Brief Historical Background \/Context<\/strong><\/p>\nTaylor observes:-<\/p>\n
\u201cduring the winter of 1953 ,Colin Chapman put pencil to paper and devised a chassis for a new car based on the theory of structural strength through triangulation.to go with this chassis Chapman wanted a more streamlined body \u2026\u2026\u2026\u2026.\u201d<\/p>\n
Smith:-<\/p>\n
\u201cDuring 1953 the 1500 cc sports car racing class had attracted a great deal of attention from manufacturers which resulted in very closely fought , fast racing .It was this class that Colin wished to design a car\u2026\u2026\u2026\u2026\u2026\u2026..the opposition was stiff and a variety of sports racing cars were appearing in the class from Connaught ,Cooper, Leonard and Tojeiro.The masters in this particular field were the Porsches .In order that Lotus should stand a chance against this machinery \u2013and Colin included the Germans in his recognising \u2013some sort of \u201cmarch must be stolen\u201d<\/p>\n
Chapman wished to move up in prestige racing and this meant competing with the \u201cestablishment\u201d. In the Lotus Story Part 4, Colin Chapman stated:-<\/p>\n
\u201cAfter three years in several classes of racing, I started to think about a car for 1954. The new car would need to be as far ahead of other competition cars in its class as the Mk. VI was when it emerged in 1951.<\/p>\n
This was the ever-present problem-always keep one or two steps ahead of the competitors. People ask me why I don\u2019t give up racing and concentrate on design-the answer to that is that I must race the cars myself to find out design faults. Drivers are always a bit vague about handling and similar details, so the only thing to do is to find out things myself\u2026\u2026\u2026\u2026\u2026<\/p>\n
It seemed to me that an efficient aerodynamic body would be the thing to have for the 1954 season\u2026\u2026\u2026..\u201d<\/p>\n
Peers and Contemporaries<\/strong><\/p>\nIt\u2019s important to study these as Chapman might. He would probably conduct an analysis of strengths and weaknesses and decided how best he might improve on existing best.<\/p>\n
Equally significant is the fact that Chapman was a realist. Budget and engine availability would focus his mind on the alternative methods to beat the competition.<\/p>\n
Included:-<\/p>\n
\n- Cooper<\/li>\n
- Tojeiro<\/li>\n
- Connaught<\/li>\n
- Porsche<\/li>\n
- Jaguar<\/li>\n
- OSCA<\/li>\n
- Maserati<\/li>\n
- Nb see appendix below for fuller cross section of marques as represented by entrants at 1954 Empire Trophy, Oulton Park.<\/li>\n<\/ul>\n
Factors determining the specification of the Mk.VIII<\/strong><\/p>\nHarvey identifies three main parameters:-<\/p>\n
\n- Aircraft aerodynamic principles<\/li>\n
- Porsche adoption of low drag bodies<\/li>\n
- Banning of cycle wings in International racing<\/li>\n<\/ol>\n
He therefore deducts:-<\/p>\n
\u201cColin had to go for a full width body if he wanted to compete among the top echelons\u201d<\/p>\n
It\u2019s worth noting that the aerodynamic body had both advantages and disadvantages.<\/p>\n
The extra weight would have to be compensated for elsewhere forcing considerations of the chassis and main mechanical components like the engine.<\/p>\n
Outline the specification of the Mk.VIII<\/strong><\/p>\nIt\u2019s believed that Colin set the guiding parameters of his concept as:-<\/p>\n
\n- Top speed in region 120-125 mph deducted from linked factors\/components \/data<\/li>\n
- 85bhp engine output<\/li>\n
- Weight in region of 1000lb<\/li>\n<\/ul>\n
Chapman, Necessity and Design Methodology<\/strong><\/p>\nRoss observes:-<\/p>\n
