Engine Series – Ford 1172

A bit on the side: Lotus and The Ford Side valve engine

Introduction

The engine series are neither technical treatise or Haynes Manuals. This information is readily available in published form or on the net.

Rather our study concentrates on how and why Chapman and his colleagues’ chose engines and their contribution to Lotus success and sales.

In his selection 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 Ford side valve engine and related components are extremely important to the Lotus story and that of Colin Chapman’s industrial design.

Lotus might not have succeeded in the way it did or so quickly without these parts.

This article therefore examines briefly the origins of the Ford side valve and Chapman’s deployment.

The humble Ford side valve powered some of the early Lotus trials cars, the dual-purpose sports car the Mk.VI and Seven. It was the basis of the 1172 Formula which Lotus dominated. These engines also found their way into the more sophisticated aerodynamic Lotus of the mid-late 1950’s. [ Eleven] Its legacy continues today and bears witness to the soundness of the basic design.

This article is illustrated with drawings /diagrams relating to installation in Lotus cars.

Subscribers might like to see complementary A&R articles:-

  • The 1172 Formula
  • Lotus Mk.VI – several themed
  • Lotus Seven – -do- including Form and Function
  • After Market Suppliers-Aquaplane, Elva ohv conversion etc.
  • S.U. Carburettors-All Choked Up
  • Coventry Climax Engines
  • Austin Powers –Austin Engines
  • The US consul in London :Lotus and the Ford Consul engine
  • The Ford pre and cross flow engines
  • T-total: MG engine
  • Ford gearboxes

20160205131322_00001

Figure 1.Editors sketch of Ford side valve engine in Lotus Mk.VI. [Nb Aquaplane head]

Figure 2 Editors photograph: Lotus Mk.VI; the Ford side valve engine seen from above. Note Aquaplane inlet manifold and twin carburetors.

The Cost Context

The post war era was characterized by austerity and rationing. There was a demand for normality and motor sport events but the war had interrupted production, mechanical parts requisitioned. Many cars had been neglected .What remained was prewar and dating primarily from the 1930’s.

Motorsport participants were not on high income. The tabulation gives some statistics. It’s against these figures that the Side valve engine and related componentry needs to be seen and judged. Their affordability is partly key to understanding their use.

Occupation 1951 1954 1956 1959 1947 1957 1952 1955 1957
Solicitor £2,086 Per ann’
Teacher £766 £891 £1,256 £1,465 Per ann’
Nurse £420 £455 £540 Per ann’
Fitter & Turner 111-7 1/4 140-11 1/4 173-0 191-4 Weekly
Average [Male] £8.30 £10.22 £11.90 £13.54 Weekly
12 hp Austin £597 £820
Road Tax £10 £12-10
Insurance Comp’ £15-10-6 £34
Petrol -gallon 1.11 1/2 4.11 1/2
Battery 12 v £9-10-7 £10-18
Labour [hour] 10-0d 15-0d
Tyres [each] £3-4-0 £6-8-6
3bed semi, Stretford £1,400
2bed terrace, Rochdale £500
New House [average] 2,390
4bed detached Chapel £3,950

Those wishing to participate and compete like Chapman were required to improvise and go with what was both available and inexpensive.

The Ford side valve parts fitted the bill.

The essential robust construction and affordability meant they could be experimented with .Their relative simplicity meant also those without extensive engineering equipment or premises could work on the engines.

The Chapman approach was functionalist and pragmatic. It went with the possible but also saw and utilized every conceivable potential contained within.

History and background: The Ford Y Type

[From the net]

The car was powered by a 933 cc, 8 (RAC) hp Ford Side valve engine. The little Ford was available in two and four-door versions. In June 1935 a reduced specification two-door model was the only closed-body car ever to sell in Britain for just £100, a price it held until July 1937.[1]

The suspension was by the traditional Ford transverse leaf springs front and rear and the engine drove the rear wheels through a three-speed gearbox which, right from the start, featured synchromesh between the top two ratios.[1] The maximum speed was just under 60 mph (95 km/h) and fuel consumption was 32 miles per imperial gallon (8.8 L/100 km; 27 mpg-US).

Even by the standards of the time, the UK-built Ford 8, like its major competitor the Austin 7, was found noteworthy for its “almost unbelievable lack of brakes.”[4]

Volumes

Some 175,000 Model Ys [citation needed] were produced worldwide (153,117 in England, 11,121 in Germany) and the ‘Y’ and ‘C’ Register has knowledge of approximately 1250 survivors.

E93A (1938–49)

[From the net]

The Ford Prefect was introduced in October 1938 and built by the Ford plant in Dagenham, Essex. The original Ford Prefect was a slight reworking of the previous year’s 7Y, the first Ford car designed outside of Detroit, Michigan. It was designed specifically for the British market. It had a 1172 cc side-valve engine with thermocirculation radiator (no pump) and the ability to be started by a crank handle should the battery not have sufficient power to turn the starter motor running from the 6 Volt charging system. The windscreen wipers were powered by the vacuum ported from the engine intake manifold — as the car laboured uphill the wipers would slow to a standstill due to the intake manifold vacuum dropping to near nil, only to start working again as the top was reached and the intake vacuum increased. The windscreen opened forward pivoting on hinges on the top edge; two flaps either side of the scuttle also let air into the car. The car has a durable 4 cylinder motor.

The most common body styles were two- and four-door saloons, but prewar a few tourers and drop head coupés were made. Post war, only four-door saloons were available on the home market, but two-door models were made for export.

