The stage was set for the development of the Oldsmobile F-85 Jetfire at the start of the 1960s. Like a beach pounded by heavy surf, the U.S. auto industry was in the path of a couple of forceful waves.
For one thing, the postwar emphasis on horsepower was bearing down to make its biggest splash yet in what would soon come to be known as muscle cars. For another, American showrooms were about to be awash in compacts, economical in size and power, inspired by a rising tide of small imports.
Just as breakers rise separately from the same ocean, these two forceful waves -- each with an energy of its own -- could still flow together. Oldsmobile would be among the carmakers that tried to reconcile these seemingly different friends. True to its history, it would do so by turning to some advanced technology.
Olds had won a reputation for itself at General Motors by leading the way in engineering breakthroughs, such as Hydra-Matric automatic transmission, first seen on the 1940 models, and the modern high compression Rocket ohv V-8 engine that debuted in 1949. Both were at the leading edge of the swing toward driving ease and abundant power that arose in the 1950s and showed no signs of abating anytime soon.
But there was an undercurrent that ran counter to the trend. Throughout the 1950s, a growing number of American motorists had drifted over to a host of small cars, most of them European. Some admired these cars purely for their economy. Others, though, discovered a nimble sporting, "fun-to-drive " character that just couldn't be had with 18 feet of fins and chrome.
When U.S. automakers decided to wade into the compact market, some of them wanted to make cars to court the latter group of customers. Oldsmobile's solution was a light, small V-8 fitted with a turbocharger to give it the performance of a heavier, larger-displacement engine.
The platform for this powerplant was Oldsmobile's unibodied F-85, introduced for 1961 as one of GM's upscale "senior" compacts (though billed as "intermediate" in size, on a 112-inch wheelbase). Related to the Buick Special and Pontiac Tempest, it was equipped with an all-aluminum, 215-cid "Rockette" V-8, a GM Engineering design refined for production by Buick and Oldsmobile engineers.
In stock form, it produced 155 bhp; an optional version with four-barrel carburetion and 10.25:1 compression yielded 185 bhp. Get more details on the Jetfire's turbocharger in the next section of this article.
For more information on cars, see:
1962-1963 Oldsmobile F-85 Jetfire's Turbocharger
On April 16, 1961, Oldsmobile added what would come to be the 1962 Oldsmobile F-85 Jetfire's predecessor -- an F-85 Cutlass coupe with bucket seats and a luxury interior -- as its response to growing demand for sporty compacts like Chevrolet's Corvair Monza. For 1962, the Cutlass coupe and its new convertible companion got the 185-horse V-8, but halfway through the model year, Oldsmobile had a bigger surprise on tap.
Placed on sale in April 1962, the Jetfire two-door hardtop -- based on the F-85 Cutlass -- held a turbo-boosted edition of the 215-cid V-8 good for 215 bhp at 4600 rpm and 300 pound-feet of torque at 3200 revs. That figure of one horsepower per cubic inch, first achieved in 1956 by the Chrysler 300-B, was a nearly magical number to enthusiasts at the time.
A turbocharger boosts the strength of the air-fuel mixture as a way to get more power out of a given engine without increasing its size. So does a supercharger, albeit via a different power source. Essentially, a turbocharger is a shaft with turbine impellers at each end. As exhaust pressure is directed against one impeller, it begins to spin. Meanwhile, the other impeller draws in air, sending it via centrifugal force into the intake manifold. This process boosts air pressure and forcefully feeds the fuel-air mixture into the engine for better combustion.
Turbocharging wasn't a new idea in 1962. Its history dates back to the early twentieth century. In 1905, according to Canadian historian Bill Vance, a Swiss engineer named Alfred Buchi patented an exhaust-driven supercharger for use on diesel engines.
As World War I brewed, General Electric and other U.S. companies were working on turbos for aircraft. GE's Dr. Sanford Moss, later named "father of the turbocharger," put a GE turbo on a V-12 Liberty aircraft engine. In high-altitude testing, it showed a dramatic power boost. After proving their worth in the Great War, turbocharged engines saw extensive use on World War II fighter planes.
Bentley and Bugatti made early use of superchargers in cars. In the U.S., makes such as Cord, Duesenberg, and Graham also used "blowers" prior to World War II, and several others resorted to them in the 1950s.
