As a result, our cars have evolved into “land yachts”, our trucks have become “monster trucks”, and the desire to drag our living spaces around with us has morphed into converted busses with rooms that pop out of the side, a Mini-Cooper hidden under the master bedroom floor, and self-tracking satellite dishes that fight for space on the roof with air conditioning equipment.
And for more than a few of us, “what if…?” has even extended to “what if my car…was a jet car?”
In today’s improbable reality I’m here to tell you that Chrysler engineers asked that exact same question, for roughly a quarter of a century, and as a result they actually designed and deployed seven generations of cars with jet engines—and they came darn close to putting the eighth-generation design on sale to the general public.
It’s a story of pocket protectors and slide rules and offices full of guys who look a bit like Drew Carey…but as we’ll see in Part Two, it may also be a story of technology that couldn’t be perfected “back then”, but could be reborn in our own times.
As so often happens, a bit of “setting up” is needed, and to get this story going we need to discuss exactly how jets—particularly gas turbines—work.
In the case of an automotive engine, the idea is that air is drawn into the engine, that air is compressed, fuel is added, and the air/fuel mixture is then set on fire with a spark plug. This rapidly heats the mixture, it expands, and the energy created by that expansion is used to turn a turbine (a variation on a fan) which is connected to the driveshaft that eventually turns the wheels.
Some aircraft and helicopter engines also use this design to turn propellers, but the majority of aircraft jet engines force the expanding air/fuel mixture out the back of the engine in the form of “thrust” that, to put it as simply as possible, “make airplane go fast”.
From an engineering point of view, there are a lot of advantages to a turbine engine.
In contrast to a design that requires pistons and valves and a crankshaft and a cooling system and a system for oil distribution, turbine engines have very few moving parts, are cheaper to manufacture, and require a relatively small amount of maintenance. They also have very long service lives compared to piston engines.
Beyond that, turbines start right up on very cold days. Because jets output lots of heat you never have to wait for the jet car’s heater to “warm up”, and they can burn virtually any combustible liquid or volatile gas as fuel.
Vibration is very low, and you get 100% of available torque at 0 rpm, which means you don’t have to “rev up” the engine to get the wheels to start turning (something that is also true of vehicles powered by electric motors).
“Eagles may soar, but weasels don't get sucked into jet engines”
--John Benfield
So that’s the why…now how about the “who did what when?”
1954, 1955, and 1956 saw Chrysler rolling out the first-generation CR-1 turbine engine. One vehicle was produced in each of those years; the ’55 version was designated the Plymouth Belvedere Sportone CR-1 Turbine Special. (The 1956 version of the same vehicle was rated at 100 horsepower and 13 MPG.)
By 1959 the CR-2 engine was in service, again only in “testbed” vehicles, and it had achieved ratings of 200 horsepower and, after a 1,200 mile demonstration run from Detroit to Princeton, New Jersey, a far more respectable 18 MPG.
Operating these vehicles had taught Chrysler a few things about the disadvantages of turbine designs:
--the gases that come out the back of the car are really, really hot (temperatures can climb above 1000 degrees F.).
--after you put your foot on the gas, there is an annoying delay before the turbines (and the wheels) start spinning faster.
--because you’re basically dumping fuel into the combustion chamber, fuel economy sucks.
--the CR-1 and CR-2 engines did not offer “engine braking”, which means there would be extra wear and tear on the brakes at the wheels, and, because the driver would be constantly “riding” the brakes, increased potential for a heat-related braking system failure.
An engine was coming along that would address these problems, and in 1961 it was dropped into the visually stunning TurboFlite, which looked like a cross between two famous automotive avians: an early 1960s T-Bird and a late 1960s Plymouth Superbird. This Chrysler-designed and Ghia-built car even featured a clear “bubble” canopy that lifted up to allow passengers to get in and out.
The CR-2A engine featured fancy new engineering that dramatically reduced the acceleration delay and provided engine braking, and in 1962 one of the two Dodge Darts that was fitted with this engine was taken on a 3,000 mile national tour (New York City to Los Angeles) to introduce the concept to the public. (Two other cars, both Plymouth Furies, were also fitted with turbine engines that year.)
At this point we need to talk about the most unusual characteristic of this type of car: its singularly unique sound.
If you can imagine the sound of a Learjet taxiing several hundred feet away you might have a pretty good idea of—well, actually, you don’t have to imagine it if you don’t want to. You can hear it for yourself by watching the film produced by Chrysler to document that 1962 cross-country trip.
By 1963, a fourth-generation engine had deployed new technology that recycled heat from the exhaust to “preheat” the intake air. This dramatically reduced the exhaust temperature while making it easier to set the intake air on fire, which significantly increased both fuel economy and horsepower.
Other improvements further reduced “acceleration lag” and provided better engine performance while idling.
There is just too much story for one day, so we will stop right here and pick up the rest next time. Before we finish, a quick recap of where we’ve been, and a preview of where we’re going:
Chrysler, among other manufacturers, was experimenting with using jet engines to turn turbines; the idea being to replace the piston engines used in virtually every car built from that day until this with something better.
Four generations of engine had already been produced, many of the problems that were associated with the original design had been either partially remediated or fully resolved, and a significant effort was underway to introduce the idea of “jet cars” to the motoring public.
In Part Two, Chrysler puts a turbine car in the hands of 200 lucky families, we continue a history that may not be over yet—and in a most unexpected development, we’ll discover the common heritage that links the 1956 Ford Thunderbird, the 1961 Lincoln Continental, the 1964 Chrysler Corporation Turbine Car, and the 2009 Dodge Challenger.
So how about that? A decade-long story of history, engineering geekery, and conceptualism…and all of it presented in the form of useful objets d’art.
And in Part Two: lots more to come.
What’s not to love?
No comments:
Post a Comment