Guide: Ferrari 275 GTB/4 & 275 GTS/4
Background
Although Ferrari engines were generally regarded as the best in the business, there was no doubt the firm took a generally conservative approach to technological advancements.
Aston Martin, Jaguar and Maserati all offered dual overhead camshaft six cylinder engines by the early 1950s and, while building a twin cam ‘six’ was simpler than a V12, that it took Ferrari until 1966 to release a DOHC motor for public sale was an eye opener.
The principle behind dual overhead camshafts was to improve gas flow to the engine thus optimising power and efficiency. The system involved a degree of extra complexity, but the benefits were obvious. Outside of Formula 1, Ferrari had used this arrangement as far back as 1957 (with the 290 Sport) but dual overhead camshaft racing cars from Maranello were generally still reserved for works use even until the late 1960s.
Ferrari’s first production road car to come equipped as such, the 275 GTB/4, was unveiled at the Paris Motor Show in October 1966. The third iteration of the venerable 275 GTB, it was arguably the best looking Gran Turismo available and, in performance terms, could hold its own against the new generation of mid-engined supercars that were beginning to emerge.
A two-seat Berlinetta, the 275 GTB/4 was offered alongside the more refined Ferrari 330 GTC which was a two-seat Coupe that could also be ordered in Spyder trim (330 GTS). Customers that wanted four seats could opt for the second series 330 GT or, if money was no object, the ultra low volume 365 California (a four-seat Cabriolet).
The second series 275 GTB that the GTB/4 replaced had ushered in a longer nose to try and reduce front end lift. A number of underbody updates had also been of great benefit, most notably the addition of a torque tube mid-way through production.
Engine / Gearbox
Aside from its redesigned DOHC heads, the GTB/4’s Tipo 226 motor also featured a new dry-sump lubrication system and an oil cooler located in front of the radiator.
Otherwise, it retained all the basic characteristics of the outgoing 275 engine.
Displacement of the Gioacchino Colombo-derived 60° short-block V12 was unchanged at 3285cc thanks to a bore and stroke of 77mm and 58.8mm respectively.
Ignition was via a single spark plug per cylinder and two coils.
Compression was kept at 9.2:1 and the previous option of six instead of three carburettors became standard. These twin choke downdraught carbs were initially of the Weber 40 DCN 9 variety, but later both DCN 17 and DCN 18 types were adopted.
As usual, Silumin light alloy was used for the engine block, heads, sump, bellhousing and cam covers.
Peak output was 300bhp at 8000rpm (identical to the six-carburettor original), but the torque rating was now 232lb-ft at 6000rpm compared to 218lb-ft at 5000rpm for the outgoing variant.
A five-speed transaxle with torque tube was employed along with a single-plate clutch and ZF limited-slip differential.
Chassis
Although the GTB/4 chassis was re-designated Tipo 596, it was practically identical to the Tipo 563/66 chassis used by the torque tubed Series 2 GTB.
A traditional welded tubular steel affair, it was equipped with unequal length wishbones, coil springs and telescopic shocks plus anti-roll bars at either end.
Dunlop disc brakes were fitted to each corner as were 7 x 14-inch Borrani 10-hole cast alloy wheels. These were typically shod with Michelin as opposed to Pirelli tyres.
275 GTB/4s retained the twin fuel tank arrangement introduced on the Series 2 GTB. Overall capacity was 94-litres.
Bodywork
Cosmetically, no major alterations were made to Pininfarina's existing masterpiece.
The GTB/4 adopted the long nose body used by the Series 2 GTB, but with a narrower hood blister to accommodate the air cleaner for the carburettors.
As usual, bodyshells were fabricated at the Scaglietti works in Modena.
Aluminium was used for the opening panels (doors, bonnet and boot lid). The rest was steel.
Like its predecessor, the GTB/4 could be ordered with a rarely requested all-aluminium body.
Interior
Little was changed inside although the use of a plain black dash fascia and upholstery-coloured oddments tray replaced the teak inserts that had gradually been phased out on the Series 2 GTB.
Black vinyl covered the dash top, knee roll, door caps, windscreen pillars and armrests.
