Air-cooled classic 270bhp 3.2-litre 1967 Porsche 911 SC restomod
Don’t mess about! If a particular competition model has caught your eye, or if a specific era of Porsche production turns you on, then go for it. This is precisely what Dave Lewis did — infatuated by the legendary 911 ST of 1967, he found just what he wanted in a 1981 SC backdate...
Words Johnny Tipler
Photography Dan Sherwood
Air-cooled classic 270bhp 3.2-litre Porsche 911 SC restomod blood orange belter inspired by iconic ST
As 911s go, it looks pretty young, but this SC retrospective sets out to evoke the 911 ST. What exactly is an ST? Let me take you back to 1967, when Porsche was not the given race winner we take for granted today. Sure, during the 1950s and 1960s, the brand was regular class victor in top-line international motorsport, even winning the Targa Florio outright, but it had yet to top the podium at Le Mans, which it did for the first time in 1970. The 911 was slowly gaining ground in the lower orders, but was yet to realise its full potential at international level.
The first factory racing 911 was simply designated R (for Renn) and was unveiled in 1967. It was an austere, pared-to-the- bone, hot two-litre coupé with many fibreglass panels and perspex windows. Its successor was the TR of 1968, quickly followed by the ST in 1970. Under the direction of Porsche motorsport director, Fritz Huschke Von Hanstein, the intention was to run the R in sportscar racing, but homologation rules pitched it in with prototypes. Consequently, in 1968, Porsche created the 911 TR, a 911 T chassis making use of a 911 S engine and homologated as a Group 3 GT car — still relatively modified, but less so than the R. Somewhere in the region of thirty-six TRs were built and campaigned by professional and amateur race and rally teams.
THE BODY HAS BEEN BACKDATED, STARTING WITH THE REAR QUARTERS, WHICH HAVE BEEN FATTENED BY HAVING STEEL ST FLARES GRAFTED ON
For 1970 and 1971, following the FIA’s decision to allow big changes to production cars for GT racing, Porsche reasoned a lightweight version of its 2.2- litre S would be the perfect 911 for touring car racing and rallying. Thus, the ST was born, and though the rally cars retained standard engines, racing versions were initially increased by 52cc, accompanied by a power hike from 180bhp to 240bhp, fired by twin-plug ignition and mated with a 901 transmission and limited-slip differential. Only a handful of 2.3-litre STs were built in race and rally form, with a further twenty-three units of the later 2.5- litre ST designated as race cars.
FLARING OF THE WHEEL ARCHES AND THE WAY THE FRONTS MARRY UP SO BEAUTIFULLY WITH THE BUMPER AND VALANCE
Like the TR, the ST designation was an in-house Porsche amalgam of existing model identifiers: an S engine and the lighter T chassis.
There was far more going on with the ST than just an increase in swept capacity. Wider wheels and tyres for enhanced grip required flared wheel arches front and rear. The solution was a fascinating mash-up of materials.
THE ST PASTICHE IS FINISHED IN GLORIOUS BLOOD ORANGE PAINTWORK, THE ENSEMBLE SET OFF BY THE PERIOD-LOOK WHEELS
For example, on the early ST, the front wings, bonnet and bumpers were made of fibreglass, the rear quarters were steel, while the doors and engine lid were constructed from aluminium. Aside from the windscreen, all windows were acrylic. The rear three-quarter panels, roof and rear seat-pans were made from thinner-than-usual gauge steel, while all extraneous fixtures and fittings were left out, from glovebox lid and ashtray to front and rear lid locks, door and bumper trim strips. There was no sound deadening or floor mats, and the paint was even thinned down.
Apart from a front strut brace, 908/2 brake calipers and a competition fuel tank with a central bonnet filler cap, the running gear was little changed from the stock 911 S. Visually, the most obvious indicator of the ST’s identity is the difference in wheel types — since Fuchs did not yet produce rims boasting nine inches of width, Porsche had to look elsewhere. It found what it needed at Minilite. The company’s eight-spoke competition wheels, ubiquitous in contemporary touring car racing, were not only available in the desired size, but they were made of sand-cast magnesium, lighter than aluminium.
