The ultimate Imp based car must surely be the Fraser GT, also known as the Killeen Monocoque. It was designed by Tom Killeen and directly followed on from the previous sports car designs, the K4 and K7. It combined in one car all the essentials of monocoque car construction, following some 13 years of successful racing of the original K1, with highly developed suspension and aerodynamic body styling. Many of Killeen's innovative ideas were patented during that period. The prototype model is shown above in a photograph from Tom Killeen. Below are two original press photos from 1966.
The K9 was powered for testing by an 1150cc Imp unit which benefitted from tuning experience gained during Alan Fraser's long racing career. The very definate aim in producing this car was to have a GT prototype car of up to 2 litres capacity, complying with the Group 6 and Le Mans regulations of 1967-8. It is possible that an Imp based 2l V8 unit was to be built. It is thought that Killeen may have become associated with Fraser following the Rootes' Asp sports car development. Killeen, at the time in 1962, worked as a consultant for Jensen Motors, who were chosen by Rootes to built the Asp as they had worked on the Tiger before. The project was eventually turned over to Fraser.
The GT car was announced at the Racing Car show in 1966 with the stated aim to compete in Group 6 race events. It was in direct competition with the Costin-Nathan unveiled at the same show.
[photos from Autocar]
[1 photo which I have copies of showing finished car]
The 1967 Le Mans 24 hour race was held on 10-11th June 1967 and the 1968 race on 28-29th September, the June date in 1968 being cancelled owing to strikes in France. The Fraser GT was to be run with backing from the Rootes Group, manufacturers of the Hillman Imp, who had a works rally team but no racing team, so always looked to Alan Fraser to represent them at international racing events. A special requirement was that the car should have exceptional cornering ability, even at the expense of maximum speed. It was considered that the two most successful innovations in post-war racing cars were firstly the extemely rigid and light monocoque construction, as patented by Tom Killeen in 1952, when he was also an engineer with Jensen and aircraft designer; secondly ultra-low profile tyres. Whilst stressed monocoque principles were established by 1966 and even used in production cars such as the Imp, no car so far had achieved the potential of the low profile tyres.
Very wide low profile tyres, ``L section'' cross plyes at that time, only function correctly if their entire surface is kept evenly in ground contact all the time. Independent suspension (as used on the Imp) could not meet these conditions since, under even a slight cornering force, the suspension would tilt, bringing one edge of the tyre into harder contact with the ground than the other and resulting in uneven wear and loss of traction. L section tyres re-produced by Dunlop are now used on Imps in historic racing, for instance the HSCC saloon car championship, but for the above reasons are still prone to rapid wear. This is even a sad but familiar story when somewhat wider radial tyres are used to replace the original cross ply ones on early Imp saloons.
To take full advantage of the tyres, the Fraser engineering team therefore specified that rigid tubular axles should be used on both front and rear suspension of the K9 - de Dion suspension was fitted.
Needless to say, the layout of the Imp engine and transaxle in K9 caused some complication. The car was mid-engined with, in test form, the transaxle upside down behind it and between the wheels, which were driven by the usual rotoflex couplings and 1" diameter Imp drive shafts. This meant that the de Dion tube forming the rigid axle had to be taken up over the transaxle and arms suspended from it to take the Imp rear hubs and bearings. The tube was made from 2 1/2" diameter chrome molybdenum steel of 0.064'' wall thickness. Technically that was itself one of Killeen's stressed tube monocoques. The tube and hubs were located on, and allowed to move relative to the chassis, by upper and lower radius arms and a Watts linkage attached to the transaxle mounting frame. This linkage also had to circumnavigate the transaxle by having a pivot lever located on one side, an idler on the other and a cross tube over the top.
The following photo shows John Barton working on the car with Alan Fraser and Leslie Sherley-Price standing behind.
