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Allis Chalmers HD7

Allis Chalmers HD7 tractor
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The Allis Chalmers HD7 is an agricultural crawler tractor produced from 1940 to 1950. It was built in Springfield, Illinois, USA, with a total production of 1,803 units. It features a General Motors 3-71 blower diesel 3-cylinder liquid-cooled 2-cycle vertical I-head engine with 213 ci (3.5 L) displacement. The tractor has a 4-speed sliding gear transmission with 4 forward and 1 reverse gears. It delivers a claimed drawbar power of 45 hp and belt power of 60 hp, with tested drawbar power of 57.31 hp and belt power of 68.68 hp. The HD7 has a crawler drive with an open operator station. Dimensions include a length of 128 inches, width of 81 inches, height of 69 inches, and operating weight of 14,000 lbs. The tracks are 16 inches wide with a length on ground of 67 inches and ground pressure of 5.83 psi. Serial numbers are stamped on the right-rear of the transmission case or on a plate near the instrument panel.
Allis Chalmers HD7tractorcrawler tractorGeneral Motors 3-71 engine4-speed sliding gear transmissiontractor specificationsagricultural tractor
Power66 hp[B]
Founded1940 - 1950
ModelHD7

Technical Specifications

Detailed specifications and technical data for Allis Chalmers HD7

Power

Belt (tested):68.68 hp (51.2 kW)
Belt (claimed):60 hp (44.7 kW)
Drawbar (tested):57.31 hp (42.7 kW)
Drawbar (claimed):45 hp (33.6 kW)

Engine

Type:blower diesel
Model:General Motors 3-71
Cooling:liquid-cooled 2-cycle vertical I-head
Cylinders:3-cylinder
Fuel tank:31 gal (117.3 L)
Rated RPM:1500
Air cleaner:oil bath
Bore/Stroke:4.25x5.00 inches (108 x 127 mm)
Compression:16.0:1
Displacement:213 ci (3.5 L)
Oil capacity:8.5 qts (8.0 L)
Starter volts:12
Coolant capacity:23 qts (21.8 L)

Tracks

Width:16 inches (40 cm)
Area on ground:2144 in² (1.4 m²)
Ground pressure:5.83 psi (0.4 bar)
Length on ground:67 inches (170 cm)

Dimensions

Gauge:52 inches (132 cm)
Width:81 inches (205 cm)
Height:69 inches (175 cm)
Length:128 inches (325 cm)
Operating weight:14000 lbs (6350 kg)

Mechanical

Drive:crawler
Operator station:Open operator station.

Production

Type:Agricultural Crawler tractor
Built in:Springfield, Illinois, USA
Years made:1940 - 1950
Total built:1,803

References

1:HD-7 2-Cycle Diesel published in 1949, by Allis Chalmers
2:Operators Manual Model HD 7 Tractor (T-203E)
3:Build a Better Farm published in 1940, by Allis Chalmers

Transmission

Type:sliding gear
Gears:4 forward and 1 reverse
Oil capacity:21 qts (19.9 L)

Serial Numbers

1940:3
1941:503
1942:1137
1943:5403
1944:5753
1945:8949
1946:12091
1947:13078
1948:15122
1949:16752
1950:18086
Location:Serial number stamped on the right-rear of the transmission case or on a plate near the instrument panel.