Given that the 1961-1963 Tempest’s four cylinder was one half of Pontiac’s 389 cubic inch V8 and that John DeLorean’s performance proclivities were well known, it’s not surprising that there was a hot version available. Thanks to a four barrel carb, 10.25:1 compression ratio and an aggressive camshaft it packed 166 hp, one-half of the top-dog 333 hp 389-A four barrel 389 V8, essentially the same engine as would be used in the 1964 GTO . Backed by a four speed manual transmission, in the relatively light (3028 lbs) Tempest the hot four made the Tempest as quick or quicker than quite a few V8s at the time. It could also be a handful thanks to its swing axle rear suspension.
Given its hot four, “rope drive”, four speed transmission and swing axle rear suspension, the Tempest was something utterly unique in America at the time — in more ways than — causing M/T to say it was “a whole bundle of fun to drive” as well as “you can scare yourself real easy.” Sounds like something I would have liked.
Pontiac offered no less than five versions of the four. A 190 hp aluminum V8 Buick V8 was also optional, but quite expensive, rarely ordered and not available with the four speed manual. The 166 hp version had the high compression ratio, a 273/283 degree camshaft (essentially the same as the standard 1964 GTO had), and a four barrel carb.
After putting on some miles to break the engine in a bit, M/T headed to the drag strip to time its acceleration. Best shifting point was 5500 rpm. The not insignificant 215 lb.ft. of torque working through the 3.73 rear axle gears resulted in just enough wheel spin to allow maximum revs at takeoff. The results were 0-30 in 3.4 seconds; 0-45 in 6.2, and 0-60 in 10.5. That’s quicker than the typical V8s did back then; a ’64 Mercury Comet with the 260 V8 and four speed took 11.3 seconds to 60. A ’62 Lincoln Continental took 12 seconds. And it’s essentially the same as DeLorean’s next hot-not-V8: the OHC Sprint six.
The 1/4 mile came in 18.5 seconds at 80 mph. Mickey Thompson said that with a proper tune he’d been able to get the 1/4 mile numbers down to high 16s and 86 mph.
The four speed transmission (essentially the same as the Covair’s) shifted easily and quickly.
M/T points out that the rear wheels could use some negative camber to improve cornering power, and that cutting off half of a coil would do the job. Both the Corvair and Tempest had a bit of positive camber when empty in order to accommodate a full load of passengers and luggage.
The rear wheel’s camber changes are very obvious in these two shots. M?T notes that “poor or inexperienced drivers might have trouble here.” A camber compensating spring like the one added to the Corvair in ’64 would have helped. The changes to the ’63 Tempest’s rear suspension somewhat improved things, but the inherent swing axle issues, with resultant oversteer were still there.
The brakes were “hot” too, but not in a good way. They were undersized and deficient in their performance. Given the availability of large finned aluminum brake drums on the big Pontiacs, this was a serious omission.
“Cornering the Tempest can be a real thrill“. In normal driving, the swing axle IRS was ok; it simply cornered with less effort due to the lack of typical understeer. But in tight and fast corners “you can scare yourself real easy…the rear end breaks loose with little warning“. A good driver in the right gear can power through, but if not, one could easily find themselves going the wrong way.
The steering was light, and of course slow, which didn’t help with recovering from a potential spin. The Le Mans interior with bucket seats covered in the excellent GM vinyl was given the thumbs up, but the sparse instrument panel wasn’t.
Related reading:
CC 1963 Pontiac Tempest Le Mans: Pontiac Tries To Build A BMW Before BMW Built Theirs
Ate Up With Motor: “Magnificent Kludge: 1961 -1963 “Rope Drive” Pontiac Tempest
With this Tempest and the Corvair, GM had two “compact” cars that were technically at least as sophisticated as anything coming out of Europe at the time, plus you could get A/C and automatic transmissions that actually worked and other luxury options not typically seen on the foreign brands, and GM build quality was still very good. Put a Volvo or MB badge on either and jack up the price 25% (or more) and they could have easily passed as upscale imports. Yet GM lost interest quickly because they couldn’t reliably sell 150K+ per year for the Tempest or 250K+ for the Corvair, even though such volume was well more than all the upscale imports combined in the early 60s. When GM revisited the emerging luxury import threat in the 1970s they gave us a fancy Nova (aka Seville), and went downhill from there.