The front suspension also used a rigid axle. It was then necessary, through lack of space, to use a cam and roller steering box made by Cam Gears. A 13'' steering wheel and suitable positioning gave conveniently 2 1/8 turns lock to lock. The drop arm from the steering box acted on a drag link connected to the right hand steering radius rod. From there was a single 4 foot track rod connected the two hubs. It was made from 1" by 16 swg T45 tube to avoid whip. The front axle was again built from a de Dion tube located by radius arms (located toward the rear on the box shaped extension to the monocoque tub) and a Watts linkage of more normal layout.
Damping was provided by single oversprung telescopic shock absorbers on all four corners of the car bearing on the axle brackets.
The body of K9 was extremely low and streamlined to achieve a low drag coefficient. Even though the track was very wide because of the wide tyres, the low height of 40 inches meant a cross sectional area of only 14.7 square feet. The centre monocoque tub used a 20swg steel box formation extending fore and aft of the two main bulkheads to carry suspension and engine mountings. Bulkheads were of sandwich material for extra stiffness. The tub was skinned with 16swg Hiduminium riveted in place (Hiduminium is a light, rigid aluminium alloy now largely superseded by fibreglass). The car had gull wing doors, as did many of Killeen's later designs, to allow the greatest depth for the sill sections.
[1 photo which I have showing car from side with John Barton working on it]
The one piece tail section was also made of Hiduminium and was hinged onto the rear roll hoop at the top. The front cowl was also of Hiduminium held in place with Dzeus fastners. A reasonably conventional body shape was used except that the Camm tail was extended somewhat to reduce potential drag. This was an idea also tried by Frank Costin in his very low drag vehicles.
A front mounted radiator had a hinged air intake which could be controlled by the driver. Coolant was carried to the engine in 7/8'' diameter Tungum alloy pipes running down the floor centre panels.
Because it was to be used in 24 hour racing, lighting was needed. The car used pop up mirrors instead of headlamps. These achieved the same aerodynamic improvement, but saved weight. The idea had been patented in 1959 during the design of the Killeen K4.
[1 photo which I have showing car from front]
By April 1967 K9 still hadn't been seen on the track. The delay had not been caused by mechanical problems, but by lack of labour and time. K9 was in fact never even tested, let alone raced. The finished car was painted in the Fraser team's familiar blue and white colours, and thought to be powered by an 1150cc Imp unit benefitting from tuning experience gained during Alan Fraser's long racing career. It was possibly intended to eventually provide a 2 litre V8 unit. Given the weight difference between the 1006cc Nathan (750lb dry) and K9 (1145lb dry) K9 would have had to have at least a 1500cc engine to be competitive, and would therefore have been in the 1301-1600cc prototype class competing with the Renault Alpine or in the 1601-2000cc class which the Porsche 907 dominated.
The takeover of the Rootes Group by Chrysler however prevented the proposed V8 engine from being built (although the whereabouts of one independently built are known). Whilst K9 didn't appear at the 1967 Le Mans race, there was another Imp based entry, the Costin-Nathan GT, which however dropped out with fuel starvation and electrical faults after only 15 laps. Stakes were high, and the race in 1967 was won by a 7 litre Ford GT 40 driven by Dan Gurney and Anthony Foyt completing 388 laps - significantly better even than Le Mans cars in more recent years!
There is another rumour of a plan to use a 2l BRM engine, possibly the ``Tasman'' V8, but that wouldn't fit. Alan Fraser says they couldn't get one in time anyway. Chrysler did indeed work with BRM later, on competition versions of the Avenger, so the contact may have been already made. There were worries about using a standard Imp engine with inverted transaxle for 24 hour racing, even though these were commonplace in Imp based single seaters, e.g. the F4 Vixen, Delta and Ginetta G17, for short duration sprint and hillclimb events. It was therefore decided to run an Imp engine backwards, which required a special camshaft and drive for the oil pump. Robin Human had acquired the remains of the oil pump drive gears from an engine of this type and has now passed them on to me. It is thought that the convertible Asp (known as CUB) would also have had this engine arrangement since it was designed for low maintenance road use. The rear axle of K9 may have been modified to fit CUB to test the arrangement, but at the time of writing this is pure speculation.
The effective take over of Rootes by Chrysler however put paid to the racing programme and Fraser closed down c.1969. Alan Fraser emigrated to Tenneriffe and opened an animal sanctuary. The GT car was acquired by a Fraser employee, John Wortley, who subsequently emigrated to Canada taking K9 with him. Unfortunately some damage to the front end of the body was caused in the cramped container. K9 returned to England c.1994 and was stored in a lock up garage in Deal, Kent by Daren Wortley, John's son. The remains of K9 were then found after an extensive search by Robin Human. It was brought, in the condition in which it was found, to the Imp Club International Weekend, Scotland, 1998. Alan Fraser was greatly saddened to see it in this condition, even though it was 30 years after he had created he car.
[some of Robin's and my photos]
K9 changed hands again in April 2001 when Robin sold it to Colin Cooper of Chipping Norton, previous owner of Killeen designed car K1 and monocoque motor cycle K11. Cooper had been looking to find K1 again, which he had sold at auction in 1985. His initial evaluation of the work required to restore K9 unfortunately indicated that this would not be a straightforward restoration. Due to other unforseen problems Cooper put up his cars for sale at Coy's auction at the new Rockingham Speedway on 27th May 2001 where K9 was bought by the author R.J. Allan. It is now in the process of a long term restoration and further information is sought to uncover its history and missing components. The rear suspension, engine and gearbox layout will be re-constructed as described above.
Classes and Winners of the Le Mans 24 Hour Endurance Race
It is interesting to see what sort of classes were available to Le Mans entrants in the mid 1960s. We can also see the sort of cars that K9 would have to compete against. There were Imp entries in 1965 and 1967, following Climax based cars in earlier times, but none completed the 24 hour time.
This a schematic showing the layout of the circuit from 1956-67.
In mid-sized engine classes under 2l competing against: Porsche, Rover-BRM Turbine, MGB, Austin-Healey, Triumph, Alfa Romeo, Renault Alpine, Elva-BMW, Ferarri, Ford Cortina, Simca Abarth, Lotus Elan, Emery-Imp, Lotus Elite, Matra Djet.
|Index of Performance||Herbert Linge/ Peter Nöcker||Porsche 904|
|Index of Thermal Efficiency||Gerhard Koch/ Toni Fischhaber||Porsche 904 GTS|
|Prototype 5001-unlimited||Regis Fraissinet/ Jean de Mortemart||Iso Grifo|
|Prototype 4001-5000cc||Pedro Rodriguez/ Nino Vaccarella||Ferrari 365 P2|
|Prototype 3001-4000cc||Masten Gregory/ Jochen Rindt||Ferrari 275|
|Prototype 1151-1300cc||Paul Hawkins/ John Rhode||Austin-Healey Sprite|
|LM Prototype 1601-2000cc||Herbert Linge/ Peter Nöcker||Porsche 904|
|GT 4001-5000cc||Jack Sears/ Richard Thompson||AC Shelby Cobra|
|GT 3001-4000cc||Willy Mairesse/ ``Beurlys''||Ferrari 275 GTB|
|GT 1601-2000cc||Gerhard Koch/ Toni Fischaber||Porsche 904 GTS|
|GT 1001-1151cc||Jean-Jacques Thuner/ Simo Lampinen||Triumph Spitfire|
The two Imp entries from Paul Emery in the 1300cc class (numbers 90 and 96), which were to be driven by Paul EMery and Chris Lambert respectively, did not appear Car 90 was not accepted..
In mid-sized engine classes under 2l competing against: Porsche, Renault Alpine, Mini, Austin Healy, Matra BRM, Peugeot, ASA, Ferarri, Alfa Romeo, Lotus Elan, Fiat Abarth.
|Index of Performance||Jo Siffert/ Colin Davis||Porsche 906|
|Index of Thermal Efficiency||Jacques Cheinisse/ Roger Delageneste||Alpine Renault A210|
|Prototype Unlimited||Bruce McLaren/ Chris Amon||Ford GT40 Mk II|
|Prototype 1601-2000cc||Jo Siffert/ Colin Davis||Porsche 906|
|Prototype 1301-1600cc||no finisher|
|Prototype 1151-1300cc||Henri Grandsire/ Leo Cella||Alpine Renault A210|
|Sports Cars||Günther Klass/ Rolf Stommelen||Porsche 906|
|GT 3001-5000cc||Piers Courage/ Roy Pike||Ferrari 275 GTB|
|GT 1601-2000cc||``Franc''/ Jean Kerguen||Porsche 911 S|
In mid-sized engine classes under 2l competing against: Porsche, Renault Alpine, Austin-Healey, Fiat Abarth, Matra-BRM, Lotus Ford, Peugeot, Nathan-Imp, Mini, Alfa Romeo, Matra-BRM, ASA.
|Index of performance||Jo Siffert/ Hans Hermann||Porsche 907|
|Index of Thermal Efficiency||Dan Gurney/ A.J. Foyt||Ford MkIV|
|Prototypes, unlimited||Dan Gurney/ A.J. Foyt||Ford MkIV|
|Prototypes 4001-5000cc||Ludovico Scarfiotti/ Mike Parkes||Ferrari P4|
|Prototypes 1601-2000cc||Jo Siffert/ Hans Hermann||Porsche 907|
|Prototypes 1301-1600cc||Jean Vinatier/ Mauro Bianchi||Alpine Renault|
|Prototypes 1151-1300cc||Henri Grandsire/ José Rosinski||Alpine Renault|
|Sports Cars 1601-2000cc||Vic Elford/ Ben Pon||Porsche 906|
|Sports Cars 1301-1600cc||no finisher|
|Sports Cars 1151-1300cc||Marcel Martin/ Jean Mesange||Abarth 1300GT|
|GT||Rico Steinmann/ Dieter Spörry||Ferrari 275 GTB|
The Costin Nathan was entered by Roger Nathan Racing Ltd. Drivers were Roger Nathan and Mike Beckwith (who, as luck would have it, did not get a drive). The car, with 1006cc engine, ran for 5 hours and completed 15 laps of the Sarthe circuit, before failing with fuel starvation, electrical and gearbox problems.
The slowest car to finish this year was the 1289cc Fiat Abarth Coupé entered by Ecurie Maine of France. It completed 262 laps or 3531 km. The rate of progress of the Nathan had been much slower than this as the team strove to fix the problems. The fastest car, the Ford GT MkIV entered by Shelby American Inc. completed 388 laps!
K9 was not entered this year.
Cars under 2l capacity: Alfa Romeo, Renault Alpine, Porsche, Austin-Healey, Fiat Abarth, Ferarri, Sanderson Ford, Healey Climax, Simca, Marcos Volvo, Piper Ford, Costin-Nathan Ford.
|Index of Performance||Jean-Claude Andruet/ Jean-Pierre Nicolas||Alpine Renault A210|
|Index of Thermal Efficiency||Jean-Luc Thérier/ Bernard Tramont||Alpine Renault A210|
|Sport-Proto. 2501-3000cc||Rolf Stommelen/ Jochen Neerpasch||Porsche 908|
|Sport-Proto. 2001-2500cc||Dieter Spoerry/ Rico Steinemann||Porsche 907|
|Sport-Proto. 1601-2000cc||Ignazio Giunti/ Nanni Galli||Alfa Romeo Tipo 33B/2|
|Sport-Proto. 1301-1600cc||Alain LeGuellec/ Alain Serpaggi||Alpine Renault A210|
|Sport-Proto. 1001-1150cc||Jean-Claude Andruet/ Jean-Pierre Nicolas||Alpine Renault A210|
|Sportscars||Pedro Rodriguez/ Lucien Bianchi||Ford GT 40|
|GT||Jean-Pierre Gaban/ Roger Van der Schrick||Porsche 911 T|
Even if K9 had been entered this year, the class structure had changed and it would not have been competitive ???.
Some more photographs and further information about K9, K18 and K19 can be found in another book, "From Weird to Wonderful Part II - Imp engined Specials" by R.J. Allan (to be published).