If turbochargers presented a bigger mystery to American enthusiasts in 1962, at least they would get a crash course in them. Anticipating a lack of understanding of turbos, Olds used the special Jetfire promotional folder to teach as much as to sell; a cutaway drawing explained the flow of intake and exhaust gases and a Q-and-A section tackled questions a prospective buyer might raise about the turbocharger's operation.
A month or so after the Jetfire's debut, Chevrolet launched the Monza Spyder with a turbo version of the Corvair's air-cooled flat six, also generating one horsepower per cubic inch. (Historically, then, the Jetfire is the first volume-production turbo car in America.)
In the next section, learn how Oldsmobile's team of engineers developed the Jetfire's turbocharger.
For more information on cars, see:
1962-1963 Oldsmobile F-85 Jetfire Engine Development
A team of Oldsmobile engineers under Gilbert Burrell, the division's chief engine designer, worked with Garrett AiResearch on the 1962 Oldsmobile F-85 Jetfire's turbocharger development.
"A turbo-supercharger unit . . . could have been designed that would have resulted in much higher high-speed power output, but this would not have given the tremendous torque increase in the road-speed or normal driving range," Burrell told Road & Track in 1962. "We wanted a hot-performing street job, not a high-speed race car."
Oldsmobile engineers decided on a small-diameter turbo unit to keep weight down and also speed up response. They also chose to employ an integral waste-gate, an idea borrowed from aircraft turbos, to drain off some of the exhaust gases and limit the amount of boost. Unless a limit was designed into the system, the turbocharger might run dangerously fast.
They determined that the turbo would be restricted to a boost of five pounds per square inch (psi). At five psi above atmospheric pressure, a waste-gate relief valve caused a portion of the exhaust gases to bypass the turbine wheel, which governed impeller speed and the amount of air being pumped.
Despite their inherent efficiency (compared to a supercharger), turbochargers had a couple of drawbacks. First, they were subject to intense heat from the exhaust gases that drove their impellers. Turbocharged engines were also prone to detonation (pinging), due to carbon buildup that resulted -- especially when using certain grades of fuel.
To help prevent pinging, Chevrolet lowered the compression of its turbo-charged Corvair. Oldsmobile took a different path, keeping the compression at 10.25:1 but employing an innovative fluid-injection system. Kept in an under-hood reservoir, "Turbo-Rocket Fluid" was an equal-parts mix of distilled water and methyl alcohol, along with a bit of rust inhibitor.
Whenever the driver tromped the gas pedal, this tank was pressurized, causing a small amount of fluid to be injected into the air-fuel mix just before it reached the intake-side impeller. As the fluid evaporated, it absorbed heat from the intake air, holding down combustion-chamber temperatures and preventing detonation.
Depending on the driver's pattern, according to historian Vance, the full reservoir could last anywhere from 200 to 2000 miles. Should the fluid run low, an indicator light inside the car would flash a warning. If it ran out, a throttle-body valve closed to prevent full-power acceleration.
That was one of several safety features that ironically caused the turbo-charged engine to be deemed troublesome. There were others. The wastegate itself, for instance, had twin diaphragms. If those failed, the fluid-reservoir cap would pop off as a final measure to prevent an overboost situation.
The Jetfire's Garrett TO-3 turbocharger sat crossways atop the engine, with a special single-throat, side-draft Rochester carburetor on the left and the exhaust system on the right. The entire installation added about 36 pounds to engine weight. The placement of the turbocharger did not impede access to spark plugs or the distributor.
To cope with the extra horsepower, the Jetfire V-8 had special pistons and heavier-duty main bearing caps, along with heavy-duty aluminum alloy for bearing inserts and what Oldsmobile called a "performance-tailored" fuel pump and connecting rods. Intake valves were aluminum-coated, and the distributor and coil worked at higher voltage. A bigger radiator was installed, too.
Read more about the Jetfire's features by continuing to the next section.
For more information on cars, see:
1962-1963 Oldsmobile F-85 Jetfire Styling and Features
The Oldsmobile F-85 Jetfire generally looked like a Cutlass coupe, but it did have the distinction of being the only true hardtop in the F-85 line; all other closed two-doors had fixed door frames and B-pillars.
Beyond that, the Jetfire featured exclusive brushed-aluminum bodyside panels and special "Jetfire" badging on the trunklid and front fenders. Two chrome hood spears were used, rather than one as seen on the Cutlass.