Looking back at the 24 Hours of Le Mans is an excellent guide for seeing what race cars were on the scene at any particular time. In 1970, four of the eleven 911s running in the daylong French enduro were ST specification. The 2.3-litre Ecurie Luxembourg entry, sporting no.47 down its flanks and driven by Erwin Kremer and Nick Koob, was the only finisher, placing seventh overall. Meanwhile, an ST dressed in the well-known (and often copied) swirling psychedelic red-and-yellow livery inspired by the Shell Oils logo was built for the 1970 XVème Tour de France Automobile. It finished third overall at the hands of Gérard Larrousse, who encouraged Porsche’s engineers to ditch even more weight from the ST than they already had.
As a result of his powers of persuasion (the promise of champagne may have helped), they dropped a scant eight hundred kilos by another twenty. Larrousse was leading the event until a clutch complaint on the final day of the tournament saw him drop to third overall. Even so, this particular ST has gone down in history as the lightest 911 ever built. The following year, however, was arguably the ST’s heyday, when there were nine STs out of eighteen 911s running at Le Mans.
Raymond Touroul and Andre Anselme finished sixth overall and first in the GT class driving the ASA Cachia Bundi entry. ST specification shifted for 1972.
Appendix J permitted only the 911 S’s fibreglass front bumper, complete with embryonic airdam, to be used on the competition car. Ahead of the season, a number of 2.5-litre 911 S coupés were built for racing under option M491, bearing the same chassis numbering as the standard 911 S, though for this reason it’s not easy to say exactly how many were created at the factory and how many were subsequently fettled to ST specification by private teams. It’s also worth noting it’s only retrospectively this group of cars has come to be known as ST — Porsche management discouraged the identifier at the time, though it was the preferred designator within Weissach.
NEXT IN LINE
These 1972 STs were fitted with bigger bore (86.7mm x 70.4mm) 2,492cc competition flat-six engines (Type 911/70) and were assigned a special serial number group, coupled with uprated gearboxes with improved cooling and full pressure lubrication. Suspension modifications included new anti-roll bars and harder Bilstein shocks. A half roll-cage was located in the rear of the stripped-out cockpit. Importantly, there were significant differences in panel composition to the earlier STs — except for the front spoiler, the rest of the body panels were fabricated in steel or aluminium, including steel front wings and an aluminium valance between the deleted overriders, adding up to a given weight of 1,025kg. Stylistically, what’s intriguing about the ST is the flaring of the wheel arches and the way the fronts marry up so beautifully with the neighbouring bumper and valance. And, of course, there’s the rather heroic swell of the rear wheel arches. Having indicators in the wings also adds to the ST’s charisma.
The interior cladding of the M491 cabin was black, with simplified door panelling. Furniture consisted of Recaro bucket seats with leather sides and cloth centre sections, criss-crossed by four-point harnesses anchored from the rear bulkhead. A smaller 380mm four-spoke steering wheel was fitted and lightweight door linings featured thong openers and manual window winders. There’s no clock and the rev counter is in the conventional position, rather than being upside-down, racer-style. Obviously, the door pulls predate those in the RS.
STs were delivered with Weber carburettors, but could later be specified with Bosch mechanical fuel injection. STs also made use of custom camshafts and pistons, each engine blueprinted with polished intake and exhaust ports, plus the aforementioned twin-spark dual ignition system. In this specification, the 2.5-litre engine developed an impressive 270bhp at 8,000rpm. The ST was priced at DM49,680, which was getting on for a heady £30,000 in 1972. To put this in perspective, back then, that sum could have bought you a couple of houses.
Enough of the history — let’s take a look at the car on these pages. It’s based on a healthy, undamaged, rustfree 911 SC from 1981, complete with matching numbers engine and gearbox and optional Type 220 spur-gear differential. Bilstein dampers and RSR-specification torsion bars are at play. The original SC anchors have been swapped for the larger calipers of the 911 Turbo (930) to ensure appropriate stopping power and have been allied with new discs and pads. The rear arms are modified to accommodate the bigger brakes.
