Allis Chalmers 8550

The Allis Chalmers 8550 is a tractor produced by Allis Chalmers. It is equipped with a 731 ci 12.0 L engine. The listed engine power is Diesel (listed): 300 hp / 223.7 kW. Transmission: Power Director. Operating weight: 26400 to 27040 pounds.

Engine Power

Diesel (listed): 300 hp / 223.7 kW

Fuel & Capacities

170 gal 643.5 L

Transmission

Power Director

Operating Weight

26400 to 27040 pounds

Overview

	1978 - 1981 Four-wheel Drive (4WD) tractor

Production
Manufacturer	Allis Chalmers
Four-wheel Drive (4WD) tractor
Original price	$86,753

Allis Chalmers 8550 Engine
Allis Chalmers 12.0L 6-cyl diesel
Fuel tank	170 gal 643.5 L
Engine details ...

Allis Chalmers 8550 Transmission
20-speed partial power shift
Transmission details ...

Allis Chalmers 8550 Power
Engine	300 hp 223.7 kW
Drawbar (claimed)	210 hp 156.6 kW
PTO (claimed)	250 hp 186.4 kW
Drawbar (tested)	217.92 hp 162.5 kW
PTO (tested)	253.88 hp 189.3 kW
Performance test details ...

Mechanical
Four-wheel drive
Steering	hydrostatic power
Hydraulic wet discs brakes
Acousta Cab II standard with heat and air-conditioning. Optional radio and 8 track tape deck.

Hydraulics
Type	closed center
Valves	3 or 4
Pump flow	74.9 gpm 283.5 lpm

Tractor hitch
Rear Type	IV/III

Power Take-off (PTO)
Rear PTO	independent
Rear PTO Type	1000

Dimensions & Tires
Wheelbase	126 inches 320 cm
Weight	26400 to 27040 pounds
Front tire	18.4x38
Rear tire	18.4x38
Full dimensions and tires ...

Electrical
Ground	negative
Charging system	alternator
Batteries	4
Battery volts	12

References

Four-wheel drives - mammoth size... published in 1978, by Allis Chalmers
8550 published in 1977, by Allis Chalmers

Engine

Engine Detail — 731 ci / 12.0 L Diesel

Manufacturer	Allis Chalmers 6120T
Configuration	turbocharged diesel, 6-cylinder 24-valve, liquid-cooled inline
Displacement	731 ci 12.0 L
Bore/Stroke	5.25x6.25 inches 133 x 159 mm
Power	300 hp 223.7 kW
Air cleaner	dry
Compression	16.25:1
Rated RPM	2500
Idle RPM	775-2800
Firing order	1-5-3-6-2-4
Starter volts	12
Oil capacity	46 qts (2 filter) 43.5 L
	60 qts (3 filter) 56.8 L
Coolant capacity	72 qts 68.1 L
Intake valve clearance	0.015 inches (hot) 0.381 mm
Exhaust valve clearance	0.020 inches (hot) 0.508 mm

Transmission

Transmission — Power Director

Transmission	Power Director
Type	partial power shift
Gears	20 forward and 4 reverse
Allis 8550 speeds with 18.4x38 tires.

Dimensions

Allis Chalmers 8550 Tires
Ag front	18.4x38
Ag rear	18.4x38
Ag front	20.8x34
	20.8x38
	23.1x30
	24.5x32
	30.5x32
Ag rear	20.8x34
	20.8x38
	23.1x30
	24.5x32
	30.5x32

Dimensions
Wheelbase	126 inches 320 cm
Length	285 inches 723 cm
Width	95.5 inches 242 cm
	119.5 inches (long axle) 303 cm
Ground clearance	17 inches 43 cm
Front tread	62 to 123 inches 157 to 312 cm
Rear tread	62 to 123 inches 157 to 312 cm

Allis Chalmers 8550 Weight
Shipping	26,400 lbs (duals) 11975 kg
Operating	27,040 lbs 12265 kg
Ballasted	29,360 lbs 13317 kg

Allis Chalmers 8550 Height
Hood	90.3 inches 229 cm
Cab	139 inches 353 cm
Exhaust	154 inches 391 cm

Tests

Nebraska Tractor Test 1262
Diesel 20-speed 4WD October 15 - 28, 1977 Link: Nebraska Tractor Test 1262 file
PTO performance
Power at rated engine speed	253.88 hp 189.3 kW
Fuel use	17.4 gal/hour 65.9 l/hour
Drawbar performance
Max power	217.92 hp 162.5 kW
Fuel use	17.5 gal/hour 66.2 l/hour
Gear 5SL used for power test.
Max pull	26,220 lbs 11893 kg
Gear 2SL used for pull test.

Photos

Allis Chalmers 8550, left side.

Allis Chalmers 8550, front-right view.

Recommended Implements & Sizing Guide

Engineering recommendations for Allis Chalmers 8550 based on its 300 HP power envelope and ASAE agricultural standards.

Implement & Operation	Recommended Size	Workload Rating	Engineering Notes
Moldboard PlowPrimary Tillage	8+ Bottom On-Land Hitch8+ 铧重型机外牵引犁	Commercial / Field Scale	High horsepower articulated/4WD field plowing.
Rotary Cutter / MowerMowing & Clearing	15 to 20 ft Batwing4.6 - 6.1 m 宽幅折叠翼	Commercial / Field Scale	Large commercial field and roadside mowing operations.
Rotary TillerSeedbed Prep	90 to 120 in Heavy Duty230 - 300 cm 重型旋耕机	Commercial / Field Scale	Deep intensive seedbed preparation for commercial row crops.
Disc HarrowSecondary Tillage	24 to 36 ft Heavy Duty Field Disc7.3 - 11.0 m 超宽重型整地耙	Commercial / Field Scale	Broad-acre grain tillage for high-drawbar tractors.
Hay BalerHay & Forage	Large Square Baler (3x4 or 4x4)大方捆商用打捆机 (1.2x1.2 m)	Commercial / Field Scale	High-capacity commercial forage harvesting (1000 RPM PTO).

Sizing & Soil Condition NoteActual implement sizing varies depending on local soil conditions (heavy clay vs sandy loam), field slope, and operating speed. Heavy tillage implements may require front ballast weights and wheel weights.

Fluids, Capacities & Working Autonomy

Standard fluid requirements, service intervals, and continuous runtime estimates for Allis Chalmers 8550.

Estimated Continuous Field Runtime: 10.9 hrs

Approximately 10.9 hours of continuous field operation at ~75% rated power on a full tank (170 gal / 643.5 L).

Estimated 75% Load Fuel Burn~15.6 gal/hr (59.1 L/hr)

Engine Crankcase Oil

SAE 15W-40 (Heavy Duty Diesel)

Standard Spec: API CK-4 / CJ-4 Heavy Duty

Service Interval: 150 – 250 Hours

Transmission & Hydraulic System

UTTO (Universal Tractor Transmission Oil)

Standard Spec: ISO VG 46 / 68 (Wet Brake & Trans Compatible)

Service Interval: 600 – 1000 Hours

Engine Cooling System

50/50 Ethylene Glycol Pre-mix

Standard Spec: ASTM D6210 / Heavy-Duty OAT Antifreeze

Service Interval: 2 Years / 1500 Hours