Guide: Something More Discrete for Ferruccio - a Historical & Technical Appraisal of the Lamborghini Islero
Background
Although the company lost money on every 350 GT it sold, Automobili Lamborghini’s first product proved arguably the best Gran Turismo in its class.
The Carrozzeria Touring-bodied 350 GT had an edge in terms of build quality, specification and performance. However, there was more to come and two years after its launch, the original 280bhp 3.5-litre V12 was phased out in favour of a 320bhp 4-litre 400 GT unit.
To further broaden the 400 GT’s appeal, a 2+2 variant with additional rear seats was also launched. However, the new four-seat Lamborghini’s arrival was completely overshadowed by a car on the very same stand: the epic new Miura which was making its world debut in finished form.
After a long gestation, Miura production began to ramp up during 1967 and Lamborghini’s attention turned to replacing the 400 GT 2+2 with an updated model. Another discrete, conservatively styled 2+2 Coupe was born: the Islero.
Meanwhile, also on Lamborghini’s drawing board was a brand new full four seater, the Espada, as the company sought to further expand its reach.
Both the Islero and Espada were scheduled for simultaneous release in early 1968.
Visually inspired by the wild Lamborghini Marzal design concept displayed at Geneva in March 1967, the Espada was (despite having been able to accommodate four adults) no less dramatic in appearance than the low slung mid-engined Miura.
Unlike the original 350 GT and 400 GT line of Lamborghinis (styled by Touring), the Miura, Marzal and Espada had all been designed by Carrozzeria Bertone (who also manufactured the Miura and Espada shells).
While Bertone was going from strength-to-strength, the Touring works up in Milan slipped into financial difficulty. Touring presented the avant-garde 400 GT-based Flying Star 2 design concept at the Turin Motor Show in November 1966, but by early ‘67 the esteemed coachbuilder had filed for bankruptcy.
From the ashes sprang Carrozzeria Marazzi which employed a workforce comprised mainly of ex-Touring personnel. Similarly based in Milan, Marazzi managed to assist Automobili Lamborghini by completing orders for new 400 GT 2+2s that Touring could no longer fulfil.
In doing so, the fledgling carrozzeria managed to secure the contract to design and build the Islero.
The decision owed much to Marazzi’s familiarity with the 400 GT assembly process as the Islero would use the same chassis and body construction techniques (which differed to those of the Miura and Espada).
In contrast to the space-age Espada and Miura, the Islero was intended for customers that wanted a more low-key piece of machinery. Ferruccio Lamborghini was typical of such an individual and it was he that laid down most of the Islero’s design directives to Marazzi.
As a result, the Islero came to personify the company founder’s vision for his marque perhaps more than any other car to wear the Lamborghini badge.
Chassis
Under the skin, the Islero employed a similar tubular steel chassis to the outgoing 400 GT 2+2. This was as per usual manufactured on Lamborghini’s behalf by Neri & Bonacini in Modena.
A 2550mm wheelbase and 1380mm track were carried over.
Like prior 350 and 400 GT models, the base chassis was subsequently equipped with a structural framework of small diameter steel tubes that conformed to the body shape. This was then covered with the outer body panels – a process originally patented by Touring of Milan and dubbed Superleggera (Superlight).
Marazzi would take a similar approach.
Suspension was once again via double wishbones with coil springs and telescopic shocks all round plus and anti-roll bar at either end. Thicker anti-roll bars were added for the Islero.
The servo-assisted twin-circuit brake system was also uprated with bigger Girling discs (up from 280mm to 300mm at the front and from 275mm to 280mm at the rear).
Instead of Borrani wire wheels (still available via the options list), Lamborghini supplied the Islero with the same 7 x 15-inch Campagnolo cast magnesium wheels fitted to the Miura and Espada. Notably these were half-an-inch wider than the wire wheels on the outgoing 400 GT 2+2.
Pirelli Cinturatio tyres were OEM equipment.
Located under the trunk floor was an 85-litre fuel tank (two-litres smaller than on the 400 GT 2+2).
Engine / Gearbox
Lamborghini’s Giotto Bizzarrini-designed all-alloy dual overhead camshaft 60° V12 was arguably the ultimate high performance road car engines of their day.