Aside from a dash badge and standard floor console with built-in turbo-function gauge, the Jetfire's interior was a close match to the Cutlass cabin, the principal features of which were foam-cushioned bucket seats and a deluxe two-spoke steering wheel.
The instrument panel was F-85 pure and simple, dominated by a horizontal 120-mph speedometer in a pod dead ahead of the driver. A column-shift three-speed manual transmission was standard, but floor levers operated the extra-cost four-speed stick and Hydra-Matic transmissions.
Enthusiasts soon found fault with the instruments, specifically the lack of a true, calibrated boost gauge. The vacuum-boost gauge on the center console instead had simple red and green segments marked "power" and "economy." (The warning light that signaled low injection-fluid levels was included in this dial, too.) To make matters worse, the gauge's position made it hard to see.
Priced at $3049, the Jetfire started at $355 more than a Cutlass coupe. Hydra-Matic added $189 to the tab; the four-speed gearbox cost $199.80 extra. Roto-Matic power steering was an $86 option, Pedal-Ease power brakes cost $42.50, and air conditioning went for $378. A vinyl "Sport Top" roof covering cost $75.32.
Next, discover what critics had to say about the Oldsmobile F-85 Jetfire's performance.
For more information on cars, see:
1962-1963 Oldsmobile F-85 Jetfire Performance
After road testing an Oldsmobile F-85 Jetfire prototype, Car and Driver magazine reported that in terms of top speed and acceleration, "the latest Oldsmobile offers sports-car performance in a deluxe compact car." Testers declared that "the power gain in mid-range torque characteristics is its most striking advance."
This made the Jetfire "a more practical traffic car" than one with a bolt-on supercharger, which was available on the aftermarket in 1962.
Despite the hefty performance increase, Oldsmobile made no significant alterations to the Jetfire's chassis or suspension. Handling, therefore, was no better than in a regular Cutlass. Oldsmobile even used 6.50 × 13 tires, rather than the 15-inchers available on the Buick Special and Pontiac Tempest (though 15s were listed as an option).
Due to effortless power steering, Car and Driver noted, it "takes quite a while to become familiar with the slow response, and precision maneuvers can only be undertaken at low speeds." With coil springs all around, the "suspension is definitely soft," though body roll "was not excessive under any conditions" and the 9.5-inch-diameter drum brakes delivered instant response.
No sound suggested the presence of a blower, as would be the case with a supercharger. "The whole unit is completely silent," Car and Driver observed. "The engine itself is one of the smoothest and least obtrusive medium-sized power plants on the market, even without the turbocharger." Engineers "also succeeded in eliminating vibration, and the entire power and drive train feels very well balanced."
With Hydra-Matic, this early Jetfire accelerated to 30 mph in 3.9 seconds, reached 60 mph in 9.2 seconds, and took 32.8 seconds to hit 100. Dashing through the standing quarter-mile required 17.5 seconds.
Gas mileage was deemed comparable to a Cutlass with four-barrel carburetion, though "under hard driving the consumption is bound to rise." At cruising speeds, Car and Driver suggested, "fuel economy may be better, because of the improved fuel atomization and mixture distribution with the whirling impeller." Premium fuel was recommended.
Summing up its test of a prototype, Car and Driver declared the Jetfire "not only the most radical design from an American factory in many years; it is an elegant and comfortable high-performance car of medium size."
The Jetfire's handling, however, was another story. In the next section, find out what handling faults reviewers noted.
For more information on cars, see:
1962-1963 Oldsmobile F-85 Jetfire Handling
Road testing a production Oldsmobile F-85 Jetfire with a Warner four-speed manual gearbox and standard 3.36:1 axle ratio in 1962, Car and Driver suggested that it "comes remarkably close to the European concept of a big car," yielding "spirited performance" along with Oldsmobile levels of comfort.
It was a bigger car for 1963. Though wheelbase was unchanged, a thorough restyling that added four inches of overall length and 2.1 inches of width made the Jetfire and its F-85 kin look more like scaled-down Eighty-Eights.
Still, 0-to-60 mph acceleration took just 8.5 seconds and a quarter-mile run was achieved in 16.8 seconds. The Jetfire topped out at 107 mph. "On a power-weight ratio basis," Car and Driver asserted, "the Oldsmobile F-85 Jetfire is a real winner."
