Cosworth DFV V8

The Lotus Ford – Cosworth DFV V8 Engine. [The Power Behind the Throne]


Ludvigsen states:

“Though neither new to Formula 1 nor Lotus the integration of the engine and frame in the 49’s chassis was carried out with consummate artistry and elegance”

This article is fundamentally about the Ford – Cosworth engine and how Chapman was instrumental in bringing it into existence. Thereafter how he exploited and integrated its potential.

As such it’s a double-layered engineering appreciation. The engine in its own right but also the complementary extraction and enhancement through thorough chassis design/ packaging.

The DFV was powerful, reliable, robust and compact. It was designed and built to ‘production standard”. It’s thought its production life was 1967-1986.

Neither of the editors are engineers. Therefore in this piece we have relied heavily on quoted published information of the time. We aplogise that we are perhaps unable to more critically check this information. However we have posed an objective, vigorous searching questioning approach relating to original sources so that the debate and conclusions can be better understood and applied.

Our interest relates to the proable contract that existed between the parties. The A&R would like to know the exact terms and conditions if any that were applied. In addition it is necessary to know if Chapman gave Cosworth a specific design brief that included dimensions. These are important to evaluate how successful the design was against predetermined expectations and to know in which sequence the engine/ chassis evolved.

Whilst conducting our analysis based on information available we shall return to these related matters.

Once again Chapman demonstrates the totality of his conceptual approach. The resolution of a problem has to be concluded in harsh realities. The holistic achievement can only be achieved when the economic resources are available. This sees him negotiate with Ford and John Players. As always there are lessons to be leant and his approach is inspirational.

Subscribers should take into account technology of the time. E.g. even in racing engines 2 vales per cylinder were common.

Context, Circumstances and Necessity

Using the statistics and appendix in William Taylor’s “The Lotus Book” we can trace the engine manufacturers for each model from Lotus inception to the 49. Variations on Cosworth and Climax are approximately equal.

Of interest is the fact that V8 engines of various manufacturers had been used on an estimated eleven occasions prior to the 49.

The Ford V8 bringing success at Indianapolis and the Climax V8 in FI World championship.

Further evidence in favour of the V8 was the Repco V8 used by Jack Brabham. It had proved simple and reliable.
However the International Regulations were changing and 3L engines would be possible. Chapman was aware that factors might rob him of a competitive engine.

At the time there was some logic and advantage in the 12 and 16 cylinder engines. Chapman had used the BRM H16 of 2996cc in the Type 43 of 1966.It is estimated it might have produced 400+ bhp but it was relatively heavy and not particularly reliable. Its crankcase was also acting as stressed member.

Feeding the known evidence, experience and a factor for the opposition response Chapman and the Lotus designers / engineers might have specified a light, compact engine [possibly able to match the 12 and 16] but this could be scaled down if weight advantage was achieved. They would also expect reliability and fuel economy.

Ford Britain: Financial Backing

In the previous chapter we note that it was Colin Chapman who was the motivating force, instigator and catalyst to the project .Its Chapman who brokered the deal .Its very likely that his charm, track record, connections and London base enabled him to unite the parties.

History informs us that a tripartite was formed between Sir Leonard Crossland, Harry Copp [Vice President Engineering] and Walter Hayes of Ford Britain, Colin Chapman/Lotus and Keith Duckworth [Cosworth]. For a project like this to precede the trust, faith and confidence in Chapman must have been absolute and this is a measure of the man to deliver. It ought be remembered too the short time scale of 9 months.

There were compelling forces that might give the project momentum:

  • In the 1960’s Ford corporate policy favoured Motor sport as means of promoting its cars to younger audience. They may have feared that competitors could grasp sales.
  • Ford had a V8 in their range from the early days. It was suitable to the American market. An updated concept may have many applications within various branches of motor sport and beyond.
  • Colin Chapman was in 1966 a multiple World Champion Constructor and had used Ford engines in many of his cars including Indianapolis, the Ford-Lotus Cortina & Elan of 1962, and Type 30/40 1964/65.
  • Keith Duckworth [Cosworth] had tuned and developed Ford engines and they had been used successfully in road and racecars including a high proportion of Lotus.
  • The cost of £100,000 pounds plus technical support seemed reasonable in relation to the potential advertising /promotion gains that would accrue in relation to their production car sales in the international market.

