The DeSoto Firesweep I 4-Door Sportsman, equipped with a 5.3-liter V8 engine producing 245 horsepower and paired with a PowerFlite automatic transmission, represented a significant offering in the mid-1950s American automotive landscape. Produced for the 1956 and 1957 model years, this variant occupied a middle ground within the Firesweep lineup, balancing performance with the convenience of an automatic transmission and the practicality of a four-door sedan body style. It was part of the first generation of the Firesweep, a model intended to modernize the DeSoto brand and compete with offerings from Buick and Oldsmobile.
Technical Specifications
| Brand | DeSoto |
| Model | Firesweep |
| Generation | Firesweep I 4-Door Sportsman |
| Type (Engine) | 5.3 V8 (245 Hp) PowerFlite |
| Start of production | 1956 |
| End of production | 1957 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 6 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Power | 245 Hp @ 4400 rpm |
| Power per litre | 46 Hp/l |
| Torque | 434 Nm @ 2400 rpm |
| Torque (lb.-ft.) | 320.1 lb.-ft. @ 2400 rpm |
| Engine Model/Code | S27 |
| Engine displacement | 5326 cm3 |
| Engine displacement (cu. in.) | 325.01 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 93.73 mm |
| Cylinder Bore (in.) | 3.69 in. |
| Piston Stroke | 96.52 mm |
| Piston Stroke (in.) | 3.8 in. |
| Compression ratio | 8.5:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Carburettor |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 4.7 l |
| Engine oil capacity (US qt) | 4.97 US qt |
| Engine oil capacity (UK qt) | 4.14 UK qt |
| Coolant capacity | 19.9 l |
| Coolant capacity (US qt) | 21.03 US qt |
| Coolant capacity (UK qt) | 17.51 UK qt |
| Fuel tank capacity | 76 l |
| Fuel tank capacity (US gal) | 20.08 US gal |
| Fuel tank capacity (UK gal) | 16.72 UK gal |
| Length | 5481 mm |
| Length (in.) | 215.79 in. |
| Width | 1986 mm |
| Width (in.) | 78.19 in. |
| Height | 1440 mm |
| Height (in.) | 56.69 in. |
| Wheelbase | 3099 mm |
| Wheelbase (in.) | 122.01 in. |
| Front track | 1547 mm |
| Front track (in.) | 60.91 in. |
| Rear track | 1516 mm |
| Rear track (in.) | 59.69 in. |
| Front overhang | 925 mm |
| Front overhang (in.) | 36.42 in. |
| Rear overhang | 1458 mm |
| Rear overhang (in.) | 57.4 in. |
| Ride height (ground clearance) | 137 mm |
| Ride height (ground clearance) (in.) | 5.39 in. |
| Minimum turning circle | 13.1 m |
| Minimum turning circle (ft.) | 42.98 ft. |
| Approach angle | 18.9° |
| Departure angle | 12.9° |
| Ramp-over angle | 10.2° |
| Drivetrain Architecture | Rear wheel drive |
| Drive wheel | Rear wheel drive |
| Number of gears | 2 |
| Gearbox type | automatic transmission PowerFlite |
| Front suspension | Independent coil spring |
| Rear suspension | Leaf spring |
| Steering type | Worm-reduction unit |
Powertrain & Engine Architecture
The heart of the Firesweep I 4-Door Sportsman was the DeSoto S27 5.3-liter (325 cubic inch) V8 engine. This engine featured a cast iron block and aluminum cylinder heads, utilizing a conventional overhead valve (OHV) valvetrain with two valves per cylinder. Fuel delivery was managed by a Carter carburetor, a common setup for the era. The 8.5:1 compression ratio was typical for the time, balancing performance and the ability to run on contemporary gasoline. The PowerFlite automatic transmission, a two-speed unit, was a key component of this variant’s appeal, offering ease of driving compared to the available manual transmission options. The PowerFlite was known for its smooth operation, though it lacked the efficiency and responsiveness of more modern automatics.
Driving Characteristics
The 245 horsepower and 320 lb-ft of torque provided by the S27 V8 were adequate for comfortable cruising and passing maneuvers in the mid-1950s. However, the two-speed PowerFlite transmission limited the engine’s potential. Acceleration was respectable, but not particularly brisk compared to competitors offering more advanced transmissions or higher-output engines. The automatic transmission prioritized smooth shifts over outright performance. Compared to the Firesweep models equipped with manual transmissions, the automatic version felt somewhat less engaging and responsive. The leaf spring rear suspension provided a comfortable ride, but didn’t offer the handling precision of independent rear suspensions found on some competing models.
Equipment & Trim Levels
The Firesweep I 4-Door Sportsman with the 5.3 V8 and PowerFlite transmission was positioned as a mid-range offering within the Firesweep lineup. Standard features included a spacious interior with seating for six passengers, a full-width bench seat, and a generously sized trunk. Interior upholstery typically consisted of cloth and vinyl, with options for upgraded materials. The dashboard featured a straightforward layout with essential gauges, including a speedometer, fuel gauge, and temperature gauge. Available options included power steering, power brakes, a radio, and whitewall tires. The trim level was characterized by bright exterior accents and two-tone paint schemes, reflecting the styling trends of the 1950s.
Chassis & Braking
The Firesweep I rode on a conventional body-on-frame chassis. The 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, which were adequate for the vehicle’s weight and performance capabilities of the time. Steering was handled by a worm-reduction unit, which provided a relatively indirect steering feel. The overall chassis design prioritized ride comfort and durability over sporty handling.
Market Reception & Comparison
The DeSoto Firesweep I 4-Door Sportsman was generally well-received by contemporary automotive critics. It was praised for its stylish design, spacious interior, and comfortable ride. However, some reviewers noted that the PowerFlite transmission felt dated compared to the more advanced automatics offered by competitors. The 5.3 V8 engine was considered adequate, but not particularly powerful compared to the engines offered by Buick and Oldsmobile. Fuel economy was typical for a full-size American sedan of the era, averaging around 14-16 miles per gallon. Reliability was generally good, though the carburetor required periodic adjustment and maintenance.
Legacy
The DeSoto Firesweep I 4-Door Sportsman, while not a groundbreaking vehicle, represents a significant chapter in American automotive history. The combination of the 5.3 V8 engine and PowerFlite automatic transmission proved to be reasonably durable, and many examples remain on the road today. While not highly sought after by collectors, well-maintained examples command a modest premium. The Firesweep’s styling and comfortable ride continue to appeal to enthusiasts of 1950s automobiles. The PowerFlite transmission, while simple, is generally reliable if properly maintained, but parts availability can be a challenge. The S27 V8 engine is also relatively robust, but requires regular maintenance to ensure optimal performance.