41,486 were made up to 1941[4] and a further 158,007 between 1945 and 1948.[5]

100E (1953–59)

[From the net]

In 1953 a much redesigned Ford Prefect was introduced alongside the similar Ford Anglia and remained in production until 1959. Externally, the Prefect can be distinguished from the Anglia by having vertical bars on the radiator grille and four doors. The old separate chassis had gone, replaced by integral construction, and coil independent front suspension supplanted the transverse leaf spring. Girling hydraulic brakes were fitted, initially 7 in drums but quickly increased to 8 in (200 mm) A new side-valve engine of 1172 cc engine was fitted having the same bore, stroke and layout of the previous engine, but in all other respects completely different – changes included adjustable tappets, raising the compression ratio from 6.3:1 to 7:1 and larger inlet valves, resulting in the power output increasing by 20% to 36 bhp.[13]

Inside there were separate front seats trimmed in PVC with leather as an option and two circular instruments in front of the driver one containing the speedometer and the other a fuel and water temperature gauges? De Luxe models from the second dashboard update in 1959 included glove box locks.[14] The gear change was floor-mounted. The heater was an optional extra. The dashboard was revised twice; the binnacle surrounding the steering column was replaced by a central panel with twin dials towards the driver’s side in 1956; the last from 1959 had twin dials in a binnacle in front of the driver and ‘magic ribbon’ AC speedo similar to the 1957 E-series Vauxhall Velox/Cresta and ’58/’59 PA models.

In 1955 an estate car version was introduced, marketed as the Ford Squire and mechanically identical to the contemporary Escort, an estate car version of the Ford Anglia 100E, but with wooden strakes and a higher trim level.

The Motor magazine tested a de-luxe 100E in 1957 and recorded a top speed of 71 mph (114 km/h) and acceleration from 0-60 mph (97 km/h) in 32.2 seconds. A “touring” fuel consumption of 33.1 miles per gallon (imperial) was recorded. On the home market it cost £658 including taxes of £220.[12]

100,554 were made.[5]

Standard Engine Data

The following data helps appreciate and benchmark the Ford side valve

Marque Model Bore Stroke CC Net BHP Rpm C’Ratio Carbs
Austin 7 63 68 848 31.5 5500 8.3 1 Zenith
Austin A35 63 76 948 4750 8.3 1 Zenith
Austin Sprite 63 76 98 42.5 5200 8.3 2 S.U.
Ford Poplar 63 92 1172 36 4500 7 1 Solex
Ford Prefect 81 48 997 39 5000 8.9 1 Solex
Ford Consul 82 79 1703 59 4400 7.8 1 Zenith
Hilman Minx 79 76 1494 53 4600 8.5 1 Zenith

Estimated Weight Engine& Gearbox

The editors believe the combined weight is in the region of 190-200 kg or perhaps approximately just under one quarter of a Lotus Mk.VI.

20160205131202_00001

Figure 3.Editors sketch of Ford side valve in Lotus Seven Series 1

Tony Weale in Lotus Seven

the 1172 cc Ford 100E side valve engine, through its predecessor the E93A was the last survival of the traditional British family car engine of the 1930’s Despite its unpromising background it was a popular and readily tunable engine for the amateur racers and special builders of the 1950’s – the 1172 formula centred around it and a few were still racing successfully in Formula 1200 events as late as 1969, when more efficient overhead valve engines were in general use. Certainly many were fitted to basic Lotus Sevens and Elevens.

The engine is very simple in construction, mostly cast iron with a three bearing crankshaft and chain driven camshaft. Access to the valves and tappets for adjustment is through a cover bolted to the nearside of the block , and the distributor is mounted on the cylinder head……….in standard single carburetor form , as fitted to Anglia and Prefect cars from 1953 to 1959 , the 100E developed about 36 bhp at 4,500 rpm .However a wide range of tuning equipment was marketed by firms such as Aquaplane and Derrington , from aluminium cylinder heads to special camshafts , supercharger kits and overhead valve conversions.

Vandervell marketed a shell bearing conversion to strengthen the bottom end, necessary when the most highly developed racing units were producing 80 bhp and revving to 8,000 rpm, albeit with a very limited lifespan.

A typical 100E engine in a series 1 or 2 Seven might have had an aluminium cylinder head, to raise the compression ratio, polished and reshaped ports , stronger valve springs , a four branch tubular exhaust system and a pair of SU carburetors. In this form it would produce around 50 bhp which was considered a worthwhile increase in power.

Engines of this type , however , are inherently inefficient and the potential for extracting more power is limited by the long stroke design and the side valve layout, both of which restrict the engines breathing………….cylinder heads are fairly flexible and inclined to warp if not treated carefully which leads to gasket problems .There is little else to go wrong:

Weale provides a section on engine data and an excellent selection of photographs featuring the 1172 installed in Seven. [Nb some of these were taken by Geoff Goddard and possibly the prototype or one the very early production cars such as FVV 877. [Cross reference with various images including those in Coulter “The Lotus and Caterham Sevens”]

Form and Function

The Ford side valve is a product totally consistent with Ford’s engineering/commercial philosophy of product design. It was correct for the era [suffering periods of world economic crisis] being simple, robust, cost effective and generally serviceable. Outright performance and weight might have been sacrificed to production economics. It was vested with durability and this made it the salvation of postwar motorsport. The main body was cast iron and the layout was in line four, water cooled. Its overall dimensions determined by the bore and stroke.

It’s worth noting it was a contemporary of the Austin Seven if not directly competing against each other.

Ford%20100E%20Engine%20Exterior

Figure 4.Exploded diagram of the side valve engine. This appeared in most of the tuning manuals of the era.

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Figure 5.Editors sketch drawing of Ford 1172 side valve engine in section ad plan. Subscribers are invited to examine this and extrapolate to installation drawings. On another drawing editor made he recorded weight of 1172 engine and gearbox at 190kg?