The three-litre SC engine was totally rebuilt as a short-stroke 3.2-litre flat-six, using new Mahle barrels and JE forged pistons, plus new bearings, larger oil pump gears and chains. The cylinder heads were rebuilt and converted to twin-spark units with gas-flowed ports. Rally camshafts were fitted, along with CP Carrillo connecting rods, new head studs, a lightweight flywheel, as well as a beefy Sachs clutch and pressure plate. The electrical system incorporates the new dual ignition with MSD 6AL control modules. The oil cooler on the engine block was equipped with an additional filter in the manner of the RSR, while fuelling is aided by a Weber adjustable fuel pressure regulator and 46mm PMO carburettors topped with K&N filters, the regular classic option. Indeed, PMO’s products have been the go-to choice for 911 enthusiasts since its first batch was launched in 1997. Interestingly, PMO is the original manufacturer of 911 carburettor conversions and the only business dedicated exclusively to producing equipment for the upgrade — the PMO triple throat carburettor improves considerably over the original Weber carburettor and manifold design adopted by Porsche in period, resulting in increased power, as well as improved drivability by way of smooth and progressive throttle response.
The engine and gearbox were installed on Wevo semi-solid mounts to minimise powertrain heave in hard cornering. There’s also a Wevo short-shift kit for tighter gear changing. Poking out from the rear is a Dansk exhaust system, appropriately loud, sending the noise through stainless-steel three-branch manifolds, silencers and heat exchangers. The body has been backdated from G-model to F-model, starting with the rear quarters, which have been fattened by having steel ST flares grafted on. The front wings (fenders in US parlance) are carbon-fibre replica ST parts. The F-model front lid is also manufactured from lightweight weave. Beneath it lies a hundred-litre RSR fuel cell with central filler neck, accessible via the bonnet cap and an essential manifestation of the period ST. The oil cooler is also housed here to assist with cooling the 3.2-litre flat-six. The ST pastiche is finished in glorious Blood Orange paintwork, the ensemble set off by the distinctive period-look PAG Campagnolo from Group 4 Wheels shod with new Michelin TB classic radial tyres. The cabin interior is embraced by a full Heigo roll cage, with removable front section if the car’s owner, Dave Lewis, decides it isn’t required. The BF Torino racing seats are partly upholstered in leather and partly in cloth, enfolded with Schroth four-point safety harnesses. The dashboard features a leather-trimmed F-model gauge binnacle housing overhauled clocks and gauges, while the deep-dish MOMO steering wheel charmingly features a Rennline hockeypuck horn button of the style fitted to original 911s. It’s fine for road use, but droll in a racing scenario.
The build, which was carried out in the Netherlands, cost in the region of €150,000 in parts alone. Dave was lucky to find it — it seems the specialist who started the transformation and acquired all the necessary parts had to check out of the project at short notice. He passed the car onto a fellow Porsche restorer, who completed the work. Dave took ownership in September of last year, driving the car back to the UK, where it joins his 912. “After restoring my early 912 back to original factory specification, I wanted a rawer and more powerful classic Porsche. I’ve always loved the look of the ST over the Carrera RS 2.7, but there been far fewer ST backdate projects over the years. I reasoned I’d have to build my own.” The aftermarket has worked wonders to provide owners of massproduced 911s with all the equipment they need to turn their air-cooled classics into ST replicas. The seldom seen race car has also provided the blueprint for many signature models produced by some of the best-known marque-specific restoration houses. And, of course, the ST look served as the starting point for Singer Vehicle Design’s series of bonkersspec 964 backdates.
