International Harvester 666 Specs ( 1972-1976 )
Overview
The International Harvester 666 is a versatile row-crop tractor built between 1972 and 1976 that offers both diesel and gasoline 6-cylinder engine options. With tested PTO performance reaching up to 69.61 hp and a variety of transmission types including the Torque Amplifier and hydrostatic options, it provides flexible power for mid-sized farming operations.
Ideal Applications
Row-Crop Operations:
The adjustable front tread width of 50 to 80 inches and rear tread up to 96 inches allow this tractor to be configured for various crop spacing requirements.
Heavy Towing and Tillage:
With a maximum tested pull of 8,427 lbs and a shipping weight of 6,780 lbs, the 666 provides the necessary traction and weight for demanding drawbar tasks.
Precision Field Work:
The availability of a hydrostatic transmission allows for infinite forward and reverse speeds, making it suitable for tasks requiring precise speed control.
Production
| Description | Row-Crop tractor / Built in Rock Island, Illinois, USA / Torque amplifier was an option. In 1973, the hydrostatic version of the 666 was renamed the 70 Hydro. |
|---|---|
| Manufacturer | International Harvester |
| Original price | $11,875 |
| Total built | 9,367 |
Engine
| Air cleaner | dual stage dry / dual stage dry |
|---|---|
| Bore/Stroke | 3.875x4.410 inches (98 x 112 mm) / 3.75x4.39 inches (95 x 112 mm) |
| Compression | 17:1 / 7.5:1 |
| Coolant capacity | 21 qts (19.9 L) / 21 qts (19.9 L) |
| Description | International Harvester D312 / diesel / 6-cylinder / liquid-cooled / International Harvester C291 / gasoline / 6-cylinder / liquid-cooled |
| Displacement | 312 ci (5.1 L) / 291 ci (4.8 L) |
| Fuel system | direct injection |
| Power (gross) | 75 hp (55.9 kW) / 75 hp (55.9 kW) |
| Rated RPM | 2000 / 2000 |
| Starter volts | 12 / 12 |
| Engine type | International Harvester 5.1L 6-cyl diesel / International Harvester 4.8L 6-cyl gasoline |
| Diesel Fuel tank | 31 gal (117.3 L) |
| Engine type | International Harvester 5.1L 6-cyl diesel / International Harvester 4.8L 6-cyl gasoline |
| Gas Fuel tank | 33 gal (124.9 L) |
| Drawbar (claimed) | 57 hp (gear) (42.5 kW) |
| Drawbar (tested) | 58.01 hp (43.3 kW) |
| Engine (gross) | 75 hp (55.9 kW) |
| PTO (claimed) | 65 hp (gear) (48.5 kW) |
| PTO (tested) | 69.61 hp (51.9 kW) |
Transmission
| Clutch | dry disc |
|---|---|
| Gears | 5 forward and 1 reverse / infinite forward and reverse / 10 forward and 2 reverse |
| Transmission | sliding gear / Torque-Amplifier |
| Type | hydrostatic / two-speed power shift |
| Description | hydrostatic |
| Transmission type | 5-speed / 10-speed two-speed power shift |
| Description | hydrostatic |
| Transmission type | 5-speed / 10-speed two-speed power shift |
Mechanical
| Cab | Open operator station. Two-post ROPS or canopy optional. Cab available with air-conditioning. |
|---|---|
| Description | Power steering / Dry disc brakes |
| Drive type | Two-wheel drive |
Hydraulics
| Pump flow | 12 gpm (45.4 lpm) |
|---|---|
| Type | open center |
Hitch
| Rear Type | II |
|---|---|
| Type | IH Fast Hitch |
PTO
| Rear PTO | independent |
|---|---|