Leather was used to upholster the bucket seats, transmission tunnel, door panels, the sidewalls and the rear quarter panels. The rear bulkhead was also trimmed in leather and came with a fluted pattern to match the seats. Leather straps were provided to hold extra luggage in place.
The large diameter speedo and tach were split by smaller gauges for oil temperature and oil pressure. A water temperature gauge, ammeter, fuel read out and clock were located centrally above a bank of rocker switches.
Options
Customers could enhance their cars with a variety of optional upgrades to include Borrani wire wheels, electric windows, head rests, a radio and (for the first time) air-conditioning.
A choice of rear axle ratios was available along with the aforementioned aluminium body.
275 GTS/4
At the New York Motor Show in April 1967, Ferrari unveiled the GTS/4 variant.
Unlike the original 275 GTS, which had a completely different body to the concurrent GTB, this latest offering was a straightforward Spyder conversion of the Berlinetta design.
A batch of 10 GTS/4s was commissioned by Ferrari’s North American distributor, Luigi Chinetti, who felt there was a market for a racier open top machine than the 330 GTS.
The handsome new 275 GTS/4 featured a folding canvas soft top that, when lowered, lay flush with the re-profiled rear deck.
Like its fixed-head counterpart, GTS/4 bodyshells were manufactured at the Scaglietti works in Modena with aluminium used for the opening panels and steel for everything else.
There was also a full aluminium body option.
Competition History
To help with promotion of the GTS/4, one week before its New York show debut, the first example (chassis 9437) was entered for the 1967 Sebring 12 Hours.
Although owned by Luigi Chinetti, the distinctive Giallo Solare machine attended under a North Vermont Racing Team entry as opposed to Chinetti's more familiar North American Racing Team (NART). This was because of ongoing legal issues after Mario Andretti's NART-entered 365 P2 had collided with a Porsche 906 which careered into the crowd killing four spectators during the 1966 event.
Prepared at the NART workshop in New York City, chassis 9437 was equipped with a roll-over bar and auxiliary driving lights, but otherwise, the aluminium-bodied roadster remained standard.
Driven by Denise McCluggage and Marianne 'Pinkie' Windridge, the female crew finished a respectable 17th overall to take second in the five-litre GT class.
This was the only showing by a GTS/4 in any kind of competition.
A small number of GTB/4s also saw competitive action.
Four examples were prepared by Ferrari's Swiss importer, Scuderia Filipinetti, three of which were for Peter Baumberger's Three Bears team. Two of Baumberger's GTB/4s were steel-bodied examples and the other was aluminium. A class win on the 1967 Ollon Villars Hillclimb for Baumberger's son-in-law, Bennett Dorrance, was Three Bear’s best result.
Across the Atlantic, the Daytona 24 Hour promoters were desperate for more Ferraris and they convinced Luigi Chinetti to run a GTB/4 in the 1969 event.
Chinetti agreed to swap a brand new Ferrari for NART co-founder Jan de Vroom’s aluminium-bodied GTB/4 (chassis 10311). In the hands of Ricardo Rodriguez and Sam Posey, the hastily prepared machine went on to finish 23rd overall and second in the five-litre GT class.
Production Changes
Just a few minor developments were made during production.
The oil cooler was eventually dropped while the original carburettors and distributor were switched for improved components.
End of Production
Production continued until late 1968.
By this time, 330 examples of the GTB/4 had been completed, 27 of which were right-hand drive.
Less than 20 GTB/4s were ordered with the aluminium body.
By contrast, the GTS/4 proved a commercial flop. This was most likely because of the enormous price - it cost over 50% more than a standard GTB/4. No others were built after the original batch of ten. All were left-hand drive and the first two came with aluminium bodies.
One famous GTS/4 buyer was actor, Steve McQueen, who acquired chassis 10453. McQueen had become smitten by the model after driving chassis 9437 in The Thomas Crown Affair (for which its colour had been changed from Giallo Solare to maroon).
Ferrari ultimately replaced this final iteration of the 275 with the new 365 GTB/4 and 365 GTS/4.
Text copyright: Supercar Nostalgia
Photo copyright: Ferrari - https://www.ferrari.com
