Guide: Porsche 911 2.7 & 3.0 I & J-series (1976 & 77 Model Year)

Jun 26

Jun 26 Guide: Porsche 911 2.7 & 3.0 I & J-series (1976 & 77 Model Year)

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Background

Although the second generation 911 was launched just a few weeks before the onset of a global energy crisis, Porsche’s heavily revised model enabled the firm to weather the economic storm better than most high end manufacturers.

Prior to this, safety and emissions legislation had been rapidly tightening since the late 1960s, particularly in the USA.

When oil prices rose exponentially between 1974 and 1975, the cost of fuel suddenly became a major issue as well. The days of cheap petrol had come to an end and demand for gas guzzlers evaporated practically overnight.

Auto makers reliant on big V8 and V12 engines saw their sales figures plummet.

Because the 911’s Flat 6 engine was comparatively fuel efficient, Porsche survived relatively unscathed. The improved safety features introduced for the 1974 model year also meant the 911 could be sold into the USA without the need for the kind of ugly exterior appendages that blighted cars like the Ferrari 308.

However, building US-compliant engines was still a challenge, even for Porsche.

The flagship 911 Carrera was locked out of the American market as it couldn’t meet emissions requirements while lesser variants had to be equipped with power-sapping air pumps and (for California) thermal reactors.

At the time, Porsche had a policy of introducing major updates every two years.

For the 1974 and 1975 model years, Porsche had offered the entry level 911, the mid-range 911 S and the flagship 911 Carrera. All came with 2.7-litre engines.

In addition to these normally aspirated variants, a turbocharged 911 (the 930) was constructed from February 1975.

Production of the 1976 model year I-series 911 began in August 1975 at which point the range of normally aspirated 911s was reduced to just two: the 2.7-litre 911 Lux (marketed as the 911 S in the USA) and the 911 3.0 Carrera, which came with a new three-litre engine.

Both variants could be ordered as either a Coupe or Targa.

1976 Model Year I-series Updates

Universal upgrades for the 1976 model year included a new body coloured driver’s side electric door mirror, improved door locks, redesigned door trim, a cast front suspension cross-member and more sound insulation. Perhaps most importantly, bodyshells were now zinc-coated to better prevent corrosion.

Engine & Gearbox

As usual, Porsche’s air-cooled all-alloy Flat 6 motors incorporated dry-sump lubrication and a single overhead camshaft for each bank of cylinders.

Both the 2.7 and 3.0-litre engines came with a more efficient five-blade cooling fan, a larger capacity oil pump, Bosch K-Jetronic fuel-injection with automatic cold start enrichment and die-cast aluminium lower valve covers (instead of magnesium).

2.7-litre Engine

The 2.7-litre 911 Lux / 911 S engine was uprated with four journal camshafts from the 930.

Power was 165bhp at 5800rpm (10bhp down on the 1974 and 1975 model year 911 S). The torque rating was unchanged: 173lb-ft at 4000rpm.

Displacement remained 2687cc thanks to a bore and stroke of 90mm and 70.4mm respectively. Compression stayed at 8.5:1.

Engine type numbers were as follows:

911 Lux: type 911/81 (911/86 if fitted with Sportomatic) 165bhp at 5800rpm
911 S ‘49 State’: type 911/82 (911/89 if fitted with Sportomatic) 165bhp at 5800rpm
911 S ‘California’: type 911/84 (911/89 if fitted with Sportomatic) 165bhp at 5800rpm

3.0-litre Engine

The new 3.0 Carrera replaced the outgoing 2.7-litre Carrera as the most expensive normally aspirated 911 available. Like its predecessor, the three-litre Carrera was not US compliant.

The engine was essentially a normally aspirated version of the turbocharged 930 lump. Displacement of both motors was 2994cc as a result of bigger 95mm cylinder bores. Stroke was 70.4mm as per the 2.7.

Thanks to higher domed pistons, the compression ratio was increased from the 930’s 6.5:1 to 8.5:1. The two engines shared the same aluminium crankcase, Nikasil-lined cylinders and Bosch K-Jetronic fuel-injection.

Motors fitted to 911 3.0 Carreras were given type number 930/02 (or 930/12 if fitted with Sportomatic).

Peak output was 200bhp at 6000rpm (10bhp down on its predecessor). However, more importantly, the torque rating improved dramatically: an unchanged 188lb-ft was now on stream at 4200rpm instead of 5100rpm.

Gearbox

A four speed Type 915/16 gearbox was standard throughput the range.