\u201cWhat set Colin apart from other contemporary racing car designers was his very practical approach .This was in part dictated by his almost total lack of working capital, which meant that he always had to have something in current production to generate cash flow, and whatever he made himself \u2026\u2026\u2026\u2026.to race had to be capable of being rapidly turned into a production vechicle to sell to paying customers \u2026\u2026\u2026.<\/p>\n
Whilst other companies could afford to start with a blank sheet of paper, Colin\u2019s first thought was \u201cwhat existing part can be used or what existing part can I adapt to do what I want \u2026\u2026\u2026\u2026\u2026\u201d<\/p>\n
Engines<\/strong><\/p>\nLotus were not an engine manufacturer until late on in their history. Our appreciation of Chapman\u2019s achievements must take this fact into account.<\/p>\n
Chapman had to work with what was available and affordable.<\/p>\n
He had to work within these constraints.<\/p>\n
It\u2019s necessary to have a brief analysis of the implications.<\/p>\n
Subscribers might like to see A&R articles on the 1172 and 750 Formula\u2019s and Lotus Power Plants.<\/p>\n
Most mass production car manufacturers make their own engines. The size and performance of those engines are determined by considerations such as:-<\/p>\n
\n- Market requirements primarily user categories<\/li>\n
- Weight and physical size\/ volume<\/li>\n
- Performance<\/li>\n
- Fuel economy<\/li>\n
- Legislation regarding taxation and insurance categories etc.<\/li>\n
- Status<\/li>\n
- Peer competition<\/li>\n
- Economies of scale and families of product offering interchangeability etc.<\/li>\n
- A lesser consideration might be aesthetics , aural and visual<\/li>\n
- Some manufacturers might consciously enter competition and develop products expressly for this<\/li>\n<\/ul>\n
However they rarely make dedicated competition engines. This was a rub. Chapman had to extract from what was available and cost effective.<\/p>\n
Some of the most used engines in the specialist sports car sector are:-<\/p>\n
\n- Austin Seven [750] plus A30\/A35 etc.<\/li>\n
- Ford 1172<\/li>\n
- Ford Cosworth<\/li>\n
- Ford crossflow<\/li>\n
- Ford V8<\/li>\n
- Jaguar XK engine series<\/li>\n
- Coventry Climax [nb this type FWA used in Mk.VIII]<\/li>\n
- Recently motor cycle engines<\/li>\n
- MG<\/li>\n
- 2L Bristol<\/li>\n
- 1.5L Connaught<\/li>\n
- Turner [a period engine of 1.5L fuel injected is reputed to have produced 110bhp.<\/li>\n<\/ul>\n
[See our dedicated articles for bhp analysis .A tabulation of common mass produced engines is included in our article on MG engines used by Lotus]<\/p>\n
Racing classes on occasions deliberately coincide with industry trends but this has never been perfect. Specialist manufacturers have sometimes been at a disadvantage regarding choice and performance. However as in Chapman case this has been the mother of invention.<\/p>\n
When considering the 1500 racing category Chapman had to decide which engine would be within the class limits, be available, affordable, and possibly capable of being improved cost effectively and probably physically able to fit.<\/p>\n
A Lotus Mk.VI registration no.UPE 9 had dome extraordinarily well in club racing c 1954 [the editors believe it won something like 14 races out of 17?] This car had a gifted driver and many other unique parts and mofifications.But the MG engine had demonstrated its potential.<\/p>\n
It\u2019s probably this specification of engine that Chapman elected to go for in the Mk.VIII<\/p>\n
M.G. Engine Summary Details<\/strong><\/p>\nHere will deliberately only provide bullet summary. The MG engine discussed is worthy of full dedicated article as it powered MkVI and MkVIII.Please see this item that also records the MG gearbox and tuning upgrades etc.<\/p>\n
