Motor Car History
Technical History of the Motor Car

      

1890s  1900s  1910s  1920s  1930s  1940s  1950s  1960s   1970s  1980s  1990s  2000s  2010s

Toggle Navigation
  • Home
  • Makes and models
  • Motor car History
  • Maintenance Guide
    • Engines By Make
    • Engine Components
    • Electrical & electronic
    • Gearbox & Drivetrain
    • Induction & Exhaust
    • Suspension Types
    • Tyres wheels Brakes
    • Vehicle Body types
  • Trivia
  • Register
  • *Top rated*
  • You are here:  
  • Motor Car
  • Makes and Models
  • A
  • AC
  • AC 428 Frua (1965-1973)

Manufacturer A-Z

  • ALL
  • A
  • B
  • C
  • D
  • E
  • F
  • G
  • H
  • I
  • J
  • K
  • L
  • M
  • N
  • O
  • P
  • Q
  • R
  • S
  • T
  • U
  • V
  • W
  • X
  • Y
  • Z
Sports Cars
Britain
1960s 1970s

AC Frua 428

AC Frua car history from 1965

ManufacturerAC Cars
Production1965 to 1973
ClassGT Sports Car 
BodyCoupé, Convertible
Engine6.9-7 litre V8
Transmission4-speed manual 3 speed automatic
Wheelbase96 in, 2,438 mm
Length174 in, 4,420 mm
Width67 in, 1,702 mm
Height51 in, 1,295 mm
Dry weight3,025 1b, 1,372 kg
DesignerPietro Frua

 

The AC Frua or AC 428 is a British sports GT built by AC Cars from 1965 to 1973.

History

The first version was presented at the London Motor Show in 1965 a prototype, two-seater convertible which was followed by the presentation of the 428 coupes with a fastback body at the Geneva show in 1966.Main production began between the end of 1966 and the beginning of 1967, continuing until 1973.With an Italian body, British chassis, and American big block V8 it is a true hybrid. Production was 81 cars built in total: 49 coupés (known as fastbacks), 29 roadsters convertibles, and 3 prototypes special bodied.  The company, which was managed by Charles and Derek Hurlock at the time, wanted to continue the tradition of the previous Cobra. The idea was to provide the well-known and proven chassis of the AC Cobra.

The Frua is built on an AC Cobra 427 Mark III chassis tube frame extended by 6 inches (150 mm) Chassis were built at the AC plant in England then shipped to Frua's workshop in Italy where the body was fitted and then sent back to England to have the power train and trim added Chassis construction was similar to most Italian supercars of that era, with square and rectangular tubing connecting the steel body to the frame The AC Frua may be confused with the very similar looking Pietro Frua designed Maserati Mistral. However, only the front quarter windows and door handles are shared. 

The chassis with new steel coupé or spider body designed by Frua in Turin. Produced exclusively by AC between 1966 and 1973 with no influence from Shelby.Cobra Mark III production began on 1 January 1965; two prototypes had been sent to the United States in October 1964. Cars were sent to the US as unpainted rolling chassis, and they were finished in Shelby's workshop. Although an impressive automobile, the car was a financial failure and did not sell well. In fact to save cost, most AC Cobra 427s were actually fitted with Ford's 428 cubic inches (7.01 L) engine, a long stroke, smaller bore, lower cost engine, intended for road use rather than racing.

A new chassis was required developed and designated Mark III. CSX2196 was revised for the show down at Nassau which allowed a more relaxed class division of racing. This allowed the GT cobras to run with prototype Ford GT, GM Grand Sport Corvett

The new car was designed in cooperation with Ford in Detroit. A new chassis was built using 4 in (102 mm) main chassis tubes (up from 3 in (76 mm)) and coil spring suspension all around. The new car also had wide fenders and a larger radiator opening. It was powered by the "side oiler" Ford 427 engine (7.0 L) rated at 425 bhp (317 kW), which provided a top speed of 164 mph (262 km/h) in the standard model and 485 bhp (362 kW) with a top speed of 185 mph (298 km/h) in the competition model.