Handling had not improved, though. The magazine noted that the .875-inch antiroll bar "permits body lean to an extent that sporting drivers find objectionable." All told, the 1963 Jetfire "does not have steering, suspension or brakes in keeping with its guise as a sporting sedan."
At the same time, the Jetfire's ride quality, "even on the worst surfaces," was considered "soft enough to keep elderly housewives from getting alarmed."
Other flaws also marred the experience. "On anything but a highly abrasive surface," Car and Driver noted, "the Jetfire's maximum acceleration is defeated by wheelspin." In addition, "gear ratios chosen for the four-speed Warner gearbox do not take full advantage of the excellent low-rpm torque of the turbo-charged V-8."
Motor Trend testers were considerably less charitable to the Jetfire, stating that "as a performance package it leaves much to be desired." With three-speed Hydra-Matic and the standard 3.36:1 axle ratio, their test car took 10.2 seconds to reach 60 mph. Running the quarter-mile took 18.7 seconds at a trap speed of 80 mph.
"Part of the lack of brilliance," Motor Trend explained, "must be blamed on the Hydra-Matic . . . one of the sloppiest-shifting boxes on the market." Yet, "the turbocharger has to share the blame, because its operation also seems less than perfect."
In theory, boost should remain constant from about 2400 rpm up to the peak of engine horsepower. The Jetfire's V-8, MT suggested, "feels as if the valve isn't allowing the impeller to pump enough mixture to keep a constant manifold pressure."
In acceleration tests at 4600 rpm, "performance takes a flop as the engine flattens out completely . . . like dead." And as the Hydra-Matic "slips its way into top gear the engine is stumbling badly . . . . [T]he engine runs out of breath in second and top gear at 4600 to 4700 rpm, which indicates that the blower isn't pumping pressure at this point. The feeling is the same as in a normally aspirated engine with too small a carburetor."
In the next section, learn how these and other issues contributed to the Jetfire's demise.
For more information on cars, see:
Decline of the 1962-1963 Oldsmobile F-85 Jetfire
Only 3765 Oldsmobile F-85 Jetfire coupes were sold in 1962, followed by 5842 more in 1963 before Oldsmobile dropped its turbo car.
The following year saw the debut of a larger F-85 -- a true intermediate -- with body-on-frame construction and a conventional cast-iron 330-cid V-8. It begat a high-performance model, the 4-4-2, that kept Oldsmobile a member in good standing in the Sixties muscle-car fraternity.
The final chapter in the Jetfire saga was written in 1965, when General Motors offered to convert turbocharged engines into four-barrel carbureted versions (with conventional intake and exhaust systems) at no cost.
Did its troublesome fluid-injection system kill the Jetfire? Not entirely, but it was the foremost culprit. "People would let them run out of fluid, then complain about the performance," Jetfire expert Bruce Sweeter told Special Interest Autos magazine in its March/April 1996 issue.
Harold Metzel, divisional chief engineer at the time of the Jetfire, recalled in the Olds centennial history Setting the Pace that "we had to have so many things that modified the engine -- so many controls -- it became a monstrosity. It was good for squealing the tires, but it was too expensive with all the controls."
Engineer Tom Leonard suggested that "the Jetfire had too many belts and suspenders on it . . . . The water-injection system ended up with too many safety features . . . to be very practical. It was overkill." In his view, too, "the wrong people were buying [Jetfires] -- little old ladies. . . . A lot of people would never kick in the turbocharger," causing it to "freeze up."
Gaskets and diaphragms leaked. Like other 215-cid engines, the Jetfire had cooling woes. Automatic transmissions sometimes shifted harshly, and driveshafts were vulnerable. Then, too, the aluminum V-8 was said to be expensive to manufacture (though that didn't stop England's Rover from buying the 215's tooling to use in its sedans and Land Rover off-road vehicles).
As it turned out, the turbocharging bandwagon passed by quickly. Chevrolet offered a turbo Corvair until 1966, but then the system disappeared from U.S. passenger cars. However, more than a decade later, when automakers again needed a way to increase power without turning to bigger engines, the turbocharger made a significant comeback.
Starting with several Buicks in 1978, turbo-boosted engines turned up in numerous American car lines into the 1990s. Ironically, none of them were Oldsmobiles.