Global InformationGM Whirlfire engine information
| Whirlfire | |
|---|---|
 Cutaway of the Detroit Diesel Allison GMT-305, the commercialized derivative of the GT-305 Whirlfire gas turbine engine | |
| Overview | |
| Manufacturer | General Motors Research / Detroit Diesel Allison |
| Production | 1953–83 |
| Layout | |
| Compression ratio | single-stage, rotary |
| Combustion | |
| Operating principle | free-turbine turboshaft |
The GM Whirlfire gas turbine engines were developed in the 1950s by the research division of General Motors Corporation and fitted to concept vehicles, including the Firebird concept cars, Turbo-Cruiser buses, and Turbo-Titan trucks through the 1960s. They are free-turbine turboshaft machines with two spools: one compressor/gasifier turboshaft and one power/output turboshaft sharing a common axis without a mechanical coupling between them. Fuel consumption of the first-generation GT-300 was high compared to piston engines, so thermal wheel regenerators were added to the second-generation GT-304, cutting consumption by approximately 1⁄2.
Initially, the engines were built by GM Research, but starting with the third generation GT-305, the Allison Engine division took over responsibility for commercializing gas turbine technology. This division, later merged with Detroit Diesel and renamed Detroit Diesel Allison, would produce approximately one hundred of the final design GT-404 engines, which incorporated ceramic components. Cost, driven by exotic turbine alloys and materials, and fuel consumption proved to be insoluble issues compared to conventional piston engines and further development of gas turbine engines at General Motors was discontinued in the early 1980s.