Engine: V.8 built by the Ford Motor Co. of America, 7,016 c.c. along with a high performance engine also available, providing 400 b.h.p. at 5,750 r.p.m.at extra cost. optional automatic gearbox also ratios, available at extra chargepower to rear via propeller shaft with Hardy Spicer needle type universal joints transmits drive to rear wheels by short halfshafts using similar joints with Salisbury limited slip differential with a 2.88 ratio is located on 3-point rubber
mountings.

Luxury touring body styled by Frua. The main chassis frame comprises 4 in. steel tubing running from front to rear cross-braced as necessary with sub-frames to support panel work fixed direct to tubes; rack and pinion steering; polished wood and aluminium steering wheel; disc brakes to all wheels, swept area 580 sq. in., front 113/4 in. diameter, rear 10 1/2 in. diameter, double master cylinder system with twin servo actuation; 15 in. road wheels with 6 in. rims, triple laced.Leather trim, with carpets, all to colour choice
from available samples; soft top retracts fully below deck cover; deep windshield with curved frameless electrically operated door windows; large 10 sq. ft. capacity luggage boot and 18 gal. tank.

The front suspension comprises twin wishbones fabricated from circular section tube and have rubber bushed chassis pivots and sealed ball joints for attachment to the vertical links, co-axial coil springs and telescopic dampers operate on the lower wishbones front and rear, the whole suspension system is mounted on rubber bushes, sealed rose ball joints and precision made hemispheres, very little service attention is required, anti-dive and anti-squat geometry contribute to the excellent road holding.The rear suspension is of twin tubular wishbone type, radius rods, for longitudinal location are used in conjunction with the lower wishbones which are of the inverted type and afford directional control of the rear wheels; cast brackets between the upper and lower wishbones carry the housings for the hub bearings, the coil spring and damper units which are behind the suspension links operate on the lower wishbones; the suspension system allows provision for independent adjustment of camber and wheel alignment.

Though the 4-inch (100 mm) tubular chassis allowed both coupé and convertible versions to be rigid, the design was intricate and prone to rust. The bonnets and boot lids were fabricated from aluminium. The cost was high and the cars could not be sold at a competitive price. Unlike similar cars such as the Iso Grifo, Iso Rivolta, Monteverdi, and De Tomaso models of the period, the AC Frua features Front engine, rear drive fully independent racing-based coil spring suspension. Fully adjustable independent suspension with double triangular wishbones, coil spring hydraulic telescopic shock absorbers at the front, at the rear adjustable independent suspension with double triangular wishbones, coil spring hydraulic telescopic shock absorbers.

First, the 6997 cc eight-cylinder Ford engine was installed, which was from the AC Cobra 427, with 385 hp (287 kW) at 5600 rpm. In March 1968 the engine was switched to Ford's larger "428" engine with 7016 cc displacement, which made 345 hp (257 kW) at 4600 rpm.

The AC Frua was never fully developed because AC Cars lacked the financial means. The car's main drawback is a tendency of the V8s heat to bleed into the cabin. with a Fully synchronized 4-speed Ford Toploader transmission (close-ratio) or 3 speed automatic Ford C6 transmission with rear differential Salisbury, limited slip with Ratios: Automatic 2.88, Manual 3.08.Brakes Four discs power assisted "Girling" 3 pistons, dual remote servo assistance. The distribution of weight was 47.4% front axle, and 52.6% at rear axle

AC 428 Frua specifications

PERFORMANCE

  • engine capacity: 428.12 cu in, 7,016 cu cm
  • fuel consumption: 17 m/imp gal, 14.2 m/US gal, 16.6 1 x 100 km
  • max speed: 150 mph, 241.5 km/h
  • power-weight ratio: 8.8 lb/hp, 4 kg/hp
  • max power (SAE): 345 hp at 4,600 rpm
  • max torque (SAE): 462 1b ft, 63.8 kg m at 2,800 rpm
  • max engine rpm: 5,250
  • specific power: 49.2 hp/l
  • max speeds: 67 mph, 107.9 km/h in 1st gear; 93 mph, 149.7 km/h in 2nd gear; 121 mph, 194.8 km/h in 3rd gear; 150 mph, 241.5 km/h in 4th gear

