneurs enter FI level motorsport.
Engineers at Coventry Climax went on to design and built engines that later supported and extended the proprietary industry. Judd is an example.
Conclusion: “The whole is greater………”
The Coventry Climax engine powered the Lotus
It therefore powered racing and road cars.
It was a superb piece of industrial design ; functional and utilitarian .
It was successful in racing gaining publicity and inspired tuning and a generation chassis designers.
The engine was attractive to owners and generated sales. Exports were possible because of the international spare’s availability.
These relatively mass-produced engines were rather expensive but generally available. They invited chassis design experimentation, and helped facilitate competition and design diversification. Thus, assisting and elevating British motor racing: design, engineering, manufacture and of course drivers.
They contributed in various racing classes giving Lotus results in Le Mans and F1.
The engine has continuing legacy and relevance and being such a significant piece of industrial design is fully worthy of analysis and appreciation.
Added value is an extremely important of Industrial Design; Chapman exploited to maximum effect and its principles are significant for a young Entrepeneur’s with low capital wishing to enter the market.
Chapman’s design and manufacturing methodology rather confirms the adage that “the whole can be greater than the sum of the parts”.
It’s an interesting an important study to consider deployment of components. It contributes to aesthetics, assembly economics and sales [attractive components/ known accepted performance and servicing ability etc.]
It is equally and mutually relevant and beneficial to the component manufacturer.
Chapman and his colleagues often took the best / most appropriate mass produced item and almost reinvented it in its service to design objectives. In this manner many components acquired a new status and indeed their aesthetic was enhanced surrounded by the Chapman conceptual whole.
It’s also extremely significant how many of these components were also used in Lotus competition and road cars. This created a powerful dynamic and interrelationship. Many components:-
- Performed well in competition gaining beneficial publicity and sales
- Both the component and racing reputation carried through to road cars and assisted sales
- The component manufacturer gained disproportionate publicity and assisted products sell in other applications
- All together a beneficial spiral was commenced. Publicity of the era [see dedicated articles on each sponsor / manufacturer] often opted to highlight the Lotus dimension in publicity material. In fact there was a powerful synergy.
The engine is possibly the most complex and expensive item of a specialist component based marque. [Cost of design, patterns casting machining, assembly and componentry etc.] needed to be bought in volume. If it’s wrong the company is likely to fold.
Therefore the availability of the Coventry climax engine allowed Chapman and his peers [e.g. Cooper] to concentrate on chassis and performance development. This did a great service to motorsport.it democratized the sport whilst placing importance on chassis innovation. The editors feel it’s no exaggeration to praise the contribution of Coventry Climax. In period they felt they did not get the acknowledgement they deserved. British motor sport engineering would not be what it is now without their contribution- financial and design skill.
The relationship between Lotus and Coventry Climax is substantial and worthy of close study and has lessons for Engineering, Industrial Design and Manufacturing disciplines.
Industrial design increasingly relies on specialist components and contracting out –for good reasons. The packaging and combination of Lotus and Coventry Climax produced superb results both in engineering and aesthetics. For this reason alone, its worthy of close examination.
Along the way it’s possible too to study the wider British motor component industry and how it has helped foster the specialist car manufacturers.
The Peacock Engineering website.
We are suppliers of fully rebuilt Coventry Climax engines, road, fast-road or full-race with over 140bhp, with all new or fully refurbished parts.
Prices start from £5900, full quotations are available on request.
We are also manufacturers of spares and replacement parts including, pistons, steel crankshafts, high delivery oil pumps, pulleys, backing plates, gears and flywheels.
The Lotus Book.Taylor.Coterie
Lotus, Coventry climax &Cosworh Engines. Unique.
Grand Prix Motor Racing.Dymock.Guiness.1980
- ‘Coventry Climax Racing Engines: The Definitive Development History’ Author — Des Hammill (ISBN 1-903706-83-1)
- ‘History of Coventry Climax’ from Archive.Org
- ‘Climax in Coventry’ Author Walter Hassan (ISBN 0953072126)
Legendary Car Engines.Simister.Motorbooks.2004.
Please note the editors of the A&R attempt to give the broadest spectrum of references but not all are available for consultation in an article. However by noting their existence it may assist students in their research.
*Items in italics non A&R library books.