Figure 6.editors sketch of Ford 100E plan view indicating relative size/scale

20160205131342_00001

Figure 7.editors sketch of side valve engine in Lotus Seven Series 1

The engine had been designed for an upright saloon body and when adopted and used for more sporting applications and lower bonnet line [radiator etc.] it became necessary to reposition components and improve cooling. This has been achieved in an attractive manner.

Chapman designed the space frame chassis to accommodate possibly a wide range of engines and the Ford side valve is relatively easily installed and normally does not require bonnet bulges .The space frame allowing for good access to those items that require servicing, attention .It’s worth noting that some Lotus cars fitted with Ford side valve have a hole cut in the nose cone so the radiator can be filled without the need to remove the nose cone. Of course the smoother line being preferred.

The Ford Gearbox

The 3 speed gearbox fitted as standard to the 1172 was just adequate for purpose seen in context of the times, roads, traffic, average speeds, desired performance /economy, and driving style. It was probably determined by cost effectiveness. The engineering accountants possibly deciding the engine size/output compensating for 4 speeds.

The 3 speed hampered outright performance, acceleration and reduced engine breaking .However it was very much part and parcel of the 1172 unit and further allowed the retention of the prop shaft /torque tube along with back axle , drum brakes, and road wheels from a donor.

These limitations could be overcome .In period this was achieved by a close ratio gears set [Buckler were a proprietary set] and Lotus offered these. Alternatively with an adjuster plate a 4 speed gearbox was possible. The M.G. “J” was the preferred item, although the editors believe other marques have been used.

When the 1172 and 3 speed box are fitted in the light weight Mk.VI and Seven they provide acceptable performance in general use .It’s worth researching contemporary road tests and with this benchmarking the performance of other marques which also adopted the same primary mechanical components.

20160122144322_00005

Figure 8.Editors photograph of i. Later type Ford Gearbox and ii. The 3 speed gearbox, note different size and that change mechanism some distance from cockpit requiring remote control linkage.

The 1172 tuned and installed in the Lotus is transformed .The low weight contributing to sparkling performance. The Ford brakes become more impressive and partly reduce the need for engine braking. In many respects the car becomes 2 speed as only 2nd and 3rd are regularly used.

The Ford Side valve 3 speed gearbox should be considered as an integral whole with our paragraph on form and function .Installed in the Lotus a remote gear change lever is necessary.

The controlling limitations of the 3 speed box ought borne in mind when considering the other proprietary engines used by Lotus as these immediately provided 4 speeds [see M.G.,Austin and Coventry Climax]

Lotus Cars and the Ford side valve

It’s difficult to establish accurately the exact numbers of Lotus cars equipped with Ford side valve components .Most of the published records suggest that approximately 100 Mk.VI were built. The editors believe that the majority were equipped with the Ford sidevalve.This can partly be cross referenced with the 1172 Race Formula.

Lotus did not sell many completed cars and the component nature of the Mk.VI and Seven encouraged owners to use an available donor.

We know that the side valve engine was used in some of the aerodynamic cars but in smaller numbers. The engine was a basic option in the Seven and this can be cross referenced with published works and of course sales brochures [see A&R –Seven Sales to Sunset]. The Ford side valve was therefore still an option in the late 1950’s but by this time other mass production manufacturers had suitable products notably A Series Austin [see A&R article]

Subscribers wishing to get further comprehension of the usage might like to explore Taylor [The Lotus Book]

The suitability, affordability, availability and the fact the Mk.VI had been expressly designed for the side valve components and eligibility for the 1172 race series ensured volume sales. [Our inclusion of income figures is intended to reinforce this connectivity] This combination generated income, publicity, success and commenced a beneficial spiral for Chapman and in the author’s estimation were the commercial /competition foundation of the marque.

Road Test with Ford side valve

There are three contemporary articles which report on the Lotus Mk.VI fitted with the Ford 10 engine. These are: Autosport, October 2nd, 1953, Autocar and The Motor.

Of the three John Bolster’s [Autosport] possibly gives the most relevant information relating to the Side valve engine. [This was reprinted as Lotus advertising material and the A&R has an example]

Bolster wrote:-

My” Lotus had a Ford 10 engine which had been warmed up as far as the “1172 Formula “allows. It had an aluminium cylinder head, raised compression ratio, larger inlet valves than standard, and double valve springs .it had twin S.U. carburetters mounted on a flexible induction system, to avoid frothing of the fuel from vibration .Two separate exhaust manifolds paired cylinders 1 and 4, 2 and 3 as is correct practice.

The three –speed Ford gearbox was converted to close ratios by the use of Buckler C –type gears………..the rear axle had been fitted with a 4.7 :1 final drive………..

The mean maximum speed was 88mph and I frequently exceeded 90 under favourably conditions .After that I had to have another look under the bonnet and yes , it really was a side valve………….

I feel that the Lotus is the best attempt yet to provide the enthusiast with a competition car at a price he can afford to pay.in essentials it is as sound an engineering job as the most expensive sports cars and the economy is only brought about by clever adaption of mass produced components……….”

The performance that Bolster experienced was perhaps slightly greater than the general constructor might have achieved .The car borrowed from the factory being perhaps more tuned than acknowledged!!

Bolster gave the following data:

Engine: Four cylinders 61.5 x 92.5 mm [1099cc] side valve.8.25:1 compression ratio. Approximately 40 bhp at 6000 rpm.Twin horizontal 1.25-inch SU carburetters. Lucas coil and distributer

Performance

Maximum speed 88mph

Speed in gears

2nd 75 mph

1st 40 mph

Acceleration

0-50 mph 9.4/5 secs

0-60 mph 12.3/5 secs

0-70 mph 16.3/5 secs

Fuel consumption 40 mpg.