The AC Frua competed with Ferrari, Lamborghini, and Maserati models. Built over a stretched AC Cobra 427 chassis, the car had immense performance; the big-block Ford FE engine had larger capacity, more torque and more power than similar Italian cars, but in a car of similar weight.

This one AC that joined that select company of very fast, very luxurious touring automobiles from the 1960s. The AC 428 coupé sported a recommended UK retail price of £5,573 (including automatic transmission), to the manual transmission Aston Martin DB6's £4,460 - itself roughly twice that of a 4.2 litre Jaguar E-Type roadster at £2,225.

Towards the end of the production run a couple of prototypes for an extended range were produced. There was a four-door version of the coupe and a more streamlined version of the convertible that included electrically operated "pop-up" headlamps. Neither were developed due to the precarious state of the company finances. Production of the AC 428 ended in the summer of 1973. There were many reasons for this. The AC was very expensive but on the other hand, the market for large and fast sports cars increasingly collapsed in view of the looming oil crisis.

Number of cars built 49 coupes, 29 convertibles and 3 special bodied cars. 

AC 428 Frua Technical details convertible (1965-1973)

Related items
Britain 1970s | Britain 1960s | Vehicles launched in 1965 | British Sports cars | Pietro Frua Design | Big-Block V8 | Holley carburetors | Sports Cars

Rating

Have you Say: Rate this
Overall Vote
93% - 6 votes
  • 1
  • 2
  • 3
  • 4
  • 5
1. Performance & Specification
80% - 1 vote
  • 1
  • 2
  • 3
  • 4
  • 5
Built to last?
2. Appearance Overall *Cool factor*
80% - 1 vote
  • 1
  • 2
  • 3
  • 4
  • 5
How good it looks ?

Technical

Service
  • AC Frua 428 Maintenance and Service Guide (1965-1973)


    Fuel type: 100 oct petrol
    Engine oil change: 8 imp pt, 9.51 US pt, 4.5 1, SAE 10W-30, change every 4,000 miles, 6,400 km
    Total lubricating system capacity: 10 imp pt, 12.05 US pt
    Cooling system capacity: 17.10 imp pt, 20.50 US pt, 9.7 1.
    Gearbox oil: 4 imp pt, 4.86 US pt, 2.3 1, SAE 80
    Final drive oil: 2.50 imp pt, 2.96 US pt, 1.4 1, SAE 90
    Greasing: every 2,500 miles, 4,000 km, 9 points
    Valve timing: inlet opens 16° before tdc and closes 60° after bdc, exhaust opens 55° before bdc and closes 21° after tdc
    Normal tyre pressure: front 25 psi, 1.8 atm, rear 27 psi, 2 atm.
    Width of rims: 6" (option) light alloy wheels
    Tyres: 205 x 15;
    Fuel tank capacity: 19 imp gal, 22.7 US gal, 86 1 (2 separate interconnected tanks).
    Carrying capacity: 706 1b, 320 kg

    © Motor car History

Technical
  • AC Frua 428 Technical details and specifications (1965-1973)


    DIMENSIONS AND WEIGHT
    wheel base: 96 in, 2,438 mm
    front track: 55 in, 1,397 mm
    rear track: 56 in, 1,422 mm
    overall length: 174 in, 4,420 mm
    overall width: 67 in, 1,702 mm
    overall height: 51 in, 1,295 mm
    ground clearance: 8 in, 203 mm
    dry weight: 3,025 1b, 1,372 kg
    distribution of weight: 47.4% front axle, 52.6% rear axle

