Mercedes OM621 Diesel Engine Manuals
The Mercedes-Benz OM621 Diesel Engine was manufactured from 1956-1968 in three displacements of 1.9L (1,897 cc), 2.0 L (1,988 cc) and Unimog version 2.2 L (2,197 cc)
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Download: OM621 OM636 Engine Service Repair Manual
Diesel OM621 OM636 Engine Manual
Download: 53.2mb, 723 pages, .pdf
OM621 Application: W110, W120, W121
OM636 Application: W120, W136, W191
$19.95
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Download: Unimog OM615 OM616 OM621 OM636 Engine Manual
Diesel
Engines Service Repair Manual
Application: Unimog
Download: 42.8mb, 329 pages
Format: pdf document
$19.95
Download Link Sent to your PayPal email address
OM621 Engine Technical Data
The OM621 is a inline-four diesel engine was the successor to the OM636 Diesel Engine and was succeeded itself by the OM615 engine. The OM621 is based on the petrol M121 engine variant, but features revised camshafts, cylinder head, pistons, and fuel injection system. In 1961, the engine capacity was increased to 2.0 L (1,988 cc) and power was upgraded to 40 kW (54 hp) for use in the newly introduced W110 models. After being replaced by the OM615, a 2.2 L (2,197 cc) updated version of the OM621 engine was used solely in Unimog vehicles until 1988.
OM621 Version Specifications
| Variant | Model | Displacement | Power | Years |
|---|---|---|---|---|
| 621.910 | OM621 I | 1.9 L (1,897 cc) | 37 kW (50 hp) @ 4,000 rpm | 1958-1959 |
| 621.913 | OM621 II | 2.0 L (1,988 cc) | 40 kW (54 hp) @ 4,000 rpm | 1961-1963 |
| 621.912 | OM621 III | 2.0 L (1,988 cc) | 40 kW (54 hp) @ 4,200 rpm | 1961-1968 |
| 621.914 | OM621 IV | 2.0 L (1,988 cc) | 35 kW (47 hp) @ 3,800 rpm | 1961-1962 |
| Variant | Model | Displacement | Power | Years |
| 621.915 | OM621 V | 2.0 L (1,988 cc) | 40 kW (54 hp) | |
| 621.916 | OM621 VI | 2.0 L (1,988 cc) | 25 kW (33.5 hp) | 1966-1967 |
| 621-918 | OM621 VIII | 2.0 L (1,988 cc) | 40 kW (54 hp) @ 3,000 rpm | 1966-1968 |
| 621.919 | OM621 | 2.0 L (1,988 cc) | 40 kW (54 hp) | |
| 621.930 | OM621 | 2.0 L (1,988 cc) | 40 kW (54 hp) | |
| 621.931 | OM621 XI | 2.0 L (1,988 cc) | 29 kW (40 hp) | |
| 621.932 | OM621 | 2.0 L (1,988 cc) | 40 kW (54 hp) | 1968-1969 |
Version Applications
- 621.910 = 190D, 190Db
- 621.912 = 190DC
- 621.913 = L319D Van/Truck, O319D Bus
- 621.914 = 180DC
- 621.915 =
- 621.916 =
- 621.918 =
- 621.919 =
- 621.930 =
- 621.931 = Unimog U 40
- 621.932 = O 309D Transporter
OM621 (37 kW version)
- 1958–1959 W121 190D, 190Db
OM621 (35 kW version)
- 1961–1962 W120 180Dc
OM621 (40 kW version)
- 1961–1965 W110 190Dc
- 1965–1968 W110 200D
- 1966–1988 Unimog 421
