The DeSoto Firesweep I 2-Door Sportsman, particularly the 1958 facelifted model equipped with the PowerPack 5.7 V8 engine producing 295 horsepower, represents a pivotal moment in the final years of the DeSoto marque. Produced from 1957 to 1958, this iteration of the Firesweep aimed to blend sporty styling with the comfort expected of a full-size American automobile. It occupied a middle ground within the DeSoto lineup, positioned above the base models but below the more luxurious Fireflite series. The Firesweep, and this Sportsman variant specifically, was intended to attract buyers seeking a stylish and powerful coupe without the higher price tag of the top-tier DeSotos.
Technical Specifications
| Brand | DeSoto |
| Model | Firesweep |
| Generation | Firesweep I 2-Door Sportsman (facelift 1958) |
| Type (Engine) | PowerPack 5.7 V8 (295 Hp) |
| Start of production | 1957 |
| End of production | 1958 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 6 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Power | 295 Hp @ 4600 rpm |
| Power per litre | 51.4 Hp/l |
| Torque | 522 Nm @ 2800 rpm / 385.01 lb.-ft. @ 2800 rpm |
| Engine displacement | 5735 cm3 / 349.97 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103.12 mm / 4.06 in. |
| Piston Stroke | 85.85 mm / 3.38 in. |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 3.8 l / 4.02 US qt | 3.34 UK qt |
| Coolant | 16.1 l / 17.01 US qt | 14.17 UK qt |
| Fuel tank capacity | 87 l / 22.98 US gal | 19.14 UK gal |
| Length | 5499 mm / 216.5 in. |
| Width | 1989 mm / 78.31 in. |
| Height | 1443 mm / 56.81 in. |
| Wheelbase | 3099 mm / 122.01 in. |
| Front track | 1547 mm / 60.91 in. |
| Rear track | 1516 mm / 59.69 in. |
| Front overhang | 940 mm / 37.01 in. |
| Rear overhang | 1461 mm / 57.52 in. |
| Ride height (ground clearance) | 142 mm / 5.59 in. |
| Minimum turning circle | 14.2 m / 46.59 ft. |
| Approach angle | 16.5° |
| Departure angle | 11.4° |
| Ramp-over angle | 10.5° |
| Drivetrain Architecture | Rear wheel drive, Internal Combustion engine (ICE) |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 3 gears, manual transmission |
| Front suspension | Independent coil spring |
| Rear suspension | Leaf spring |
| Front brakes | Drum, 279 mm |
| Rear brakes | Drum, 279 mm |
| Steering type | Worm-reduction unit |
Powertrain & Engine Architecture
The heart of the 1958 Firesweep Sportsman was the DeSoto PowerPack 5.7 V8 engine. This engine, displacing 349.97 cubic inches (5735 cm³), was a cornerstone of DeSoto’s performance offerings. It featured a cast iron block and cylinder heads, with an overhead valve (OHV) valvetrain operating two valves per cylinder. The PowerPack designation indicated a higher level of tuning, including a larger carburetor and revised ignition timing, resulting in the advertised 295 horsepower at 4600 rpm and 385 lb-ft of torque at 2800 rpm. The engine utilized a conventional carbureted fuel system, common for the era. The standard transmission for this model was a three-speed manual, although a TorqueFlite automatic transmission was available as an option. The engine’s 10:1 compression ratio contributed to its robust power output, but also necessitated the use of premium gasoline.
Driving Characteristics
The 1958 Firesweep Sportsman with the 5.7L V8 and manual transmission offered a spirited driving experience for its time. While not a dedicated sports car, the engine’s torque output provided ample acceleration, particularly in the lower and mid-range. The three-speed manual gearbox allowed for driver control, but the gear ratios were spaced to prioritize cruising comfort over outright performance. Compared to the base engine Firesweeps, the PowerPack V8 provided a noticeable increase in responsiveness. The leaf spring rear suspension, while providing a comfortable ride, could exhibit some axle hop under hard acceleration. Handling was typical of large American cars of the era – body roll was present, and the steering, utilizing a worm-reduction unit, lacked the precision of more modern systems.
Equipment & Trim Levels
The Firesweep Sportsman trim level included a number of standard features designed to enhance comfort and style. The interior typically featured cloth and vinyl upholstery, with a focus on durability. Dashboard appointments included a full-width instrument panel with prominent gauges displaying speed, fuel level, coolant temperature, and oil pressure. Optional extras included power steering, power brakes, a radio, and whitewall tires. The two-door coupe body style offered a more sporty appearance than the four-door sedan, and the Sportsman trim often included exterior brightwork and distinctive badging.
Chassis & Braking
The Firesweep rode on a conventional body-on-frame chassis. Front suspension utilized independent coil springs, providing a relatively comfortable ride. The rear suspension employed leaf springs, a cost-effective and durable design. Braking was accomplished via drum brakes on all four wheels, measuring 279mm in diameter. While adequate for the time, the drum brakes lacked the stopping power and fade resistance of disc brakes. Steering was handled by a worm-reduction unit, which provided a relatively high steering ratio and required more driver effort than modern rack-and-pinion systems.
Market Reception & Comparison
The 1958 Firesweep Sportsman received generally positive reviews from automotive publications of the time. Critics praised the PowerPack V8 engine’s performance and the car’s stylish design. However, some noted the car’s large size and relatively basic interior appointments compared to competitors like Buick and Oldsmobile. Fuel economy, typical for a large V8-powered American car of the era, was modest. Compared to other DeSoto models, the Firesweep offered a more affordable entry point into the brand, appealing to buyers who wanted a stylish and powerful car without the expense of the Fireflite series. The manual transmission version, while less common, was favored by enthusiasts for its greater driver engagement.
Legacy
The 1958 DeSoto Firesweep Sportsman, along with the entire DeSoto line, was discontinued after the 1961 model year. The marque ultimately succumbed to declining sales and internal competition within the Chrysler Corporation. Today, the 1958 Firesweep is a sought-after classic car, particularly examples equipped with the PowerPack V8 engine. While parts availability can be a challenge, the robust construction of the engine and chassis ensures that many examples remain on the road. The 5.7L V8, while not known for exceptional longevity compared to some later Chrysler engines, is generally considered a reliable powerplant when properly maintained. The Firesweep represents a final flourish of American automotive styling from the 1950s, and the Sportsman variant, with its potent V8 engine, remains a desirable piece of automotive history.
