Overview
The Hart-Parr 20 is a standard-tread farm tractor produced in Charles City, Iowa, from 1920 to 1924, featuring an open operator station and manual steering. It is equipped with a 2-cylinder engine that transitioned from a 4.6L to a 5.1L displacement starting with serial number 35501, and it utilized a gear transmission with two forward speeds.
Ideal Applications
Tested Power Output:
According to Nebraska Tractor Test 79, this model achieved a maximum belt power of 23.01 hp and a maximum drawbar pull of 2500 lbs while operating on kerosene.
Engine Configuration:
The tractor utilizes a liquid-cooled 2-cylinder Hart-Parr engine with an 800 rated RPM, available in 281.4 ci and 309 ci displacements depending on the production year.
Physical Specifications:
This two-wheel drive machine weighs 4440 lbs and is fitted with steel ag tires measuring 28x5 in the front and 46x10 in the rear.
Production
| Description | Standard-tread tractor / Built in Charles City, Iowa, USA / Original price was $1,195 in 1924 |
|---|---|
| Manufacturer | Hart-Parr |
Engine
| Bore/Stroke | 5.25x6.50 inches (133 x 165 mm) / 5.50x6.50 inches (140 x 165 mm) |
|---|---|
| Description | Hart-Parr / gasoline / 2-cylinder / liquid-cooled / Hart-Parr / 2-cylinder / liquid-cooled / The larger engine was used in the model 20C beginning at tractor serial number 35501. |
| Displacement | 281.4 ci (4.6 L) / 309 ci (5.1 L) |
| Rated RPM | 800 |
| Engine type | Hart-Parr 4.6L 2-cyl gasoline / Hart-Parr 5.1L 2-cyl |
| Engine type | Hart-Parr 4.6L 2-cyl gasoline / Hart-Parr 5.1L 2-cyl |
| Belt (claimed) | 20 hp (14.9 kW) |
| Belt (tested) | 23.01 hp (17.2 kW) |
| Drawbar (claimed) | 10 hp (7.5 kW) |
| Drawbar (tested) | 14.08 hp (10.5 kW) |
Transmission
| 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 |
| Final drives | bull gear |
Dimensions & Tires
| Weight | 4440 lbs (2013 kg) |
|---|---|
| Front tire | 28x5 |
| Rear tire | 46x10 |
| Weight | 4440 lbs (2013 kg) |
| Ag front | 28x5 steel |
| Ag rear | 46x10 steel |
20 Serial Numbers
| 1920 | 35001 |
|---|---|
| 1921 | 35025 |
| 1922 | 35200 / 35501 (20C) |
| 1923 | 35522 (20C) |
| 1924 | 35750 (20C) |
| Description | FAQ: How to read a serial number table. |
Nebraska Tractor Test 79
| Belt power (max) | 23.01 hp (17.2 kW) |
|---|---|
| Description | Kerosene 2-speed 2WDJune 11 - 17, 1921Link: Nebraska Tractor Test 79 file / Drawbar performance |
| Max power | 14.08 hp (10.5 kW) |
| Max pull | 2500 lbs (1134 kg) |