An open secret for some time, the Lotus-Cortina was shown to the Press by Ford during January. It has been known for some time that Colin Chapman was co-operating closely with Ford on several new projects and the highly-modified Cortina is one of the first fruits of this collaboration. It must be conceded by even the most ardent Ford enthusiast that the Cortina is an unexciting car but the modifications carried out by Lotus have turned it into a “Q” car par excellence.
The changes carried out by Lotus are probably the greatest that have ever been made to a road-going production car. The performance has been altered out of all recognition by the fitting of the twin overhead camshaft Lotus version of the Ford five-mainbearing 1½-litre engine, which has been enlarged to 1,558 c.c. and fated with two twin-choke DCOE2 Weber carburetters. In this form the engine develops 105 b.h.p. at 5,500 r.p.m. and 108 lb. ft. of torque at 4,000 r.p.m., although it has been tuned to develop 140 b.h.p., and it is claimed that even at this high output the engine is perfectly reliable. Claimed performance figures, using 6,500 r.p.m. as a gear-change point, are 45 m.p.h., 69 m.p.h., 92 m.p.h., and 115 m.p.h., with acceleration of 0-100 m.p.h. in “around 30 sec.”
Naturally with such performance available some serious suspension modifications were called for and as Colin Chapman said in his speech at the Press reception, “We have made the best of a bad job.” He wanted to convert the Cortina to independent rear suspension but Ford would not allow this, presumably because the recent statements of their engineers that they cannot make an independent layout handle better than a rigid axle would be made to look rather foolish if Chapman had succeeded. As it is he has thrown away the leaf-springs and converted the rigid axle to coilspring suspension. Location is taken care of by twin radius arms and an “A” bracket with single-point mounting below the differential. To reduce the weight of the axle an aluminium alloy differential housing has been fitted. Front suspension remains basically unaltered but has been modified to give zero camber. The suspension has also been lowered considerably and stiffened with 140 lb. per inch springs at the front and a stiffer anti-roll bar. Ground clearance below the rear axle is 5.3 in.
Weight saving has also been made in the transmission with an aluminium alloy bell-housing, gearbox extension and remote-control extension. An 8-in. diaphragm type clutch is used and close-ratio all-synchromesh gears are fitted. Standard final-drive ratio is 3.9 : 1 but other ratios are available on request.
Braking is by a combined disc/drum layout, with 9¾-in. discs (taken from an as yet secret new Ford, so Colin Chapman said) at the front and 9 in. x 1¾ in. drums at the rear, the system being servo assisted. The recirculating ball steering now has a reduced 13.4 : 1 ratio and a wood-rimmed 15-in. steering wheel is fitted as standard. Other modifications include wide-based rim road wheels fitted with 6.00 x 13 in. tyres and the 12-volt battery is moved to the boot. Further weight saving has been made by using aluminium outer panels for doors and bonnet.
Inside, bucket seats are fitted and the trim is greatly altered with a central arm-rest and the other panels finished in black Vynide. A complete set of instruments, including a 140-m.p.h. speedometer and 8,000-r.p.m. tachometer, is supplied.
The cars, which will be converted by Lotus, will be supplied only in white with a wide green flash. Team Lotus will run a works team in saloon-car races with Jim Clark, Trevor Taylor and Peter Arundell as the main drivers, while the Ford works will rally a team of cars. The price of the Lotus Cortina, or “Consul Cortina Sports Special” as Ford hope we will call it, is not available as we go to press but is expected to be in the region of £1,000.