The five-speed Type 915/06 was an optional extra.

Another option was a clutchless manual Sportomatic transmission. As the existing four-speed Sportomatic gearbox had reached the limit of its torque capacity, a new three-speed unit was developed for these 1976 model year 911s.

Chassis / Body

Aside from the aforementioned zinc coating and cast front suspension cross-member (as used on the 930), the 911’s unitary steel bodyshell was unchanged.

Suspension was fully independent with torsion bars and telescopic shocks plus an anti-roll bar at either end. The front used a compact MacPherson strut arrangement with a single lower wishbone. At the rear, semi-trailing arms were installed.

Thicker torsion bars were fitted to the 3.0 Carrera as standard.

Brakes were four-wheel ventilated discs. Beefier A-type calipers were added to the 911 Lux / 911 S compared to its predecessor.

The standard wheels were 6 x 15-inch ATS ‘Cookie Cutter’ rims for the 911 Lux / 911 S while the 3.0 Carrera had 7-inch rims at the rear. In some markets, the 3.0 Carrera automatically came with Fuchs alloys.

An 80-litre fuel tank was once again located underneath the front lid but now came with lead lining to better prevent corrosion.

The 3.0 Carrera was equipped with wider rear fenders.

The impact-absorbing bumpers introduced for 1974 had proven a remarkable success. An elegant solution to tightening safety legislation, they also enabled Porsche to sell the 911 internationally with relatively few cosmetic differences from country to country.

Interior

Aside from redesigned door panels with new fluted centres, no major changes were made inside.

The 911’s classic five-gauge instrument binnacle was retained. Directly behind the steering wheel was a rev counter. To the left were combined gauges for oil pressure / oil temperature and oil level / fuel. To the right was a speedometer and a clock.

Manual windows and a four-spoke steering wheel were standard.

The high-backed seats with integrated headrests introduced for the 1974 model year were retained.

Options

A comprehensive list of optional extras was available.

In addition to a five-speed manual or three-speed Sportomatic gearbox, buyers could specify Bilstein shocks, Fuchs alloy wheels, front and rear spoilers (Carrera only), a limited-slip differential, metallic paint, fog lights, headlight washers and automatic heating control.

There was also the Black Look chrome delete package and body coloured headlight surrounds, both of which were standard on the 3.0 Carrera.

Other extras included sill decals, leather upholstery, air-conditioning, tinted glass, electric windows, a heated rear window, an electric sunroof, a rear wiper and a choice of audio systems.

Wider Fuchs wheels ( 7-inch front and 8-inch rear) could also be specified on the 3.0 Carrera.

Weight / Performance

The 3.0 Carrera Coupe weighed 1120kg. It had a top speed of 149mph and 0-62mph time of 6.2 seconds.

The 2.7 S / Lux Coupe also weighed 1120kg. This version had a 135mph top speed and 0-62mph time of 7.2 seconds.

Targas weighed 50kg more and US variants all came with an additional 25kg of safety / emissions equipment.

End of 1976 Model Year I-series Production

Production of the I-series 911 lasted until July 1976 by which time just over 9400 had been completed. This was split as follows:

911 Lux Coupe: 1868 / 911 Lux Targa: 1576
911 S Coupe: 2209 / 911 S Targa: 2179
911 Carrera 3.0 Coupe: 1093 / 911 Carrera 3.0 Targa: 479

1977 Model Year J-series

The 1977 model year J-series 911s would be the last before a new SC ‘Super Carrera’ was introduced.

Production started in August 1976 and universal upgrades included Dilavar cylinder head studs, camber adjustments and further uprated K-Jetronic.

Inside, face-level vents were added in the centre of the dash, better quality carpet was fitted and more sound insulation installed. New door locks that disappeared into the door tops could be raised or lowered via a recessed circular knob on the door panel.

Targas now came with a matt black instead of stainless steel roll hoop.

Two new options were added: pinstripe fabric upholstery (only available on the 3.0 Carrera) and a Comfort Pack (available on both variants). The Comfort Pack comprised softer Bilstein shocks, electric windows and 14-inch Fuchs alloy wheels with thicker sidewall tyres. In the USA, the Comfort Pack also included cruise control.

911 S Signature

Another limited edition 911 was offered for 1977. The 911 S Signature came with Metallic Platinum paint and matching Fuchs wheels, special beige and tweed upholstery and a three spoke sports steering wheel embossed with the signature of Ferry Porsche.