This page provides a detailed comparison of the specifications for the Allis Chalmers HD21 and the Caterpillar D7G SA Special Application.
| Allis Chalmers HD21 | Caterpillar D7G SA Special Application | |
|---|---|---|
| Images | ||
|
|
||
| Engine | ||
| Engine Manufacturer | Allis-Chalmers | Caterpillar |
| Engine Model | - | 3306 |
| Engine Cooling Type | Liquid-Cooled | Liquid-Cooled |
| Engine Fuel Type | Diesel | Diesel |
| Engine Induction Type | Supercharged | Turbocharged Aftercooled |
| Engine Cylinders | 6 | 6 |
| Engine Displacement Value | 844 ci (13.8 L) | 638 ci (10.5 L) |
| Engine Rated Rpm | 1800 | 2000 |
| Engine Power Output Value | 225 hp (167.8 kW) | 250 hp (186.4 kW) |
| Transmission | ||
| Transmission Type | Torque Converter | Gear |
| Transmission Forward Gears | 2 | 6 |
| Transmission Reverse Gears | 1 | 4 |
| Dimensions | ||
| Length Value | 198 | 179 |
| Width Value | - | 103 |
| Operating Weight Value | 45500 lb (20638 kg) | 40700 lb (18461 kg) |
| Miscellaneous | ||
| Chassis | - | Crawler |
| Hydraulic System Type | - | Open Center |
| Starter Type | Electric | Electric |