    ENGINE
    Location front
    4 stroke cylinders: 8, Vee-slanted at 90°
    bore and stroke: 4.13 x 3.98 in, 104.9 x 101.1 mm
    engine capacity: 428.12 cu in, 7,016 cu cm
    compression ratio: 10.5
    cylinder block: cast iron
    cylinder head: cast iron
    crankshaft bearings: 5
    valves: 2 per cylinder, overhead, in line, push-rods and rockers, hydraulic tappets
    camshafts: 1, at centre of Vee
    lubrication: rotary pump, full flow filter
    carburation: 1 Ford downdraught 4-barrel carburettor
    fuel feed: mechanical pump
    cooling system: water

    TRANSMISSION
    driving wheels: rear
    clutch: single dry plate
    gearbox: mechanical
    gears: 4 + reverse
    synchromesh gears: all
    gearbox ratios: 1st 2.320, 2nd 1.690, 3rd 1.290, 4th I, rev 2.320
    (option) automatic gearbox, hydraulic torque convertor and planetary gears with 3 ratios
    automatic gearbox ratios (1st 2.460. 2nd 1.460, 3rd 1, rev 2.180)
    gear lever location: central
    final drive: hypoid bevel, limited slip
    axle ratio: 2.880. (auto) 3.070.

    CHASSIS
    type tubular
    front suspension: independent, wishbones, coil springs, telescopic dampers
    rear suspension: independent, wishbones, trailing radius arms, coil springs, telescopic dampers.

    STEERING
    rack-and-pinion
    turns of steering wheel lock to lock: 3.30
    turning circle (between walls): 36 ft, 11 m

    BRAKES
    disc (front diameter 11.75 in, 298 mm, rear 10.50 in, 267 mm), servo
    area rubbed by linings: total 580 sq in, 3,741 sq cm.

    ELECTRICAL EQUIPMENT
    voltage: 12 V
    battery: 57 Ah
    alternator
    ignition distributor: Ford

    © Motor car History 

Manuals

Download: Workshop manuals Tech Guides exclusive to registered users.

Media

Gallery
  • AC Previous 5 / 21 Next

Related AC

  • AC Models
    • AC Cobra replica
    • Ace
    • Greyhound
    • 3000ME
    • Aceca
    • Invacar
    • Petite
    • Sociable

On Motor Car

  • Maintenance Guide
  • Makes and Models
  • Motor car History
  • Film & TV
  • Your Top Rated
  • Join here

log on

Log in to Motor car

  • Forgot your username?
  • Forgot your password?

Welcome To Motor Car

  • Worldwide
  • Argentina
  • Australia
  • Austria
  • Belgium
  • Brazil
  • British
  • Bulgaria
  • canada
  • Czech
  • Chile
  • Czechoslovakia
  • China
  • Denmark
  • Egypt
  • Finland
  • Greece
  • Guernsey
  • Germany
  • Hungary
  • India
  • Ireland
  • Indonesia
  • Korean
  • Mexico
  • Netherlands
  • New Zealand
  • Norway
  • Philippines
  • Poland
  • Portugal
  • South Africa
  • sweden
  • Romania
  • Turkey
  • Spain
  • Switzerland
  • Taiwan
  • Serbia
  • Uruguay
  • Ukraine
  • United States
  • Venezuela
  • Yugoslavia
  • 3 wheel car
  • Sports Cars
  • Race Cars
  • Villiers Engine
  • Le Mans
  • Straight-6 cars
  • Roadster
  • Ghia
  • Grand tourer
  • British Sports cars
  • AC Cobra related
  • Vehicles launched in 1953
  • Vehicles launched in 1964
  • Vehicles launched in 1965
  • Britain 1940s
  • Britain 1950s
  • Britain 1960s
  • Britain 1970s
  • Britain 1990s
  • AC Cobra

Please help to keep this site active.

Enjoy all of Motor Car Here


Back to Top

© 2025 Motor Car History