(first posted at CC on 11/30/2012) In the thirties and forties, GM pioneered and brought to market some of the most innovative, successful and lasting new technologies: Diesel-electric locomotives; the modern diesel bus; automatic transmissions; refrigeration and air conditioning systems; high-compression engines; independent front suspension; and many more. But GM’s technological prowess was just one facet of its constantly-at-war multiple personalities. Planned obsolescence, chrome, fins and financial rationalization were the real moneymakers, especially during the technologically conservative fifties.
Nonetheless, from 1960 to 1966 GM built three production cars that attempted to upend the traditional format: The rear-engined 1960 Corvair, the front-wheel drive 1966 Toronado and the 1961 Tempest. Although the Corvair and the Toronado tend to get the lion’s share of attention, the Tempest’s format was by far the most enduring; essentially, the Tempest was a BMW before BMW built one of their own. If only Pontiac had stuck with it.
Consider its high-performance, four-cylinder engine with four-venturi carburetion; four-wheel independent suspension; four-speed stick shift; perfect 50-50 weight distribution; a light, compact, yet fairly roomy body; decent manual steering; and neutral- to over-steering handling: Those specs parallel those of the all-new 1962 BMW 1500/1800–or perhaps even a Mercedes or Rover 2000? But there was one thing none of those cars had: A rear transaxle and a totally revolutionary flexible drive shaft. When GM gave its engineering talent the freedom to innovate, the results were often extraordinary. But in true GM fashion, penny-pinching resulted in a 1961 Tempest that, like the Corvair, was flawed from the day of its introduction. Sadly, and unlike the Corvair, the Tempest was never given a chance to sort out its easily fixable blemishes; if it had been, the result could have been even more remarkable than the ’65 Corvair.
John DeLorean’s tenure at Pontiac may be more remembered for the ’59 Wide-Tracks, the GTO, the Pontiac OHC six, and the ’69 Grand Prix, but in my opinion the 1961-1963 Tempest stands as his most ambitious and creative engineering effort. He was as aware as anyone of the limitations of Detroit’s big-car formula: What it produced was invariably too big, too thirsty, front-heavy and dull-handling. Now, with the 1960 Corvair waiting in the wings, DeLorean’s longstanding plans to build a truly advanced and practical car would finally come to (not quite ripe) fruition.
DeLorean was particularly interested in the benefits of independent rear suspension, which so many European cars, including VW, Porsche and Mercedes, had been using since the thirties. In the mid-fifties, his engineering team had developed an even more radical evolution of Mercedes’ approach for the 1959 full-sized Pontiacs: A rear transaxle (to balance weight distribution) connected to the engine by a flexible-shaft drive inside a rigid torque tube. That innovation was DeLorean’s alone, and he received a patent on it. And please, don’t call it “rope drive”– if you try to send power through anything resembling a rope, good luck. This was a single flexible piece of steel, more akin to a torsion bar or speedometer drive shaft.
The big 1959 Pontiacs arrived with their ad-friendly wide tracks, but otherwise were utterly conventional. Actually, GM wanted to foist the new rear-engine Corvair on Pontiac in order to spread around its high development and production costs. The prototype Pontiac Polaris (above) was classic badge-engineering, with a ’59 Pontiac-ish front end grafted onto an otherwise unaltered Corvair. But the Pontiac brass, Bill Knudsen, Pete Estes and DeLorean, weren’t buying it, partly because DeLorean was aware of the Corvair’s tricky handling and nasty habit of spinning, or even flipping, when pushed too far.
Initially, DeLorean’a plans envisioned a front-engined car that used the Corvair body and kept the entire Corvair rear suspension and its transaxle as originally placed, not even turning it around to face the motor. Utilizing a hollow shaft, the Corvair transmission would actually be “driven” from the rear of the car; as a result, the torque converter would hang from the back of the differential, where normally it would have mated up to the Corvair’s rear engine.
Very creative indeed, and it’s rather bizarre to see the torque converter out there in the open, like an appendage (as pictured above). The drive shaft had three inches of deflection (curvature), and two intermediate bearings to help smooth out the vibrations.
