Pontiac Tempest – Back to a Different Future

Pontiac’s Tempest was packed with improbable engineering and ingenious bodgery from a young John DeLorean. Sam Glover drives an early survivor

The Pontiac Tempest was a product of General Motors’ post-war ‘anything goes’ period. These halcyon years of designer-led innovation and iconoclastic engineering brought us the plastic-bodied 1953 Chevrolet Corvette, the fuel-injected 1957 Pontiac Bonneville, the 1957 Cadillac Eldorado Brougham with Citroën DS-inspired pneumatic suspension, and the 1960 Chevrolet Corvair with its unitary construction and air-cooled rear-mounted flat-six engine. It gave birth to the world’s first two turbocharged production cars – the 1962 Oldsmobile Jetfire and Corvair Monza Spyder – and climaxed with the 1966 Oldsmobile Toronado, which had a 7.0-litre V8 driving its front wheels via a Hy-Vo chain.

The 1961 Pontiac Tempest was the dark horse of this bunch. Its unassuming Eisenhower-cool body cloaked what was possibly GM’s weirdest-ever drivetrain: a 3.2-litre slant-four engine at the front, a transaxle at the rear, and a curved torsion bar ‘rope drive’ connecting the two.

Pontiac enjoyed a renaissance in the late 1950s. The marque occupied a narrow ledge in GM’s hierarchy, above Chevrolet but below Oldsmobile, Buick, and Cadillac. It had ticked over post-war by building competent but unstimulating cars for the elderly and unadventurous. A step-change came in 1956 when 43-year-old Semon ‘Bunkie’ Knudsen was appointed division manager. He recruited Oldsmobile’s 40-year-old Elliot ‘Pete’ Estes as chief engineer and Packard’s 31-year-old John Zachary DeLorean as head of a new department titled ‘Advanced Engineering’. Estes went on to become president of GM; DeLorean would make it as far as vice president before stomping off to establish the DeLorean Motor Company.

As DeLorean suggested in a 1979 biography, Knudsen’s turnaround was swift and effective. ‘The Pontiac was a solid, reliable and sturdy car that evoked no discernible emotion one way or the other. Knudsen told us that this was a good situation because we would not have to combat a negative image before building a new one. We could choose where we wanted to be in the market by being daring, innovative and by taking chances. The image he would build for Pontiac was that of a youthful, exciting and fast-moving car.’ Pontiac was soon dominating stock car racing and producing some of GM’s most dynamic and desirable models, epitomised by the dashing ‘wide track’ range of 1959.

Meanwhile, the US market was evolving. The nuclear family wanted two cars on its suburban driveway. Changing fashions and the Eisenhower Recession of 1958 caused many to shun the excesses of the gas-guzzling land yachts dubbed ‘Detroit dinosaurs’ by AMC chairman George Romney. Almost all manufacturers launched programmes to develop all-American ‘compacts’ to compete with European imports and, of course, with each other. GM’s solution, the Chevrolet Corvair, was the most radical – and led to a managerial standoff.

GM’s top brass wanted to recoup costs by rolling out the platform to Pontiac, Oldsmobile, and Buick, even building prototypes badged Pontiac Polaris and Oldsmobile Sixty-Six. Yet those divisions were proudly autonomous, and they baulked at being handed a leftfield design with minimal development potential. Knudsen explained in 1994: ‘The Corvair is a rear-engined, air-cooled car. How do I make it different? There’s no grille to be restyled and the engine can’t be exchanged for a Pontiac powerplant – so how do I justify the extra $500 to $1000 to sell it with a Pontiac nameplate?’

A compromise was reached with Oldsmobile and Buick. They would get their own version of the Corvair’s unitary body, produced by GM’s in-house coachbuilder, Fisher. This new ‘Y-body’ gained 102mm in wheelbase and was adapted to accept a water-cooled engine at the front, a traditional propshaft, and a live rear axle. Pontiac, though, would remain lumbered with the Corvair body and drivetrain.

A rear-engined design progressed as far as a full-size clay model. Though its Space Age styling was not unattractive, it illustrated Knudsen’s point that the car’s fundamental Corvair-ness was impossible to hide. GM was not unsympathetic to the problem but made clear that no corporate money would be made available for an alternative solution. Happily, Pontiac had a limited development budget of its own. Enter John DeLorean and Advanced Engineering.