GM (and Detroit in general) just couldn’t wrap their minds around the notion of a small but upscale car. Small cars had to be cheaper than big ones, and if cheap small cars weren’t profitable they weren’t built. It took decades for GM to take small but upscale imports seriously, and by then those imports were entrenched in the USA.
The original Nash Rambler came nicely equipped and in Deluxe versions, One of the small, but upscale cars. But with Buick being the number 3 best seller in the era, Americans weren’t big on smaller cars.
I would say much better than what Europe had in that class. A really amazing car, beautiful and sporty.
The cost to produce these compacts was their demise. Aluminum engines, independent rear suspension, uni-body, constant velocity drive shafts, all cost a ton of money, but the conventionally built Ford and Chrysler competition sold just as well, so GM went fully conventional for their 1964 model compacts, or you could say smaller than full size.
True enough, but GM could afford to make both technically sophisticated compacts to appeal to the import buyer and true enthusiast, and the boring conventional compacts to compete with Falcon and Valiant. Olds would have been a better home for the Corvair, leaving Chevy with the volume/cheap Chevy II. GM had good brands with distinct target audiences and images, and they never used their resource advantages to exploit this advantage when the market started splintering away from full-size cars in the late 1950s – probably because they were under anti-trust threat.
The thing is, “GM” did not develop the Corvair; Chevrolet did, at considerable expenditure in divisional R&D resources. There were styling mockups of an Oldsmobile clone (badged Oldsmobile Sixty-Six), but Oldsmobile general manager Jack Wolfram’s screams of bloody murder at the thought of having to accept it were loud enough to be dissuasive. Pontiac didn’t want it either, which is how they ended up with the rope-drive Tempest instead.
True enough, only Chevy but not Olds saw the Beetle as competition, which explains why Chevy developed the Corvair, but from a branding point of view it would have been a better fit with Olds “innovation” brand status and perhaps more profitable selling at a slight upscale Olds price.
The divisions just didn’t work that way in this era. You’re making the mistake of presuming a post-Smith environment, where the corporation was managed from the top down with brand identities imposed by brand management MBAs. The idea, for instance, that Oldsmobile was a technological innovator, which didn’t stand close analysis, was because Wolfram’s predecessors had spent some money on the development of Hydra-Matic in the late ’30s and the Rocket V-8 in the ’40s (then 15 to 20 years earlier), not because somebody in the corporate offices said, “Oldsmobile’s brand identity is technological innovation!”
Realistically, the more sophisticated specifications of the Corvair and Tempest did not result in a huge real-world advantage over the more conventional Mopar A-bodies.
Once Chrysler got the styling and quality issues fixed for 1963, the conventional Valiant and Dart began making serious inroads into the compact market. Their drivetrains were probably better than the GM compacts (particularly their automatics), and their handling characteristics were good, without the “trickiness” if one really pushed the car. The addition of the new V-8s part of the way through the 1964 model year only made them more appealing.
The Tempest’s unusual layout didn’t provide much of any real-world advantage other than marginally better snow traction. The extra weight of the Trophy 4 (which weighed as much as the complete Buick 215/Dual Path Turbine Drive powertrain combined) meant there wasn’t much benefit in weight distribution on four-cylinder cars, and handling was terrible unless you modified the rear suspension in ways the factory didn’t provide for.
I enjoyed reading your write up and then MT’s, Paul. Back in the day I knew these were somehow different from Coment/Fairlane, Chevy II, etc. but never paid attention to the driveline that set it apart.
Interesting to see the (California) PCV valve coming in, Detroit engines’ “road tube” vents were starting to disappear. If clean and functioning, did they in any way diminish performance?
This Tempest ad must be from one of the enthusiast magazines, with all the data about ratios and such:
Not much mention of the “rope drive” (not actually a rope of course), but it seems like such a great idea, allowing a nearly-flat floor on a front-engine/RWD car back in an era when both front and rear center seats were widely used. Why didn’t it catch on?
Rope drive is practical on the input side of the transmission. The output side has its torque multiplied.
In other words, rope drive would only work with a front engine rear transaxle, which is a configuration that GM didn’t revisit until the C5 Corvette in the late 1990s.
I had a few in my wrecking yard, the drive shaft was broke on all of them. Another yard in Wyoming had either the drive shaft missing, (meaning sold), or broke on a large group. So perhaps the technology didn’t work.
I wonder what the failure mode was. I assume that on a conventional driveshaft, one of the U-joints would fail.