\n- MG\/Morris based XPAG<\/li>\n
- Claimed 85bhp at 6,200rpm<\/li>\n
- Laystall Lucas alloy head and other Laystall modifications<\/li>\n
- Bored out to 1467cc<\/li>\n
- Twin SU carburetters<\/li>\n
- Costin&Phipps suggest engine weight at 228lb , gearbox 32lb<\/li>\n<\/ul>\n
The claimed output of 85bhp ought to be noted. The standard engines were quoted in the mid 50 bhp range. Peter Gammon achieved some remarkable successes in Mk.VI [UPE 9] .It has to be questioned what was done to the engine and if independent dyno meter tests could confirm .The extraction of 85bhp was an achievement.<\/p>\n
MG had been record breaking and it\u2019s possible they developed some modifications that were not available on production cars.<\/p>\n
Chapman would have calculated both the power output of the engine, chassis and rolling chassis. It\u2019s from this data he probably realized that an extremely efficient and aerodynamic body was required to provide a chance of winning.<\/p>\n
The Chassis<\/strong><\/p>\nRight from the outset it\u2019s important to state two very different chassis types were used in the 7 Mk.VIII produced.Costin &Phipps perhaps providing the best technical analysis.<\/p>\n
\n- SAR5 \u2013first road registered 27th<\/sup> March 1954<\/strong><\/li>\n<\/ol>\n
This was an extraordinarily sophisticated chassis for the era. Chapman went to great lengths to reduce weight in order to possibly compensate for the engine output. Subscribers are directed to the full and comprehensive technical description of this chassis provided by Costin and Phipps who had close firsthand experience. Here we summarise and paraphrase .Our model with mannequin is based on this first concept.<\/p>\n
Costin&Phipps:-<\/p>\n
\u201cThe Lotus Mk.VIII structurally , the most nearly perfect sports car chassis yet made \u2026\u2026\u2026..very simple extremely light yet very stiff ,this chassis the only one of its type ever made \u2013is still giving good service after six years of use ,and this despite the fact it is made up of 20and 18 gauge tube\u2026\u2026\u2026\u2026\u201d<\/p>\n
The editors find in strange that most accounts explain this chassis caused problem for the mechanics regarding engine servicing .Access is importance when racing ,particularly if a highly stressed engine is to be kept in tune. If Chapman was aware of this, and as we believe using not a fully ideal engine he might have been more generous in space allowance.<\/p>\n
We suggest the following might have occurred:-<\/p>\n
\n- That Chapman took dimensions for a standard engine from drawings. That these varied from engine eventually used<\/li>\n
- That Chapman used an existing engine to dictate chassis layout ,then discovered the commissioned engine was at variance ,possibly as result of tuning<\/li>\n
- That a genuine mistake occurred in measuring, drawing or translation into reality or that to meet other strict structural criteria the engine bay became sacrificial to overall concept<\/li>\n
- That the all-enveloping body once fitted so ensconced the engine that access was reduced to impracticality<\/li>\n<\/ol>\n
<\/strong><\/p>\nFigure 2.Editors model of the basic stage chassis with artist\u2019s mannequin to indicate approximate scale. Model made from drawings.<\/p>\n
Ross provides some insights into this anomaly.<\/p>\n
Taylor comments that the chassis was of steel tubes of 1.25 inch 20swg.It reputedly weighed 35lb? Whereas Costin &Phipps suggest:-<\/p>\n
\u201cOnly 19 members are used in its construction, and the total weight is 21 lb. al lmembers are straight and there are no structural offsets\u201d<\/p>\n
