| Manufacturer | Hart-Parr |
| Price | 2,250(USD) |
| Model | 40 |
| Equipment Type | Standard-Tread Tractors |
| Factory | Charles City, Iowa, USA |
NEBRASKA TRACTOR TEST 97
| Description | Kerosene 2-speed 2WD/July 10 - 19, 1923/Link: Nebraska Tractor Test 97 file/Drawbar performance |
| Belt power (max) | 46.40 hp/34.6 kW |
| Belt fuel use (max) | 6.3 gal/hour/23.8 l/hour |
| Max power | 28.23 hp/21.1 kW |
| Max pull | 4830 lbs/2190 kg |
HART-PARR 40 POWER
| Drawbar (claimed) | 22 hp/16.4 kW |
| Belt (claimed) | 40 hp/29.8 kW |
| Drawbar (tested) | 28.23 hp/21.1 kW |
| Belt (tested) | 46.40 hp/34.6 kW |
ENGINE DETAIL
The Hart-Parr 40 tractor features a unique four-cylinder engine configuration utilizing two joined two-cylinder blocks, providing robust torque suitable for heavy-duty agricultural tasks. With a substantial displacement of 617.7 cubic inches and a relatively low operational RPM of 800, it emphasizes torque output over high speed, making it ideal for field work but potentially limiting in speed for transport. The transition from dual to single carburetion can improve fuel efficiency and simplify maintenance, although early models may experience tuning challenges due to the dual setups.
| Description | Hart-Parr/gasoline/4-cylinder/liquid-cooled/The Hart-Parr 22-40 used a pair of two-cylinder engine blocks from the 20C on a single crankshaft to create the four-cylinder engine. Early models used two carburetors while later models had a single carburetor to feed both blocks. |
| Displacement | 617.7 ci/10.1 L |
| Bore/Stroke | 5.50x6.50 inches/140 x 165 mm |
| Rated RPM | 800 |
HART-PARR 40 ENGINE
The Hart-Parr 40 is powered by a 10.1L 4-cylinder gasoline engine, providing robust horsepower suited for heavy-duty agricultural tasks. Its design emphasizes durability and ease of maintenance, though the reliance on gasoline might limit fuel efficiency compared to diesel counterparts, leading to higher operational costs. Ideal for smaller farms or vintage machinery enthusiasts, it offers significant traction and power for plowing and tilling.
| Description | Hart-Parr 10.1L 4-cyl gasoline |
TRANSMISSION
The Hart-Parr 40 features a simplistic two-speed forward and one-speed reverse gearbox, enhancing ease of operation for basic agricultural tasks. Its mechanical contracting band clutch provides reliable engagement, though it may require more maintenance compared to modern hydraulic clutches. This tractor is well-suited for farmers requiring robust, straightforward machinery for light to moderate fieldwork, where advanced transmission systems are unnecessary.
| Type | gear |
| Gears | 2 forward and 1 reverse |
| Clutch | mechanical contracting band |
MECHANICAL
The Hart-Parr 40 tractor features a 4x2 2WD chassis, offering simplicity and ease of maintenance, but may compromise traction on uneven terrain compared to 4WD systems. Its manual steering can be a challenge in tight maneuvers, especially in field operations, while the open operator station provides good visibility but offers limited protection from weather conditions. The 2-speed gear transmission allows for versatility in speed adjustments, making it suitable for tasks ranging from tilling to light hauling, though it may lack the advanced features of modern transmissions.
| Chassis | 4x2 2WD |
| Steering | manual |
| Cab | Open operator station. |
| Transmission | 2-speed gear |
HART-PARR 40 TIRES
The Hart-Parr 40 tractor features an Ag front tire size of 28x5 inches and a rear tire size of 52x13 inches, both made of steel, which provides durability but can result in reduced traction on soft terrain. These steel wheels are advantageous for weight distribution and stability but may lead to increased ground compaction and reduced soil aeration. Ideal for row-crop applications, the tractor's tire specifications suggest suitability for hard surfaces or rocky conditions, though challenges may arise in muddy or loose soil scenarios.
| Ag front | 28x5 (steel) |
| Ag rear | 52x13 (steel) |
DIMENSIONS
| Length | 140 inches/355 cm |
| Width | 96 inches/243 cm |
| Height | 67 inches/170 cm |
| Weight | 7500 lbs/3402 kg |
DIMENSIONS & TIRES
The Hart-Parr 40 tractor, weighing 7,500 lbs (3,402 kg), features large rear tires (52x13) that provide excellent traction, especially in agricultural applications. Its narrower front tires (28x5) can lead to improved maneuverability but may reduce stability, particularly in soft or uneven terrain. A potential challenge is balancing the tractor's weight distribution for optimal performance during heavy-duty tasks or fieldwork.
| Weight | 7500 lbs/3402 kg |
| Front tire | 28x5 |
| Rear tire | 52x13 |
40 SERIAL NUMBERS
| 1923 | 70001 |
| 1924 | 70020 |
| 1925 | 70095 |
| 1926 | 70251 |
| 1927 | 70491 |
| Final | 70500 |
BELT PULLEY
| Diameter | 14 inches/35 cm |
| Width | 9 inches/22 cm |
| RPM | 800 |
| Speed | 2750 ft/min/838.20 meters/min |