Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

[cjforumadmin]

http://www.bangshift.com/blog/Awesome-Vintage-Promotional-Video-The-Turbocharged-Oldsmobile-Jetfire-V8.html

[Birdman]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

I LOVE these vintage auto commercials, particularly the campy acting!

If Oldsmobubble had dropped the compression to, say, 8.5-9.0, they might have been able to safely increase the PSI to around 6.5-7.0 and picked up a few more ponies - and a LOT more reliability and potential sales - w/out the need for the exclusive "Turbo Jet Fluid". Had this occurred, might turbocharging have been more accepted and therefore more mainstream at a much earlier space in time? One can only guess.

[38P]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

Compression was lower in the turbo Corvair. That didn't help turbocharging to catch on. With 32-cent/gallon gasoline and adding cubic inches so cheap, the cost to develop and sell turbocharging in the 1960s exceeded demand.

I also liked this analysis of the ill-fated Jetfire in the Car Craft Board's long-running turbo thread:

Corky Bell's celebrated turbo book Maximum Boost: Designing, Testing, and Installing Turbocharger Systems introduces readers to the acronym PLAN to explain power production:

P -- Pressure (as in cylinder pressure)
L -- Length (as in stroke length)
A -- Area (as in bore area)
N -- Number (as in number of combustion events per minute)

Bell uses PLAN to show why turbocharging is more practical and cost-effective than most other forms of Car Crafting at boosting the output of production engines.

PLAN is also useful to explain yesterday's low boost comparison. The Indy V8's greater ability to consume air (and thereby extract power from fuel) is the result of optimizing PLAN within restrictive rules. The Jetfire's weak numbers are mostly from ignoring PLAN.

First, let's look at the Jetfire:

The Jetfire V8 used an early, less-efficient, smallish turbo compressor drawing through a restrictive gasoline carburetor. It forced the hot supercharged air-fuel mix into a constrictive cast iron intake through small ports regulated by a mild camshaft.

Although the Jetfire's static compression was in excess of 10:1 (which in many driving conditions jacked up peak cylinder pressure beyond the detonation threshold), it exhausted the waste gasses into simple log manifolds that joined together before a single scroll turbine section. The turbine exhausted into a small, restrictive exhaust and muffler system. Maximum effective RPM was less than 5,000.

In terms of PLAN, average cylinder pressure (Factor P) was held down by inefficient induction. It was artificially spiked by high compression, but that did not increase the amount of "working fluid" (air and fuel) available for combustion and ultimately led to less available power than an equivalent peak cylinder pressure produced by other means. Heat and kinetic energy use was not optimized.

The number of compbustion events per minute (Factor N) was also limited by induction design, cam timing, valve size, port size, short-block design, materials and exhaust design. (Pumping up Factor N is usually the most expensive way to increase power because it requires either adding more cylinders or increasing R.P.M.)

Thus, although the Jetfire has a small advantage in displacement (Factors A & L) over the turbo Indy V8, it is far outweighed by other factors limiting mass air flow.

Still, the Jetfire is a milestone engine that should be remembered (and preserved) by Bangshifters and that video is bitchin.

[SuperBuickGuy]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

I had a 215 Buick motor in a 62 Buick.... it wouldn't keep head gaskets in it - I can only imagine what they must have been with the turbo.... of course, the Olds version had 5 bolt heads - but they were not equally spaced - GM must have recognized the problem with the 4 bolt, but rather then redesign the block - they simply added another bolt.

I've been considering building a 215 for the fiat - the turboing the wee out of it - however, I'm not sure the rest of the motor would be up to the challenge - especially the bottom end.

[38P]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

It seems like there are a few British dudes who turbo the Rover version of the engine without disaster.






Isn't that what you're supposed to do with 'em?

[abadwillys]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

cool 8) i remember when i was younger this dude having one of those motors, complete with turbocharger in a ..get this 67 camaro convertible and uhh.. it was four wheel drive!!! complete with early corvette sharks tooth grille!!. an automotive oddity to say the least!!

[38P]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

That's fairly far out there. Corvette grille teeth on a Camaro? 4wd? What? were they having an all-you-can-carry sale down at the U-pull-it yard?

[Barry Donovan]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

was that the engine a lesson is self combusting fuels with metal oxides?

thermites, hydrazine.. whatever else may still be unknown to mankind.

definite one to preserve, go very easy.

[abadwillys]

Re: Awesome Vintage Promotional Video: The Turbocharged Oldsmobile Jetfire V8

That's fairly far out there. Corvette grille teeth on a Camaro? 4wd? What? were they having an all-you-can-carry sale down at the U-pull-it yard?

LOL yeah, dont forget it was a ragtop too!!, actually it was really nice, and crafted nicely, the guy was a bodyman and pretty skilled, i dont recall what 4wd chassis it sat on, i was just getting into cars at the time, just a youngin..