DeLorean ditched the Corvair platform and set to work on ‘Pontiac-ising’ the Y-body. The first problem was that Pontiac didn’t have a suitable engine for a compact, nor enough money to produce one from scratch. The cost of the 3.5-litre all-aluminium ‘Rover’ V8 that would power the Oldsmobile and Buick was too high for a car that needed to undercut its glitzier brethren, though Pontiac would end up begrudgingly offering it as an option.

DeLorean’s solution was an inspired piece of bodgery. Powertrain engineer Malcolm ‘Mac’ McKellar adapted Pontiac’s proven 6.4-litre cast iron V8 with large holes in its left bank of pistons and the corresponding valvegear disabled. It gave unexpectedly adequate performance when installed in a standard Pontiac. Prototype engines followed with their left banks hacked off and new camshafts and crankshafts. These exhibited increased levels of adequacy.

The production engine shared a remarkable number of components with the V8, including its cylinder head, exhaust manifold, valvegear, pistons, con-rods, main bearings, timing chain and sprockets, oil pump, sump, spark plugs, dipstick, and a smattering of minor parts. The water pump, fuel pump, distributor, dynamo, starter motor, and crank pulley had only minor differences. The only significant all-new components were the crankshaft, camshaft, inlet manifold, timing chain tensioner, and cooling fan. The block was a different casting, but it was similar enough to be machined on the V8 production line. The resulting ‘Trophy 4’ engine was gutsy but heavy and gyratory, with horizontal and vertical motion caused by the 45º angle of its pistons.

DeLorean had experimented with transaxles and torsion-bar driveshafts on senior Pontiacs, and the Corvair offered a choice of manual and automatic transaxles, with coil-sprung swing-axle suspension that could be transferred to the Y-body. Connecting the transaxle and engine was DeLorean’s magnum opus: the ‘rope drive’. This was a 2.2-metre-long forged steel shaft running inside a pressed steel tube, with rigid connections at each end and two rubber-isolated ball bearings along its length. The shaft could be surprisingly slender – 16.5mm on automatics, 19.1mm on manuals – as it ran at engine speed, with torque multiplication occurring further down the line in the transaxle. It was able to twist up to 30º under torque. This helped to dampen the engine’s lumpiness but could lead to unwelcome ‘snatch’ in manual cars if they were driven clumsily.

The engine and transaxle were tilted towards each other at 11º, and the shaft’s casing formed a gentle arc, its centre 75mm lower than its ends. The uniform stress the curvature placed on the shaft eliminated harmonic vibrations, which DeLorean had found to be a problem in earlier tests. As a bonus, it reduced the shaft’s infringement on interior space. This, and the fact that the leaping around of an exposed propshaft and live axle didn’t need to be accommodated, meant that the Tempest’s floor could be flatter than that of the other Y-body cars.

The ‘rope drive’ was intensively tested and proved to be extremely reliable. ‘Because we realised it was critical, it probably received more attention in manufacturing and quality than any other part of the car,’ recalled development engineer William Collins in 1979.

The TempesTorque two-speed automatic transaxle was a clever redevelopment of the Corvair’s Powerglide. It featured three concentric shafts running one inside the other, all turning in the same direction but at different speeds. The innermost shaft ran front-to-rear, connecting the driveshaft to the impeller of the torque converter, which protruded from the back of the transaxle. The next shaft out ran rear-to-front, connecting the turbine of the torque converter to the planetary gear set. The outer shaft ran front-to-middle, connecting the gear set to the crown wheel of the final drive. There was also a mechanical link between the input shaft and the gear set in top gear, allowing around 40% of torque to bypass the torque converter for more economical cruising.

The optional three-speed manual transaxle was also an adaptation of the Corvair’s, with closer gear ratios and the input relocated from the rear to the front. The gear change was floor-mounted, and the clutch was conventionally located in a bellhousing behind the engine, both of which impinged on front legroom.

Steel subframes carried the swing-axle suspension at the rear and an unequal-length double-wishbone set-up borrowed from senior Pontiacs at the front. The drivetrain was supported on two very soft rubber mounts at each end, allowing the imbalanced engine to rock around to its heart’s content with minimal shock transmission to the body. All this formed a pseudo-chassis when bolted together, which allowed the Tempest to be assembled on the same ‘body drop’ production line as its larger body-on-frame siblings.

