Puff and bluster
GROUNDBREAKING TURBO WITH A FAMOUS AUSSIE CONNECTION
FANS OF FORCE-FEEDING often trace automotive turbocharging to 1970s Euro exotics like the BMW 2002 Turbo or Porsche
930. In fact, it began with General Motors in 1962, with the Chevrolet Corvair Monza and the Oldsmobile Jetfire.
Other than sharing a parent (and an ongoing argument over which came first), this pair of two-door models couldn’t have been more different: the Corvair a 2.4-litre flat-six, air-cooled and rear-mounted; the Jetfire a more conventional front-mounted 3.5-litre V8.
Just as unlikely was the world-beating Aussie connection that lay in store for the latter.
The US was a leader in turbocharging via WW2 aircraft like the P-38 Lightning and P-47 Thunderbolt, both of which used General Electric turbos to deliver their high-altitude power.
The Jetfire, based on Olds’ F-85 Cutlass coupe, was destined for force-feeding. Olds’ version of the GM 3.5-litre (215ci) Buick/Oldsmobile all-alloy V8 engine, launched in 1961, featured stronger six-bolt (per cylinder) heads to resist warping under higher cylinder pressures. This key difference would not be lost on a certain Jack Brabham and his friends at Repco, who turned it into a dual F1 title-winning engine.
The handsome Jetfire sold at a 12 percent premium to its atmo-V8 Cutlass cousin and was available with three-speed auto or four-speed manual transmissions. Fitted with a single Garrett AiResearch turbocharger and special Rochester carb, the so-named Turbo Rocket V8 engine boasted a lusty 160kW, but the space-age technology brought owner obligations that would contribute to its quick demise.
Most notable was the fluid injection system that, along with a low 0.34-bar (5psi) boost pressure, helped avoid detonation. The water-methanol mix required topping up about as often as the fuel tank. Running it empty triggered a boost-limiting valve.
Ignorant owners soon complained about a lack of power, and turbos were failing through lack of vigorous exercise. Owners weren’t entirely to blame; the Jetfire ran the same wallowy suspension settings as lesser cruise-liner Cutlasses and was never as quick as the big-bore V8s anyway.
Between the 1963 original and 1964 rebody, Oldsmobile sold a paltry 9607 Jetfires. The ‘215’ alloy engine was dropped at the end of 1963, after plenty of scrapped porous castings and the arrival of new iron rivals like GM’s new-for-’62 327ci V8.
In 1965, GM offered owners a free ‘downgrade’ to atmo spec, losing 11kW but bringing reliability. Most owners jumped at the offer, making original Turbo Rocket V8 Jetfires automotive unicorns today.