To understand the £100,000 design and manufacturing costs it helps to consider what elements would be needed. These might be summarized as:

  • Design and drafting, specifications, contracts
  • Pattern making and casting, hardening etc
  • Machining and equipment of workshop
  • Purchasing parts. Ancillaries etc
  • Testing and running
  • Possible experimental and sacrificial pieces
  • Overheads and premises
  • Quality control discipline and inherent “production” standard.
  • Salaries

We invite our subscribers to goggle average wages and house prices for 1966/67 and the relative achievement is seen in more realistic context. The design and construction of the DFV to the deadline set would probably have taken most of the company’s time and workforce. Although not recorded it seems that the fundamental correctness of the design avoided any wasteful loses and modifications. Enormous dedicated thought planning and analysis must have been involved.

The editor’s estimation and budget breakdown corresponds roughly with the contract sum. Ford therefore we feel were treated fairly and the resultant promotion and entry into the higher echelons of FI as a result. I.e. their return was disproportionately greater than investment made.

The A&R believe that there must have been contract documentation and that such a large sum might have required approval from America. We feel that the analysis and greater critical appraisal would be increased if the terms of the contract were made known.

For example it might have been Chapman and his designers who made the specification but did Ford have to confirm this or make / amend alterations?

The editors would wish to know if Chapman issued dimensions to fit a chassis or the converse or as very possible there was a confluence, which ensured this perfect “fit”.

Obviously at the time secrecy was paramount but knowledge of possible conditions would better enable evaluation against declared objectives. There may have been stipulations requiring Ford trademark and Ford might have benefited from research and technological advancement and evidence gained through the race programme. There may have also been arrangements whereby the Ford engine would have use/ publicity at other levels of motor sport.
It’s understood that the contract may have been in two parts. The initial of £25,000 for initial experimentation.

It goes without saying the Ford contribution was extremely significant and almost immeasurable in the advancement of British motor sport specifically and international in general.

The Lotus 49: Lateral v linear thinking

As is today FI in 1966 required totally dedicated and exhaustive thinking and analysis to extract optimum results. Straight-line linear thinking or deduction from a predetermined fixed aspect may produce a logically executed design but this may not be competitive. If one element is given priority then it may have disproportionate negative knock on to related components

All engineers ought read Ludvigsen where he quoates at length the Chapman design methodology of 17 July 1975. Here Chapman explains the imperative is to win and therafter sets out parameters and suggested criteria.

Chapman, Phillipe and Duckworth probably spent an extended period exploring scenarios with their consequence, implication and interaction. Chapman’s demonstrated methodology is that of a totality based on lateral thinking not the linear. He analysis is a constant trade off towards a perfection of the interrelated parts and their harmonious integration in complementary coexistence. The package was in unison and a coherent whole. As in the past Chapman looked for the beneficial cycle.

Chapman’s design brief for the 49 might have included / anticipated:

  • Detailed and extensive analysis / digestion of regulations [mandatory requirements] how to meet yet extract advantage.
  • Theoretical knowledge
  • Previous design experience
  • Competitors likely response
  • Race conduct strategy i.e. pit stops reliability, fuel consumption, tyres etc
  • The relationship between chassis and engine, suspension and aerodynamics.

In reality the DFV evolved as a package with the 49 chassis. The engine, gearbox and chassis were beautifully integrated.

The engine acted, as a chassis member and the forward monocoque became a nacelle.

The estimated weight of the 49 is 1102 lbs.

The Lotus 49 made a spectacular debut at the Dutch Grand prix in 1967.

The Lotus 49 won the World Championship in 1968.

Keith Duckworth [Cosworth] and Technical details of the DFV V8 [Double Four Valve]

Keith Duckworth and his partners at Cosworth designed the DFV. These comprised Mike Costin, Bill Brown, and Berny Rood. This was a young team in their mid thirties.

They were and remain based at Northampton.

The timescale was approximately 9 months.

Keith Duckworth was a no-nonsense North countryman who was known as “The Practical Man”.

This would be ‘clean sheet of paper” design.

From the outset the engine would be mid mounted on longitudinal axis and form part of the cars structure.

  • Flat crankshaft sometimes expressed as 180 degree per bank of cylinders
  • Gerotar-type oil pump
  • 2 banks of 4 cylinders arranged in 90 degree “V” compact layout.
  • Each cylinder having twin inlet and exhaust valves, [i.e. 4 valves per cylinder] former on top of the engine giving direct passage to air allowing for good breathing and combustion.
  • Narrow valve angle for compactness
  • Pent roof combustion chamber
  • DOHC per bank of cylinders with bucket tappets
  • Camshaft driven by gears
  • Quad cam
  • Power output estimated 400 bhp @9000rpm developed to approx 510 bhp @ 11,200rpm [136 bhp / litre]
  • Conventional 4-stroke water-cooled petrol engine with reciprocating pistons.
  • Flat top piston with valve pocket
  • Lucas port fuel injection and slide throttle
  • Lucas electronic ignition
  • Aluminum-alloy cylinder head
  • Aluminum–alloy cylinder block with wet liners
  • Aluminum-alloy stressed lower crankcase
  • Dry sump achieves shallower more compact profile [although separate oil tank needed]
  • Compression Ratio 11.0:1
  • 85.7mmX 64.8mm bore and stroke, over square contributed to compact design
  • 2993 cc
  • Space saving placement of fuel pump, alternator and distributor between “V” of cylinder blocks
  • Low placed exhaust manifolds and internal mechanical design permitting simple but effective four-cylinder extraction.
  • Oil pump, filter and water pump located below exhausts
  • Internal oil chemistry and mechanics analysed/ i.e. minimum friction loss
  • Use of “O” ring seals
  • 10/12mm? Spark plugs
  • Its believed the DFV is constructed from 3550 parts [see web reference below]

