Guide: Ford Escort Mk1 Mexico - a Historical & Technical Appraisal
Background
Over the course of five weeks during April and May of 1970, members of the Royal Automobile Club and Motor Sports Association in the UK organised a high profile marathon that travelled a 16,000 mile route across 20 different countries from England to Mexico.
Conceived to celebrate the upcoming FIFA World Cup which had in 1966 taken place in England and for 1970 was to be held in Mexico, the London to Mexico World Cup Rally attracted a field of over 100 entries among which was a seven car works team from the Ford Motor Company.
At the time, the Blue Oval had a brace of high performance Mk1 Escorts in its product line: the Lotus Ford-powered Twin Cam (launched back in January 1968) and the Cosworth BDA-powered RS1600 (launched a few months prior in January 1970).
While both variants had been conceived as Group 2 homologation specials for circuit and rally use, even the most gruelling events expected to be undertaken by these models represented a walk in the park compared to what lay ahead for the World Cup Rally participants.
With this in mind, Ford took the reinforced Type 49 bodyshell shared by the Twin Cam and RS1600 and fitted specially prepared 140bhp 1834cc iterations of the practically bombproof Kent crossflow engine which was expected to offer greater reliability and much easier servicing.
It proved an inspired decision as the Escorts went on to finish first, third, fifth, sixth and eighth with the car driven by Hannu Mikkola and Gunnar Palm taking a famous victory.
Six months later, Ford launched a celebratory production model to coincide with the opening of its new Advanced Vehicle Operations plant in Aveley, Essex. Dubbed the Escort Mexico in honour of that epic win by Mikkola and Palm, it was essentially a Type 49-shelled Mk1 with all the same equipment as the Twin Cam / RS1600 but with a less expensive 1.6-litre Kent engine thus bridging the gap to the 1300 GT.
Developed and produced at the AVO plant alongside its pricier brethren, the Escort Mexico quickly became the choice for boy racers and clubman competitors and went on to become a massive commercial hit, outselling the RS1600 by nearly ten-to-one.
Following the production of 5000 cars, Group 1 homologation was approved on May 1st 1972.
Engine / Gearbox
Ford had released its crossflow version of the existing Kent engine during 1967 for use in various iterations of the Cortina, Capri and Escort. Compared to earlier iterations, it most notably featured a crossflow-type overhead valve cylinder head with redesigned combustion chamber in the top of the piston as opposed to the head.
In 1970, the significantly improved and much more reliable 1.6-litre A711M block had been introduced with thicker block wall, square main bearing caps, large diameter cam followers, wider cam lobes and a taller deck height.
It was this 1.6-litre A711M unit that Ford fitted to the Mexico.
Comprising a cast-iron block with light alloy twelve valve head, displacement was normally 1599cc thanks to a bore and stroke of 80.98mm and 77.72mm respectively. However, some cars left Aveley with a 1601cc displacement as a result of an 81.07mm bore and 77.62mm stroke (as confirmed by Ford’s homologation application for the model).
The compression ratio was always 9.0:1 and fuel feed was courtesy of a single twin-choke downdraught Weber 32/36 DGV carburettor.
A four-to-one exhaust manifold was a unique addition.
In this configuration, peak output was 85bhp at 5500rpm and 92lb-ft at 4000rpm.
For comparison, the RS1600 with its Cosworth BDA motor pumped out 115bhp at 6500rpm and 110lb-ft at 4500rpm in standard trim.
Like the Escort Twin Cam and RS1600, the Mexico transmitted its power through a four-speed manual Type 3 2000 E Cortina gearbox with a hydraulic clutch and open differential. The same gear ratios and rear axle ratios were carried over, but the clutch diameter was reduced from 8 to 7.5-inches.
Chassis
As per the Escort Twin Cam and RS1600, the Mexico used Ford’s special Type 49 pressed steel bodyshell which was in turn an uprated and stiffened incarnation of the Type 48 used by the two-door 1300 GT. Like every Mk1 Escort, the Mexico had a 2400mm wheelbase and rear-wheel drive layout.
The Type 49 shell came with inner wing strut towers that had small flitch plate strengtheners and a wing-rail-to-strut-top strengthener on the top of the strut tower. The front suspension top plates had a double skin spot welded in place.
In terms of the floor, the centre and rear exhaust hangers were modified. The back of the floor had axle tramp bars mounted to it. Rear spring hangers were of the skidded type. A stone deflector was bolted in place underneath the boot floor.
Offset engine mounts were used that pushed the nose of the engine towards the left-hand side of the car (a hangover from the Twin Cam’s wide Lotus cylinder head with its pair of sidedraught Weber carburettors that fouled the right-hand side inner wing). For similar reasons, the brake and clutch master cylinders were mounted on the front bulkhead.
Type 49 shells also received modifications to the gearbox tunnel with the gear lever cavity moved further back and a supplementary plate welded in place.
To improve weight distribution (and because there was originally insufficient space in the engine bay), the battery was housed in the left-hand side rear fender. Moving the battery to the trunk meant that the spare wheel now had to be bolted to the boot floor (instead of the usual upright position) which resulted in reduced luggage space than a regular Escort of the time.
Also housed in the trunk was a 9 gallon (40.9-litre) fuel tank located in the right-hand side rear fender.