Don’t know, I assume they break in two. Maybe some one will comment. Picture a large speedometer cable broke in two. The other issue is that I’ve never heard of these being reproduced, so if you have a Tempest and it breaks, you’re parked permanently.
I wonder if the vibey (uneven pulses) of the massive four put ultimately unmanageable strains on the surely already-pushed torsion-bar-like rope drive? It IS asking a lot out of a piece of steel made with ’60’s metallurgy.
The flexibility of the driveshaft was deliberately chosen to absorb the torsional vibrations of the four-cylinder engine by allowing the shaft to twist up to 30 degrees in each direction. It wasn’t a matter of arbitrarily choosing a drivetrain layout that the Trophy 4 then beat the hell out of; the flexible shaft and rigid torque tube were selected FOR the engine.
What seems like a likely longevity concern for the shaft itself is the lifespan of the anti-corrosion coating applied to the outside of the driveshaft after machining. If that coating eventually cracked or fragmented from being twisted back and forth, it would probably create paths for corrosion of the bar itself, leading to failure.
The torque tube itself also seems vulnerable to corrosion or road hazard damage, and I’m pretty sure the torque tube bearings would eventually wear out, since they weren’t serviceable and had rubber and plastic internal components.
I’m sure some shafts eventually failed due to metal fatigue — there are limits to how many times you can twist a steel bar back and forth before it’s had enough — but my suspicion is that the above things were more common failure points.
It ended up being very expensive. DeLorean was very keen on the possibilities — you could theoretically have an engine driving a transmission around a corner, without universal or CV joins, which isn’t very useful for cars, but might have intriguing industrial applications — but for it to work, the shaft needed to be forged steel, machined along its entire length, shot-peened, and heat-treated. In practice, that ended up costing more than a conventional driveshaft with universal joints.
To me the most dramatic change from this Tempest to today’s cars is the tires. Somehow the photo’s in this test really highlight how skinny they are, though of course that was the norm for compacts 60 years ago. I know the sizing equivalence may not be exact, but those 6.00-15’s are roughly 155/80-15 in modern metric sizing. Like a VW Beetle, but four times the horsepower and a lot more weight.
590x13s equate to 195x65x15 in rollout
How did the performance and curb weight measure up to its platform-mates that were sold with aluminum V8s as Buicks and Oldsmobiles? I was watching a car show a while back where they said that there aren’t any more ropes around to keep these on the road, which is too bad. There’s some reason that 928 cables can’t be repurposed.
I used to drive a Buick with the 215 V-8 and 4 brl carburetor. Seemed like it really accelerated fast and would wipe out a Tempest 4 cylinder.
The 928 driveshaft is the wrong length (too short) and the wrong diameter (too thick). It doesn’t come close to fitting any of the Tempest variants.
(Driveshafts are not interchangeable between different Tempest model years, and manual and automatic cars had different shafts of different length and sometimes different diameters.)
The Tempest was significantly heavier than the F-85 or Buick Special, except with the aluminum V-8 (which went into very, very few cars). It was in the same general ballpark as the base 2V Olds or Buick, with the difference in acceleration coming down mostly to which version had which transmission and axle ratio. A Skylark or Cutlass with the 4V engine was a bit quicker than a Tempest 4V, but not by a vast amount, and a bunch quicker than any of the 1V Tempest variants.
For reference, Motor Trend tested a 1963 Skylark convertible with the four-barrel engine and four-speed gearbox (with the 3.36 axle), which weighed 17 lb more than this Tempest, and got the following performance:
0–30: 3.9 seconds
0–45: 6.7 seconds
0–60: 10.4 seconds
Quarter: 18.0 @ 77 mph
Top speed: 103 mph @ 4,800 rpm (observed top speed)
Road & Track‘s slightly lighter 1962 Skylark did:
0–30: 3.6 seconds
0–60: 10.2 seconds
Quarter: 17.9 @ 79 mph
So, the four-barrel V-8 cars were quicker, and probably would have been a bit more so with shorter gearing, but it wasn’t dramatic. The four-barrel Trophy 4 gave away only 20 cubic inches in displacement and was in a higher state of tune with a higher numerical axle ratio, so that’s to be expected.
Even if the Porsche 928 shaft fit, it might not take well to being bent into a curve.
