1968 AC 428

There have been several perfect unions in the automotive industry that, by all logic, should have been successful - but weren't. The ASA 1000 was essentially a smaller version of the Ferrari, with similar styling and mechanical fortitude, but fewer than 100 units were built, far below the anticipated volume of over 3000 cars annually. The Apollo 5000GT (Vetta Ventura) proved that 'success in the automotive world is not always measured by financial statements alone.' They wore attractive Italian aluminum coachwork by Intermeccanica and were powered by Buick V8 power, but only 88 examples were eventually built between 1962 and 1965. Annual production of the Facel Vega vehicles rarely exceeded 100 units annually. The Swiss-based Monteverdi and Italian-based Iso Autoveicoli S.p.A. followed similar 'hybrid' formulas with production remaining exclusive.

Among the unions that were successful, both in popularity and in profitability, was the AC/Shelby Cobra. This was the driving inspiration for AC Cars which wanted to reconfigure its potent sports car into a luxurious Grand Routier. The formula would incorporate similar key components, including Italian styling, American V8 horsepower, and the Cobra MK III coil-suspended chassis with a 6-inch increase in the wheelbase. The chassis was dispatched to Italy to be clothed in steel coachwork by Pietro Frua.

Pietro Frua was a leading Italian coachbuilder during the 1950s and 1960s, whose early work included the Fiat 1100C Spyder and the Maserati A6G. Their styling on the Maserati Mistral (1963 - 1970) would share numerous similarities with the AC 428, including the gently sloping hood flanked by round headlights, the fastback rear styling, and the wraparound windshield. While similar, only the front quarter windows and door handles were shared. Both had a similar footprint, with the Mistral's wheelbase of 94.5 inches and an overall length of 177.2 inches being very similar to the 95-inch wheelbase of the AC and an overall length of 176 inches. The Mistral, however, was powered by a 3.5-liter inline-6 (eventually growing to 4 liters), while the AC Frua (also known as the AC 428) was given a Ford 428 cubic-inch (7.0-liter) V8.

The chassis of the AC Frua used square and rectangular tubing connecting the frame to the steel body. Body styles included both a coupe (fastback) and convertible, with their boot lids and bonnets formed from aluminum. The suspension was adjustable independently with coil springs, double triangular wishbones, and hydraulic telescopic shock absorbers. Stopping power was courtesy of 'Girling' 3-piston disc brakes and steering was by Rack and Pinion.

The 'big block' Ford FE 428 engine had a bore of 104.9mm and a stroke of 101.2mm. It had a compression ratio of 10.5:1, hydraulic lifters, Autolite or Holley four-barrel carburetors, and delivered 345 horsepower at 4,600 RPM and 474 lb-ft of torque at 2,800 RPM. Some examples received high-performance, cross-bolted main Ford 427 side-oiler engines with 385 horsepower and 460 ft-lb of torque. Transmission options included a fully synchronized four-speed close-ratio Ford Toploader or a three-speed Ford C6 automatic. Since these vehicles leaned more towards 'touring' than 'sport,' the majority were outfitted with the automatic transmission. Power was sent via a Salisbury limited-slip differential with a 2.88 axle ratio for the automatic transmission and 3.08 for the manual.

Like so many great Grand Touring vehicles throughout history, the AC Frua was a victim of 'outside' influences. The energy crisis of the early 1970s was instrumental in its demise, along with Ford's ability to supply engines, and Frua's production limitations. Shipping the rolling chassis to Turin and back again after the bodies had been installed was both time-consuming and expensive, resulting in delayed deliveries. Due to the inflated price, the 428 was more expensive than the contemporary Aston Martin DB6.

Just 29 convertibles would leave the Thames Ditton factory along with 49 coupes, 31 of those with right-hand drive. Near the close of production, several prototypes were produced including a four-door version of the coupe and a streamlined and modernized version of the convertible, complete with electrically operated 'pop-up' headlights.

The AC Frua weighed a mere 1,416kg and was capable of sub-six-second 0-60mph times and 0-100 mph times of approximately 14.5 seconds. The top speed was achieved in excess of 140 mph.

The AC 428 outshone its rivals in terms of speed and comfort but was limited due to its price and lack of the prestigious mystique as similar thoroughbreds, including Maserati, Ferrari, Aston Martin, and Lamborghini.

by Dan Vaughan

Roadster
Chassis number: CF14

The first owner of this AC 428 Spider was Grand Prix privateer Rob Walker, heir to the Johnny Walker whisky fortune and long-term entrant for Stirling Moss. This car is equipped with a strengthened Ford C6 3-speed automatic transmission and a limited-slip differential. It is finished in bright red (a color change from original) and has black leather upholstery, a black cloth top, and chrome wire wheels. At some point, the engine was replaced and a subsequent owner installed air conditioning.