| Rear PTO Type | 540 (1.375) |
Electrical
| Battery volts | 12 |
|---|---|
| Charging system | alternator |
Dimensions & Tires
| Clearance (drawbar) | 14 inches (35 cm) |
|---|---|
| Clearance (front axle) | 21 inches (53 cm) |
| Front tread | 50 to 74 inches (127 to 187 cm) / 56 to 80 inches (142 to 203 cm) |
| Height (steering wheel) | 77 inches (195 cm) |
| Length | 161 inches (408 cm) |
| Rear tread | 50 to 96 inches (127 to 243 cm) |
| Shipping weight | 6780 lbs (gas gear) (3075 kg) |
| Wheelbase | 103 inches (261 cm) |
| Width | 87 inches (220 cm) |
| Front tire | 7.50-16 |
| Rear tire | 15.5-38 |
| Weight | 6780 to 7420 pounds |
| Wheelbase | 103 inches (261 cm) |
| Ag front | 7.50-16 |
| Ag rear | 15.5-38 |
666 Serial Numbers
| 1972 | 7500 |
|---|---|
| 1973 | 8200 |
| 1974 | 11585 |
| 1975 | 13131 |
| 1976 | 15739 |
| Description | FAQ: How to read a serial number table. |
| Location: | Clutch housing, right side |
Nebraska Tractor Test 1151
| Description | 312 diesel Torque Amplifier 2WDNovember 3 - 14, 1973Link: Nebraska Tractor Test 1151 file / PTO performance / Drawbar performance / Gear 3-Direct used for power test. / Gear 2-TA used for pull test. |
|---|---|
| Fuel use | 4.7 gal/hour (17.8 l/hour) / 4.6 gal/hour (17.4 l/hour) |
| Max power | 58.01 hp (43.3 kW) |
| Max pull | 8,012 lbs (3634 kg) |
| Power at rated engine speed | 66.29 hp (49.4 kW) |
Nebraska Tractor Test 1152
| Description | Gasoline Torque Amplifier 2WDNovember 5 - December 3, 1973Link: Nebraska Tractor Test 1152 file / PTO performance / Drawbar performance / Gear 3-Direct used for power test. / Gear 2-TA used for pull test. |
|---|---|
| Fuel use | 12.0 gal/hour (45.4 l/hour) / 5.7 gal/hour (21.6 l/hour) |
| Max power | 57.29 hp (42.7 kW) |
| Max pull | 7,981 lbs (3620 kg) |
| Power at rated engine speed | 66.30 hp (49.4 kW) |
Nebraska Tractor Test 1154
| Description | Gasoline hydrostatic 2WDNovember 14 - December 3, 1973Link: Nebraska Tractor Test 1154 file / PTO performance / Drawbar performance |
|---|---|
| Fuel use | 6.9 gal/hour (26.1 l/hour) / 5.8 gal/hour (22.0 l/hour) / 7.7 gal/hour (29.1 l/hour) |
| Max power | 53.86 hp (40.2 kW) |
| Max pull | 8,427 lbs (3822 kg) |
| Power at rated engine speed | 69.61 hp (51.9 kW) |
| Power at rated PTO speed | 64.10 hp (47.8 kW) |
Nebraska Tractor Test 1155
| Description | Diesel hydrostatic 2WDNovember 14 - December 3, 1973Link: Nebraska Tractor Test 1155 file / PTO performance / Drawbar performance |
|---|---|
| Fuel use | 5.6 gal/hour (21.2 l/hour) / 5.3 gal/hour (20.1 l/hour) / 5.6 gal/hour (21.2 l/hour) |
| Max power | 53.10 hp (39.6 kW) |
| Max pull | 8,310 lbs (3769 kg) |
| Power at rated engine speed | 69.51 hp (51.8 kW) |
| Power at rated PTO speed | 65.41 hp (48.8 kW) |
References
| Description | Farm Equipment Reference Catalog published in 1972, by International Harvester |
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Tractor Tests
| Description | NTTL 1151: 312 diesel Torque Amplifier 2WD / NTTL 1152: gasoline Torque Amplifier 2WD / NTTL 1154: gasoline hydrostatic 2WD / NTTL 1155: diesel hydrostatic 2WD |
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