Independent front suspension was via coil springs with Capri-sourced MacPherson struts and track control arms. Ford also added an anti-roll bar.
The back end employed a live axle with semi-elliptic leaf springs, radius arms and double-action telescopic dampers. The biggest change compared to the 1300 GT was the Type 49’s adoption of different radius arms which were essential to keep the beefier rear axle (sourced from the Lotus Cortina) in position.
As a consequence of the uprated suspension, ride height was lower than normal.
Like the Twin Cam and RS1600, the Mexico’s hydraulically-operated and servo-assisted brake system ran 244mm discs up front and 229mm drums at the rear.
Similarly, 5.5 x 13-inch pressed steel rims with chrome hub caps from the Lotus Cortina were used and originally shod with 175HR70 tyres.
Bodywork
Like the Twin Cam and RS1600, at first glance the Mexico’s all steel body looked like any other Mk1 Escort. However, there were a handful of subtle differences.
At the front, Ford fitted a special two-piece front bumper that allowed increased airflow to the engine bay.
A black instead of natural alloy front grille was installed and all four wheelarches were subtly flared.
Otherwise, aside from the wider than normal wheels, the only external change were Mexico badges affixed to the boot lid and front fenders.
Interior
Inside, the Mexico and RS1600 were pretty much identical aside from some different instrumentation.
Behind the imitation leather-rimmed three-spoke sports steering wheel was an oval six-gauge oval binnacle with a natural alloy fascia. The two large dials were new: a 7000rpm instead of 8000rpm rev counter and 130mph instead of 140mph speedometer. They were flanked to the right-hand side by a cluster of four smaller read outs (fuel, oil pressure, water temperature and battery charge).
The original natural aluminium dash fascia and deep-dish ‘Springalex’ steering wheel were later switched a satin black and flat RS-branded item respectively. The seat pattern was also changed in later years.
Upholstery was a mix of vinyl PVC and carpet. Fluted seat centres matched the door trim panels.
The windscreen washer control was a foot-operated button mounted on the floor to enable the driver to keep both hands on the steering wheel.
Standard equipment included wind-down windows, a heater / de-mister, two-speed wipers with non-lift blades, sun visors and an ashtray.
Options
Customers could upgrade their Mexico with a number of optional extras to include a stripe kit (for the sides, trunk lid and roof in red, white or black), a Webasto sunroof, faux wood cockpit trim, a vinyl roof, a cigar lighter and map reading light.
Performance-inspired options included Rallye Sport alloy wheels, Bilstein dampers, a limited slip differential, a roll cage, a fire proof rear bulkhead, a sump guard, a supplementary oil cooler, a battery isolator switch, flared wheelarches, wider magnesium alloy Minilite wheels and spot lights.
Weight / Performance
In standard trim the Escort Mexico weighed 851kg which was 66kg more than the RS1600.
It had a top speed of 99mph and 0-62mph time of 10.4 seconds (down from 115mph and 8.5 seconds respectively).
Production Changes
In early 1971, Ford began to offer two option packs: Custom and Clubman.
The Custom Pack was created for those customers that wanted a slightly more refined vehicle than the standard offering. It came with extra sound deadening (to include floor and under bonnet), plush deep-pile black carpet, special ‘comfort contoured’ front seats, Bri-Nylon fabric upholstery, a new centre console complete with oddments tray, a map reading light, a heated rear window, the black vinyl roof, a cigar lighter, a radio, a brake warning light, headrests and a triple coachline down each flank.
The Clubman Pack was aimed at those buyers who wanted to go rallying. It comprised four seven-inch spot lamps complete with plastic covers (two driving lights and two fog lights), uprated front springs with heavy-duty top mountings, dual gas/oil dampers, a map reading light, front bucket seats and a rollcage. At extra cost customers could also specify stone guards for the spot lights along with a magnesium alloy sump shield and off-road tyres.
During 1972, Ford introduced the AVO Special Build programme that enabled customers to choose from the full range of competition upgrades direct from the factory in order to create what they called an International Rally car, Club Rally car or Hi-Series Street car.
The list of potential upgrades was extensive. It included: a heavy duty front chassis crossmember, a heavy duty rear axle assembly, heavy duty rear axle shafts and bearings, a rear axle cooler kit, a rear axle diff protection shield, a front strut brace, thicker stabilising mounts, reinforced lower suspension arms, uprated front hubs, rear disc brakes, larger diameter brake discs with uprated calipers, alloy wheels, a magnesium alloy sump shield with mounting bar, a five-speed ZF gearbox, a magnesium alloy bellhousing for the five-speed ZF ‘box, a twin or triple-plate clutch, a steel flywheel, a wheelarch extension kit, a fibreglass hood and trunk lid, lightweight doors (a mixture of steel and aluminium), plastic side and rear windows and a competition-spec. four-gauge instrument cluster.
Also in 1972, Ford relocated the battery from the trunk to the engine bay.
In 1973, the rear suspension layout was subtly revised.
End of Production
Mk1 Escort Mexico production ended in January 1975 when Ford closed its AVO plant at Aveley.
By this time, 10,352 examples had been built although demand had dropped significantly after the RS2000’s introduction in July 1973.
Text copyright: Supercar Nostalgia
Photo copyright: Ford - https://www.ford.com