This AC Frua was displayed at the Pebble Beach Concours in 1990 where it earned 2nd in Class, then scored class wins in 1991 at the Hillsborough and Forest Grove Concours d'Elegance.

by Dan Vaughan

Roadster
Chassis number: CF14

AC Cars had 82 chassis in stock when Ford switched in preference from Cobra to the GT40. In a stroke of genius, AC shipped the surplus chassis to Frua in Italy to receive coachwork, and then shipped them back to the United Kingdom for installation of the 428 engine. Only 29 were bodied in convertibles on a lengthened 427 Cobra chassis, with Frua coachwork that was similar to the Maserati Mistral. This spyder was completed in 1968 and owned by Rob Walker, a whiskey heir, race car driver, RAF pilot, and privateer Formula 1 team owner. Recipient of a new Ford 428 engine in 1971, and a recent refreshment, this AC 428 has both street credibility and styling gravitas, with its huge 345 horsepower engine and restrained yet elegant Frua Spyder body.

Roadster

Each of the 29 AC 428s constructed were handbuilt, and currently, there are approximately 20 left. Zero to sixty mph takes 5.9 seconds, and zero to 100 mph is accomplished in 14.5 seconds.

AC Cars built the AC 428 (also known as the AC Frua) was produced from 1965 through 1973 with 81 examples produced. 49 were fastback coupes, 29 were convertibles, and three were given special bodies. The cars were built on an AC Cobra 427 Mark III chassis that was extended by 6 inches. The chassis's were built by AC Cars and then sent to Italy where they received their coachwork from Frua. After that work was completed, they were sent back to England where they were given their power train and trim. Power was from a big-block Ford FE engine that gave the car a top speed of 141 mph and a zero-to-sixty time of just 6.2 seconds. The transmissions were either a fully synchronized 4-speed Ford Toploader close-ratio transmission or a three-speed Ford C6 gearbox. Four-wheel 'Girling' 3-piston disc brakes with dual remote servo assistance were fitted at all four corners.

by Dan Vaughan

An extremely limited edition model, the AC Frua was designed by Pietro Frua, rather than Caroll Shelby, like most AC cars. The 'Frua' name was chosen accordingly and featured a huge seven-liter big-block V8 from the current Ford Mustang. A British 'GT' car of the 1960s and early 1970s, the Classic AC Frua was also known as the AC 428. Only eighty-one models were ever built from 1965 through 1973, 49 of them fastback Coupe's, 29 Convertibles and 3 special bodied.

The Italian-bodied AC 428 was built on the classic AC Cobra 427 Mark III race-bred coil spring chassis elongated by 6 inches. The 428's chassis were constructed at the AC plant in England before being shipped to Frua's Italian workshop. The body was fitted before returning back to England where the power train and trim were added. Unfortunately, the cost behind this was extensive and cars couldn't be sold at a competitive price. Due to a lack of financial means the AC Frua was never fully developed. One of the biggest disadvantages of the Frua was the V8's tendency to bleed heat into the cabin.

The AC Frua featured fully independent racing-based coil spring suspension, unlike comparable vehicles of the period like the classic Iso Rivolta, Iso Grifo, Monteverdi's, and classic De Tomasos. The 428 shares a similar look with the Maserati Mistral (also designed by Pietro Frua) and is often confused, though only the front quarter windows and the door handles are the same.

Similar to Italian supercars of the time, the chassis construction featured square and rectangular tubing that connected the steel body to the frame. The tubular chassis was 4 inches in length and made both the coupe and convertible quite rigid. The intricate design was, unfortunately, susceptible to rust. Both the hood and trunk lid was constructed from aluminum. The transmissions were either a three-speed Ford C6 gearbox or a fully synchronized 4-speed Ford Toploader close-ratio transmission. Fitted to all four corners were four-wheel 'Girling' 3-piston disc brakes with dual remote servo assistance.

Created to compete with Lamborghini, Ferrari, and Maserati models, the AC Frua was powered by the big-block Ford FE engine, which featured larger capacity, more power, and more torque when compared to comparable Italian cars. The Frua was built over a stretched AC Cobra 427 chassis. The snappy little sports car was recorded with a maximum speed of 141 mph and could achieve 0-60mph in just 6.2 seconds. It was estimated to have an overall fuel consumption of 15.6 mph, which was around 15% better than the Aston Martin DB6.

Weighing around 3,153 pounds, the AC 428 was produced from 1965 to 1973. The AC 428 had a recommended UK retail price of £5,573, which was nearly twice the cost of a 4.2-liter Jaguar E-Type roadster, priced at £2,225. Several prototypes for an extended range were produced near the end of the production run. Though never produced due to an absence of finances, the AC Company produced a four-door version of the coupe, along with a more streamlined version of the convertible that featured electrically operated 'pop-up' headlamps.

Sources:

http://ac428.zoomshare.com/

http://en.wikipedia.org/wiki/AC_Frua

http://www.supercars.net/cars/4754.html

http://www.longstonetyres.co.uk/page/ac-428

by Jessican Donaldson