Colin Chapman had been wishing to build his own engines for Lotus, mainly because the Coventry Climax unit was so expensive.

Almost as soon as the engine appeared in production cars (Lotus Elan), it was replaced with a larger capacity unit (82.55 mm bore to give 1,557 cc).

Ford supplied the 2-door Cortina bodyshells and took care of all the marketing and selling of the cars, whilst Lotus did all the mechanical and cosmetic changes.

The major changes involved installing the 1,557 cc (105 bhp (78 kW; 106 PS)) engine, together with the same close-ratio gearbox as the Elan.

The cars also received front quarter bumpers and round Lotus badges were fitted to rear wings and to the right side of the radiator grille.

Interior modifications were limited to a centre console designed to accommodate the new gear lever position, different seats and the later style dashboard, featuring tachometer, speedometer, oil pressure, water temperature and fuel level gauges.

This problem was mainly caused by the high loads put on the axle because of the A bracket it was an integral part of the rear suspension.

All these changes made the cars less specialised but far more reliable and all the special parts were still available for competition as well as to members of the public.

In order to do this the Mk2 had to be much easier to build than the Mk1 so that it could be made alongside Mk2 GT production, just with a different engine and suspension.

The main difference was the choice of colours and the lack of a stripe, although most had them fitted at Ford dealers at extra cost.

The Mk2 was a wider car than the Mk1, so although they looked the same, the steel wheels had a different offset so as not to upset the tracking, and radial tyres were now standard.

The Mk2 did exactly what Ford wanted, it was far more reliable whilst still quick enough to be used in competition, until it was replaced by the Escort Twin Cam.

[9] Two 4-door versions were supplied to the Mid-Anglia Constabulary for evaluation as use as a fast patrol and pursuit car by British Police forces.

1965 saw the Cortina Lotus winning regularly, the car being more competitive due to the increased reliability of the new leaf spring rear end.

Fuel-injection and dry sumping were allowed, and with Lucas injection and tuning by BRM, the engines could produce 180 bhp (130 kW; 180 PS) at 7750 rpm, increasing their ability to stay with the Mustangs.

The cars also had the MacPherson struts replaced with coil springs and shock absorbers and a revised wishbone geometry.

In the European Touring Car Challenge, Sir John Whitmore scored another four wins, not enough to give him the title, being beaten by Alfa Romeo Giulia GTAs.

Cortina Lotus Mark 1's are a consistent class winner in modern Historic Touring Car racing throughout the world.

The fastest official recorded speed is 147 mph (237 km/h) at Mount Panorama Bathurst in Australia by Marc Ducquet.

[11] The car was owned by Bob Pearson and had a 203HP Twin Cam engine built by Randall Edgell in New Zealand.

For example, the legendary Australian driver "Gelignite Jack" Murray[13] driving a Cortina GT500 - Australia's answer to the Cortina Lotus produced to comply with the local build requirements to be able to be raced of 100 units; initial batch 122, as opposed to running the Cortina Lotus which would have been imported with a minimum requirement of 250 - built by and intended for Harry Firth in the 1965 Bathurst 500 was clocked at 118 mph down Conrod Straight using a 3.9 diff, Lotus gearbox, large diameter (non radial) tyres and 7,900 rpm.

Canadian born Australian Allan Moffat shocked the outright class cars, winning Round 3 of the inaugural series in 1966 at the Bryar Motorsports Park in Loudon, New Hampshire.

Whilst the Cortina Lotus is somewhat overshadowed by the success of the Ford Escort in rallying, it performed admirably in the mid-1960s, which might be surprising, given its reputation for unreliability.

The A-bracket was persevered with by Vic Elford and David Seigle-Morris for the 1964 Tour de France Automobile, a 10-day, 4,000-mile (6,400 km) event, as it was run completely on sealed roads, unlike the rough RAC Rally.

New cars were used for the Coupe des Alpes (Alpine Rally), where Elford's engine blew up after leading, while Roger Clark finished second.

Clark was always competitive, but suffered with unreliable cars, coming 3rd in the Canadian Shell 4000, 2nd in Greece, and 4th in Poland.