The benefits of the rigid torque tube went well beyond producing a nearly flat floor. For instance, it was a key adaptation to the four cylinder engine that helped reduce inherent vibration. In theory, a four-cylinder has perfect primary balance, but with only two power impulses per crankshaft rotation, second order and torsional vibrations can be quite significant, especially as displacement increases. Traditionally, the Europeans kept their fours at or below two liters for just that reason. In 1975, Mitsubishi reintroduced the balance shaft in its 2.6-liter four; it proved highly effective, and is now very commonly used to smooth out large fours.
That’s why Detroit shunned fours like the plague: In order to provide American-style torque and power, American fours had almost always been large. At low engine speeds, as in Ford’s Models T and A, they were not too bothersome. A suitable six might have been perfect, but Pontiac had little choice but to create a compact, low-cost four the quick and dirty way: By eliminating one bank of its 389 CID V8. It was a very cost-effective solution because it not only used a high percentage of the V8′s parts, but could also be machined on the same lines as the V8.
Rigidly mounting the four to the front end of the torque tube eliminated the need for the engine mounts to control its front-to-back movements, so it was possible to isolate it and its vibrations from the body to a much greater degree than if had been mounted in the usual fashion. The mounts on the four only had to control its vertical movements, so they could be very soft. That does result in an impressive display of vertical “jumping” when the throttle is opened from idle.
That’s not to say that the 195 cubic inch (3.2 L) four’s noise, vibration and harshness issues were all miraculously solved by DeLorean’s innovative mounting solutions. It’s a very big four, for better or for worse. It does have a fatter torque curve than a comparable six or eight for its displacement, and therefore is very responsive. And thanks to Pontiac’s high performance experience, it could be quite powerful; output started at 110 hp, and went up to 165 hp with the optional four barrel carburetor. That overshadows the 1961 Corvair’s 98 hp optional engine.
As it turned out, Pontiac didn’t have to use the actual 108″ wheelbase Corvair body after all; GM relented and let them share the Corvair-based but slightly larger 112″ wheelbase Y Body that Buick and Oldsmobile were preparing for their 1961 compacts. But Pontiac was given a very tiny budget to adapt it, so the 1961 Tempest (above) used most of the Olds F85 sheetmetal with a ’59 Pontiac-derived front end and a new rear end grafted on. But the four cylinder, flex-drive and Corvair transaxle and its rear suspension were retained, for better or for worse.
The worst was that it was a simple swing axle: rigid half-axles jointed only at each side of the rigidly mounted differential. This was the hot new thing in Europe back in the thirties, but its tendency to jack up in fast corners and create snap oversteer and flipping had become all-too well known.
That’s why Mercedes developed its innovative single low-pivot rear axle (above) with an anti-jacking compensating spring in the early fifties, a temporary step before it adopted a double-jointed irs in 1968. BMW’s “Neue Klasse” 1500/1800/2000 sedans first arrived in 1962 with a double-jointed rear suspension. As did the Jaguar S sedan. Europe was moving on, and GM would quickly learn this painful lesson in penny-pinching. The 1963 Corvette Sting Ray had a new double-jointed rear axle, which the 1965 Corvair also adopted to great effect.
I showed you the odd Tempest automatic transaxle earlier, but here’s the (leaky) four speed in the featured convertible. That round bolted cover on the end is where the Corvair bellhousing would have attached.
And here’s the front of the same unit, showing the shift linkage which the Tempest conveniently shared with Corvair too. It wasn’t a model of precision and quickness, but Porsche had to have something left to improve when it adopted a highly similar torque tube rear transaxle for their 928 and 924/944/968. The 968′s three liter four was only slightly smaller than the Tempest 3.2, and its ferocious torque showed to best advantage the benefits of a large displacement four with balance shafts. If John Z. had remembered about the 1904 Lanchester’s patented balance shafts and adapted them, the Tempest would really have been a milestone car.
Speaking of Porsche, here’s their false claim about their “pioneering”:
The ’61 and ’62 Tempests did also offer a version of the aluminum Buick 215 CID V8 optionally, but only 1-2% of them were built with it, and only a tiny handful with a stick. Theoretically, the combination of the light and smooth V8 with a four speed and the Tempest’s independent suspension and perfect weight balance would have potentially made a very appealing package. But the V8 was troublesome from the beginning, and Pontiac had to “buy” it from Buick, so the four was pushed heavily. And the hi-po four did make almost as much horsepower as the V8.