The wheels were 15in and shod with crossplies; steering was by a Saginaw recirculating-ball box, with a slow 5.5 turns lock-to-lock and optional power assistance. Weight distribution was 52.3:47.7% front:rear with the Trophy 4 engine or 49.4:50.6% with the lighter V8.

Being late to the Y-body party, Pontiac’s styling input was limited. The body and doors were shared with the Oldsmobile F-85 and the Buick Special. Luckily, the body was sharp, modern and attractively proportioned, particularly in the four- and five-door forms that initially were the sole Tempest configurations. Styling director Jack Humbert made a fine job of extending the doors’ contours fore and aft and grafting on the split-grille face that Pontiac had then recently adopted as its trademark. The result was the prettiest of the three Y-body cars, its unfussy lines and tasteful lack of adornment imbuing some poise and elegance that its gaudier stablemates lacked.

The theme continued inside the minimalist, glassy and spacious cabin, its twin bench seats clad in colour-matched combinations of funky synthetic fabrics and metallic ‘Morrokide’ vinyl.

Pontiac dealerships took their first deliveries in October 1960, with the Tempest replacing the Vauxhall Victor – an unpopular compact stop-gap – on their forecourts. The Trophy 4 engine launched with a confusing combination of optional compression ratios, camshafts, and carburettors, with power ranging from 110hp to 155hp. The Buick V8 also produced 155hp. Ticking the top-spec Trophy 4 box, however, would cost the buyer an extra $39, while ticking the V8 box would set them back $261. Inevitably, therefore, the V8 accounted for less than 2% of sales.

The automatic 130hp Trophy 4 sedan in our photographs is owned by Corvair specialist Larry Claypool. While it has a few ergonomic departures from its original specification – its front bucket seats are borrowed from a Cadillac Eldorado – it’s mechanically original and probably one of the best-fettled examples around.

From the driver’s seat, its ease of operation is striking. The controls consist of two pedals, a steering wheel, a handbrake, an ignition switch, and a tiny lever on the dashboard that puts the TempesTorque into R, N, D or L.

The engine has enough grunt and punch to pull smoothly across a wide rev range, so you rarely feel short-changed with only two gears. The supple mountings give little indication of the engine’s intrinsic imbalance or of there being anything weird about the drivetrain, although occasional combinations of road speed and throttle position can set up tell-tale resonant vibrations.

The ride is soft, vision out is excellent, and the steering, though unassisted, is light. It drives like a grown-up Chevrolet Corvair, cruising comfortably at speeds up to – and probably beyond – 80mph. As a car designed for easy motoring in the USA’s expanding suburbia, it’s impossible to fault.

The Corvair comparison extends to the handling, which is unsurprising as it features the same rear suspension that got Ralph Nader so excited in Unsafe at Any Speed. The rear is certainly on the loose side, but the car is stable, grippy, and pointy. Like the Corvair, it’s possible to get the rear wheels to some really weird angles when cornering hard, but there’s no feeling of anything untoward happening from behind the steering wheel.

I think it’s brilliant, even if the slowness of the steering calls for a frantic flailing of elbows when the rear starts to break away.

I do concede, however, that my own predilections do not necessarily represent those of the 1960s American proletariat, who were accustomed to cars that exhibited galloping understeer under duress. Period reviews of the handling varied from glowing to damning, but Motor Trend hit the nail on the head with: ‘The average American driver will notice as much difference in driving the Tempest as he would in driving a radically engineered import.’

The Tempest sold in solid but unspectacular numbers, totalling 375,466 over three years. Like the Corvair, it rapidly gained power and sportiness as its concept veered towards the burgeoning ‘pony car’ market. A coupé came in late 1961; a cabriolet in 1962; revised rear suspension and a 5.3-litre cast-iron V8 in 1963.

The second generation that arrived in 1964 was bigger, uglier and completely conventional, with a Système Panhard drivetrain and body-on-frame construction. The rope drive, slant-four engine and rear transaxle ultimately proved to be design cul-de-sacs.

As an audacious piece of alternative engineering that also happens to be good fun to drive, however, the Tempest deserves to be remembered fondly.

1961 Pontiac Tempest specifications