Lotus published these following figures in their Sales brochure for the Mk.VI.

[Subscribers might like to cross reference these with our related articles on the engines mentioned]

“Performance Figures [approx.]

ENGINE STANDARD MEDIUM HIGH
Ford 10 Degree of tuning Normal/Perfect Limits of 1172 Formula Special cam etc.
Maximum speed 75 mph 88 mph 94 mph
Petrol consumption 45 mpg 48 mpg 40 mpg
Standing 1/4 mile 21 secs. 19 secs. 17.5 secs.
Ford Consul Degree of tuning Normal Consul Twin Carbs etc. Special cam etc.
Maximum speed 99 mph 106 mph 113 Plus
Petrol consumption 40 mpg 42.5 mpg 38 mpg
Standing 1/4 mile 18.8 secs. 17.4 secs. 16.5 secs.
M.G Degree of tuning Normal 1250 Max.of 1250 1500 Special cam etc.
Maximum speed 104 mph 113 mph 120 mph
Petrol consumption 40 mpg 42.5 mpg 38 mpg
Standing 1/4 mile 17.8 secs. 16.5 secs. 15.8 secs.”

Learning Opportunities

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:-

  • In early Lotus era what other low cost mass produced engines were available?
  • Contemplate the relationship of race series /formulas with engine availability [e.g. up to present with Caterham] what is impact on racing and drivers?
  • What are modern day equivalents, which marques use proprietary engines?
  • Consider economic/ commercial implications of proprietary engines and aftermarket specialists –who are modern providers?
  • What engineering /constructional factors made the Ford side valve attractive for specialists
  • Consider the period tuning manuals of era and project cost effective tuning
  • Consider how attractive a dual use car was in early Lotus era, how might this impact on sales
  • Estimate what costs/skills were required to build and race a special /own –race in 1172 formula
  • What other British specialist car marques used the Ford side valve engine gearbox units?
  • Discover the numbers of Lotus cars built with Ford side valve engines. From which contemplate the commercial benefit to Chapman and Lotus

Education, Exhibitions and Economics

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. It’s suggested there will be catalogue for on line purchasing.

In particular we consider the scope for an extensive set of exhibitions that celebrate the Ford mechanical components and the range of marques that adopted them .Such an exhibition is not merely automobile orientated but educates designers in the manner of finding and making added value.

  • Side valve –the winning margin
  • Side valve sidelined: Alternative engine sources
  • Side valve sidestepped: Increasing performance contrary to intentions
  • Side Valve-Taking sides -A point of view –evaluating significance
  • From side to side-fitting the side valve in the Lotus
  • Side Valve: Side effects-Chapman’s Genius for added value from racing to trials
  • Crossing a Ford: Not water under the Bridge: British Specialist Sports Cars

Conclusion

The ford side valve .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 modification, 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 mass-produced engines were robust, inexpensive, widely available and spawned aftermarket components industry. Furthermore, they invited experimentation, and helped facilitate competition and design diversification. Thus assisting and elevating British motor racing :design , engineering , manufacture and of course drivers.

In the case of the Ford 1172 cc side valve it formed a dedicated race formula in the early 1950’. This was dominated by the Lotus Mk.VI

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 entrepreneur with low capital wishing to enter the market.

The contribution to British motorsport by the Ford side valve and indeed the Austin 750 is colossal and ought never to be taken for granted.

The Ford side valve was a product of Ford engineering /commercial logic. It was practical and it sold in volume. This ensured its widespread availability. The engine /gearbox unit were conceived as sound, robust, durable and serviceable.

In the immediate British post war context it was the right product at the right time and place. What the Ford side valve delivered was:-

  1. Widespread availability across the UK
  2. Affordability , there were many second hand examples, crash damaged items could be sourced from breakers as Chapman did on many occasions
  3. The engine was known , it could be serviced , there was spares availability and the DIY owner could maintain it
  4. The above factors contributed to a democracy of participation –noting our social income statistics
  5. Wide participation was healthy. To overcome some of the mechanical inadequacies enthusiasts like Chapman experimented and many of these designers contributed to the British dominance in post war motor racing
  6. The Ford engine made for close racing and perhaps placed emphasis on driving ability as contestants had similar power limitations
  7. The Ford engine helped Britain with exports and reestablish its Specialist car manufacturers post war. Note Morgan used the components
  8. The existence of the unit contributed to aftermarket sales and generally acted like a multiplier in the development of innovations and related employment

There are few engines which can claim such a significant role .There are not many modern day equivalents although Ford recreated and updated their contribution with the cross flow, VW, Rover V8’s and perhaps the Caterham -Vauxhall along with Cosworth-Ford engines perhaps?

The Ford side valve engine in the dual purpose Mk.VI had a disproportionate impact. It dominated the 1172 formula garnering beneficial publicity. The cars were seen on the road and track. The numbers sold established the commercial footing for Lotus. When a customer bought a Lotus and installed a Ford side valve they knew they had the best of both worlds. When we examine the second hand sales values of Lotus Mk.VI in the 1950’s they held their value extremely well.

This unit gained considerably extra credibility and status when fitted in the Lotus which of course was about packaging and Chapman’s added value but it ought be remembered the basic unit itself is worthy of study and appreciation. The Lotus very much relied and depended on it.

The Ford 1172 side valve is an Engine associated with Hornsey built cars.

Reference:

A Reprint of an article which appeared in the Autosport 1953.SUBJECT –The Lotus Mk.VI Sports Car.

Lotus Mk.VI Sales brochure

Lotus Seven.Weale.Osprey.1991.

ISBN: 185532153X

The Value of a Pound 1900-1993.Gale Research International.1995

ISBN: 1873477317

The Lotus Book.Taylor.Coterie.