The pre-1987 928 driveshaft is only 20.9 inches (531.5mm) long. The shortest iteration of the Tempest driveshaft is 80.3 inches (2,040mm) long, the longest 87.6 inches (2,224.8mm) — four times as long as a 928 shaft. So, it’s not just that it wouldn’t fit, it’s that it’d be like trying to use a chopstick as a tent pole.
The 928 driveshafts were also much thicker than the Tempest shafts, and thus much stiffer. The torsional constant of a bar with a circular cross section increases with the fourth power of the bar’s diameter, so all else being equal, a shaft 25mm in diameter (like the early 928) would be about three times as stiff as a shaft 19.1mm in diameter (like a manual-shift Tempest), while a shaft 28mm in diameter (like a post-1987 928) would be more than eight times as stiff as one 16.5mm in diameter (like an automatic-shift Tempest). (Torsional stiffness is also inversely proportional to length, so a shorter shaft is generally stiffer in torsion than a longer one.)
The curvature of the Tempest driveshaft was not arbitrarily selected, and it was not primarily for packaging reasons: It was selected to alter the critical speed of the shaft so that it wouldn’t fall within the engine’s normal operating speeds and suffer destructive vibration. A shaft of a different diameter or composition would have a different critical speed and would likely need a different curvature to avoid the problem the curvature was supposed to prevent. This would also mean a new torque tube of different shape.
I had a 1963 tempest wagon when I was 16. Of course i hated it as a teenager. I wrecked it on a rainy night, totaling it. I sure wish I had it now. I broke two axles spinning on dirt the hit payment. It had the 4 cylinger, automatic. It was a good car, and pretty strong,for the times.
I know a guy who raced one of those motors. Seeing one with a Roots blower hanging on the side was something else.
DeLorean authored a lengthy and detailed SAE technical paper on the 1961 Tempest. Therein, in what is a very creative presentation, are detailed descriptions of the Tempest’s interesting engineering features. Another technical paper was presented 3 years later for Pontiac by James Lagergren on the 1964 Tempest. The introduction to this technical paper describes why the Tempest was redesigned and the problems with the previous Tempest.
The following is from the above referenced technical paper: “Before discussing the new 1964 Pontiac Tempest, let us take a brief look at the Tempest history. The original Tempest, which was introduced in 1961, was designed with the following objectives in mind: It was to—
• Be a family sized car with maximum passenger comfort for the package size available.
• Provide outstanding economy and lively performance.
• Have ride and handling features which would excel other cars of its size.
• Be competitive within the price class objective of this automobile.
• Lend itself to the production facilities available so that it could be built on the same assembly line as the larger Pontiac.
Thus, a transaxle concept with a 4 cylinder engine and independent rear suspension was designed and developed by Pontiac engineers to fulfill these objectives. The torque tube and rear mounted transmission eliminated the hump to provide maximum interior roominess. The 4 cylinder engine which was actually made by cutting our V-8 in half and derived from 8 cylinder tooling was an effective price leader for our car.
With this original Tempest concept we were able to compete successfully in the market with a combined sales of over 375,000 units. However, for 1964, the torque tube and transaxle was abandoned to permit integrated manufacturing in the Chevrolet and Buick, Oldsmobile and Pontiac (BOP) assembly plants of a car that shares a basic body structure design.The body- frame integral construction was dropped because of vibration and structural tuning considerations.”
It was a given prior to the use of balance shafts that the displacement limit of 4 cylinder engines due to excessive vibration was 2 liters or 122 cubic inches. I wondered how well Pontiac dealt with this problem with a 195 cubic inch 4 cylinder engine. Apparently not very well according to the 64 Tempest technical paper.
“As is well known, the 4 cylinder engine itself has inherent unbalance characteristics. It acts as a vibrator, and the shaking force exceeds 4000 pounds at peak horsepower. While the torque tube mounting arrangement smoothed out the engine pulsations better than any other large displacement 4 cylinder engine we have ever driven, it was recognized that an in-line 6 cylinder engine would provide greater smoothness, quietness, and versatility than was possible with the 4 cylinder engine.
Probably, the most serious limitation of the original Tempest was in the body-frame integral construction. One inherent characteristic of integral construction is the limited amount of isolation that can be introduced into the system to separate the power train and chassis components from the passenger compartment. Even with the generous amount of rubber isolation which was used in the integral Tempest, and after 3 years of concentrated effort, we found it difficult or impossible to eliminate many of the objectionable noise and vibrations by any economical or reasonable means.”