The Tempest was widely (and rightfully) hailed when it arrived. It won Motor Trend’s COTY, and accolades from the press: “a breakthrough for Detroit”…”a wonderfully refreshing automobile”…”a significant coup of major import”…”may be the forerunner of a new generation”…”unquestionably a prototype American car for the sixties”.
Testers praised its 50-50 front-rear balance, which resulted in lighter steering, less understeer, better traction and braking, and a good ride. But its ability to create the dreaded snap oversteer in the wet or on quickly driven curves was not totally left behind with the Corvair’s rear engine. The Tempest’s handling could also be tricky at the limit, and its agricultural sounding four could not be fully tamed, even if some of its shaking was mitigated. Consumer Reports was not so enthralled.
The Tempest met its sales expectations, selling 100k in 1961, 140k in ’62, and 130k in ’63. That helped Pontiac clinch third place in the sales stats. But it suffered the same problem as the Corvair: profitability was not up to snuff. The extra costs in converting the Olds body and the drive shaft and rear transaxle bit into the already slim margins on compact cars. The whole ambitious Corvair/Tempest/Olds F85/Buick Special Y-body experiments left GM with a bad aftertaste, especially since Ford was doing so well with its utterly conventional Falcon and Comet. The dull 1962 Chevy II was the effective replacement for the Corvair, and the B-O-P compacts became highly conventional mid-sized cars in 1964.
Our next door neighbor in Iowa City, a Russian professor, drove a white ’62 LeMans convertible like the one above. I vividly remember the throb of the big four as I rode with her to Sears to get her lawnmower fixed. But the open top was even more effective than DeLorean’s other efforts to drown out its agricultural sounds, at least above thirty or so. And I once briefly drove a co-worker’s base ’61 sedan in LA: despite being elderly, its intrinsic balance (which could be all-too easily upset for amusing purposes) and decent steering for an American car was downright un-American. If only its engine ran sweetly like my Peugeot 404′s. But the trade-off was the torque: very American indeed.
Our featured car is a 1963 LeMans, which was the sporty/upscale variant analogous to the Corvair’s Monza with the same bucket seats and higher trim. The ’63s were restyled to make them appear bigger, wider and longer, but the inside was no larger. This convertible has all the right options, at least for those that have a soft spot for the four. I found it in front of this shop where it had just been converted to the factory 165 hp four barrel setup. And it also has the four-speed stick. Not surprisingly, its owner turns out to be a ’63 Tempest junkie; it was the car he always wanted in high school.
Norman has over half a dozen ’63s in and a round his shop and back yard, including this sedan still on the trailer that he just picked up. And he has another convertible (below) with the optional 326 V8 that replaced the aluminum V8 for 1963. This was a prescient move by DeLorean, and foreshadowed the 1964 GTO.
The 326 is a 389 with smaller bores (and actually displaced 336 cubic inches), and although no lightweight, it still results in a quite decent 54/46 weight distribution because of the rear transaxle. With a two barrel carb, the 326 made a fairly modest 260 hp, but the Tempest was light (2800-3000lbs) so with the V8 it scoots right along. Because of limited funds, the four speed was not upgraded to handle the V8′s torque, so as far as is known, all the 326s came with the three speed stick or the two-speed Powerglide/aka: TempesTorque automatic. Norman says his fours get 18 – 20 mpg, and the 326 around 16 – 18 mpg.
To mitigate its handling rep, the 1963 Tempest’s rear suspension was revised with a modified control arm geometry and other tricks. But it was still a swing axle, and the Tempest’s end was already in sight, to be replaced by live-axle conformity.
But in my imagination, I see an update of DeLorean’s original Tempest idea: a 1965 Tempest coupe based on the stunningly beautiful ’65 Corvair body, with the 230 hp Sprint OHC six under a lengthened front end and sharing that Corvair’s new Corvette-based rear suspension.
What a genuine American BMW that would have been, right down to the dash (the BMW’s Tempest look-alike dash appeared on the ’66 1602). In my oft-repeated GM coulda-shoulda-woulda dreams.