Subscribers are directed to our extensive bibliography associated with articles listed in introduction

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.

A bit on the side: Lotus and The Ford Side valve engine

Introduction

The engine series are neither technical treatise or Haynes Manuals. This information is readily available in published form or on the net.

Rather our study concentrates on how and why Chapman and his colleagues’ chose engines and their contribution to Lotus success and sales.

In his selection 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 Ford side valve engine and related components are extremely important to the Lotus story and that of Colin Chapman’s industrial design.

Lotus might not have succeeded in the way it did or so quickly without these parts.

This article therefore examines briefly the origins of the Ford side valve and Chapman’s deployment.

The humble Ford side valve powered some of the early Lotus trials cars, the dual-purpose sports car the Mk.VI and Seven. It was the basis of the 1172 Formula which Lotus dominated. These engines also found their way into the more sophisticated aerodynamic Lotus of the mid-late 1950’s. [ Eleven] Its legacy continues today and bears witness to the soundness of the basic design.

This article is illustrated with drawings /diagrams relating to installation in Lotus cars.

Subscribers might like to see complementary A&R articles:-

  • The 1172 Formula
  • Lotus Mk.VI – several themed
  • Lotus Seven – -do- including Form and Function
  • After Market Suppliers-Aquaplane, Elva ohv conversion etc.
  • S.U. Carburettors-All Choked Up
  • Coventry Climax Engines
  • Austin Powers –Austin Engines
  • The US consul in London :Lotus and the Ford Consul engine
  • The Ford pre and cross flow engines
  • T-total: MG engine
  • Ford gearboxes

20160205131322_00001

Figure 1.Editors sketch of Ford side valve engine in Lotus Mk.VI. [Nb Aquaplane head]

Figure 2 Editors photograph: Lotus Mk.VI; the Ford side valve engine seen from above. Note Aquaplane inlet manifold and twin carburetors.

The Cost Context

The post war era was characterized by austerity and rationing. There was a demand for normality and motor sport events but the war had interrupted production, mechanical parts requisitioned. Many cars had been neglected .What remained was prewar and dating primarily from the 1930’s.

Motorsport participants were not on high income. The tabulation gives some statistics. It’s against these figures that the Side valve engine and related componentry needs to be seen and judged. Their affordability is partly key to understanding their use.

Occupation 1951 1954 1956 1959 1947 1957 1952 1955 1957
Solicitor £2,086 Per ann’
Teacher £766 £891 £1,256 £1,465 Per ann’
Nurse £420 £455 £540 Per ann’
Fitter & Turner 111-7 1/4 140-11 1/4 173-0 191-4 Weekly
Average [Male] £8.30 £10.22 £11.90 £13.54 Weekly
12 hp Austin £597 £820
Road Tax £10 £12-10
Insurance Comp’ £15-10-6 £34
Petrol -gallon 1.11 1/2 4.11 1/2
Battery 12 v £9-10-7 £10-18
Labour [hour] 10-0d 15-0d
Tyres [each] £3-4-0 £6-8-6
3bed semi, Stretford £1,400
2bed terrace, Rochdale £500
New House [average] 2,390
4bed detached Chapel £3,950

Those wishing to participate and compete like Chapman were required to improvise and go with what was both available and inexpensive.

The Ford side valve parts fitted the bill.

The essential robust construction and affordability meant they could be experimented with .Their relative simplicity meant also those without extensive engineering equipment or premises could work on the engines.

The Chapman approach was functionalist and pragmatic. It went with the possible but also saw and utilized every conceivable potential contained within.

History and background: The Ford Y Type

[From the net]

The car was powered by a 933 cc, 8 (RAC) hp Ford Side valve engine. The little Ford was available in two and four-door versions. In June 1935 a reduced specification two-door model was the only closed-body car ever to sell in Britain for just £100, a price it held until July 1937.[1]

The suspension was by the traditional Ford transverse leaf springs front and rear and the engine drove the rear wheels through a three-speed gearbox which, right from the start, featured synchromesh between the top two ratios.[1] The maximum speed was just under 60 mph (95 km/h) and fuel consumption was 32 miles per imperial gallon (8.8 L/100 km; 27 mpg-US).

Even by the standards of the time, the UK-built Ford 8, like its major competitor the Austin 7, was found noteworthy for its “almost unbelievable lack of brakes.”[4]

Volumes

Some 175,000 Model Ys [citation needed] were produced worldwide (153,117 in England, 11,121 in Germany) and the ‘Y’ and ‘C’ Register has knowledge of approximately 1250 survivors.

E93A (1938–49)

[From the net]

The Ford Prefect was introduced in October 1938 and built by the Ford plant in Dagenham, Essex. The original Ford Prefect was a slight reworking of the previous year’s 7Y, the first Ford car designed outside of Detroit, Michigan. It was designed specifically for the British market. It had a 1172 cc side-valve engine with thermocirculation radiator (no pump) and the ability to be started by a crank handle should the battery not have sufficient power to turn the starter motor running from the 6 Volt charging system. The windscreen wipers were powered by the vacuum ported from the engine intake manifold — as the car laboured uphill the wipers would slow to a standstill due to the intake manifold vacuum dropping to near nil, only to start working again as the top was reached and the intake vacuum increased. The windscreen opened forward pivoting on hinges on the top edge; two flaps either side of the scuttle also let air into the car. The car has a durable 4 cylinder motor.

The most common body styles were two- and four-door saloons, but prewar a few tourers and drop head coupés were made. Post war, only four-door saloons were available on the home market, but two-door models were made for export.