B) \u201cProduction Mk.VIII- Modified from Mk.VI<\/strong><\/p>\nTaylor comments:-<\/p>\n
\u201cAfter the start of the 1954 season a number of privateers began demanding Mk.VIII… the \u201cproduction \u201dMk.VIII differed from the prototype in many ways ,not least the chassis design ,in order to ease the maintenance problems associated with SAR 5 ,Chapman reverted to the earlier Mk.VI chassis with several important differences \u2026\u2026\u2026\u2026\u2026.\u201d<\/p>\n
The alternative and possibly more practical chassis for the Mk.IX was a version of the Lotus Mk.VI and weighed 75lb.<\/p>\n
Technical Specification from Taylor<\/strong><\/p>\n\n\n\nModel<\/td>\n | Mk.VIII<\/td>\n<\/tr>\n |
\nYear<\/td>\n | 1954<\/td>\n<\/tr>\n |
\nVolume<\/td>\n | 7<\/td>\n<\/tr>\n |
\nEngine<\/td>\n | MG\/Morris<\/td>\n<\/tr>\n |
\nC.C.<\/td>\n | 1467<\/td>\n<\/tr>\n |
\nCarburation<\/td>\n | Twin H6 S.U.<\/td>\n<\/tr>\n |
\nPower Output<\/td>\n | 85 bhp<\/td>\n<\/tr>\n |
\nTransmission<\/td>\n | MG.4 speed<\/td>\n<\/tr>\n |
\nChassis<\/td>\n | Tubular steel space frame<\/td>\n<\/tr>\n |
\nBody<\/td>\n | Aluminium<\/td>\n<\/tr>\n |
\nFront Suspension<\/td>\n | Split swing axle with cs dampers<\/td>\n<\/tr>\n |
\nRear Suspension<\/td>\n | de Dion axle with transverse cs piston dampers<\/td>\n<\/tr>\n |
\nBrakes F\/R<\/td>\n | Lockheed 9x 1.75 Alfin drums , [inboard at rear]<\/td>\n<\/tr>\n |
\nWheels F\/R<\/td>\n | 15 inch 40 spoke wires<\/td>\n<\/tr>\n |
\nTyres F\/R<\/td>\n | 4.50 x 25 and 5.25 x 15<\/td>\n<\/tr>\n |
\nLength<\/td>\n | 156 inches<\/td>\n<\/tr>\n |
\nWidth<\/td>\n | 55 inches<\/td>\n<\/tr>\n |
\nHeight<\/td>\n | 32 inches to scuttle<\/td>\n<\/tr>\n |
\nWheelbase<\/td>\n | 87.5 inches<\/td>\n<\/tr>\n |
\nTrack<\/td>\n | 48.25\/47.5 inches<\/td>\n<\/tr>\n |
\nWeight<\/td>\n | 1148 lbs.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Mk.VIII Registration No.<\/strong><\/p>\nAlthough Taylor quotes a production volume of 7 cars photographic and other sources suggest that the following might be included:-<\/p>\n SAR 5<\/p>\n TYC 700<\/p>\n 624 BMG<\/p>\n 867 BMX<\/p>\n HUD 139<\/p>\n KJA 91<\/p>\n 777 FRE<\/p>\n SXB 500<\/p>\n Form, Function and Flight Tested by Frank Costin<\/strong><\/p>\nTaylor:-<\/p>\n \u201cThe body was developed by Mike Costin\u2019s brother, Frank\u2026\u2026at de Havilland .Frank had no experience of car design, but realized that the potentially high top speed and light weight of the car would require a high degree of straight line stability\u2026\u2026\u2026.he produced an exceptionally graceful and low body design with extended front wings tapering to points, the passenger side of the cockpit fully enclosed by metal tonneau, spats over the rear wheels and twin tail fins\u201d<\/p>\n <\/strong><\/p>\nFigure 3.Editors drawing of the chassis and Mk.VIII in side elevation [relate drawing to model to better comprehend form function]<\/p>\n Typical of the era Frank Costin allowed himself to be strapped to the car and driven at high speed in order he could personally observe air flow\/ stream .the tests at a disused airfield [see photo reference in most textbooks ] were conducted at about 100mph.<\/p>\n The significance of which is to forgo personal safety in order to establish his design correctness. It\u2019s also a measure of confidence and commitment to get the best possible.<\/p>\n This behavior was that of the boffins of the era.<\/p>\n Subscribers wishing to comprehend the sophisticated body shape of the Mk.VIII might like to obtain scale models by the likes of Merrymeet and Midlantic.The editors believe these are in the small scale of 1\/43rd<\/sup>.