Overview
The Hart-Parr 40 is a powerful standard-tread farm tractor produced in Charles City, Iowa, featuring a unique 10.1L four-cylinder engine derived from paired two-cylinder blocks. Known for its performance in the Nebraska Tractor Test 97, it delivered a tested 46.40 hp on the belt and over 4,800 lbs of maximum pull, making it a robust choice for heavy agricultural tasks during the 1920s.
Ideal Applications
Heavy Belt Work:
With a tested belt power of 46.40 hp and a 14-inch pulley operating at 800 RPM, this tractor is highly capable of powering stationary machinery like threshers and shellers.
High-Traction Field Operations:
Equipped with 52-inch steel rear tires and a maximum tested pull of 4,830 lbs, this machine is built to handle demanding primary tillage and heavy draft loads on the farm.
General Farm Production:
The 2-speed gear transmission and 28.23 hp drawbar rating provide the necessary force for standard-tread field applications across various soil conditions.
Production
| Description | Standard-tread tractor / Built in Charles City, Iowa, USA / Original price was $2,250 in 1927 |
|---|---|
| Manufacturer | Hart-Parr |
Engine
| Engine type | Hart-Parr 10.1L 4-cyl gasoline |
|---|---|
| Bore/Stroke | 5.50x6.50 inches (140 x 165 mm) |
| 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) |
| Rated RPM | 800 |
| Belt (claimed) | 40 hp (29.8 kW) |
| Belt (tested) | 46.40 hp (34.6 kW) |
| Drawbar (claimed) | 22 hp (16.4 kW) |
| Drawbar (tested) | 28.23 hp (21.1 kW) |
Transmission
| Clutch | mechanical contracting band |
|---|---|
| Gears | 2 forward and 1 reverse |
| Transmission type | 2-speed gear |
| Type | gear |
Mechanical
| Cab | Open operator station. |
|---|---|
| Description | Manual steering |
| Drive type | Two-wheel drive |
Dimensions & Tires
| Height | 67 inches (170 cm) |
|---|---|
| Length | 140 inches (355 cm) |
| Weight | 7500 lbs (3402 kg) |
| Width | 96 inches (243 cm) |
| Front tire | 28x5 |
| Rear tire | 52x13 |
| Weight | 7500 lbs (3402 kg) |
| Ag front | 28x5 (steel) |
| Ag rear | 52x13 (steel) |
40 Serial Numbers
| 1923 | 70001 |
|---|---|
| 1924 | 70020 |
| 1925 | 70095 |
| 1926 | 70251 |
| 1927 | 70491 |
| Description | FAQ: How to read a serial number table. |
| Final | 70500 |
Belt Pulley
| Diameter | 14 inches (35 cm) |
|---|---|
| RPM | 800 |
| Speed | 2750 ft/min (838.20 meters/min) |
| Width | 9 inches (22 cm) |
Nebraska Tractor Test 97
| Belt fuel use (max) | 6.3 gal/hour (23.8 l/hour) |
|---|---|
| Belt power (max) | 46.40 hp (34.6 kW) |
| Description | Kerosene 2-speed 2WDJuly 10 - 19, 1923Link: Nebraska Tractor Test 97 file / Drawbar performance |
| Max power | 28.23 hp (21.1 kW) |
| Max pull | 4830 lbs (2190 kg) |