41,486 were made up to 1941[4] and a further 158,007 between 1945 and 1948.[5]

100E (1953–59)

[From the net]

In 1953 a much redesigned Ford Prefect was introduced alongside the similar Ford Anglia and remained in production until 1959. Externally, the Prefect can be distinguished from the Anglia by having vertical bars on the radiator grille and four doors. The old separate chassis had gone, replaced by integral construction, and coil independent front suspension supplanted the transverse leaf spring. Girling hydraulic brakes were fitted, initially 7 in drums but quickly increased to 8 in (200 mm) A new side-valve engine of 1172 cc engine was fitted having the same bore, stroke and layout of the previous engine, but in all other respects completely different – changes included adjustable tappets, raising the compression ratio from 6.3:1 to 7:1 and larger inlet valves, resulting in the power output increasing by 20% to 36 bhp.[13]

Inside there were separate front seats trimmed in PVC with leather as an option and two circular instruments in front of the driver one containing the speedometer and the other a fuel and water temperature gauges? De Luxe models from the second dashboard update in 1959 included glove box locks.[14] The gear change was floor-mounted. The heater was an optional extra. The dashboard was revised twice; the binnacle surrounding the steering column was replaced by a central panel with twin dials towards the driver’s side in 1956; the last from 1959 had twin dials in a binnacle in front of the driver and ‘magic ribbon’ AC speedo similar to the 1957 E-series Vauxhall Velox/Cresta and ’58/’59 PA models.

In 1955 an estate car version was introduced, marketed as the Ford Squire and mechanically identical to the contemporary Escort, an estate car version of the Ford Anglia 100E, but with wooden strakes and a higher trim level.

The Motor magazine tested a de-luxe 100E in 1957 and recorded a top speed of 71 mph (114 km/h) and acceleration from 0-60 mph (97 km/h) in 32.2 seconds. A “touring” fuel consumption of 33.1 miles per gallon (imperial) was recorded. On the home market it cost £658 including taxes of £220.[12]

100,554 were made.[5]

Standard Engine Data

The following data helps appreciate and benchmark the Ford side valve

Marque Model Bore Stroke CC Net BHP Rpm C’Ratio Carbs
Austin 7 63 68 848 31.5 5500 8.3 1 Zenith
Austin A35 63 76 948 4750 8.3 1 Zenith
Austin Sprite 63 76 98 42.5 5200 8.3 2 S.U.
Ford Poplar 63 92 1172 36 4500 7 1 Solex
Ford Prefect 81 48 997 39 5000 8.9 1 Solex
Ford Consul 82 79 1703 59 4400 7.8 1 Zenith
Hilman Minx 79 76 1494 53 4600 8.5 1 Zenith

Estimated Weight Engine& Gearbox

The editors believe the combined weight is in the region of 190-200 kg or perhaps approximately just under one quarter of a Lotus Mk.VI.

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Figure 3.Editors sketch of Ford side valve in Lotus Seven Series 1

Tony Weale in Lotus Seven

the 1172 cc Ford 100E side valve engine, through its predecessor the E93A was the last survival of the traditional British family car engine of the 1930’s Despite its unpromising background it was a popular and readily tunable engine for the amateur racers and special builders of the 1950’s – the 1172 formula centred around it and a few were still racing successfully in Formula 1200 events as late as 1969, when more efficient overhead valve engines were in general use. Certainly many were fitted to basic Lotus Sevens and Elevens.

The engine is very simple in construction, mostly cast iron with a three bearing crankshaft and chain driven camshaft. Access to the valves and tappets for adjustment is through a cover bolted to the nearside of the block , and the distributor is mounted on the cylinder head……….in standard single carburetor form , as fitted to Anglia and Prefect cars from 1953 to 1959 , the 100E developed about 36 bhp at 4,500 rpm .However a wide range of tuning equipment was marketed by firms such as Aquaplane and Derrington , from aluminium cylinder heads to special camshafts , supercharger kits and overhead valve conversions.

Vandervell marketed a shell bearing conversion to strengthen the bottom end, necessary when the most highly developed racing units were producing 80 bhp and revving to 8,000 rpm, albeit with a very limited lifespan.

A typical 100E engine in a series 1 or 2 Seven might have had an aluminium cylinder head, to raise the compression ratio, polished and reshaped ports , stronger valve springs , a four branch tubular exhaust system and a pair of SU carburetors. In this form it would produce around 50 bhp which was considered a worthwhile increase in power.

Engines of this type , however , are inherently inefficient and the potential for extracting more power is limited by the long stroke design and the side valve layout, both of which restrict the engines breathing………….cylinder heads are fairly flexible and inclined to warp if not treated carefully which leads to gasket problems .There is little else to go wrong:

Weale provides a section on engine data and an excellent selection of photographs featuring the 1172 installed in Seven. [Nb some of these were taken by Geoff Goddard and possibly the prototype or one the very early production cars such as FVV 877. [Cross reference with various images including those in Coulter “The Lotus and Caterham Sevens”]

Form and Function

The Ford side valve is a product totally consistent with Ford’s engineering/commercial philosophy of product design. It was correct for the era [suffering periods of world economic crisis] being simple, robust, cost effective and generally serviceable. Outright performance and weight might have been sacrificed to production economics. It was vested with durability and this made it the salvation of postwar motorsport. The main body was cast iron and the layout was in line four, water cooled. Its overall dimensions determined by the bore and stroke.

It’s worth noting it was a contemporary of the Austin Seven if not directly competing against each other.

Ford%20100E%20Engine%20Exterior

Figure 4.Exploded diagram of the side valve engine. This appeared in most of the tuning manuals of the era.

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Figure 5.Editors sketch drawing of Ford 1172 side valve engine in section ad plan. Subscribers are invited to examine this and extrapolate to installation drawings. On another drawing editor made he recorded weight of 1172 engine and gearbox at 190kg?

