Introduction
International Harvester 666 Row-Crop Tractor
The International Harvester 666 is a row-crop tractor produced between 1972 and 1976 in Rock Island, Illinois. Designed as a versatile utility platform, it served as a significant model within the brand's mid-range agricultural lineup, bridging the transition between the 656 and 686 series.
Engine and Performance
The tractor is powered by the International Harvester C291, a 4.8-liter, 6-cylinder gasoline engine. It is liquid-cooled and operates at a rated speed of 2000 RPM, delivering a gross power output of 75 hp. The engine features a 7.5:1 compression ratio and utilizes a dual-stage dry air cleaner to maintain performance in dusty field conditions.
Transmission and Drivetrain
The 666 offers three distinct transmission configurations to accommodate different operational needs: a standard 5-speed sliding gear transmission, a hydrostatic transmission providing infinite forward and reverse speeds, and a 10-speed Torque-Amplifier transmission featuring a two-speed power shift. These options allow operators to match ground speed precisely to the task at hand.
Hydraulics and PTO
Equipped with an open-center hydraulic system, the tractor provides a pump flow of 12 gpm. The rear power take-off (PTO) is independent and operates at 540 RPM. The rear hitch is a Category II system, featuring the IH Fast Hitch design, which facilitates the rapid attachment and detachment of implements.
Dimensions and Operator Environment
The tractor features a 103-inch wheelbase and adjustable front and rear tread widths, allowing for customization based on row spacing requirements. The operator station is of an open design, with optional two-post ROPS or canopy configurations. A factory-fitted cab with air conditioning was also available, improving operator comfort during extended work hours.
Conclusion
With its robust build quality, multiple transmission choices, and adjustable configuration, the International Harvester 666 is well-suited for general row-crop farming and medium-duty agricultural operations. It remains a notable example of 1970s North American tractor engineering.
Production Information of International Harvester, 666
- Row-Crop tractor
- Torque amplifier was an option. In 1973, the hydrostatic version of the 666 was renamed the 70 Hydro.
- Built in Rock Island, Illinois, USA
| Manufacturer | International Harvester |
|---|---|
| Original price | $11,875 |
| Total built | 9,367 |
Dimension and Tires Information of International Harvester, 666
| Rear tread | 50 to 96 inches [127 to 243 cm] |
|---|---|
| Wheelbase | 103 inches [261 cm] |
| Shipping weight | 6780 lbs (gas gear) [3075 kg] |
| Height (steering wheel) | 77 inches [195 cm] |
| Length | 161 inches [408 cm] |
| Clearance (drawbar) | 14 inches [35 cm] |
| Clearance (drawbar)(optional) | 7420 lbs (diesel hydro) [3365 kg] |
| Width | 87 inches [220 cm] |
| Front tread | 56 to 80 inches [142 to 203 cm] |
| Front tread | 50 to 74 inches [127 to 187 cm] |
| Clearance (front axle) | 21 inches [53 cm] |
| Ag front | 7.50-16 |
|---|---|
| Ag rear | 15.5-38 |
Engine Specifications of International Harvester, 666
- International Harvester C291
- Liquid-cooled
- Gasoline
- 6-cylinder
| Starter volts | 12 |
|---|---|
| Displacement | 291 ci [4.8 L] |
| Air cleaner | Dual stage dry |
| Bore/Stroke | 3.75x4.39 inches [95 x 112 mm] |
| Coolant capacity | 21 qts [19.9 L] |
| Coolant capacity | 21 qts [19.9 L] |
| Rated RPM | 2000 |
| Compression | 7.5:1 |
| Power (gross) | 75 hp [55.9 kW] |
Transmission Information of International Harvester, 666
Transmission variants 1
| Transmission | Sliding gear |
|---|---|
| Gears | 5 forward and 1 reverse |
Transmission variants 2
| Type | Hydrostatic |
|---|---|
| Gears | Infinite forward and reverse |
Transmission variants 3
| Transmission | Torque-Amplifier |
|---|---|
| Clutch | Dry disc |
| Type | Two-speed power shift |
| Gears | 10 forward and 2 reverse |
- 5-speed
- Hydrostatic
- 10-speed two-speed power shift
Mechanical Specs of International Harvester, 666
- Two-wheel drive
- Open operator station. Two-post ROPS or canopy optional. Cab available with air-conditioning.
- Power steering
- Dry disc brakes
Power Information of International Harvester, 666
| Rear PTO | Independent |
|---|---|
| Rear PTO Type | 540 (1.375) |
Hydraulics Specifications of International Harvester, 666
| Type | Open center |
|---|---|
| Pump flow | 12 gpm [45.4 lpm] |
Three-Point Hitch of International Harvester, 666
| Rear Type | II |
|---|---|
| Type | IH Fast Hitch |
Electrical System of International Harvester, 666
| Charging system | Alternator |
|---|---|
| Battery volts | 12 |
Where it sits
With 75 HP, the International Harvester 666 sits just above 686 (73 HP) in International Harvester's range. Its power puts it in the 55th percentile of 1970s models in our database (1259 machines).
Frequently asked questions
How much horsepower does the International Harvester 666 have?
The International Harvester 666 delivers 75 HP.
What years was the International Harvester 666 produced?
The International Harvester 666 was produced in 1972-1976.
What engine does the International Harvester 666 have?
The International Harvester 666 is powered by a Gasoline, 6-cylinder engine.
What transmission does the International Harvester 666 use?
The International Harvester 666 uses a Sliding gear transmission.
How much does the International Harvester 666 weigh?
The International Harvester 666 weighs 6780 lbs (gas gear) [3075 kg].
Is the International Harvester 666 4WD?
The International Harvester 666 is available in 2WD.