That’s most interesting. They’re admitting in ’64 that the car had NVH issues that just couldn’t be economically solved.
Interesting too that you describe John Z’s ’61 paper as “creative and interesting”, which might also be words used to describe a lot of his career, and not necessarily in always flattering ways. I wonder if he mentioned the unsolvable NVH troubles identified in the ’64 paper? If so, I’ll wager it was done creatively, and interestingly….
In DeLorean’s book, “On a Clear Day You Can See GM”, he mentioned the Tempest as driving around with large rocks banging around in the trunk.
Who introduced balance shafts and when?
Frederick William Lanchester patented the concept for inline two- and four-cylinder engines in 1912 (US1163832), but its value was limited relative to its cost and power consumption, so it wasn’t widely used until much later.
Mitsubishi introduced their “Silent Shaft” in the 1970’s.
https://www.curbsideclassic.com/vintage-reviews/road-and-track-vintage-review-1976-mitsubishi-arrow-gt-balance-shafts-to-the-rescue/
Wowzer, 5,500 rpm shift points from an un-balance-shafted 3.2 litre four! Must’ve vibed enough to remove not merely fillings but good teeth too. From what I’ve read, the engine mounts were made really soft in compensation, so much so that the engine could be seen to rise upon revving – at 5,500, I reckon it must’ve been trying to push the hood open.
The two-doors are pretty cars, and technically interesting ones. It’s just a pity the compromise in execution: every angle of the wheels is scary wrong in the cornering photos. All for the saving of one extra universal-type joint on the outer end of each rear driveshaft, which would absolve the swing axle of its nefarious sins and bless it into new life as a proper independent rear end…
Do I have the following right? These share the main body with the Corvair; the Corvair had sought to bring good and big-car proportions to a small car: the only effective way was to make the car very low: this meant a rear-engine, if there was to be any passenger room: thus, when Pontiac got it, the rope drive was a way (the only?) of making a front-engine/rear drive set-up work without having a very high hump through the car.
A lower driveline tunnel may have been a reason for the rope drive, but it wasn’t the main reason. The Ate Up With Motor article goes into this in more depth.
How else were they going to get 27.5 cu ft of luggage space?
/jk
Do I have the following right? These share the main body with the Corvair; the Corvair had sought to bring good and big-car proportions to a small car: the only effective way was to make the car very low: this meant a rear-engine, if there was to be any passenger room:
In parts. The Corvair didn’t get a rear engine in order to make it low and look like a 7/8 scale big car. Ed Cole was determined that a rear engine car was just the way to go, period. That came first. But of course that did allow a low flat floor and thus a room interior with a lower overall height. It was just an inherent advantage. And of course a lower car had a lower center of gravity thus better handling, especially given its rear engine.
All of this turned out to be somewhat irrelevant as a cheap compact, but was very fortuitous in turning the Corvair into a sporty car, which totally saved its ass.
The Tempest had rope drive because DeLorean wanted a rear transaxle in order to have better weight distribution and because he was rather obsessed with IRS at the time. The Buick and Olds versions had a conventional tunnel and their interior space utilization was ok.
The Buick and Olds version also utilized a very expensive two piece drive shaft with constant velocity joints to achieve their design goals.
The Tempest used the Corvair transaxle and rear suspension, and the driveshaft and slant-four engine were compromises to enable Pontiac to give the Tempest a front engine (rather than using the Corvair six) with minimal additional tooling expense. it was about persuading the corporation they could make something that wasn’t a Corvair clone while still having enough commonality to bring down the net cost of the Corvair.
The BOP compacts look taller than the Corvair to me. Were they? The seats must have been near the ground to still have adequate headroom, but GM had to maintain their proportions in the US. It is odd to think they went from all full-size to these with nothing between, then to four different sizes in a few years.
Yes, they were about 2 inches taller.
That Tempest is a nice ‘medium-sized’ car that reminds me of the Corvair, esp. the front end! It would have been a great car for a young single guy like me in the 70s, as I could never afford new cars, so they had to be at least 10 years old for me to purchase.
Ransom Eli Olds
Ransom Eli Olds (June 3, 1864 – August 26, 1950) was a pioneer of the American automotive industry, after whom the Oldsmobile and REO brands were named.
I just Giggled “Olds” to see WHO the car was named after! As a bonus, I also found out that the REO was named after him too.