The Islero’s motor was identical to that of the Espada and in turn only slightly different from the Miura.
These front-engined models most notably ran with a reduced compression ratio (9.5:1 instead of 9.8:1) and sidedraught instead of downdraught carburettors (40 DCOE instead of 40 IDL). Sidedraught carburettors were fitted to allow the lowest engine profile (not an issue for the mid-engine Miura). The Islero and Espada also had larger air-conditioning units (when specified) and servo-assisted brakes which further deviated from Miura trim.
All of Lamborghini’s production engines from this period displaced 3929cc thanks to a bore and stroke of 82mm and 62mm respectively.
Peak output for the Islero was 325bhp at 6500rpm compared to 350bhp at 7000rpm for Miura. However, the torque rating was improved with 276lb ft on tap at 4500rpm against the Miura’s 262lb ft at 5000rpm.
An all-synchromesh five-speed Lamborghini gearbox was mounted in unit with the engine. Transmission was via a Borg & Beck single dry-plate clutch and limited-slip differential. A 4.5:1 final drive ratio was adopted instead of the 4.08:1 used by the 400 GT 2+2.
Bodywork
Ferruccio Lamborghini wanted the Islero to be a more conservatively styled machine than the Miura or Espada. Accordingly, Mario Marazzi created the perfect low key Gran Turismo; a crisp design that was a complete departure from Touring’s prior work for Lamborghini.
In a nod to the latest sharply creased design language the Islero mixed chiselled features with traditional soft curves.
At the front was an air-piercing nose with pop-up headlights and an unconventionally high single piece bumper underneath which was a full width intake aperture.
Set back behind the long hood was an angular five window cockpit with single piece side glass (electric front, hinged rear). Otherwise slab-sided flanks were tapered at the top and bottom; no fender flares or cutaways were present to disturb the airflow.
Perhaps the Islero’s most distinctive angle was its back end where Marazzi repeated the high bumper styling trick. On this occasion the bumper was mounted at the top of the rectangular tail fascia between the trunk lid and rear lights. Two banks of purposeful twin exhausts poked out from underneath a satin black apron.
Despite Mario Marazzi’s short history as a coachbuilder, his perfectly proportioned design for the Islero was arguably one of the best front-engined 2+2s of its era.
Body panels were fashioned entirely from steel.
Compared to the outgoing 400 GT 2+2 the Islero was 115mm shorter and stood 15mm lower. Width was unchanged.
Interior
Inside, the Islero’s cockpit was completely new
Behind the three-spoke wood-rimmed steering wheel was a seven-gauge instrument binnacle dominated by large read outs for engine and road speed. Housed in between was a small oil pressure gauge while out on the flanks were stacked dials for oil and water temperature, fuel and battery voltage.
Located on the central control panel were the electric window switches, a clock and various toggle switches.
The instrument fascia was typically trimmed in the same coloured leather as the seats, door panels, transmission tunnel, centre console and rear quarters. The rest of the full width dash was upholstered in black leather.
If the optional air-conditioning upgrade was specified, a large rectangular single-piece air box was incongruously mounted underneath the passenger side of the dash.
Options
In addition to Borrani wire wheels and custom paint, Islero buyers could specify full or half leather upholstery (the latter with special velour fabric seat centres).
Other extras included fog lights, an audio system and air-conditioning.
Special high output engines were available on request.
Weight / Performance
At 1240kg the Islero weighed in 10kg lighter than the outgoing 400 GT 2+2: 1240kg as opposed to 1250kg.
The factory quoted a top speed of 154mph and 0-62mph time of 6.4 seconds.
Production
Unfortunately, it transpired that quality control at the fledgling Marazzi works was below par and the Islero was not initially well received comparing unfavourably to it’s world class Touring-built predecessors and those contemporary models coming out of Bertone.
To rectify the situation, barely a year after Islero production had got underway, Lamborghini introduced a much-improved S version in May 1969.
By this time 125 examples of the original Islero had been completed, just a tiny proportion of which were right-hand drive.
Text copyright: Supercar Nostalgia
Photo copyright: Lamborghini - https://www.lamborghini.com