“I was planning to work closely with Mick Pacey at Cranfield-based marque restoration and sales specialist, Export 56, in the hope of developing an ST replica from scratch,” Dave continues. “We were looking at potential donor cars when this one suddenly became available, already finished. I jumped at the opportunity to take ownership — this is exactly the ST evocation I had in mind. Plus, even though the car was pretty much finished, there remained scope to put my own ideas into it. I should stress, I never wanted an exact ST recreation, just a really cool 911 taking heavy influence from the ST aesthetic.” Export 56 might not be responsible for the build, but Mick’s team takes care of servicing, maintenance and modification of the car now it is in Dave’s possession. For example, he immediately asked Mick to swap the black engine lid grille with a silver part. More fundamentally, Export 56 also rebuilt the transmission, altering the gearing and fitting a new input shaft. JPS Motorsport in Bletchley carried out full suspension and chassis tuning. For engine setup and balance of the PMOs, the car visited the rolling road at Marlin Motor Engineers (also in Bletchley), where it delivered 270bhp at 6,000rpm. Needless to say, Dave is keen to get the most out of this stunning 911, including using it to learn how to drive an air-cooled 911 in earnest. To this end, he plans to use the car on regular track days and tells us it is also likely to be driven to major historic motorsport events, both at home in the UK and abroad.
We’re in the presence of such a distinctive car that, inevitably, at least one precedent springs to mind — this ST evocation is one of the most comprehensive builds we’ve covered, vying with a similar 911 produced by the doyen of Porsche tuners, Alois Ruf Jr, who created an ST replica for one of his discerning clients. Inspired by the winning 911 R from the 1967 Marathon de la Route, the RUF-readied Porsche came out looking not so much like an R, but an ST, since it was able to present slightly more user-friendly specification. Alois calls these backdates ‘neo-classics’, a very apt term for a recreation.
ZEST IS BEST
The RUF-built car was based on a fully restored 1969 two-litre 911 E and was similarly finished in Blood Orange, with bigger barrels and pistons taking it up to 2.8 litres of displacement, with twinspark ignition and a 10.3:1 compression ratio, fed by 46mm Weber carbs and chucking out about 250bhp. It had a five-speed manual gearbox, plus limitedslip differential, running on deep-dish fifteen-inch Fuchs with seven inches of width at each corner. The wheels wore 185x70 profile tyres at variance with the traditional wide rear Minilites, which 911 STs are known for. Closure panels were made from light steel, resulting in kerb weight just shy of nine hundred kilos. And what about the ST driving experience? In the case of Dave’s car, the 3.2-litre motor inevitably means it’s torquier than a 2.5-litre ST, though power output is in the same ballpark. It’s lightweight, and that undoubtedly helps too, enabling a vigorous set-to where its dynamics can be explored to the full. The later ST and the 2.8-litre RSR are pretty close in the way they perform, though the ST is less rigid. In fact, I would say the ST is more like a raw Carrera RS 2.7, the way it writhes under hard braking and twitches at the slightest hump, while its nose explores every nuance of the road surface, however smooth.
It’s a hectic ride, but optimum control comes by simply being the guide rather than the hustler. The steering is light, requiring a deft touch rather than brute force, and lock is not bad, considering the girth of the tall Michelins. This 911 is beautifully set up and easily controllable, with pinpoint turn-in ensuring I can place it exactly where I want. It responds gamely as I ease on the loud pedal.
Acceleration is sharp, from 2,500rpm right around to the redline. It’s an aural delight up around the top end, where I’m using third and fourth gears. Down to second for tighter bends, surging from corner to corner in a glorious six-pot shriek. The short-shifter’s gear knob produces a decidedly metallic sensation in the hand, but it’s niftily precise slotting from notch to notch. And those 911 Turbo brakes ensure braking is as secure and effective as possible.
Few other classic 911s present such a purposeful stance and no-nonsense attitude. Even fewer evoke such an aching nostalgia for the purity of the halcyon days, pre-Turbo, pre-aero, when tweaked engines and light weight were principal enhancements. The ST is the model which established a foothold for the 911 on the international competition ladder. It’s easy to see why it earns a crucial place in the evolution of Porsche motorsport machines. Good on Dave Lewis for promulgating its reputation with his outstanding orange evocation.
Above 911 G-body becomes F-body with this fantastic backdated SC, which Dave bought in the Netherlands during autumn last year. Above and below Fueling and ignition systems have been completely overhauled. Above When viewed side-on, the car’s fat tyres make it look like a Hot Wheels model Below Cabin furniture is wrapped inside a full Heigo roll cage. Below Three-litre engine has been rebuilt and lifted to 3.2 litres of displacement.