<\/p>\n<\/strong><\/p>\nFigure 4.Lotus Mk.VIII [SAR5] features on cover of Unique Books<\/p>\n Body Construction<\/strong><\/p>\nThe complex body comprising double curvature was executed by Williams &Pritchard.<\/p>\n Taylor:-<\/p>\n \u201cthe body shell was built of 20swg alloy\u2026.only the front section of the bodywork was removable ,the remainder being riveted to the supporting sheet alloy and chassis tubes\u2026..the \u201cproduction bodies were built of 18g alloy and were similar to the prototype but without the rear air outlet in the boot lid\u201d<\/p>\n The editors have not been able to discover the man hours required to construct the complex body shape. However we have extrapolated for other data that it might be approximately 40-45% of the cost.<\/p>\n RAC British GP, Silverstone.1954, Racing Sports cars. [Peers]<\/strong><\/p>\nThe editors publish this information from the net to:-<\/p>\n \n- Allow subscribers to research other marques of the era<\/li>\n
- To forensically analysis the Mk.VIII performance against this opposition factoring in elements like budget, engine performance, weight etc.<\/li>\n<\/ol>\n
\n\n\nNo.<\/strong><\/th>\nCar<\/strong><\/th>\nChassis<\/strong><\/th>\nRegistry<\/strong><\/th>\nEngine<\/strong><\/th>\nType<\/strong><\/th>\nSize<\/strong><\/th>\nCyl.<\/strong><\/th>\nTurbo<\/strong><\/th>\n<\/tr>\n<\/thead>\n\n\n1<\/strong><\/td>\nBuckler <\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n2<\/strong><\/td>\nKieft <\/strong><\/td>\n<\/td>\n | LDA 1 <\/strong><\/td>\nClimax<\/strong><\/td>\nFWA<\/strong><\/td>\n1100 cc <\/strong><\/td>\n<\/td>\n | <\/td>\n<\/tr>\n | \n3<\/strong><\/td>\nKieft <\/strong><\/td>\n<\/td>\n | <\/td>\n | Climax<\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n4<\/strong><\/td>\nLotus Mark VI<\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n5<\/strong><\/td>\nMG Special<\/strong><\/td>\n<\/td>\n | <\/td>\n | MG<\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n6<\/strong><\/td>\nMorris Minor<\/strong><\/td>\n<\/td>\n | <\/td>\n | Riley<\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n7<\/strong><\/td>\nOsca MT4<\/strong><\/td>\n1134<\/strong><\/td>\nMO24307 <\/strong><\/td>\nOsca<\/strong><\/td>\nno:1123<\/strong><\/td>\n1100 cc <\/strong><\/td>\nL4<\/strong><\/td>\nN\/A<\/strong><\/td>\n<\/tr>\n\n8<\/strong><\/td>\nRWG <\/strong><\/td>\n<\/td>\n | <\/td>\n | MG<\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n9<\/strong><\/td>\nPorsche 550<\/strong><\/td>\n09<\/strong><\/td>\n<\/td>\n | Porsche<\/strong><\/td>\n<\/td>\n | 1100 cc <\/strong><\/td>\nF4 2v DOHC<\/strong><\/td>\nN\/A<\/strong><\/td>\n<\/tr>\n\n10<\/strong><\/td>\nLotus Mark VIII<\/strong><\/td>\n<\/td>\n | <\/td>\n | MG<\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n11<\/strong><\/td>\nLotus Mark VIII<\/strong><\/td>\n8\/01<\/strong><\/td>\nSAR 5 <\/strong><\/td>\nMG<\/strong><\/td>\n<\/td>\n | 1500 cc <\/strong><\/td>\nL4<\/strong><\/td>\n<\/td>\n<\/tr>\n | \n12<\/strong><\/td>\nLotus Mark VI<\/strong><\/td>\n<\/td>\n | UPE9 <\/strong><\/td>\nMG<\/strong><\/td>\n<\/td>\n | 1500 cc <\/strong><\/td>\nL4<\/strong><\/td>\n<\/td>\n<\/tr>\n | \n13<\/strong><\/td>\nLotus Mark VI<\/strong><\/td>\n<\/td>\n | NUF 100 <\/strong><\/td>\nMG<\/strong><\/td>\n<\/td>\n | <\/td>\n | <\/td>\n | <\/td>\n<\/tr>\n | \n14<\/strong><\/td>\nConnaught ALSR<\/strong><\/td>\n12<\/strong><\/td>\nMCA 200 <\/strong><\/td>\nLea Francis<\/strong><\/td>\n<\/td>\n | 1500 cc <\/strong><\/td>\nL4<\/strong><\/td>\nN\/A<\/strong><\/td>\n<\/tr>\n\n15<\/strong><\/td>\nLotus Mark VIII<\/strong><\/td>\n<\/td>\n | <\/td>\n | Connaught<\/strong><\/td>\n<\/td>\n | 1500 cc <\/strong><\/td>\n | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |