The Build Up

Lotus had to find a more robust, and much cheaper, engine for the Elite’s replacement, the Elan, and early in 1961, the use of Ford’s engine was first discussed at Lotus.

Colin saw great merit in using the Ford engine as it was strong, cheap and Ford had a long term strategy for its use. However, the standard engines at the time, the 105E from the Anglia and the 109E from the Classic, were not considered to be capable of developing the sort of power required, so the concept of a new, twin overhead cam cylinder head on a Ford block was developed.

Harry Mundy, ex chief designer at Coventry Climax, completed the initial design work in early 1961, and Richard Ansdale continued the detail design over the summer of 1961. By the winter of 1961 a couple of prototype engines had been built, and fitted with a new front cover and head cast by Birmid in Wolverhampton.

In early 1962 an Anglia was built with an over bored 109E engine with the twincam head, and further refinements were made by Mike Costin, who was technical director at Lotus, and Harry Weslake. The next step was in May 1962, when the 1500 block (116E) with a 5 bearing crank was announced by Ford. Within 2 weeks, a 116E engine had been built with the twincam head, installed in a Lotus 23 which was raced by Jim Clark before May was out!

The Twincam Engine, Autocar June 1st 1962

There were still a lot of problems to sort out with the engine, but refinement continued throughout the rest of 1962 and into early 1963. The Elan was launched at the London Motor show in October 1962, but it didn’t run.

So looking back on 1962, Lotus had a car that cost them money every time they sold one (the Elite) and they were having difficulty selling it. They were having a lot of development problems with the Elan, which is where their main efforts were being focused, and the new Twincam engine was taking a lot longer than anticipated (at least, by Mr Chapman!) to get all the bugs ironed out. It was the perfect environment for the birth of yet another new car, the Type 28 Lotus Cortina, and another set of problems to solve.

Sometime in the middle of 1962, Colin Chapman had a meeting with Walter Hayes from Ford. Walter had been charged by the US parent to develop a programme in the UK that would promote the Ford product in motor sport over the coming 5 years, and he had heard about what Lotus were doing with his engine.

The cash-strapped Lotus organisation and the ever optimistic Colin Chapman were delighted to enter into a deal whereby Lotus would modify the Cortina for fast road use, and build sufficient numbers for it to be homologated for racing. Ford were responsible for producing the bodyshell and for the sales and marketing of the car, whilst Lotus would build the cars. By September 1963 the car was homologated for group 2 saloon car racing, after Lotus had built 1000 cars. Production started very slowly over February / March, which means that Lotus managed to build nearly 40 cars a week, which of course, it didn’t!

Modifications to a standard 1200 Cortina were started in July 1962, and the car was first track tested at Snetterton by Jim Clark in October of that year. The standard Ford Cortina was announced to the world in October, at the London Motor Show, but work still hadn’t started in earnest to refine the Lotus Cortina project due to the focus on the Elan and the twincam engine issues. But by January 1963, the Lotus Cortina was shown at the Dorchester Hotel in London, and announced to the press in Monte Carlo on January 21st.

The Lotus Cortina Is Born

It is quite amazing that in a few months Lotus managed to design and put into production a considerable number of changes to the standard Cortina, and of course, convey to Ford the changes required for them to make to the bodyshell. And have the factory at Cheshunt extended to provide the facility to build the car!Graham Arnold used to say that Lotus spent the same amount designing and putting into production the Lotus Elan as Ford did designing and putting into production the bumpers of the Mk 1 Cortina, and looking at how quickly the Lotus Cortina was developed, by only a handful of people, he was probably right.

In summary, these changes to the Cortina designed by Lotus were:

The Twincam engine was mated to the Elan close ratio gearbox, which had an aluminium tailpiece, remote and bell housing to reduce weight. The carburettors obtained cold air via an air cleaner in the nose of the car, and the engine was cooled by a larger capacity radiator. The propshaft was one piece with the main tube diameter of 3 inches and the ends swaged to take standard production UJs.

The rear suspension was fundamentally redesigned using vertical coil over damper instead of leaf springs, with the axle located by a wide ‘A Frame’ beneath trailing radius arms, a design taken from the Lotus Seven. The rear suspension was lower than the standard car. An aluminium differential nose housing was used to reduce un-sprung weight.

The front suspension was redesigned using shortened spring and McPherson strut with heavier damping properties, fractionally longer forged (rather than pressed) track control arms to eliminate wheel camber, and a heavier duty anti-roll bar some half inch longer at the ends bar to reduce castor. Shorter and straight steering arms were employed to effectively give higher steering gearing, whilst reducing the Ackermann angle. A 15 inch steering wheel gave a more responsive feel to the steering. A new high-geared steering box assembly reduced the overall gearing by 12%.

5.5 inch steel wheels were fitted with 6.00 x 13 inch cross ply tyres.

Girling brakes were employed working on 9.50 inch discs at the front and 9 x 1.75 inch drums at the rear, operated by a remote servo running at 2.04 : 1 ratio mounted at the rear of the nearside inner front wing.

For the interior, special seats were developed on the standard frames just for the Lotus, which provided more lateral support, greater rake and more comfort. A centre console with elbow rest / cubby box was installed between the seats. Dunlop ‘Hytone’ moulded rubber mats were fitted. Four instruments were contained in the dash pod, with a 140mph speedometer, an 8000rpm rev counter, a fuel gauge and a split oil pressure / water temperature gauge, all similar to the new Elan instrumentation. A studded 15 inch woodrim steering wheel with Lotus hornpush was fitted onto a steering column of reduced length, to increase arm reach, and a concave top pear shaped wood gearknob completed the Lotus specification inside. The metalwork inside the cabin was the same as the exterior colour…Ermine White.

The bodyshell used the panels from the Type 74 Cortina Saloon 2 door deluxe Floor Change, built up with enhancements to make it stronger, lighter and to accommodate changes to specification made above. The shells were built in batches in Dagenham outside the standard production line, as so many variations were built into the shells at a very early stage of manufacture that couldn’t have been ‘added’ to a standard shell once the shell was completed. The shells, complete with panels, were part assembled at Dagenham with all the parts common to other Cortinas (headlining, glass, lights, heater, wiper motor, door locks, etc.). They were then delivered to Cheshunt for final assembly using the Lotus specific components  and to have the stripe added.

The enhancements to the bodyshell included:

Aluminium skins for the doors, boot lid and bonnet.

The battery tray moved to the boot.

Tubular members were added on both sides of the boot between the top of the dampers and the (former) front and rear spring shackle mounting points.

A ‘hump’ panel was introduced in the forward boot floor over the differential to accommodate the lower rear suspension.

Brackets were installed to take the radius arms (at the original spring shackle location) and A Frame (via another bracket underneath the radius arm bracket).

Re-enforcement was added to the rear chassis members.

On the outside, the Lotus Cortina was painted in Ermine White with a Sherwood green stripe, sported (painted) Lotus badges on each rear wing and one on the grille, which now had a black infill. Quarter bumpers were fitted to the front, pinched from the back of the Anglia Van!

In January 1963 the Consul Cortina Sports Special was launched to the world, but by the time they were available, they were known by Ford as the Cortina (developed by) Lotus. The Press started to call them the Lotus Cortina, but Ford stuck to having ‘Cortina’ first in all their brochures and manuals.

10.0 1 Lotus Cortina Launch Dorchester

 The Lotus Cortina in January 1963 at The Dorchester