Figure 6.editors sketch of Ford 100E plan view indicating relative size/scale

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Figure 7.editors sketch of side valve engine in Lotus Seven Series 1

The engine had been designed for an upright saloon body and when adopted and used for more sporting applications and lower bonnet line [radiator etc.] it became necessary to reposition components and improve cooling. This has been achieved in an attractive manner.

Chapman designed the space frame chassis to accommodate possibly a wide range of engines and the Ford side valve is relatively easily installed and normally does not require bonnet bulges .The space frame allowing for good access to those items that require servicing, attention .It’s worth noting that some Lotus cars fitted with Ford side valve have a hole cut in the nose cone so the radiator can be filled without the need to remove the nose cone. Of course the smoother line being preferred.

The Ford Gearbox

The 3 speed gearbox fitted as standard to the 1172 was just adequate for purpose seen in context of the times, roads, traffic, average speeds, desired performance /economy, and driving style. It was probably determined by cost effectiveness. The engineering accountants possibly deciding the engine size/output compensating for 4 speeds.

The 3 speed hampered outright performance, acceleration and reduced engine breaking .However it was very much part and parcel of the 1172 unit and further allowed the retention of the prop shaft /torque tube along with back axle , drum brakes, and road wheels from a donor.

These limitations could be overcome .In period this was achieved by a close ratio gears set [Buckler were a proprietary set] and Lotus offered these. Alternatively with an adjuster plate a 4 speed gearbox was possible. The M.G. “J” was the preferred item, although the editors believe other marques have been used.

When the 1172 and 3 speed box are fitted in the light weight Mk.VI and Seven they provide acceptable performance in general use .It’s worth researching contemporary road tests and with this benchmarking the performance of other marques which also adopted the same primary mechanical components.

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Figure 8.Editors photograph of i. Later type Ford Gearbox and ii. The 3 speed gearbox, note different size and that change mechanism some distance from cockpit requiring remote control linkage.

The 1172 tuned and installed in the Lotus is transformed .The low weight contributing to sparkling performance. The Ford brakes become more impressive and partly reduce the need for engine braking. In many respects the car becomes 2 speed as only 2nd and 3rd are regularly used.

The Ford Side valve 3 speed gearbox should be considered as an integral whole with our paragraph on form and function .Installed in the Lotus a remote gear change lever is necessary.

The controlling limitations of the 3 speed box ought borne in mind when considering the other proprietary engines used by Lotus as these immediately provided 4 speeds [see M.G.,Austin and Coventry Climax]

Lotus Cars and the Ford side valve

It’s difficult to establish accurately the exact numbers of Lotus cars equipped with Ford side valve components .Most of the published records suggest that approximately 100 Mk.VI were built. The editors believe that the majority were equipped with the Ford sidevalve.This can partly be cross referenced with the 1172 Race Formula.

Lotus did not sell many completed cars and the component nature of the Mk.VI and Seven encouraged owners to use an available donor.

We know that the side valve engine was used in some of the aerodynamic cars but in smaller numbers. The engine was a basic option in the Seven and this can be cross referenced with published works and of course sales brochures [see A&R –Seven Sales to Sunset]. The Ford side valve was therefore still an option in the late 1950’s but by this time other mass production manufacturers had suitable products notably A Series Austin [see A&R article]

Subscribers wishing to get further comprehension of the usage might like to explore Taylor [The Lotus Book]

The suitability, affordability, availability and the fact the Mk.VI had been expressly designed for the side valve components and eligibility for the 1172 race series ensured volume sales. [Our inclusion of income figures is intended to reinforce this connectivity] This combination generated income, publicity, success and commenced a beneficial spiral for Chapman and in the author’s estimation were the commercial /competition foundation of the marque.

Road Test with Ford side valve

There are three contemporary articles which report on the Lotus Mk.VI fitted with the Ford 10 engine. These are: Autosport, October 2nd, 1953, Autocar and The Motor.

Of the three John Bolster’s [Autosport] possibly gives the most relevant information relating to the Side valve engine. [This was reprinted as Lotus advertising material and the A&R has an example]

Bolster wrote:-

My” Lotus had a Ford 10 engine which had been warmed up as far as the “1172 Formula “allows. It had an aluminium cylinder head, raised compression ratio, larger inlet valves than standard, and double valve springs .it had twin S.U. carburetters mounted on a flexible induction system, to avoid frothing of the fuel from vibration .Two separate exhaust manifolds paired cylinders 1 and 4, 2 and 3 as is correct practice.

The three –speed Ford gearbox was converted to close ratios by the use of Buckler C –type gears………..the rear axle had been fitted with a 4.7 :1 final drive………..

The mean maximum speed was 88mph and I frequently exceeded 90 under favourably conditions .After that I had to have another look under the bonnet and yes , it really was a side valve………….

I feel that the Lotus is the best attempt yet to provide the enthusiast with a competition car at a price he can afford to pay.in essentials it is as sound an engineering job as the most expensive sports cars and the economy is only brought about by clever adaption of mass produced components……….”

The performance that Bolster experienced was perhaps slightly greater than the general constructor might have achieved .The car borrowed from the factory being perhaps more tuned than acknowledged!!

Bolster gave the following data:

Engine: Four cylinders 61.5 x 92.5 mm [1099cc] side valve.8.25:1 compression ratio. Approximately 40 bhp at 6000 rpm.Twin horizontal 1.25-inch SU carburetters. Lucas coil and distributer

Performance

Maximum speed 88mph

Speed in gears

2nd 75 mph

1st 40 mph

Acceleration

0-50 mph 9.4/5 secs

0-60 mph 12.3/5 secs

0-70 mph 16.3/5 secs

Fuel consumption 40 mpg.

Lotus published these following figures in their Sales brochure for the Mk.VI.