The DFV permitted Chapman and his designers:

  • Compact engine with potential for short wheel base or alternative component distribution/ deployment/ wheelbase
  • Possibility of body width of approximately 27”
  • Light weight with competitive power output [power to weight ratio]
  • Acting as chassis component permitted weight reduction in remaining chassis
  • Fuel efficiency, reducing carrying capacity, hence reduced space and weight or less refueling
  • Aerodynamics, profile frontal area reduced i.e. determined by engine cross section
  • Greater access for maintenance no chassis obstructing engine
  • Centre of gravity reduced with potential for optimum concentration
  • Engine power to match opposition so advantage could be achieved through chassis and performance
  • Consistent engine performance over race distance.
  • Consistent engine through quality control productionisation discipline

British Industrial Design

The editors consider it a grave omission that the DFV engine has not been accorded greater status in Industrial Design circles considering its International impact and particularly how it became the mainstay on British Motor acing for over a decade.

To many it’s referred to as the “Immortal Ford –Cosworth DFV”

Considering that the engine became so legendry winning twelve drivers titles between 1968-1982, [including a further two for Team Lotus in 1972 and 1978] and ten Constructors Championships. It powered two Le Mans winners and provided something of a mainstay to F3000 and CART.

It is considered the most successful FI engine of all time. The winner of 155 World championship GP’s.

“One of the most revered pieces of engineering throughout the history of motor sport”

The DFV changed the conventional wisdom. The designers deserve greater recognition based on the success, influence and engineering reputation accredited to Britain.

Cosworth is part of the British engineering Cultural Landscape.

The Proposed CCM&EC

The proposed museum believes that commercial considerations are both necessary and complementary with its educational objectives.

For these reasons our 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. Its projected there will be a catalogue for on line purchasing.

In particular we feel that it fully appropriate to have links with Ford. Lotus and Ford history and competition success are interwoven. Both have had a long and continuous presence in Britain. Both retain an interest in motor sport to the present day. Displays at the proposed museum will allow for the interpretation of the Ford connection.


The Ford –Cosworth DFV from its inception until the turbo era was the backbone of International Motor sport and allowed a wide contingent of British entries and providing close racing.

With this came significant prestige and earnings.

The editors consider it a significant part of our sporting and engineering Cultural Landscape and heritage. Part legacy but more so ongoing continuity and aspiration for engineering quality and integrity.

The DFV and Lotus 49 are a case study in creative engineering design, collaboration and marketing opportunity. The design and function of engine and chassis were integrated with the resultant whole being greater than the sum of the parts. Both the package and lessons are inspirational.

The proposed CCM&EC is not a passive acceptance or reverence of the past glory. Our declared aim is to drive inspiration thinking and problem solving in engineering though critical analysis. We believe it has the potential to be the “Exploratory- Laboratory” providing education and exhibitions not available anywhere else.
In summary are objects are:

  • To critically display and interpret the designs of Colin Chapman/Lotus
  • To use the tools of analysis and investigation for inspirational problem solving in current and future engineering matters
  • To use by every means the facilities to create training, work experience and related learning opportunities
  • To celebrate the British sporting and cultural achievements obtained through Motor racing and its related engineering. This will be supported by the development, expression and cultivation of engineering aesthetics.

Lotus: 49.49B.49C.49F. Unique Books. *
ISBN: 1841555185
Lotus, Coventry Climax and Cosworth Engines. Unique Books*
ISBN: 1841555177
Inside the Innovator by Karl Ludvigsen, Haynes, 2010 *
ISBN: 9781844254132
The Lotus Book by William Taylor, Coterie Press, 1999*
ISBN: 1902351002
The Ford Cosworth DFV. Andrew Noakes.Haynes 2007
ISBN: 9781844253371
Motor Racing: The Records. Ian Morrison. Guild Publishing.1987
*A&R Library.