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GM Motorama Firebirds

Plans for the GM Motorama Firebird II

By the time GM's Harley Earl turned his attention to the next Firebird project, design engineer Bill Turunen and his staff had come up with an improved gas turbine engine, the GT-304, for the GM Motorama Firebird II.

Unlike the 302, this engine utilized two rotating heat exchangers that recycled some of the combustion energy that had previously gone out the exhaust pipe. Recycling this heat made the GT-304 more fuel-efficient and responsive. Fuel availability was far less of a problem. Although the GM Firebirds relied on kerosene, a gas turbine engine will run on just about anything that burns.

Earl again turned to Bob McLean's studio to design and engineer the Firebird II. This time, though, Earl wanted to impress Motorama showgoers with the "Family Sedan of the Future." He realized that people had a hard time relating to the jet-like Firebird I, but had no problem accepting a stock Plymouth or Dodge with a gas-turbine engine.

Even so, Earl asked McLean to use titanium body skins, a Plexiglas greenhouse, aircraft-style instruments and steering wheel, and four thin-section individual seats. He also ordered the car to be set up with an electronic guidance system that would follow wires buried in automated roadways.

An early version of the 1956 GM Motorama Firebird II
The gas-turbine car concept evolved into the larger
Firebird II of 1956. Distinctive features of the
Firebird II included a titanium body and seating for
four under a Plexiglas dome.

Besides McLean, the Firebird II design staff included freshman stylist Norman J. James, who'd recently come from Pratt Institute; engineer Stefan Habsburg, also on his first major GM assignment; and veteran designers Byron Voight and Al Aldregetti. James and Habsburg did most of the creative work, and both agree that they didn't set any styling precedents. Yet Habsburg in particular points out that the car absolutely bristled with technical innovation.

The GM Motorama Firebird II's high-tech headlights.
When the GM Motorama Firebird II's
headlights were needed...

The GM Motorama Firebird II's high-tech headlights.
...they sprang from hiding places in the bodysides.

The use of titanium had to be the fabricators' most interesting challenge. There were actually two Firebird IIs built, one with a fiberglass body, the other with titanium skins. GM Styling had never worked with titanium before, but Earl wanted to try it, especially after Republic Steel made sheet stock available. Republic supplied Earl's fabrication people with 10-foot-by-4-foot sheets of 0.040-inch thickness, as well as 0.050-inch stock for the hood and decklid.

Titanium weighs half as much as steel, can't rust, and is extremely tough and unbending -- which makes it maddeningly hard to work with, as the parts fabrication crew immediately found out. When hammered, the surface picks up impurities that lead to cracking. The material is so armor-like, according to McLean, that edges couldn't be contoured, and cuts required special tools. A panel that would have taken 30 minutes to form in steel took 24 hours in titanium. Welds tended to discolor the metal, which Earl wanted to leave unpainted.

How did the Firebird II get out of the planning stage into fabrication? Find out on the next page.

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