[Subscribers might like to cross reference these with our related articles on the engines mentioned]

“Performance Figures [approx.]

ENGINE STANDARD MEDIUM HIGH
Ford 10 Degree of tuning Normal/Perfect Limits of 1172 Formula Special cam etc.
Maximum speed 75 mph 88 mph 94 mph
Petrol consumption 45 mpg 48 mpg 40 mpg
Standing 1/4 mile 21 secs. 19 secs. 17.5 secs.
Ford Consul Degree of tuning Normal Consul Twin Carbs etc. Special cam etc.
Maximum speed 99 mph 106 mph 113 Plus
Petrol consumption 40 mpg 42.5 mpg 38 mpg
Standing 1/4 mile 18.8 secs. 17.4 secs. 16.5 secs.
M.G Degree of tuning Normal 1250 Max.of 1250 1500 Special cam etc.
Maximum speed 104 mph 113 mph 120 mph
Petrol consumption 40 mpg 42.5 mpg 38 mpg
Standing 1/4 mile 17.8 secs. 16.5 secs. 15.8 secs.”

Learning Opportunities

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:-

  • In early Lotus era what other low cost mass produced engines were available?
  • Contemplate the relationship of race series /formulas with engine availability [e.g. up to present with Caterham] what is impact on racing and drivers?
  • What are modern day equivalents, which marques use proprietary engines?
  • Consider economic/ commercial implications of proprietary engines and aftermarket specialists –who are modern providers?
  • What engineering /constructional factors made the Ford side valve attractive for specialists
  • Consider the period tuning manuals of era and project cost effective tuning
  • Consider how attractive a dual use car was in early Lotus era, how might this impact on sales
  • Estimate what costs/skills were required to build and race a special /own –race in 1172 formula
  • What other British specialist car marques used the Ford side valve engine gearbox units?
  • Discover the numbers of Lotus cars built with Ford side valve engines. From which contemplate the commercial benefit to Chapman and Lotus

Education, Exhibitions and Economics

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. It’s suggested there will be catalogue for on line purchasing.

In particular we consider the scope for an extensive set of exhibitions that celebrate the Ford mechanical components and the range of marques that adopted them .Such an exhibition is not merely automobile orientated but educates designers in the manner of finding and making added value.

  • Side valve –the winning margin
  • Side valve sidelined: Alternative engine sources
  • Side valve sidestepped: Increasing performance contrary to intentions
  • Side Valve-Taking sides -A point of view –evaluating significance
  • From side to side-fitting the side valve in the Lotus
  • Side Valve: Side effects-Chapman’s Genius for added value from racing to trials
  • Crossing a Ford: Not water under the Bridge: British Specialist Sports Cars

Conclusion

The ford side valve .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 modification, 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 mass-produced engines were robust, inexpensive, widely available and spawned aftermarket components industry. Furthermore, they invited experimentation, and helped facilitate competition and design diversification. Thus assisting and elevating British motor racing :design , engineering , manufacture and of course drivers.

In the case of the Ford 1172 cc side valve it formed a dedicated race formula in the early 1950’. This was dominated by the Lotus Mk.VI

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 entrepreneur with low capital wishing to enter the market.

The contribution to British motorsport by the Ford side valve and indeed the Austin 750 is colossal and ought never to be taken for granted.

The Ford side valve was a product of Ford engineering /commercial logic. It was practical and it sold in volume. This ensured its widespread availability. The engine /gearbox unit were conceived as sound, robust, durable and serviceable.

In the immediate British post war context it was the right product at the right time and place. What the Ford side valve delivered was:-

  1. Widespread availability across the UK
  2. Affordability , there were many second hand examples, crash damaged items could be sourced from breakers as Chapman did on many occasions
  3. The engine was known , it could be serviced , there was spares availability and the DIY owner could maintain it
  4. The above factors contributed to a democracy of participation –noting our social income statistics
  5. Wide participation was healthy. To overcome some of the mechanical inadequacies enthusiasts like Chapman experimented and many of these designers contributed to the British dominance in post war motor racing
  6. The Ford engine made for close racing and perhaps placed emphasis on driving ability as contestants had similar power limitations
  7. The Ford engine helped Britain with exports and reestablish its Specialist car manufacturers post war. Note Morgan used the components
  8. The existence of the unit contributed to aftermarket sales and generally acted like a multiplier in the development of innovations and related employment

There are few engines which can claim such a significant role .There are not many modern day equivalents although Ford recreated and updated their contribution with the cross flow, VW, Rover V8’s and perhaps the Caterham -Vauxhall along with Cosworth-Ford engines perhaps?

The Ford side valve engine in the dual purpose Mk.VI had a disproportionate impact. It dominated the 1172 formula garnering beneficial publicity. The cars were seen on the road and track. The numbers sold established the commercial footing for Lotus. When a customer bought a Lotus and installed a Ford side valve they knew they had the best of both worlds. When we examine the second hand sales values of Lotus Mk.VI in the 1950’s they held their value extremely well.

This unit gained considerably extra credibility and status when fitted in the Lotus which of course was about packaging and Chapman’s added value but it ought be remembered the basic unit itself is worthy of study and appreciation. The Lotus very much relied and depended on it.

The Ford 1172 side valve is an Engine associated with Hornsey built cars.

Reference:

A Reprint of an article which appeared in the Autosport 1953.SUBJECT –The Lotus Mk.VI Sports Car.

Lotus Mk.VI Sales brochure

Lotus Seven.Weale.Osprey.1991.

ISBN: 185532153X

The Value of a Pound 1900-1993.Gale Research International.1995

ISBN: 1873477317

The Lotus Book.Taylor.Coterie.

Subscribers are directed to our extensive bibliography associated with articles listed in introduction

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.